WO2025152031A1 - Coffee granule measurement device and method - Google Patents

Abstract

A coffee granule measurement device and method. The measurement device (10) comprises an accommodating space (11) for accommodating coffee granules, a condensation surface (12), a cooling module (13), a first temperature measurement module (14), a dew point measurement module (15), and a calculation module (16). The cooling module (13) is used for cooling the condensation surface (12) so that water vapor of the coffee granules condenses on the condensation surface to form dew. The dew point measurement module (15) is used for detecting whether dew occurs on the condensation surface (12). The first temperature measurement module (14) is used for measuring the temperature of at least one position on the condensation surface (12). The calculation module (16) is used for: determining a first moment, the first moment being the moment when dew is detected to occur on the condensation surface (12); determining a dew point temperature on the basis of the first moment and the temperature of the at least one position; acquiring a first vapor pressure on the basis of the dew point temperature; acquiring the temperature of the accommodating space (11) and the temperature of the coffee granules; acquiring a second vapor pressure on the basis of the temperature of the accommodating space (11) and the temperature of the coffee granules; and calculating the water activity of the coffee granules on the basis of the first vapor pressure and the second vapor pressure.

Description

Coffee particle detection device and method Technical Field

The present application relates to the field of coffee measurement, and in particular to a coffee particle detection device and method.

Background Art

Water activity (also known as water activity or water activity) refers to the ratio of the equilibrium vapor pressure of a certain food to the saturated vapor pressure of pure water at the same temperature in a confined space. The value of water activity ranges from 0 to 1. The closer the water activity of coffee beans is to 1, the more water in the coffee beans can be used by microorganisms, which means that it is easier to be affected by mold, bacteria, etc. and reduce the quality and flavor. It is generally recommended to maintain the water activity of green coffee beans between 0.4 and 0.6 to ensure the preservation of the green coffee beans and avoid the influence of microorganisms. When the water activity of green coffee beans is higher than 0.6, it means that there is more free water available for microorganisms and they may be infected by mold or fungi. When the water activity of green coffee beans is lower than 0.4, it means that the green coffee beans are over-dried when they are processed, or the environment in which the coffee beans are transported and stored is too dry, which will affect the original flavor of the green coffee beans and the subsequent coffee roasting.

The existing measurement of water activity of coffee beans generally uses an electronic hygrometer, which uses a resistor or capacitor sensor to measure relative humidity. The sensor converts the electrical signal and the humidity signal through the change of capacitance or resistance, and obtains an equilibrium relative humidity value. When the sample temperature and the sensor temperature are consistent, the equilibrium relative humidity is numerically equal to the sample water activity. This method requires regular calibration due to the indirectness of the measurement, and the definition of capacitance, resistance and humidity is irrelevant. This indirect technology requires calibration of the correlation between capacitance changes and humidity changes. Because humidity is only one of the many factors in measuring capacitance and resistance, capacitance and resistance may be affected by factors such as condensation, aging, and contact with certain chemicals. In addition, full equilibrium needs to be achieved in the sensor during measurement. This process generally takes 30 minutes to 1 hour to stabilize the final value.

There is still room for improvement in the current measuring devices for measuring the water activity of coffee beans.

Summary of the invention

The present application provides a coffee particle detection device and method, which can quickly and accurately measure the water activity of coffee particles.

In a first aspect, the present application provides a coffee particle detection device, comprising a accommodating space, a condensation surface, a cooling module, a first temperature detection module, a dew point detection module and a calculation module; the accommodating space is used to accommodate coffee particles; an air passage is connected between the condensation surface and the accommodating space; the cooling module is used to cool the condensation surface so that the water vapor in the coffee particles condenses on the condensation surface to precipitate dew; the dew point detection module is used to detect whether dew appears on the condensation surface; the first temperature detection module is used to detect the temperature of at least one place on the condensation surface; the calculation module is used to: determine a first moment, the first moment is the moment when the dew appears on the condensation surface; determine the dew point temperature according to the first moment and the temperature of the at least one place; obtain a first vapor pressure according to the dew point temperature; obtain the temperature of the accommodating space and the coffee particles; obtain a second vapor pressure according to the temperature of the accommodating space and the coffee particles; and calculate the water activity of the coffee particles according to the first vapor pressure and the second vapor pressure.

Optionally, the cooling module includes a refrigeration component and a control component, wherein the control component is used to control the refrigeration component to cool the condensation surface to a first temperature at maximum power in the first stage, and to control the refrigeration component to cool the condensation surface at dynamic power in the second stage, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage. Optionally, the device pre-stores first temperatures corresponding to different types of coffee particles; the control component is also used to obtain the type of the coffee particles, and determine the value of the first temperature according to the type of the coffee particles. Optionally, the device also pre-stores the correspondence between different types of coffee particles or different water contents and water activity intervals; the control component is also used to obtain the type of the coffee particles or the water content of the coffee particles, confirm the water activity interval corresponding to the coffee particles according to the type of the coffee particles or the water content of the coffee particles, and control the refrigeration component to continue cooling when the water activity is not within the water activity interval corresponding to the coffee particles.

Optionally, the device also includes a first imaging module, which includes at least two light sources with different spectra, and is used to sequentially emit light beams of different spectra to the coffee particles in the accommodating space; the first imaging module also includes a photosensitive array for sequentially receiving reflected light of the coffee particles to the at least two light beams with different spectra and sequentially imaging the coffee particles, wherein the photosensitive array is used to generate at least two frames of images corresponding to the at least two light sources respectively; the calculation module is also used to calculate the chromaticity value of the coffee particles based on the at least two frames of images; the control component is also used to obtain the category of the coffee particles based on the imaging of the coffee particles.

Optionally, the device also pre-stores a correspondence between different moisture contents and types of coffee particles; the control component also Used to obtain the moisture content of the coffee particles, and determine the type of the coffee particles according to the moisture content.

Optionally, the cooling component is located on one side of the condensation surface, and the device further includes a heat sink located on a side of the cooling component facing away from the condensation surface and arranged adjacent to the cooling component, and a heat sink fan arranged adjacent to the heat sink.

Optionally, the device further comprises a circulation fan located on one side of the condensation surface and a motor for driving the circulation fan, wherein the circulation fan is used to increase the air circulation speed between the accommodating space and the condensation surface.

Optionally, the dew point detection module is also used to detect the condensation position on the condensation surface; the first temperature detection module is used to obtain the temperatures of at least two locations on the condensation surface; the calculation module is used to obtain the distances between the positions of the at least two locations and the condensation positions, determine the weights corresponding to the at least two locations according to the distances between the positions of the at least two locations and the condensation positions, and calculate the dew point temperature according to the temperatures of the at least two locations and the weights corresponding to the at least two locations.

Optionally, the dew point detection module includes a second imaging module for acquiring images of the condensation surface at different times; the calculation module is further used to detect whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface according to the grayscale values of the images at different times. Optionally, the calculation module is used to acquire the grayscale value mean of the images of the condensation surface at different times, and the grayscale value distribution of different partitions on the images of the condensation surface at different times, to determine whether dew points appear on the condensation surface.

Optionally, the dew point detection module includes a second imaging module for obtaining images of the condensation surface at different times; the calculation module is also used to obtain an initial image of the condensation surface containing dew, and to perform edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, the dew in the initial image is confirmed to be the dew.

Optionally, the dew point detection module includes a laser emitter and a laser detector; the laser beam emitted by the laser emitter covers the condensation surface, the laser detector is used to receive the laser beam reflected by the condensation surface, and to generate an electrical signal based on the received laser beam; the calculation module is also used to confirm the presence of dew on the condensation surface based on changes in the electrical signal.

Optionally, the first temperature detection module includes a platinum resistance sensor located on one side of the condensation surface, and the calculation module is used to obtain the lag time of the platinum resistance sensor, and calculate the dew point temperature based on the temperature measured by the platinum resistance sensor at the lag time after the first moment.

Optionally, the second vapor pressure is calculated based on the equilibrium temperature measured when the temperature of the accommodating space and the coffee particles reach equilibrium; the calculation module pre-stores a first relationship model between the water activity measured at the equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; the calculation module is also used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the equilibrium temperature, the water activity and the first relationship model.

Optionally, the second vapor pressure is calculated based on the temperature when the temperatures of the accommodating space and the coffee particles have not reached equilibrium; the calculation module pre-stores a second relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; the calculation module is also used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the temperatures of the accommodating space and the coffee particles, the water activity and the second relationship model.

Optionally, the device is also used to obtain at least one of the following parameters of the coffee particles: moisture content, density, interstitial ratio, diameter, area, color, circularity, color uniformity, texture, and chromaticity.

Optionally, the device includes an upper cover structure and a main body structure that are movably connected, the device also includes a removable inner liner located in the main structure, the accommodating space is located in the removable inner liner, and the device also includes: a chassis structure, a first electrode and a second electrode, on the surface of which are provided with a first electrode contact and a second electrode contact, and a first electrode and a second electrode, which are fixed in the main structure; the first electrode and the second electrode are fixed on the chassis structure and are respectively connected to the first electrode contact and the second electrode contact; when the removable inner liner is combined into the main structure, the accommodating space is embedded between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; the calculation module is also used to calculate the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode.

Optionally, the first electrode is located on the chassis structure, and the second electrode is in a ring shape surrounding the first electrode, so that an annular hollow cavity is formed between the first electrode and the second electrode; at least a portion of the removable inner liner is made of non-conductive material, and a groove extending toward the accommodating space is formed on the bottom surface of the removable inner liner, and the accommodating space is in a ring shape surrounding the groove, so that when the removable inner liner is fixed to the main structure, the accommodating space in the removable inner liner is embedded in the annular hollow cavity, and the first electrode is embedded in the groove from the outside of the bottom surface of the removable inner liner. Optionally, the removable inner liner includes an annular wall made of oxidized metal, and the bottom surface and the groove are made of non-conductive material. Optionally, a base is provided at the bottom of the first electrode on the chassis structure, the first electrode contact is provided on the base, and the first electrode is fixed on the base and connected to the first electrode contact, so that The bottom of the first electrode is higher than the bottom of the second electrode.

Optionally, the device includes an upper cover structure and a main body structure that are movably connected, and the device includes a chassis structure located in the main body structure and provided with a first electrode contact and a second electrode contact on the surface; a part of the detachable inner liner is a first electrode and a part is a second electrode, when the detachable inner liner is combined with the main body structure, the first electrode contacts the first electrode contact, the second electrode contacts the second electrode contact, and the accommodating space is located between the first electrode and the second electrode; the calculation module is also used to calculate the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode. Optionally, the device also includes a detection circuit located in the main body structure, the detection circuit includes a measured loop and a reference loop, the first electrode contact and the second electrode contact are located on the measured loop, and a reference capacitor with a known capacitance value is provided on the reference loop; the calculation module is used to obtain the capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; the calculation module is also used to calculate the moisture content of the coffee particles according to a pre-stored relationship model between the capacitance difference and the moisture content, and the obtained capacitance difference. Optionally, the detection circuit is also used to obtain at least two capacitance values between the first electrode and the second electrode corresponding to at least two different electrode frequencies; the calculation module is also used to calculate at least two corresponding moisture contents according to the at least two capacitance values, and to perform weighted calculation of the at least two moisture contents to obtain the moisture content of the coffee particles.

Optionally, the condensation surface, the cooling module, the first temperature detection module and the dew point detection module are located in the upper cover structure; a third imaging module is also provided in the upper cover structure for imaging the coffee particles in the accommodating space; a preset correction model is also pre-stored in the device for indicating the relationship between the moisture content and at least the gap ratio; the calculation module is also used to obtain the gap ratio of the coffee particles according to the imaging, and to correct the moisture content according to the gap ratio and the preset correction model. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the device also includes a second temperature detection module for detecting the temperature of the coffee particles; the calculation module is used to correct the moisture content according to the temperature of the coffee particles detected by the second temperature detection module, the gap ratio and the preset correction model.

Optionally, the device further comprises a pressure sensor located under the chassis structure in the main structure, for detecting the weight of the coffee particles in the detachable inner container; the calculation module is further used to calculate the volume of the coffee particles according to the gap ratio and the volume of the detachable inner container, and to calculate the density of the coffee particles according to the weight of the coffee particles and the volume of the coffee particles detected by the pressure sensor. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the density; the calculation module is used to correct the moisture content according to the gap ratio, the density and the preset correction model.

Optionally, the device is also preset with a relationship model between the diameter of the coffee particles and the gap ratio, density and moisture content, and the calculation module is further used to calculate the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; the device also includes a user interface for displaying the diameter of the coffee particles to the user.

Optionally, the calculation module is further used to classify the coffee particles into one of a plurality of preset levels according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity, chromaticity; the user interface is further used to display the level of the coffee particles to the user. Optionally, the calculation module is further used to pre-store or query in real time at least one of the guidance suggestions for storage, roasting, grinding, and brewing of coffee beans of different levels; the user interface is further used to display the guidance suggestions corresponding to the level of the coffee particles. Optionally, the calculation module is further used to pre-store a prediction model, and to predict the pre-treatment method and/or pre-treatment time of the coffee particles according to the at least one parameter of the coffee beans and the prediction model; the user interface is further used to display the pre-treatment method and/or pre-treatment time to the user. Optionally, the calculation module is further used to: obtain the pre-stored initial moisture content of the detachable inner liner; obtain the current moisture content of the detachable inner liner when it is empty; and correct the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content.

Optionally, the device comprises an upper cover structure and a main body structure that are movably connected, and the accommodating space is located in the main body structure; the upper cover structure comprises a concave cavity, and when the upper cover structure covers the main body structure, the concave cavity is connected to the accommodating space; the concave cavity is provided with a first platform at a first depth, and the condensation surface is located on the first platform; the first imaging module is located in the upper cover structure, and the at least two light sources with different spectra are located at a second depth of the concave cavity, and the second depth is farther away from the accommodating space than the first depth. Optionally, the photosensitive array is located at a third depth of the concave cavity; the upper cover structure is also provided with an infrared anti-reflection glass located between the first depth and the third depth of the concave cavity to block the air passage between the first imaging module and the accommodating space; or, at least one reflector is also provided in the upper cover structure or the main body structure, and the second imaging module is used to receive the reflected light of the coffee particles to the at least two light beams with different spectra through the at least one reflector to image the coffee particles.

Optionally, the device comprises an upper cover structure and a main body structure that are movably connected, and the device also comprises a The detachable inner liner in the structure, the accommodating space is located in the detachable inner liner, the bottom of the detachable inner liner is infrared anti-reflection glass, and the first imaging module is located below the bottom of the detachable inner liner. Optionally, the device also includes a temperature and humidity sensor for detecting the temperature and humidity of the environment in which the coffee beans are located; the device also includes an air pressure sensor for detecting the air pressure of the environment in which the coffee beans are located; the calculation module is also used to calculate the altitude data according to the air pressure; the user interface is also used to display the temperature and humidity, the air pressure and the altitude data as the picking environment data of the coffee beans.

The device also includes a calibration kit, which includes at least one of the following: a calibration inner tank, a calibration color card, a water activity standard solution, and a standard solution holding container; the calculation module is also used to perform at least one of the following: compensating for the moisture content measurement result of the coffee particles based on the moisture content measurement result of the calibration inner tank; compensating for the chromaticity measurement result of the coffee particles based on the chromaticity measurement result of the calibration color card; compensating for the water activity measurement result of the coffee particles based on the measurement result of the water activity standard solution in the standard solution holding container.

In a second aspect, the present application provides a method for detecting coffee particles, comprising: cooling a condensation surface having an air passage connected to a accommodating space, the accommodating space being used to accommodate coffee particles, so that water vapor in the coffee particles condenses on the condensation surface to form dew; detecting whether the dew appears on the condensation surface; determining a first moment, the first moment being the moment when the dew point is detected to appear on the condensation surface; detecting the temperature of at least one point on the condensation surface, and determining the dew point temperature based on the temperature of the at least one point at the first moment; obtaining a first vapor pressure based on the dew point temperature; obtaining the temperature of the accommodating space and the coffee particles; obtaining a second vapor pressure based on the temperature of the accommodating space and the coffee particles, and calculating the water activity of the coffee particles based on the first vapor pressure and the second vapor pressure.

Optionally, cooling the condensation surface having an air passage connected to the accommodating space includes: in a first stage, controlling the refrigeration component at maximum power to cool the condensation surface to a first temperature; in a second stage, controlling the refrigeration component at dynamic power to cool the condensation surface, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage.

Optionally, the step of controlling the refrigeration component with a first power to cool the condensation surface to a first temperature also includes obtaining the category of the coffee particles; and determining a value of the first temperature according to the category of the coffee particles.

Optionally, the method further includes: obtaining the category of the coffee particles or the correspondence between different moisture contents and water activity ranges; obtaining the category of the coffee particles or the different moisture contents; confirming the water activity range corresponding to the coffee particles based on the category of the coffee particles or the different moisture contents and the correspondence; when the water activity is not within the water activity range corresponding to the coffee particles, controlling the refrigeration component to continue cooling.

Optionally, the method of obtaining the category of the coffee particles includes: providing the user with options of different categories of coffee particles through an interactive interface; and determining the category of the coffee particles according to the option selected by the user. Optionally, the method further includes: emitting at least two light beams of different spectra to the coffee particles in the accommodating space; receiving reflected light of the coffee particles from the at least two light beams of different spectra and imaging the coffee particles; and calculating the chromaticity value of the coffee particles based on the imaging of the coffee particles; the method of obtaining the category of the coffee particles includes: obtaining the category of the coffee particles based on the imaging of the coffee particles. Optionally, the method of obtaining the category of the coffee particles includes: obtaining the moisture content of the coffee particles; and determining the category of the coffee particles based on the moisture content and a pre-stored correspondence between different moisture contents and categories of coffee particles.

Optionally, the detecting whether the dew appears on the condensation surface includes: detecting whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface according to the grayscale values of the images at different times. Optionally, the detecting whether dew points appear on the condensation surface according to the grayscale values of the images at different times includes: obtaining the grayscale value mean of the images of the condensation surface at different times, and/or the grayscale value distribution of different partitions on the images of the condensation surface at different times; determining whether dew points appear on the condensation surface according to the grayscale value mean and/or the grayscale value distribution.

Optionally, the method further includes: obtaining an initial image of the condensation surface containing dew, and performing edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, confirming that the dew in the initial image is the dew. Optionally, the detection of whether the dew appears on the condensation surface includes: emitting a laser beam through a laser transmitter to cover the condensation surface; receiving the laser beam reflected by the condensation surface through a laser detector; generating an electrical signal according to the received laser beam; and confirming the presence of dew on the condensation surface according to changes in the electrical signal.

Optionally, detecting the temperature of at least one location on the condensation surface and determining the dew point temperature based on the temperature of the at least one location at a first moment include: detecting the temperature by a platinum resistance sensor located on one side of the condensation surface; obtaining the lag time of the platinum resistance sensor; and calculating the dew point temperature based on the temperature measured by the platinum resistance sensor at the lag time after the first moment.

Optionally, the second vapor pressure is calculated based on the equilibrium temperature measured when the temperature of the accommodating space and the coffee particles reaches equilibrium; the method further comprises: obtaining the water activity measured at the pre-stored equilibrium temperature of 25 degrees Celsius and comparing it with the water activity measured at the pre-stored equilibrium temperature of 25 degrees Celsius; The method further comprises: obtaining a pre-stored second relationship model of the water activity measured at the equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; calculating the water activity of the coffee particles at the equilibrium temperature of 25 degrees Celsius according to the equilibrium temperature, the water activity and the first relationship model. Optionally, the second vapor pressure is calculated according to the temperature when the temperature of the accommodating space and the coffee particles are not in equilibrium; the method further comprises: obtaining a pre-stored second relationship model of the water activity measured at the equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; calculating the water activity of the coffee particles at the equilibrium temperature of 25 degrees Celsius according to the temperature of the accommodating space and the coffee particles, the water activity and the second relationship model.

Optionally, the method further comprises: obtaining at least one of the following parameters of the coffee particles: moisture content, density, interstitial ratio, diameter, area, color, circularity, color uniformity, texture, and chromaticity.

Optionally, the method further includes: placing the accommodating space between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; detecting the capacitance value between the first electrode and the second electrode by a detection circuit; and calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode. Optionally, the detection circuit includes a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop. The method further includes obtaining a capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; the calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: calculating the moisture content of the coffee particles according to a pre-stored relationship model between the capacitance difference and the moisture content, and the obtained capacitance difference. Optionally, detecting the capacitance value between the first electrode and the second electrode by means of a detection circuit includes: obtaining at least two capacitance values between the first electrode and the second electrode corresponding to at least two different electrode frequencies respectively; calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: calculating at least two moisture contents corresponding to the at least two capacitance values respectively, and obtaining the moisture content of the coffee particles by weighted calculation of the at least two moisture contents.

Optionally, the method further comprises: acquiring a pre-stored preset correction model, wherein the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; imaging the coffee particles in the accommodating space;

The gap ratio of the coffee particles is obtained according to the imaging; and the moisture content is corrected according to the gap ratio and the preset correction model.

Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the method further includes: detecting the temperature of the coffee particles; correcting the moisture content according to the detected temperature of the coffee particles, the gap ratio and the preset correction model. Optionally, the method further includes: detecting the weight of the coffee particles by a pressure sensor; calculating the volume of the coffee particles according to the gap ratio and the volume of the accommodating space; calculating the density of the coffee particles according to the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, the preset correction model is a relationship model between the gap ratio, the density and the moisture content; correcting the moisture content according to the gap ratio and the preset correction model includes: correcting the moisture content according to the gap ratio, the density and the preset correction model.

Optionally, the method also includes: obtaining a pre-stored relationship model between the diameter and gap ratio, density and moisture content of coffee particles; calculating the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; and displaying the diameter of the coffee particles to the user through a user interface.

Optionally, the method further comprises: classifying the coffee particles into one of a plurality of preset grades according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity, chroma; and displaying the grade of the coffee particles to the user via a user interface.

Optionally, the method further includes: obtaining pre-stored or real-time query of at least one of the guidance suggestions for storage, roasting, grinding, and brewing of coffee beans of different grades; and displaying the guidance suggestions corresponding to the grade of the coffee particles through the user interface. Optionally, the method further includes: obtaining a pre-stored inference model; inferring the pretreatment method and/or pretreatment time of the coffee particles based on the at least one parameter of the coffee beans and the inference model; and displaying the pretreatment method and/or pretreatment time to the user through the user interface.

Optionally, the method further includes: obtaining the pre-stored initial moisture content of the detachable inner container; obtaining the current moisture content of the detachable inner container when it is empty; and correcting the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content. Optionally, the method further includes: detecting the temperature and humidity of the environment in which the coffee beans are located through a humidity sensor; detecting the air pressure of the environment in which the coffee beans are located through an air pressure sensor; calculating the altitude data according to the air pressure; and displaying the temperature and humidity, the air pressure and the altitude data as the picking environment data of the coffee beans through a user interface.

The method further comprises at least one of the following steps: compensating the moisture content measurement result of the coffee particles according to the measurement result of the moisture content of the calibration inner container; compensating the colorimetric measurement result of the coffee particles according to the colorimetric measurement result of the calibration color card; compensating the water activity measurement result of the coffee particles according to the measurement result of the water activity standard solution in the standard solution carrying container; Compensate for the results.

In the embodiment of the present application, since the water activity (AW) is the ratio of the actual water vapor pressure P0 to the saturated water vapor pressure P1 at the same temperature, the cooling module is used to quickly cool the condensation surface while keeping the air pressure unchanged, so that the air is cooled to the saturated temperature; when the saturated temperature is reached, water vapor will precipitate on the condensation surface, and the dew point temperature can be obtained by detecting the first moment of condensation on the condensation surface and then obtaining the temperature at the time of condensation through the first temperature detection module to calculate the actual water vapor pressure P0. The saturated vapor pressure P1 is then calculated by the temperature of the coffee particles and the cavity temperature, and the ratio of the two is the water activity. Through this measurement structure and method, the water activity of the coffee particles can be quickly and accurately measured.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the logical framework of an embodiment of a coffee particle detection device of the present application; Figures 2 and 3 are schematic diagrams of the structure of a coffee particle detection device of an embodiment of the present application in two different states; Figure 4 is a perspective view of the internal structure of the coffee particle detection device of the embodiment shown in Figure 2; Figure 5 is a schematic diagram of the partial structure inside the upper cover structure of the coffee particle detection device shown in Figure 4; Figure 6 is a schematic diagram of the relationship between the voltage of the laser detector and the temperature of the condensation surface in an embodiment of the present application; Figure 7 is a schematic diagram of the positional relationship between the condensation surface, the cooling module, the first temperature detection module and the dew point detection module in an embodiment of the present application; Figure 8 is a comparison diagram of the results of measuring the temperature of the same condensation surface at different times by an RTD sensor and a thermistor in an embodiment of the present application; Figure 9 is a schematic diagram of the temperature detection points and condensation positions on the condensation surface in an embodiment of the present application; Figure 10 is an exploded schematic diagram of the chassis structure, electrode structure and detachable inner tank of the coffee particle detection device of an embodiment of the present application; Figure 11 is a schematic diagram of the chassis structure shown in Figure 10 and an electrode structure; FIG12a is a bottom side view of the detachable inner liner shown in FIG9; FIG12b is a structural schematic diagram of the chassis structure and the first electrode of a coffee particle detection device according to an embodiment of the present application; FIG13 is an exploded schematic diagram of the chassis structure and the detachable inner liner of a coffee particle detection device according to an embodiment of the present application; FIG14 is a schematic diagram of the assembly relationship between the chassis structure and the detachable inner liner shown in FIG13; FIG15 is a schematic diagram of an image of coffee particles located in a detachable inner liner in an example; FIG16 is a bottom view of the upper cover structure of the coffee particle detection device in an embodiment of the present application; FIG17 is a schematic diagram of the positional relationship between the photosensitive array, coffee particles and the reflector in an embodiment of the coffee particle detection device of the present application; FIG18a is a schematic diagram of the positional relationship between the detachable inner liner and the first imaging module in the coffee particle device in an embodiment of the present application; FIG18b is a structural schematic diagram of the self-calibration kit in an embodiment of the present application; and FIG19 is a flow chart of an embodiment of a coffee particle detection method of the present application.

DETAILED DESCRIPTION

The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described here. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to be able to fully convey the scope of the present application to those skilled in the art. The terms used in this application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "one", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used herein refers to and includes any or all possible combinations of one or more associated listed items. It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

As shown in Figure 1, Figure 1 is a logical framework diagram of an embodiment of the coffee particle detection device of the present application. The coffee particle water activity detection device 10 includes a accommodating space 11, a condensation surface 12, a cooling module 13, a first temperature detection module 14, a dew point detection module 15 and a calculation module 16. The accommodating space 11 is used to accommodate coffee particles. There is an air passage connected between the condensation surface 12 and the accommodating space. The cooling module 13 is used to cool the condensation surface 121 so that the water vapor in the coffee particles condenses on the condensation surface 121 to precipitate dew. There are various positional relationships between the condensation surface 12 and the accommodating space 11. For example, the condensation surface 12 is located on one side of the accommodating space 11, or the condensation surface 12 is located in the accommodating space 11. Regardless of the positional relationship, there is an air passage connected between the condensation surface of the condensation surface 12 and the accommodating space 11, so that the water vapor in the coffee particles in the accommodating space can precipitate and form dew on the condensation surface when the temperature of the condensation surface decreases, so as to detect the dew point temperature of the coffee particles. There are many types of coffee particles. For example, the coffee particles in this application can refer to any one of green coffee beans, roasted beans, shelled beans, dried coffee fruits, and coffee powder.

The dew point detection module 15 is used to detect whether dew appears on the dew condensation surface 12. The first temperature detection module 14 is used to detect the temperature of at least one point on the dew condensation surface. The calculation module 16 is used to determine a first moment, which is the moment when dew appears on the dew condensation surface; the calculation module 16 is used to determine the first moment according to the first moment and the temperature of at least one point. Point temperature, obtain a first vapor pressure according to the dew point temperature, obtain the temperature of the accommodating space and the coffee particles, obtain a second vapor pressure according to the temperature of the accommodating space and the coffee particles, and calculate the water activity of the coffee particles according to the first vapor pressure and the second vapor pressure. Since the measurement of water activity (AW) is the ratio of the actual water vapor pressure P0 to the saturated water vapor pressure P1 at the same temperature, that is, AW = P0/P1, by keeping the air pressure unchanged, in the embodiment of the present application, the condensation surface is cooled by the cooling module to cool the air to the saturation temperature; when the saturation temperature is reached, water vapor will precipitate on the condensation surface, and the dew point temperature can be obtained by detecting the first moment when condensation appears on the condensation surface, and then obtaining the temperature at the time of condensation through the first temperature detection module to obtain the dew point temperature, and the actual water vapor pressure P0 can be calculated. Then the saturated vapor pressure P1 is calculated by the equilibrium temperature, and the ratio of the two is the water activity. Optionally, the temperature balance refers to the overall temperature (including the cavity temperature and the temperature of the coffee particles) reaching equilibrium.

Optionally, the coffee particle detection device also includes a second temperature detection module for monitoring the cavity temperature and the temperature of the coffee particles to provide temperature information in multiple dimensions. In one example, the second temperature detection module includes an infrared temperature sensor, which is located on one side of the accommodating space. The temperature of the coffee particles in the accommodating space can be measured by infrared temperature measurement, and the temperature of the environment in which it is located, that is, the cavity temperature, can be output to the calculation module to determine whether the temperature balance is achieved. Optionally, the second temperature detection module also includes a temperature and humidity sensor for detecting the temperature and humidity in the cavity, which can provide more environmental information for the calculation of the calculation module and improve the accuracy of the calculation results. Optionally, the coffee particle detection device also includes a circulating fan and a motor for driving the circulating fan, and the circulating fan is used to increase the air circulation speed in the accommodating space, accelerate the cavity temperature and the temperature of the coffee particles to reach a balance, so that the equilibrium temperature can be measured as soon as possible.

When measuring water activity, for the saturated vapor pressure at the equilibrium temperature, the standard stipulates that the measurement needs to be performed at 25 degrees Celsius. At other equilibrium temperatures, the water activity will have a certain error. Optionally, the coffee particle detection device in some examples also pre-stores a first relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures. In this way, there is no need to wait until the stable temperature reaches 25 degrees Celsius. The calculation module can calculate the vapor pressure P1 when other equilibrium temperatures are obtained, and when the water activity WA_0 is calculated based on P1 and P0, the water activity corresponding to the equilibrium temperature of 25 degrees Celsius is calculated based on the water activity WA_0 corresponding to the other equilibrium temperature and the first relationship model, which can improve the measurement speed while ensuring the accuracy of the measurement results. In one example, the first relationship model is WA=WA_0+a*(T1-25), where WA_0 is the water activity measured under the equilibrium temperature T1, a is a fixed constant that can be obtained through experiments, and a*(T-25) is the compensation value of the equilibrium temperature T1 for the standard water activity at 25 degrees Celsius. The calculated WA is the compensated standard water activity.

Alternatively, in some examples, the calculation module may calculate the vapor pressure P1 based on the equilibrium temperature without waiting for the temperature to be balanced, but may calculate the vapor pressure P2 based on the currently measured temperature T2 before the temperature is balanced. The coffee particle detection device also pre-stores a second relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures. The calculation module calculates the corresponding vapor pressure P2 based on the currently measured temperature T2, and after calculating the water activity WA_1 based on P2 and P0, it also calculates the water activity corresponding to the equilibrium temperature of 25 degrees Celsius based on the water activity WA_1 corresponding to the temperature T2 and the second relationship model, which can improve the measurement speed while ensuring the accuracy of the measurement results. In one example, AW=AW_ub+b*(T2-T1), where b is a fixed constant that can be obtained through experiments, T1 is the temperature of the coffee particles, T2 is the cavity temperature, AW_ub is the water activity of the coffee particles obtained by using the cavity temperature T2 as the equilibrium temperature, and AW is the water activity compensated by the difference between the cavity temperature and the temperature of the coffee particles.

There are many methods for cooling the condensation surface by the cooling module. In one example, the cooling module includes a refrigeration component and a control component, the refrigeration component is in contact with the condensation surface, and the control component is used to control the cooling of the refrigeration component to drive the cooling of the condensation surface. Optionally, the control component is used to control the refrigeration component to cool the condensation surface to a first temperature at a first power in the first stage, and the first temperature is higher than the dew point temperature. Then the control component controls the refrigeration component to cool the condensation surface at a dynamic power in the second stage, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate, and the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage. Optionally, the first power is the maximum power of the control component, so that the refrigeration component cools the condensation surface from the current temperature to the first temperature at the fastest speed in the first stage. In the first stage, the cooling rate of the condensation surface may not be fixed. When the control component is controlled at maximum power, the condensation surface is likely to cool in a nonlinear manner. The second-stage control component controls the temperature of the condensation surface to cool down in a linear manner, which can match the cooling speed with the resolution of the collected temperature, and then allow the calculation module to more accurately determine the temperature at the time of condensation from the temperatures at different times monitored by the first temperature detection module. Optionally, in the second stage, the control power of the control component can be reversely controlled according to the temperature changes measured in real time. Specifically, the pulse width modulation (PWM) can be reversely controlled by the temperature changes measured in real time, so that the temperature of the second stage can be reduced at a linear speed.

For example, in the second stage, when the control component cools down the condensation surface, the measured temperature of the condensation surface is obtained in real time. When it is determined that the temperature change of the condensation surface in each preset time interval does not reach the preset temperature change, the power is increased so that the temperature change of the condensation surface in the next preset time interval reaches the preset temperature change; when it is determined that the temperature change of the condensation surface in each preset time interval does not reach the preset temperature change, the power is increased. When the temperature change exceeds the preset temperature change, the power is reduced so that the temperature change of the condensation surface in the next preset time interval drops to the preset temperature change.

Since the dew point temperatures of different categories of coffee particles are different, the control inflection point (preset as the first temperature) set when controlling the cooling of the condensation surface may be different. Optionally, the control component is also used to obtain the category of the coffee particles, and determine the value of the first temperature according to the category of the coffee particles. There are many ways to obtain the category of coffee particles. In one example, the category of coffee particles can be obtained by pre-storing a mapping table of multiple categories and corresponding first temperatures, and obtaining the category selected by the user from multiple category options. Or, in one example, the coffee particle detection device also pre-stores the correspondence between different moisture contents and the category of coffee particles; the control component can obtain the moisture content of the coffee particles, and determine the category of the unsealed particles according to the moisture content and the correspondence. Among them, a module for detecting moisture content is also provided in the coffee particle detection device, and the specific details can be referred to the description below. After the module for detecting moisture content obtains the moisture content, it is also used to determine the category of coffee particles for the control component. Or, in one example, the coffee particle detection device also includes a first imaging module for imaging coffee particles. Specifically, the first imaging module includes a light source and a photosensitive array, the light source is used to emit a light beam to the accommodating space, and the photosensitive array is used to receive the light beam reflected by the coffee particles in the accommodating space and to form an image. The control component obtains the category of the coffee particles by identifying the content of the imaging. In some examples, the imaging of the first imaging module can also allow the calculation module to calculate the chromaticity value of the coffee particles. Optionally, the first imaging module includes a light source for at least two different spectra, which is used to sequentially emit light beams of different spectra to the coffee particles in the accommodating space, and a photosensitive array for sequentially receiving the reflected light of the coffee particles to the light beams of at least two different spectra and sequentially imaging the coffee particles, wherein the photosensitive array is used to generate at least two frames of images corresponding to the at least two light sources. Optionally, the at least two frames of images are original images with an upper limit of pixel values of 30 to 40 million or even higher. The calculation module is also used to calculate the chromaticity value of the coffee particles based on the at least two frames of images. By fusing the images formed when light sources of different spectra illuminate the coffee particles, the problem of poor stability of chromaticity value detection results caused by using a single spectrum acquisition can be effectively avoided.

Optionally, the coffee particle detection device also pre-stores the correspondence between different categories of coffee particles or different moisture contents and water activity intervals. After the calculation module calculates the water activity, the calculation module also finds the corresponding water activity interval according to the category of the coffee particles or the moisture content of the coffee particles, and confirms whether the calculated water activity is within the corresponding water activity interval. If not, it means that an error occurred in the process of measuring the water activity, for example, the dew point detection module may have mistakenly detected dew. Optionally, when the calculation module confirms that the calculated water activity is outside the corresponding water activity interval, the cooling module is used to continue to cool the condensation surface to find the true dew point temperature.

There are many structures of the coffee particle detection device, as shown in Figures 2 and 3, which are schematic diagrams of the structure of the coffee particle detection device of one embodiment of the present application in two different states. The coffee particle detection device includes an upper cover structure 21 and a main body structure 22 that are movably connected. Among them, the removable inner liner 23 is located in the main body structure 22. The removable inner liner 23 has an opening 231 and a space 232 for loading coffee particles. When the upper cover structure 21 covers the main body structure 22, the opening of the removable inner liner 23 is sealed. In Figure 2, the upper cover structure 21 is in an open state, so that the user can remove the removable inner liner 23 to install coffee particles. In Figure 3, the removable inner liner 23 is detached from the main body structure 22, so that the user can load the coffee particles to be tested into the removable inner liner 23. Optionally, the condensation surface 24, the cooling module (not shown), the first temperature detection module (not shown) and the dew point detection module (not shown) are located in the upper cover structure 21. When the upper cover structure 21 covers the main structure 22, a connected air passage is formed between the condensation surface 24 and the accommodating space 232. After the cooling module cools down the condensation surface, the water vapor in the coffee particles can condense on the condensation surface 24 to achieve condensation. As shown in Figures 4 and 5, Figure 4 is a perspective view of the internal partial structure of the coffee particle detection device of the embodiment shown in Figure 2, and Figure 5 is a schematic diagram of the partial structure inside the upper cover structure of the coffee particle detection device shown in Figure 4. The upper cover structure 21 includes a concave cavity 211, and when the upper cover structure 21 covers the main structure 22, the concave cavity 211 is connected to the accommodating space. The concave cavity 211 is provided with a first platform 2111 at a first depth, and the condensation surface 24 is located on the first platform 2111.

The cooling module 25 includes a cooling component 251 located on one side of the condensation surface 24, a heat sink 252 located on the side of the cooling component 251 facing away from the condensation surface 24 and fixed to the cooling component 251, and a heat sink fan 253 disposed adjacent to the heat sink 252. Optionally, the coffee particle detection device further includes a circulation fan 26 located in the upper cover structure on one side of the condensation surface 24 and a motor 28 for driving the circulation fan 26.

Optionally, the dew point detection module 27 includes a laser emitter 271 and a laser detector 272 opposite to the first platform 2111, and a detection module (not shown) located in the upper cover structure. The laser emitter 271 is used to emit a laser beam covering the condensation surface 24. The laser detector 272 is used to receive the laser beam reflected by the condensation surface 24, and to generate an electrical signal based on the received laser beam. The detection module is used to confirm the appearance of a dew point on the condensation surface based on changes in the electrical signal. As shown in Figure 6, Figure 6 is a schematic diagram of the relationship between the voltage of the laser detector and the temperature of the condensation surface in an embodiment of the present application. In the figure, L1 represents the temperature of the condensation surface, and L2 represents the voltage of the laser detector 272. It can be seen that in the laser emitter 771 When the output power remains constant, the voltage of the laser detector 272 also remains stable. As the temperature of the condensation surface decreases, when condensation appears on the condensation surface 24, the light energy received by the laser detector 272 will decrease due to the diffuse reflection of the laser beam by the condensation, and the corresponding voltage will also decrease. The detection module can accurately capture the moment when condensation appears on the condensation surface by real-time monitoring the voltage change of the laser detector, and determine the moment as the first moment. The temperature of the condensation surface at the first moment is the dew point temperature.

The first temperature detection module includes at least one temperature sensor for detecting the temperature of at least one point of the condensation surface 24. As shown in FIG. 7, FIG. 7 is a schematic diagram of the positional relationship between the condensation surface, the cooling module, the first temperature detection module and the dew point detection module in one embodiment of the present application. The first temperature detection module includes at least one temperature sensor located on at least one side of the condensation surface 24. In FIG. 7, the first groove 71 and the second groove 72 are respectively provided on both sides of the condensation surface 24 for illustration, and the first temperature detection module includes a first temperature sensor (not shown) and a second temperature sensor (not shown) respectively located in the first groove 71 and the second groove 72. In one example, the first temperature sensor is a platinum resistance sensor (such as an RTD sensor), and the second temperature sensor is a thermistor. The platinum resistance sensor is a device made of platinum, and its resistance changes linearly with the change of temperature. It has the advantage of high measurement accuracy, but its sensitivity is low, and the measured temperature has a hysteresis problem. The thermistor includes a thermistor, which is usually made of a semiconductor material, and its resistance changes nonlinearly with the change of temperature. It has the characteristics of high sensitivity but low measurement accuracy. In this application, it is necessary to accurately obtain the moment when the dew point temperature is detected. By combining the platinum resistance sensor and the thermistor, the measurement lag time of the platinum resistance sensor can be calculated using the temperatures measured by the thermistor and the platinum resistance sensor respectively, and then the real measurement time of the dew point temperature can be accurately obtained according to the first moment and the lag time. Optionally, the platinum resistance sensor can adopt a four-wire platinum resistance sensor. The four-wire lead method is to connect two wires at both ends of the root of the thermal resistor, where two leads provide a constant current I for the thermal resistor and convert R into a voltage signal U. This wiring method does not require equal resistance for the leads, and can eliminate the influence of lead resistance on temperature measurement.

As shown in Figure 8, Figure 8 is a comparison chart of the results of measuring the temperature of the same condensation surface at different times by an RTD sensor and a thermistor in one embodiment of the present application. Wherein L3 is a schematic diagram of the temperature curve of the RTD sensor, and L4 is a schematic diagram of the temperature curve of the thermistor. It can be seen from the figure that for the same measured temperature, the measured time of the RTD sensor lags behind the measured time of the thermistor. There are many ways to calculate the lag time of the RTD sensor. In one example, the condensation surface is rapidly cooled down and then heated up by a cooling module, and the lag time of the RTD sensor can be obtained by measuring the time difference of the temperature inflection points of the platinum resistance sensor and the thermistor respectively. The inflection point temperature can be a preset temperature. Alternatively, optionally, since the lag time of the platinum resistance sensor is not strictly consistent at different temperatures, the temperature inflection point is set near the dew point temperature, which can more accurately measure the lag time of the platinum resistance sensor.

Optionally, the hysteresis time of the platinum resistance sensor can be measured online, for example, the coffee particle detection device is provided with a calibration mode, and the hysteresis time is measured by the user starting the self-calibration mode. Optionally, when the user starts the self-calibration mode, the type of coffee particles to be calibrated can also be selected, so that the inflection point temperature is set at a preset temperature corresponding to the type in the self-calibration mode, wherein the preset temperature is a temperature close to the temperature of the coffee particles of the type. Alternatively, in an example, the hysteresis time may not be measured online, but may be calibrated and stored in the coffee particle detection device before leaving the factory, and used when the calculation module calculates the dew point temperature. In this way, the coffee particle detection device may not be provided with a thermistor, and the calculation module determines the dew point temperature according to the pre-stored hysteresis time when determining the first moment and obtaining the temperature measured by the platinum resistance sensor, for example, the temperature of the platinum resistance sensor at the interval of the hysteresis time after the first moment is used as the dew point temperature. There are many methods and structures for detecting the condensation position and the dew point temperature. In some examples, the dew point detection module may include a thermal imaging module for thermal imaging the condensation surface. The calculation module is also used to confirm at least one of the following items based on the thermal image output by the thermal imaging module: whether a dew point appears on the condensation surface, the position of the dew point on the condensation surface, and the dew point temperature.

Alternatively, in some examples, the coffee particle detection device does not include a thermal imaging module, but includes a second imaging module for performing ordinary imaging of the condensation surface, and the image output by the second imaging module is used to determine for the computing module whether condensation occurs on the condensation surface and/or the position of the condensation on the condensation surface. For example, after the computing module obtains multiple output images of the second imaging module, it performs image recognition on each image to confirm whether condensation occurs in the image. In some examples, the computing module is used to detect whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface based on the grayscale values of the imaging at different times.

For example, since the grayscale values of images with and without condensation are different, the calculation module distinguishes whether condensation occurs in each image by counting the mean grayscale values of the images of the condensation surface at different times. When counting the mean grayscale values, the calculation module can count the overall mean grayscale value of each image, or divide the image into fixed different partitions, and count the mean grayscale value of each partition in each image, and identify the image with condensation in the partition by comparing the mean grayscale values of different partitions in the same image, and/or the mean grayscale values of the same partition in different images. In this way, the images with condensation and the positions of condensation in the images can be screened out at the same time. Alternatively, in some examples, the calculation module can also determine the region of interest from the image before counting the grayscale values, and then only count the grayscale values of the region of interest. Statistics, which can improve the correlation of the image area used to determine condensation, and then improve the accuracy and efficiency of condensation position detection. Optionally, in some examples, the calculation module is also used to screen the initial image containing dew from the multiple images output by the second imaging module, and perform edge detection on the dew on the condensation surface in the initial image. When it is confirmed that the smoothness of the edge of the dew is greater than a preset threshold, the calculation module confirms that the dew in the initial image is the dew. The edge of the dew is relatively smooth and has a relatively gentle change, while the edge of the dirt will have a larger mutation. By setting a threshold for smoothness to determine whether it is dew, it can be avoided that the calculation module mistakenly detects the dirt on the condensation surface as dew. There are many ways to measure the smoothness of the dew edge. For example, the degree of change of the pixel value at the edge of the dew can be detected. The smaller the degree of change of the pixel value, the higher the smoothness. Alternatively, the texture feature at the edge of the dew can also be obtained, and the dew in the initial image is confirmed to be dew when the texture feature meets the preset requirements.

Optionally, in some examples, the second imaging module is combined with multiple temperature sensors to more accurately measure the temperature of the condensation location. For example, multiple temperature detection points are set on the condensation surface, and the first temperature detection module is used to obtain the temperature of at least two points. For example, a temperature sensor probe is respectively set at each temperature detection point, and the temperature of the corresponding temperature detection point is detected at a certain frequency by the temperature sensor probe. After the calculation module confirms the first moment when the dew point appears on the condensation surface, the temperature detected by each temperature sensor probe at the dew point moment is determined according to the first moment.

The calculation module is also used to obtain the condensation position on the condensation surface according to the image output by the second imaging module, and obtain the distance between the position of the at least two temperature detection points on the condensation surface and the condensation position, and determine the weights corresponding to the at least two temperature detection points according to the distance between the position of the at least two temperature detection points and the condensation position. Optionally, the weight corresponding to the temperature detection point farther from the condensation position is, the lower the weight. The calculation module is used to calculate the dew point temperature at the condensation position according to the temperatures of the at least two temperature detection points and the weights corresponding to the at least two temperature detection points. In the case where the condensation surface area is large or the condensation surface is heated unevenly, the temperature of multiple points on the condensation surface is measured by multiple temperature sensors, and the temperature of the condensation position is calculated according to the temperature of the multiple points, which can improve the accuracy of the temperature measurement at the condensation position.

In some examples, the calculation module may be located in the upper cover structure or in the main structure, or the calculation module may include different parts for performing different calculations, and the different parts are located in different positions. For example, the part of the calculation module used to calculate water activity is located in the upper cover structure, and the part used to calculate water content is located in the main structure, which is not limited here.

For example, in one example, as shown in FIG. 9 , FIG. 9 is a schematic diagram of temperature detection points and condensation positions on a condensation surface in an embodiment of the present application. Nine temperature detection points are arranged on the condensation surface (represented by nine small dots in the figure respectively), and the first temperature detection module detects that the temperatures of the nine temperature detection points at the first moment are T1 to T9 respectively, and according to the condensation position L5 detected by the dew point detection module, the distances between the nine temperature detection points and the condensation position are calculated to be d1 to d9 respectively. Among them, when calculating the distance between the temperature detection point and the condensation position, the distance between the temperature detection point and the centroid position of the dew point, or the distance to one of the edge positions of the dew point can be calculated, and the distance can be the Euler distance or the straight-line distance or other distance, which is not limited here. The first temperature detection module calculates the weights a1 to a9 of the nine temperature detection points according to the distances d1 to d9. In one example, ai＝1/di/(1/d1+1/d2+1/d3+1/d4+1/d5+1/d6+1/d7+1/d8+1/d9), where i＝1,…,9. Then the temperature of the condensation position is calculated as T＝a1*T1+a2*T2+a3*T3+a4*T4+a5*T5+a6*T6+a7*T7+a8*T8+a9*T9.

Optionally, the coffee particle detection device of the present application is not only used to detect the water activity of coffee particles, but also used to detect other parameters of coffee particles, such as at least one of the following: moisture content, density, gap ratio, diameter, area, color, circularity, color uniformity, texture, chromaticity. Optionally, the coffee particle detection device also includes an interface for displaying these parameters of coffee particles. In one example, at least one of the diameter, area, color, circularity, color uniformity, texture, and chromaticity of coffee particles can be obtained by identifying the image output by the first imaging module. Among them, the color and chromaticity are calculated in different ways. For example, in one example, the calculation module obtains the image of the coffee particles and calculates the final color value according to the values of the image in different color channels under a certain color space. The color space can be an RGB color space, a Lab color space, or an HSV color space. In one example, by sequentially irradiating the coffee particles with light sources of different spectra, different images corresponding to different spectra are obtained, and corresponding different chromaticity diagrams are obtained according to the different images, and then the chromaticity value is calculated according to a frame of chromaticity diagram obtained after weighted processing of the different chromaticity diagrams.

Optionally, the calculation module can also classify the coffee particles into one of a plurality of preset levels according to the detected parameters. Optionally, the coffee particle device further includes a user interface for displaying the level of the coffee particles to the user, so that the user can have a more intuitive understanding of the detected coffee particles and can quickly distinguish which are poor quality coffee beans and which are good quality coffee particles. For example, as shown in FIG4 , the user interface 20 is located on the top surface of the upper cover structure 21. Optionally, the calculation module also pre-stores or queries in real time guidance suggestions for at least one of the storage, roasting, grinding, and brewing of coffee beans of different grades, and the user interface is also used to display guidance suggestions corresponding to the level of the coffee particles to the user. Optionally, the calculation module also pre-stores an inference model, and infers the pre-processing of the coffee beans based on the at least one parameter of the coffee beans and the inference model. Method and/or pretreatment time. Optionally, the pretreatment method includes at least one of the following: sun drying, water washing, honey treatment. The user interface is also used to display the inference result to the user. Optionally, the inference model can be obtained through a DNN neural network model. Optionally, the inference model can be obtained through traditional machine learning methods, such as SVM methods. In one example, a pretreatment data set of at least one parameter of moisture content, density, gap ratio, diameter, area, color, circularity, color uniformity, texture, chromaticity and the corresponding pretreatment method and/or pretreatment date is established, and then the pretreatment data set is sent to the DNN neural network model for training to obtain an SVM model of these parameters and the pretreatment method and/or pretreatment date.

The following is an example of how coffee particles can detect these parameters.

As shown in FIG. 10 , FIG. 10 is an exploded schematic diagram of a chassis structure, an electrode structure and a detachable inner liner of a coffee particle detection device according to an embodiment of the present application, and FIG. 11 is a schematic diagram of the assembly relationship between the chassis structure and the electrode structure shown in FIG. 10 . The coffee particle detection device further includes a chassis structure 90 located in the main structure 22, an electrode contact 91 located on the chassis structure 90, a first electrode 92 and a second electrode 93. The first electrode 92 and the second electrode 93 are fixed on the chassis structure 93 and are respectively connected to different electrode contacts 91. When the detachable inner liner 23 is combined into the main structure 22, the accommodating space 232 loaded with coffee particles is embedded between the first electrode 92 and the second electrode 93 to change the capacitance value between the first electrode 92 and the second electrode 93. The calculation module further includes a moisture content calculation module (not shown) located in the main structure 22, which is used to calculate the moisture content (Moisture Content, MC) of the coffee particles according to the capacitance value between the first electrode 92 and the second electrode 93.

There are many structures of the first electrode 92 and the second electrode 93. In FIG10, the first electrode 92 is a columnar electrode located on the chassis structure 93, and the second electrode 93 is in a ring shape surrounding the first electrode 92, so that an annular hollow cavity is formed between the first electrode and the second electrode. As shown in FIG12a, FIG12a is a bottom side view of the removable liner shown in FIG9. At least part of the removable liner 23 is made of non-conductive material, and the bottom surface of the removable liner 23 is formed with a groove 233 extending toward the accommodation space, and the accommodation space is in a ring shape surrounding the groove 233, so that when the removable liner 23 is fixed to the main structure, the accommodation space 232 in the removable liner 23 is embedded in the annular hollow cavity, and the first electrode is embedded in the groove 233 from the outside of the bottom surface of the removable liner 23. In some other examples, the first electrode and the second electrode may not be columnar, but may be two rectangular blocks facing each other and side by side, which is not limited here.

The removable liner can be made entirely of plastic, or, in some examples, the removable liner includes a ring wall made of oxidized metal, and the bottom surface and the groove made of non-conductive material (such as plastic). Since the removable liner is made of metal, it will shield the electric field and make it impossible to measure the moisture content of the coffee particles in the removable liner. In this example, the ring wall made of metal is stronger than plastic and more wear-resistant. In addition, the metal will not conduct electricity after oxidation, which can avoid affecting the distance between the first electrode and the second electrode and thus affecting the measurement of the capacitance value.

In some examples, the bottom of the first electrode is set to be higher than the bottom of the second electrode so as to concentrate the electric field generated between the first electrode and the second electrode in the middle area of the detachable inner liner, which can avoid the situation where the detachable inner liner cannot be completely placed in the annular hollow area between the first electrode and the second electrode when the depth is shallow, resulting in inaccurate moisture content measurement. As shown in Figure 12b, Figure 12b is a schematic diagram of the chassis structure and the first electrode of a coffee particle detection device of an embodiment of the present application. A base 95 is also provided on the chassis structure 90 at the bottom of the first electrode 92. The first electrode contact is arranged on the base 95, and the first electrode 92 is fixed on the base 95 and connected to the first electrode contact, so that the bottom of the first electrode 92 is higher than the bottom of the second electrode.

Alternatively, in some examples, the electrode can be used as part of a removable liner. For example, as shown in Figures 13 and 14, Figure 13 is an exploded schematic diagram of a chassis structure and a removable liner of a coffee particle detection device according to an embodiment of the present application, and Figure 14 is a schematic diagram of the assembly relationship between the chassis structure and the removable liner shown in Figure 13. The coffee particle detection device includes a chassis structure 90 located in the main structure and an electrode contact 91 located on the chassis structure 90. A portion of the removable liner 23 is a first electrode 1411 and a portion is a second electrode 1412, and the first electrode 1411 and the second electrode 1412 are connected by a non-conductive material 1413. When the removable liner 23 is combined into the main structure 22, the first electrode 1411 and the second electrode 1412 are in contact with different electrode contacts 90 respectively, and the accommodating space 232 is located between the first electrode 1411 and the second electrode 1412.

Optionally, the coffee particle detection device is equipped with removable liners of different sizes to allow users to flexibly choose. For example, as shown in Figures 10 and 13, the coffee particle detection device is also equipped with removable liners 96 and 97 of small volume and small depth, respectively. In the example where the removable liners are made of non-conductive materials (such as plastic liners), compared to the removable liners containing electrodes, the plastic liners can be more convenient for users to operate the coffee particles to be tested, and the volume of the plastic liners is easier to customize and modify than the metal liners, which can better meet the customized needs of users. Compared with the example of the removable liners containing electrodes, the removable liners made of non-conductive materials will generate a fixed capacitance value C2 when placed between the electrodes in the main structure. Before the calculation module calculates the moisture content based on the capacitance value measured by the detection module and the relationship model, the capacitance value measured by the detection module is also subtracted. Remove the fixed capacitance value C2.

A detection circuit is also provided in the main structure of the coffee particle detection device, and the detection circuit includes a measured loop respectively connecting the first electrode contact and the second electrode contact. When the detachable inner container containing coffee particles is assembled to the main structure for measurement, the measured loop is turned on to detect the capacitance value C1 between the first electrode and the second electrode. The calculation module also includes a moisture content calculation module, in which a relationship model MC=f(C1) between the capacitance value C1 between the first electrode and the second electrode and the moisture content MC of the coffee particles is pre-stored. The corresponding moisture content can be calculated based on the capacitance value between the first electrode and the second electrode detected by the detection circuit and the relationship model. Optionally, the relationship model is a cubic fitting model for the capacitance value.

In some examples, the detection circuit is further provided with a temperature sensor for detecting temperature changes of the circuit, and after measuring the capacitance value C1 between the first electrode and the second electrode, the calculation module is optionally further used to correct the capacitance value C1 according to the temperature t measured by the temperature sensor. For example, the corrected capacitance C=C1+k1*t, where k1 is a fixed constant that can be obtained through experiments.

In some examples, a reference loop is also provided in the detection circuit, and a reference capacitor with a known capacitance value C0 is provided on the reference loop. The moisture content calculation module pre-stores a relationship model MC=f(C_diff) between C_diff and the moisture content of the coffee particles, wherein C_diff is the difference between the capacitance value C1 between the first electrode and the second electrode detected by the detection circuit and the reference capacitance C0. The moisture content calculation module can calculate the corresponding moisture content according to the capacitance value C1 between the first electrode and the second electrode detected by the detection circuit, the capacitance value C0 of the reference capacitor, and the relationship model MC=f(C_diff). By setting the reference capacitor, the influence of the error can be removed during the calculation process. In one example, the moisture content MC=b1*C_diff+b2*C_diff ² +b3*C_diff ³ +b4, wherein b1, b2, b3, b4 are model parameters obtained by fitting experimental data.

In some examples, when the detection circuit detects the capacitance value between the first electrode and the second electrode, it can be measured at a fixed electrode frequency. Alternatively, the electrode frequency can also be changed. Since the capacitance corresponding to the coffee particles between the first electrode and the second electrode will change with the change of the electrode frequency, the detection circuit can also obtain at least two capacitance values corresponding to at least two different electrode frequencies between the first electrode and the second electrode. The calculation module is also used to calculate at least two corresponding moisture contents according to the at least two capacitance values, and to obtain the moisture content of the coffee particles by weighted calculation of the at least two moisture contents. For example, the detection circuit detects the capacitance value between the first electrode and the second electrode as C1 at the electrode frequency f1, the capacitance value between the first electrode and the second electrode as C2 at the electrode frequency f2, and the capacitance value between the first electrode and the second electrode as C3 at the electrode frequency f3. The calculation module calculates the corresponding water activities MC1, MC2, and MC3 according to the three capacitance values, and then performs weighted calculation to obtain the water activity of the coffee particles MC=c1*MC1+c2*MC2+c3*MC3, where c1, c2, and c3 are the weighted values of the three water activities, respectively. The weighted value may be pre-stored in the calculation module.

In some examples, the moisture content calculation module has pre-stored relationship models for different coffee particle categories. For example, the moisture content calculation module has pre-stored at least one of the following: a first relationship model for green coffee beans, a second relationship model for roasted beans, a third relationship model for dried coffee fruits, and a fourth relationship model for shelled beans.

In the modern coffee industry, coffee beans have high requirements for drying and preservation. The amount of water directly affects the production quality and storage time. How to effectively check and control the moisture content of the substance is the key to keeping the substance dry. Moisture content has become one of the important indicators for evaluating the quality of coffee beans. For a long time, the measurement of moisture content has been mainly carried out by the loss on drying method. The principle is to heat the coffee particles so that the internal moisture of the coffee particles is evaporated, measure the weight of the sample before and after evaporation, and then calculate the weight of the lost water to obtain the moisture content. However, this method will consume coffee beans and is time-consuming. In the embodiment of the present application, a capacitive sensor is used to measure the capacitance change caused by the different moisture content of the object to establish a model between moisture content and capacitance value, which has the advantages of fast measurement speed and no loss.

In some examples, since the removable liner will wear out during long-term use, the wear will cause deviations in the measurement of the moisture content of the coffee particles. Optionally, the calculation module is also used to obtain the pre-stored initial moisture content of the removable liner; obtain the current moisture content of the removable liner when it is empty; and correct the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content. The initial moisture content can be the moisture content of the removable liner measured before leaving the factory and pre-stored by the coffee particle detection device. Optionally, before each user uses the coffee particle detection device to measure the moisture content, the user interface is also used to remind the user to put in an empty removable liner and measure the moisture content to obtain the current moisture content. Alternatively, instead of measuring the latest moisture content of the detachable inner liner every time before the user uses the moisture content measuring function, the moisture content of the empty detachable inner liner can be measured at regular intervals, and the measured moisture content of the detachable inner liner can be used as the current moisture content of the detachable inner liner to correct the moisture content of the coffee particles over the next period of time.

In measuring the moisture content of coffee particles, due to the shape of coffee particles, it is inevitable that there will be gaps between coffee particles. The gaps are generally filled with air, and the size of the gaps will affect the measurement of moisture content. In theory, the denser the coffee particles, that is, the smaller the gaps, the higher the moisture content. Alternatively, the gap ratio can be used to represent the size of the gaps between coffee particles. The rate is the ratio of the surface gap area of the coffee particles to the total area occupied by the coffee particles. Therefore, there is a certain relationship between the moisture content and the gap rate of the coffee particles. In some examples, a preset correction model between the moisture content and the gap rate may be pre-stored in the coffee particle detection device, and the calculation module also obtains the gap rate of the coffee particles, and corrects the moisture content according to the gap rate and the preset correction model. In one example, the preset correction model is MC=MC_0+k2*R, where MC_0 is the initial moisture content, k2 is a fixed parameter obtained by the experiment, R is the gap rate, and MC is the moisture content after correction. In some examples, the preset correction model is a relationship model between the moisture content and at least the gap rate and the temperature of the coffee particles, and the calculation module is also used to correct the moisture content according to the temperature of the coffee particles detected by the second temperature detection module, the gap rate and the preset correction model.

There are many ways to obtain the gap ratio of coffee particles. In one example, the coffee particle detection device also includes a third imaging module for imaging the coffee particles in the accommodating space. As shown in FIG. 15, FIG. 15 is a schematic diagram of an image of coffee particles 151 located in a detachable inner liner 23 in an example. After the calculation module obtains the image, it calculates the total area occupied by the gaps between the coffee particles in the image by an image recognition method. Optionally, the calculation module can binarize the image of the coffee particles. For example, in the right figure of FIG. 15, black represents the gap and white represents the coffee particles, and the gap area is obtained by calculating the area of the black area. The calculation module also obtains the area of the total area occupied by the coffee particles (that is, the opening area of the detachable inner liner) and calculates the gap ratio of the coffee particles. Optionally, the third imaging module and the above-mentioned first imaging module can be the same imaging module, and the imaging module can output different images respectively, which are used to calculate the chromaticity, gap ratio, etc. Alternatively, the imaging module can also be used to output an original image so that the calculation module performs different processing and calculates different types of information according to the original image.

There are many ways to set the first imaging module or the third imaging module in the coffee particle detection device. In one example, as shown in Figure 16, Figure 16 is a bottom view of the upper cover structure of the coffee particle detection device in one embodiment of the present application. Taking the first imaging module as an example, the first imaging module is located in the upper cover structure 21, and the at least two light sources 161 with different spectra in the first imaging module are located at the second depth of the cavity, and the second depth is farther away from the accommodating space than the first depth. Specifically, in Figure 16, at least two light sources 161 with different spectra are distributed in a ring shape on the second platform 162 located at the second depth of the cavity, and the direction of the emitted light is toward the main structure. Optionally, the photosensitive array is located at the third depth of the cavity. Optionally, as shown in Figure 16, the photosensitive array 163 is located on the central area of the third platform 164 at the third depth of the cavity to image the coffee particles in the accommodating space.

Optionally, the coffee particle detection device further includes an infrared anti-reflection glass located in the upper cover structure and between the first depth and the third depth of the concave cavity to block the air passage between the photosensitive array and the accommodating space. Optionally, the infrared anti-reflection glass can be between the first depth and the second depth to further reduce the volume of the space connected to the accommodating space. By reducing the volume of the space connected to the accommodating space, the temperature of the cavity and the temperature of the coffee particles can be quickly balanced, while ensuring the distance requirement between the photosensitive array and the coffee particles, avoiding the situation where the distance between the photosensitive array and the coffee particles is too short to image all the coffee particles. Alternatively, in some examples, the short distance between the photosensitive array and the coffee particles can be maintained to ensure that the volume of the space connected to the accommodating space is small and then ensure the speed at which the temperature of the cavity and the temperature of the coffee particles reach equilibrium; at the same time, at least one reflector is also provided in the upper cover structure or the main structure, and the photosensitive array is used to receive the reflected light of the coffee particles to the at least two light beams of different spectra through the at least one reflector to image the coffee particles. In this way, the optical path between the coffee particles and the photosensitive array can be extended by setting a reflector. As shown in Figure 17, Figure 17 is a schematic diagram of the positional relationship between the photosensitive array, coffee particles and the reflector in an embodiment of the coffee particle detection device of the present application. The light beam reflected by the coffee particle 171 is reflected to the photosensitive array 173 by the reflector 172. The mirror position 174 of the coffee particle and the original position 171 of the coffee particle are symmetrical about the reflector 172. By setting the reflector, the distance between the coffee particles and the photosensitive array can be shortened while ensuring the optical path requirements between the coffee particles and the photosensitive array. There are many arrangements of the reflector and the photosensitive array. For example, both are located in the upper cover structure, wherein the photosensitive array can be located at the bottom or side of the upper cover structure. Alternatively, the reflector is located in the upper cover structure, and the photosensitive array is located in the main structure. In some examples, the number of reflectors can be 1 or at least two, which is not limited here.

In some examples, the first imaging module may not be located in the upper cover structure, but may be located outside the bottom of the removable liner. As shown in FIG. 18a, FIG. 18a is a schematic diagram of the positional relationship between the removable liner and the first imaging module in the coffee particle device in one embodiment of the present application. The bottom of the removable liner 23 is an infrared anti-reflection glass. The light sources in the first imaging module 180 are located below the bottom of the removable liner 23, and are used to emit a light beam to the bottom of the removable liner 23, and the emitted light beam can pass through the bottom of the removable liner to irradiate the coffee particles 181 in the accommodating space, and be reflected back to the photosensitive array located below the bottom of the removable liner by the coffee particles. The field of view of the first imaging module 180 covers the entire bottom of the removable liner 23. Optionally, the light sources in the first imaging module are arranged around the photosensitive array. Of course, there are other arrangements of the light source and the photosensitive array, which are not limited here. In the example where the first imaging module is located in the upper cover structure, since it is from the opening side of the accommodating space to the accommodating space, the light source is arranged around the photosensitive array. In order to avoid the different distances between the coffee particles and the first imaging module in different chromaticity measurements, which may cause different reflected light intensities of the coffee particles and the inaccurate chromaticity measurements, it is necessary to ensure that the distance wave between the coffee particles and the first imaging module is consistent in each chromaticity measurement. Generally, before the measurement, it is necessary to fill the coffee particles to a fixed height in the accommodation space and flatten the surface of the coffee particles to facilitate the corresponding detection according to the imaging of the coffee particles. In the example where the first imaging module is located outside the bottom of the detachable liner, since the distance between the bottom of the liner and the first imaging module is kept fixed when the detachable liner is fixed to the device, the distance between the coffee particles in the detachable liner and the first imaging module can be kept fixed, which can save the user from the step of filling the coffee particles to a fixed height in the accommodation space and then flattening the coffee particles, thereby improving the user experience and avoiding the chromaticity measurement error caused by the user not filling the coffee particles to a fixed height or not flattening them in each chromaticity measurement.

In some examples, the coffee particle detection device can also obtain the density of coffee particles. Coffee particles are basically like a honeycomb, which is a cellulose structure. The function of this structure is to store nutrients for the bean embryo. Coffee beans with higher density can store more sugar and light aroma substances than coffee beans with lower density, which directly leads to more flavor. Therefore, the density of green coffee beans is an important indicator for grading by quality. Green coffee beans with greater hardness and density are usually more popular and generally sold at higher prices. There are many ways to measure the density of coffee beans. One existing method is to use a measuring cylinder, pour the coffee beans into the line marked with a specific volume, weigh the coffee, and then divide the weight by the specific volume. However, this method does not measure the true density of coffee beans because there are some gaps between the coffee beans in the cylinder. Another existing method for measuring density is the displacement method. By adding a certain weight of green coffee to a certain volume of water and observing the change in the volume of water (i.e., the displacement), the actual volume of the coffee can be known. The original weight of the coffee is divided by its actual volume to get the true volume. However, this method is more cumbersome to operate.

In one embodiment of the present application, the coffee particle detection device can also compensate for the detected gap ratio to obtain a more accurate volume of the coffee particles. Specifically, as shown in FIG11 , the coffee particle detection device also includes a pressure sensor 94 located under the chassis structure 90 in the main structure, which is used to detect the weight of the coffee particles in the detachable inner liner. The calculation module is also used to calculate the volume of the coffee particles according to the gap ratio and the volume of the detachable inner liner, and to calculate the density of the coffee particles according to the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, in the example of calculating the density of the coffee particles, the preset correction model can also be a relationship model between the gap ratio, the density and the moisture content; the calculation module is used to correct the moisture content according to the gap ratio, the density and the preset correction model. Optionally, the user interface in the coffee particle detection device is also used to display the density before correction and the density after correction by the gap ratio.

In some examples, the coffee particle detection device is also preset with a relationship model between the diameter and the gap ratio, density and moisture content of the coffee particles. The calculation module is also used to calculate the diameter of the coffee particles according to the relationship model, the gap ratio, density and moisture content of the coffee particles. Optionally, the coffee particle detection device also includes a user interface for displaying the diameter of the coffee particles to the user. Optionally, the coffee particle detection device can also record the temperature and humidity of the environment in which the coffee particles are located through the temperature and humidity sensor, and record the measurement results as one of the coffee bean picking environment parameters. Optionally, the coffee particle detection device is also provided with an air pressure sensor for measuring the air pressure of the environment in which the coffee beans are located. The calculation module is also used to calculate the altitude data according to the air pressure, and record it as one of the coffee bean picking environment parameters. The user interface is also used to display the temperature and humidity, the air pressure and the altitude data as the picking environment data of the coffee beans. Through the detection, recording and display of the coffee bean picking environment, the coffee particle detection device allows users to more comprehensively detect and record relevant information about coffee particles. Optionally, the coffee particle detection device further includes a self-calibration kit for calibrating at least one measurement result of the coffee particle detection device. The self-calibration kit includes at least one of the following: a calibration liner, a calibration color card, a water activity standard solution, and a standard solution holding container. The calculation module is also used to perform at least one of the following: compensating the moisture content measurement result of the coffee particles according to the measurement result of the moisture content of the calibration liner; compensating the chromaticity measurement result of the coffee particles according to the chromaticity measurement result of the calibration color card; compensating the water activity measurement result of the coffee particles according to the measurement result of the water activity standard solution in the standard solution holding container.

As shown in Figure 18b, Figure 18b is a structural schematic diagram of a self-calibration kit in an embodiment of the present application. The self-calibration kit includes a calibration liner 182, a calibration color card 183, a water activity standard solution (not shown) and a standard solution carrying container 184. The shape of the calibration liner 182 can be consistent with the shape of the detachable liner. The calculation module can compare the moisture content measurement result of the calibration liner with the moisture content of the pre-stored calibration liner, and compensate the moisture content of the measured coffee particles according to the difference. The calibration color card 183 includes a plane portion 1831 with color. When fixed to the calibration liner or the detachable liner, the plane portion 1831 is placed horizontally to measure the chromaticity value of the plane portion. The calculation module can compare the chromaticity value measurement result of the calibration color card with the chromaticity value of the pre-stored calibration color card, and compensate the chromaticity value of the measured coffee particles according to the difference. The standard liquid carrier 184 is used to fix the calibration liner or the detachable liner. The opening is used to carry the water activity standard solution to measure the water activity of the water activity standard solution. The calculation module can compare the water activity measurement result of the standard solution with the pre-stored water activity of the standard solution and compensate the water activity of the measured coffee particles according to the difference.

The present application also provides a method for detecting coffee particles. As shown in FIG. 19 , FIG. 19 is a flow chart of an embodiment of the method for detecting coffee particles of the present application. The method comprises: step S1901, cooling a condensation surface having an air passage connected to a containing space, the containing space being used to contain coffee particles, so that water vapor in the coffee particles condenses on the condensation surface to precipitate dew. Step S1902, detecting whether the dew appears on the condensation surface. Step S1903, determining a first moment, the first moment being the moment when the dew point appears on the condensation surface. Step S1904, detecting the temperature of at least one point on the condensation surface, and determining the dew point temperature according to the temperature of the at least one point at the first moment. Step S1905, obtaining a first vapor pressure according to the dew point temperature. Step S1906, obtaining the temperature of the containing space and the coffee particles. Step S1907, obtaining a second vapor pressure according to the temperature of the containing space and the coffee particles. Step S1908: calculating the water activity of the coffee particles according to the first vapor pressure and the second vapor pressure.

Optionally, cooling the condensation surface having an air passage connected to the accommodating space includes: in a first stage, controlling the refrigeration component at maximum power to cool the condensation surface to a first temperature; in a second stage, controlling the refrigeration component at dynamic power to cool the condensation surface, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage.

Optionally, the method further includes: obtaining the category of the coffee particles or the corresponding relationship between different water contents and water activity intervals; obtaining the category of the coffee particles or the different water contents; confirming the water activity interval corresponding to the coffee particles according to the category of the coffee particles or the different water contents and the corresponding relationship; and controlling the refrigeration component to continue cooling when the water activity is not within the water activity interval corresponding to the coffee particles.

Optionally, the method of obtaining the category of the coffee particles includes: providing the user with options of different categories of coffee particles through an interactive interface; and determining the category of the coffee particles according to the option selected by the user. Optionally, the method further includes: emitting at least two light beams of different spectra to the coffee particles in the accommodating space; receiving reflected light of the coffee particles from the at least two light beams of different spectra and imaging the coffee particles; and calculating the chromaticity value of the coffee particles based on the imaging of the coffee particles; the method of obtaining the category of the coffee particles includes: obtaining the category of the coffee particles based on the imaging of the coffee particles. Optionally, the method of obtaining the category of the coffee particles includes: obtaining the moisture content of the coffee particles; and determining the category of the coffee particles based on the moisture content and a pre-stored correspondence between different moisture contents and categories of coffee particles.

Optionally, the detecting whether the dew appears on the condensation surface includes: detecting whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface according to the grayscale values of the imaging at different moments.

Optionally, the detecting whether dew points appear on the dew condensation surface according to the grayscale values of the images of the dew condensation surface at different times includes: obtaining the grayscale value mean of the images of the dew condensation surface at different times, and/or the grayscale value distribution of different partitions on the images of the dew condensation surface at different times; determining whether dew points appear on the dew condensation surface according to the grayscale value mean and/or the grayscale value distribution. Optionally, the method also includes: obtaining an initial image of the dew condensation surface containing dew, and performing edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, confirming that the dew in the initial image is the dew.

Optionally, the detecting whether the dew appears on the dew condensation surface includes: emitting a laser beam through a laser transmitter to cover the dew condensation surface; receiving the laser beam reflected by the dew condensation surface through a laser detector; generating an electrical signal according to the received laser beam; and confirming the presence of dew on the dew condensation surface according to the change of the electrical signal. Optionally, the detecting the temperature of at least one point on the dew condensation surface and determining the dew point temperature according to the temperature of at least one point at a first moment include: detecting the temperature through a platinum resistance sensor located on one side of the dew condensation surface; obtaining the hysteresis time of the platinum resistance sensor; and calculating the dew point temperature according to the temperature measured by the platinum resistance sensor at the hysteresis time after the first moment.

Optionally, the second vapor pressure is calculated based on the equilibrium temperature measured when the temperatures of the accommodating space and the coffee particles reach equilibrium; the method further includes: obtaining a first relationship model between the water activity measured at a pre-stored equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; and calculating the water activity of the coffee particles at the equilibrium temperature of 25 degrees Celsius according to the equilibrium temperature, the water activity and the first relationship model. Optionally, the second vapor pressure is calculated based on the temperature when the temperatures of the accommodating space and the coffee particles do not reach equilibrium; the method further includes: obtaining a second relationship model between the water activity measured at a pre-stored equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; and calculating the water activity of the coffee particles at the equilibrium temperature of 25 degrees Celsius according to the temperatures of the accommodating space and the coffee particles, the water activity and the second relationship model.

Optionally, the method further comprises: obtaining at least one of the following parameters of the coffee particles: moisture content, density, interstitial ratio, diameter, area, color, circularity, color uniformity, texture, and chromaticity.

Optionally, the method further includes: placing the accommodation space between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; detecting the capacitance value between the first electrode and the second electrode by a detection circuit; and calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode. Optionally, the detection circuit includes a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop; the method further includes obtaining a capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; the calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: calculating the moisture content of the coffee particles according to a pre-stored relationship model between the capacitance difference and the moisture content, and the obtained capacitance difference. Optionally, detecting the capacitance value between the first electrode and the second electrode by means of a detection circuit includes: obtaining at least two capacitance values between the first electrode and the second electrode corresponding to at least two different electrode frequencies respectively; calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: calculating at least two moisture contents corresponding to the at least two capacitance values respectively, and obtaining the moisture content of the coffee particles by weighted calculation of the at least two moisture contents.

Optionally, the method further includes: obtaining a pre-stored preset correction model, the preset correction model being a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; imaging the coffee particles in the accommodating space; acquiring the gap ratio of the coffee particles according to the imaging; and correcting the moisture content according to the gap ratio and the preset correction model. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the method further includes: detecting the temperature of the coffee particles; and correcting the moisture content according to the detected temperature of the coffee particles, the gap ratio and the preset correction model. Optionally, the method further includes: detecting the weight of the coffee particles by a pressure sensor; calculating the volume of the coffee particles according to the gap ratio and the volume of the accommodating space; and calculating the density of the coffee particles according to the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, the preset correction model is a relationship model between the interstitial ratio, the density and the moisture content; and correcting the moisture content according to the interstitial ratio and the preset correction model includes: correcting the moisture content according to the interstitial ratio, the density and the preset correction model.

Optionally, the method also includes: obtaining a pre-stored relationship model between the diameter and gap ratio, density and moisture content of coffee particles; calculating the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; and displaying the diameter of the coffee particles to the user through a user interface.

Optionally, the method further comprises: classifying the coffee particles into one of a plurality of preset levels according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity, chromaticity; and displaying the level of the coffee particles to the user through a user interface. Optionally, the method further comprises: obtaining pre-stored or real-time querying guidance suggestions for at least one of storage, roasting, grinding, and brewing of coffee beans of different levels; and displaying the guidance suggestions corresponding to the level of the coffee particles through the user interface. Optionally, the method further comprises: obtaining a pre-stored inference model; inferring the pre-treatment method and/or pre-treatment time of the coffee particles according to the at least one parameter of the coffee beans and the inference model; and displaying the pre-treatment method and/or pre-treatment time to the user through the user interface. Optionally, the method further comprises: obtaining a pre-stored initial moisture content of the detachable liner; obtaining the current moisture content of the detachable liner when it is empty; and correcting the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content.

Optionally, the method further includes: detecting the temperature and humidity of the environment in which the coffee beans are located through a humidity sensor; detecting the air pressure of the environment in which the coffee beans are located through an air pressure sensor; calculating the altitude data according to the air pressure; and displaying the temperature and humidity, the air pressure and the altitude data as the picking environment data of the coffee beans through a user interface. Optionally, the method further includes at least one of the following steps: compensating the moisture content measurement result of the coffee particles according to the measurement result of the moisture content of the calibration inner tank; compensating the colorimetric measurement result of the coffee particles according to the colorimetric measurement result of the calibration color card; compensating the water activity measurement result of the coffee particles according to the measurement result of the water activity standard solution in the standard solution holding container.

For an explanation of the coffee particle detection method, please refer to the above explanation of the coffee particle device, which will not be repeated here.

The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (67)

A coffee particle detection device, characterized in that it comprises a containing space, a dew condensation surface, a cooling module, a first temperature detection module, a dew point detection module and a calculation module; The accommodating space is used to accommodate coffee particles; An air passage is provided between the condensation surface and the accommodating space; The cooling module is used to cool the condensation surface so that the water vapor in the coffee particles condenses and precipitates dew on the condensation surface; The dew point detection module is used to detect whether dew appears on the dew condensation surface; The first temperature detection module is used to detect the temperature of at least one point on the condensation surface; The calculation module is used for: Determining a first moment, where the first moment is a moment when dew is detected to appear on the dew condensation surface; Determine the dew point temperature according to the first time and the temperature of the at least one location; acquiring a first vapor pressure according to the dew point temperature; Acquiring the temperature of the accommodating space and the coffee particles; Acquiring a second vapor pressure according to the temperature of the accommodating space and the coffee particles; and The water activity of the coffee particles is calculated based on the first vapor pressure and the second vapor pressure. The device according to claim 1 is characterized in that the cooling module includes a refrigeration component and a control component, the control component is used to control the refrigeration component to cool the condensation surface to a first temperature at maximum power in the first stage, and to control the refrigeration component to cool the condensation surface at dynamic power in the second stage, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage. The device according to claim 2, characterized in that first temperatures corresponding to different types of coffee particles are pre-stored in the device; The control component is also used to obtain the category of the coffee particles and determine the value of the first temperature according to the category of the coffee particles. The device according to claim 2 is characterized in that the device also pre-stores the correspondence between different types of coffee particles or different moisture content and water activity ranges; The control component is also used to obtain the type of the coffee particles or the moisture content of the coffee particles, confirm the water activity range corresponding to the coffee particles according to the type of the coffee particles or the moisture content of the coffee particles, and control the refrigeration component to continue cooling when the water activity is not within the water activity range corresponding to the coffee particles. The device according to claim 3 or 4 is characterized in that the device further comprises a first imaging module, the first imaging module comprises at least two light sources of different spectra, and is used to sequentially emit light beams of different spectra to the coffee particles in the accommodating space; the first imaging module further comprises a photosensitive array used to sequentially receive reflected light of the coffee particles to the at least two light beams of different spectra and sequentially image the coffee particles, wherein the photosensitive array is used to generate at least two frames of images corresponding to the at least two light sources respectively; The calculation module is further used to calculate the chromaticity value of the coffee particles according to the at least two frames of images; The control component is also used to obtain the category of the coffee particles based on the imaging of the coffee particles. The device according to claim 3 or 4, characterized in that the correspondence between different moisture contents and types of coffee particles is also pre-stored in the device; The control component is also used to obtain the moisture content of the coffee particles and determine the type of the coffee particles according to the moisture content. The device according to claim 2 is characterized in that the cooling component is located on one side of the condensation surface, and the device also includes a heat sink located on the side of the cooling component facing away from the condensation surface and arranged adjacent to the cooling component, and a heat sink fan arranged adjacent to the heat sink. The device according to claim 1 is characterized in that the device also includes a circulation fan located on one side of the condensation surface and a motor for driving the circulation fan, wherein the circulation fan is used to increase the air circulation speed between the accommodating space and the condensation surface. The device according to claim 1, characterized in that the dew point detection module is also used to detect the condensation position on the condensation surface; The first temperature detection module is used to obtain the temperatures of at least two locations on the condensation surface; The calculation module is used to obtain the distances between the positions of the at least two locations and the condensation location, determine the weights corresponding to the at least two locations according to the distances between the positions of the at least two locations and the condensation location, and calculate the dew point temperature according to the temperatures of the at least two locations and the weights corresponding to the at least two locations. The device according to claim 1, characterized in that the dew point detection module comprises a second imaging module for acquiring images of the dew condensation surface at different times; The calculation module is also used to detect whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface according to the grayscale values of the images at different times. The device according to claim 10 is characterized in that the calculation module is used to obtain the mean grayscale value of the imaging of the condensation surface at different times, and the grayscale value distribution of different partitions of the imaging of the condensation surface at different times, so as to determine whether dew points appear on the condensation surface. The device according to claim 1, characterized in that the dew point detection module comprises a second imaging module for acquiring images of the dew condensation surface at different times; The calculation module is further used to obtain an initial image of the condensation surface containing dew, and perform edge detection or texture feature detection on the dew in the initial image; When it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirement, the dew in the initial image is confirmed to be the dew. The device according to claim 1, characterized in that the dew point detection module comprises a laser emitter and a laser detector; The laser beam emitted by the laser emitter covers the dew condensation surface, and the laser detector is used to receive the laser beam reflected by the dew condensation surface, and generate an electrical signal according to the received laser beam; The calculation module is also used to confirm the presence of dew on the condensation surface according to the change of the electrical signal. The device according to claim 1, characterized in that the first temperature detection module comprises a platinum resistance sensor located on one side of the condensation surface, The calculation module is used to obtain the hysteresis time of the platinum resistance sensor, and calculate the dew point temperature according to the temperature measured by the platinum resistance sensor at the hysteresis time after the first moment. The device according to claim 1, characterized in that the second vapor pressure is calculated based on an equilibrium temperature measured when the temperature of the accommodating space and the coffee particles reaches equilibrium; The calculation module pre-stores a first relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; The calculation module is further used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the equilibrium temperature, the water activity and the first relationship model. The device according to claim 1, characterized in that the second vapor pressure is calculated based on the temperature when the temperature of the accommodating space and the coffee particles are not in equilibrium; The calculation module pre-stores a second relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; The calculation module is further used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the temperature of the accommodating space and the coffee particles, the water activity and the second relationship model. The device according to claim 1, characterized in that the device is also used to obtain at least one of the following parameters of the coffee particles: Moisture content, density, void ratio, diameter, area, color, circularity, color uniformity, texture, chromaticity. The device according to claim 1 is characterized in that the device comprises an upper cover structure and a main body structure that are movably connected, the device further comprises a detachable inner liner located in the main body structure, the accommodating space is located in the detachable inner liner, and the device further comprises: a chassis structure having a first electrode contact and a second electrode contact disposed on the surface, a first electrode and a second electrode fixed in the main body structure; The first electrode and the second electrode are fixed on the chassis structure and are connected to the first electrode contact and the second electrode contact respectively; When the detachable liner is assembled into the main structure, the accommodating space is embedded between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; The calculation module is further used to calculate the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode. The device according to claim 18, characterized in that the first electrode is located on the chassis structure, The second electrode is in a ring shape surrounding the first electrode, so that a ring-shaped hollow cavity is formed between the first electrode and the second electrode; At least a portion of the removable inner liner is made of non-conductive material, and a groove extending toward the accommodating space is formed on the bottom surface of the removable inner liner, and the accommodating space is in an annular shape surrounding the groove, so that when the removable inner liner is fixed to the main structure, the accommodating space in the removable inner liner is embedded in the annular hollow cavity, and the first electrode is embedded in the groove from the outside of the bottom surface of the removable inner liner. The device according to claim 19 is characterized in that the removable inner liner includes an annular wall made of oxidized metal, and the bottom surface and the groove are made of non-conductive material. The device according to claim 18 is characterized in that a base is provided on the chassis structure at the bottom of the first electrode, the first electrode contact is arranged on the base, and the first electrode is fixed on the base and connected to the first electrode contact, so that the bottom of the first electrode is higher than the bottom of the second electrode. The device according to claim 1, characterized in that the device comprises an upper cover structure and a main body structure that are movably connected, and the device comprises a chassis structure located in the main body structure and having a first electrode contact and a second electrode contact disposed on the surface; A portion of the detachable inner liner is a first electrode and a portion of the detachable inner liner is a second electrode. When the detachable inner liner is assembled to the main structure, the first electrode contacts the first electrode contact point, the second electrode contacts the second electrode contact point, and the accommodation space is located between the first electrode and the second electrode. The calculation module is further used to calculate the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode. The device according to any one of claims 18 to 22, characterized in that the device further comprises a detection circuit located in the main structure, the detection circuit comprises a measured loop and a reference loop, the first electrode contact and the second electrode contact are located on the measured loop, and a reference capacitor with a known capacitance value is provided on the reference loop; The calculation module is used to obtain a capacitance difference between a capacitance value between the first electrode and the second electrode detected by the detection circuit and a capacitance value of the reference capacitor; The calculation module is also used to calculate the moisture content of the coffee particles according to the pre-stored relationship model between the capacitance difference and the moisture content and the acquired capacitance difference. The device according to claim 23, characterized in that the detection circuit is further used to obtain at least two capacitance values between the first electrode and the second electrode corresponding to at least two different electrode frequencies; The calculation module is further used to calculate at least two moisture contents corresponding to the at least two capacitance values, and to obtain the moisture content of the coffee particles by weighted calculation of the at least two moisture contents. The device according to any one of claims 18 to 22, characterized in that the condensation surface, the cooling module, the first temperature detection module and the dew point detection module are located in the upper cover structure; a third imaging module is also provided in the upper cover structure for imaging the coffee particles in the accommodating space; The device also has a preset calibration model pre-stored therein for indicating the relationship between the moisture content and at least the void ratio; The calculation module is also used to obtain the gap ratio of the coffee particles according to the imaging, and to correct the moisture content according to the gap ratio and a preset correction model. The device according to claim 25, characterized in that the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; The device further comprises a second temperature detection module, for detecting the temperature of the coffee particles; The calculation module is used to correct the moisture content according to the temperature of the coffee particles detected by the second temperature detection module, the gap ratio and the preset correction model. The device according to claim 25, characterized in that the device further comprises a pressure sensor located below the chassis structure in the main structure, for detecting the weight of coffee particles in the removable inner container; The calculation module is also used to calculate the volume of the coffee particles according to the gap ratio and the volume of the detachable inner capsule, and to calculate the density of the coffee particles according to the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. The device according to claim 27, characterized in that the preset correction model is a relationship model between the moisture content and at least the void ratio and the density; The calculation module is used to correct the water content according to the void ratio, the density and the preset correction model. The device according to claim 17 is characterized in that a relationship model between the diameter and gap ratio, density and moisture content of coffee particles is preset in the device. The calculation module is further used to calculate the diameter of the coffee particles according to the relationship model, the gap ratio, the density and the moisture content; The device also includes a user interface for displaying the diameter of the coffee particles to a user. The device according to claim 17, characterized in that the calculation module is further used to classify the coffee particles into one of a plurality of preset levels according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity; The user interface is also used to display the grade of the coffee particles to the user. The device according to claim 30, characterized in that the computing module is further used to pre-store or query in real time the guidance suggestions for at least one of the storage, roasting, grinding, and brewing of coffee beans of different grades; The user interface is also used to display the guidance suggestions corresponding to the grade of the coffee particles. The device according to claim 30, characterized in that the calculation module also pre-stores a prediction model, and predicts the pretreatment method and/or pretreatment time of the coffee particles based on the at least one parameter of the coffee beans and the prediction model; The user interface is also used to display the preprocessing method and/or preprocessing time to the user. The device according to claim 18, characterized in that the calculation module is further used for: Obtaining the pre-stored initial moisture content of the detachable liner; Obtaining the current moisture content of the detachable inner liner when it is empty; The moisture content of the coffee particles is corrected according to the difference between the current moisture content and the initial moisture content. The device according to claim 5, characterized in that the device comprises an upper cover structure and a main body structure that are movably connected, and the accommodating space is located in the main body structure; The upper cover structure comprises a concave cavity, and when the upper cover structure covers the main structure, the concave cavity is communicated with the accommodating space; The concave cavity is provided with a first platform at a first depth, and the condensation surface is located on the first platform; The first imaging module is located in the upper cover structure, and the at least two light sources with different spectrums are located at a second depth of the cavity, and the second depth is farther away from the accommodating space than the first depth. The device according to claim 34 is characterized in that the photosensitive array is located at a third depth of the cavity; the upper cover structure is further provided with an infrared anti-reflection glass located between the first depth and the third depth of the cavity to block the air passage between the first imaging module and the accommodating space; or At least one reflector is also provided in the upper cover structure or the main body structure, and the second imaging module is used for receiving the reflected light of the coffee particles to the at least two light beams of different spectra through the at least one reflector to image the coffee particles. The device according to claim 5 is characterized in that the device comprises an upper cover structure and a main body structure that are movably connected, and the device also comprises a detachable inner liner located in the main body structure, the accommodating space is located in the detachable inner liner, and the bottom of the detachable inner liner is infrared anti-reflection glass, The first imaging module is located below the bottom of the detachable inner liner. The device according to claim 1, characterized in that the device further comprises a temperature and humidity sensor for detecting the temperature and humidity of the environment in which the coffee beans are located; The device also includes an air pressure sensor for detecting the air pressure of the environment in which the coffee beans are located; the calculation module is also used to calculate the altitude data according to the air pressure; The user interface is also used to display the temperature and humidity, the air pressure and the altitude data as the picking environment data of the coffee beans. The device according to claim 1, characterized in that the device further comprises a calibration kit, wherein the self-calibration kit comprises at least one of the following: a calibration liner, a calibration color card, a water activity standard solution, and a standard solution carrying container; The computing module is further configured to perform at least one of the following: Compensating the moisture content measurement result of the coffee particles according to the moisture content measurement result of the calibration inner container; Compensating the colorimetric measurement result of the coffee particles according to the colorimetric measurement result of the calibrated color card; The water activity measurement result of the coffee particles is compensated based on the measurement result of the water activity standard solution in the standard solution holding container. A coffee particle detection method, comprising: Cooling a condensation surface having an air passage connected to a receiving space for receiving coffee particles so that water vapor in the coffee particles condenses and precipitates dew on the condensation surface; detecting whether the dew appears on the condensation surface; Determining a first moment, the first moment being a moment when the dew point is detected to appear on the dew condensation surface; detecting a temperature of at least one location on the condensation surface, and determining a dew point temperature according to the temperature of the at least one location at a first moment; acquiring a first vapor pressure according to the dew point temperature; Acquiring the temperature of the accommodating space and the coffee particles; acquiring a second vapor pressure according to the temperature of the accommodating space and the coffee particles; The water activity of the coffee particles is calculated based on the first vapor pressure and the second vapor pressure. The method according to claim 39, characterized in that cooling the condensation surface having an air passage communicating with the accommodating space comprises: In the first stage, the refrigeration component is controlled at maximum power to cool the condensation surface to a first temperature; In the second stage, the refrigeration component is controlled to cool the condensation surface with dynamic power, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; Wherein, the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage. The method according to claim 40, characterized in that the step of controlling the refrigeration component at the first power to cool the condensation surface to the first temperature further comprises: Obtaining the category of the coffee particles; The value of the first temperature is determined according to the type of the coffee particles. The method according to claim 40, characterized in that the method further comprises: Obtaining the types of the coffee particles or the corresponding relationships between different moisture contents and water activity ranges; Obtaining the types or different moisture contents of the coffee particles; Determining the water activity range corresponding to the coffee particles according to the types of the coffee particles or different moisture contents and the corresponding relationship; When the water activity is not within the water activity interval corresponding to the coffee particles, the refrigeration component is controlled to continue cooling. The method according to claim 40 or 41, characterized in that obtaining the category of the coffee particles comprises: Providing users with options of different types of coffee particles through an interactive interface; The category of the coffee particles is determined according to the option selected by the user. The method according to claim 40 or 41, characterized in that the method further comprises: Emits at least two light beams with different spectra toward the coffee particles in the accommodating space; receiving reflected light from the coffee particles to the at least two light beams of different spectra and imaging the coffee particles; Calculating the chromaticity value of the coffee particles according to the imaging of the coffee particles; The obtaining the category of the coffee particles comprises: The categories of the coffee particles are obtained based on the imaging of the coffee particles. The method according to claim 40 or 41, characterized in that obtaining the category of the coffee particles comprises: Obtaining the moisture content of the coffee particles; The category of the coffee particles is determined according to the moisture content and the pre-stored correspondence between different moisture contents and categories of the coffee particles. The method according to claim 39, characterized in that the detecting whether the dew appears on the condensation surface comprises: Whether dew points appear on the condensation surface and/or the position of the dew on the condensation surface are detected according to the grayscale values of the images at different moments. The method according to claim 46, characterized in that the detecting whether a dew point appears on the dew condensation surface according to the grayscale value of the image of the dew condensation surface at different times comprises: Obtaining a mean value of grayscale values of the images of the condensation surface at different times, and/or a distribution of grayscale values of different partitions of the images of the condensation surface at different times; It is determined whether a dew point appears on the condensation surface according to the gray value mean and/or the gray value distribution. The method according to claim 39, characterized in that the method further comprises: Acquire an initial image of the condensation surface containing dew, and perform edge detection or texture feature detection on the dew in the initial image; When it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirement, the dew in the initial image is confirmed to be the dew. The method according to claim 39, characterized in that the detecting whether the dew appears on the condensation surface comprises: The laser emitter emits a laser beam to cover the condensation surface; Receiving the laser beam reflected by the condensation surface by means of a laser detector; generating an electrical signal according to the received laser beam; The presence of dew on the condensation surface is confirmed based on the change in the electrical signal. The method according to claim 39, characterized in that the detecting the temperature of at least one location on the condensation surface and determining the dew point temperature according to the temperature of the at least one location at the first moment comprises: Detecting the temperature by a platinum resistance sensor located on one side of the condensation surface; Obtaining the hysteresis time of the platinum resistance sensor; The dew point temperature is calculated according to the temperature measured by the platinum resistance sensor at the lag time after the first moment. The method according to claim 39, characterized in that the second vapor pressure is calculated based on an equilibrium temperature measured when the temperature of the accommodating space and the coffee particles reaches equilibrium; the method further comprises: Obtaining a first relationship model between the water activity measured at a pre-stored equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; The water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius is calculated according to the equilibrium temperature, the water activity and the first relationship model. The method according to claim 39, characterized in that the second vapor pressure is calculated based on the temperature when the temperature of the accommodating space and the coffee particles are not in equilibrium; the method further comprises: Obtaining a pre-stored second relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; The water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius is calculated according to the temperature of the accommodating space and the coffee particles, the water activity and the second relationship model. The method according to claim 39, characterized in that the method further comprises: Obtain at least one of the following parameters of the coffee particles: Moisture content, density, void ratio, diameter, area, color, circularity, color uniformity, texture, chromaticity. The method according to claim 39, characterized in that the method further comprises: Placing the accommodation space between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; Detecting the capacitance value between the first electrode and the second electrode by a detection circuit; The moisture content of the coffee particles is calculated according to the capacitance value between the first electrode and the second electrode. The method according to claim 54, characterized in that the detection circuit comprises a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop; The method further includes obtaining a capacitance difference between a capacitance value between the first electrode and the second electrode detected by the detection circuit and a capacitance value of the reference capacitor; The calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode comprises: The moisture content of the coffee particles is calculated according to a pre-stored relationship model between the capacitance difference and the moisture content and the acquired capacitance difference. The method according to claim 54, characterized in that the detecting the capacitance value between the first electrode and the second electrode by the detection circuit comprises: obtaining at least two capacitance values between the first electrode and the second electrode corresponding to at least two different electrode frequencies respectively; The calculating the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode comprises: At least two moisture contents corresponding to the at least two capacitance values are calculated respectively, and the moisture content of the coffee particles is obtained by weighted calculation of the at least two moisture contents. The method according to claim 54, characterized in that the method further comprises: Obtaining a pre-stored preset correction model, wherein the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; Imaging the coffee particles in the accommodating space; Acquire the gap ratio of the coffee particles according to the imaging; The water content is corrected according to the gap ratio and the preset correction model. The method according to claim 57, characterized in that the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; The method further comprises: detecting the temperature of the coffee particles; The moisture content is corrected according to the detected temperature of the coffee particles, the gap ratio and the preset correction model. The method according to claim 57, characterized in that the method further comprises: Detecting the weight of the coffee particles by a pressure sensor; Calculating the volume of the coffee particles according to the gap ratio and the volume of the accommodating space; The density of the coffee particles is calculated based on the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. The method according to claim 59, characterized in that the preset correction model is a relationship model among the void ratio, the density and the water content; The correcting the water content according to the gap ratio and a preset correction model includes: The moisture content is corrected according to the void ratio, the density and the preset correction model. The method according to claim 49, characterized in that the method further comprises: Obtaining a relationship model between the diameter and interstitial ratio, density and moisture content of pre-stored coffee particles; Calculating the diameter of the coffee particles according to the relationship model, the gap ratio, the density and the moisture content; The diameter of the coffee particles is displayed to the user through a user interface. The method according to claim 49, characterized in that the method further comprises: classifying the coffee particles into one of a plurality of preset classes according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity, chroma; The user interface is also used to display the grade of the coffee particles to the user. The method according to claim 62, characterized in that the method further comprises: Obtaining pre-stored or real-time guidance suggestions on at least one of storage, roasting, grinding, and brewing of coffee beans of different grades; The guidance suggestions corresponding to the grade of the coffee particles are displayed through the user interface. The method according to claim 62, characterized in that the method further comprises: Obtain a pre-stored inference model; Inferring a pretreatment method and/or pretreatment time of the coffee particles according to the at least one parameter of the coffee beans and the inference model; The preprocessing method and/or preprocessing time are displayed to the user through the user interface. The method according to claim 49, characterized in that the method further comprises: Obtaining the pre-stored initial moisture content of the detachable liner; Obtaining the current moisture content of the detachable inner liner when it is empty; The moisture content of the coffee particles is corrected according to the difference between the current moisture content and the initial moisture content. The method according to claim 39, characterized in that the method further comprises: The temperature and humidity of the environment where the coffee beans are located are detected by a humidity sensor; The air pressure of the environment where the coffee beans are located is detected by an air pressure sensor; Calculating altitude data based on the air pressure; The temperature and humidity, the air pressure and the altitude data are displayed as the coffee bean picking environment data through a user interface. The method according to claim 39, characterized in that the device further includes a calibration kit, and the method further includes at least one of the following steps: Compensating the moisture content measurement result of the coffee particles according to the moisture content measurement result of the calibration inner container; Compensating the colorimetric measurement result of the coffee particles according to the colorimetric measurement result of the calibrated color card; The water activity measurement of the coffee particles is compensated based on the measurement of the water activity standard solution in the standard solution holding container.