WO2019115375A1

WO2019115375A1 - Movable apparatuses operable for orientation determinations using multiple pressure sensors

Info

Publication number: WO2019115375A1
Application number: PCT/EP2018/083924
Authority: WO
Inventors: Wim Besling; Maarten Pennings; Hooman HABIBI
Original assignee: Ams International AG
Current assignee: Ams International AG
Priority date: 2017-12-15
Filing date: 2018-12-07
Publication date: 2019-06-20
Anticipated expiration: 2020-06-15
Also published as: TW201932794A

Abstract

A moveable apparatus included multiple pressure sensors in or on the moveable apparatus. Each of the pressure sensors is operable to generate a respective output signal indicative of pressure. The moveable apparatus also includes one or more processors operable to determine an orientation of the moveable apparatus based, at least in part, on the output signals from the multiple pressure sensors. The techniques can be integrated into a wide range of moveable apparatus, including mobile devices, vehicles, game console controllers, wearable devices, and others.

Description

MOVABLE APPARATUSES OPERABLE FOR ORIENTATION

DETERMINATIONS USING MULTIPLE PRESSURE SENSORS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional Application No.

62/599,123, filed December 15, 2017, the contents of which are incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

[0001] This disclosure relates to moveable apparatuses operable to determine the orientation of the apparatus using multiple pressure sensors.

BACKGROUND

[0002] Consumer, industrial, automotive, medical and other applications use a wide range of sensors. Some applications, for example, make use of sensors that determine the spatial orientation of a device. For example, accelerometers, which are

electromechanical device used to measure acceleration forces, sometime are used in mobile phones to detect the orientation of the phone. Such information can be used to determine, for example, if the phone is in portrait or landscape orientation (e.g., if the device’s display screen is facing upward, downward or sideways).

[0003] In addition to small, hand-held devices such as smart phones, larger objects such as vehicles also can make use of sensors that determine spatial orientation. Thus, automobiles may include accelerometers to determine, for example, the vehicle’s pitch. Such sensors can be useful, for example, in automatic hill start systems, parking brake systems, antitheft systems and automatic headlight control systems, among others.

[0004] Accurate device inclination and/or orientation, however, cannot easily be obtained under dynamic conditions using only an accelerometer. Such dynamic conditions may occur, for example, during swift hand or head movements, during shaking or simulated swinging, serving or throwing that occur in some applications (e.g., in a remote controller for a game console). To measure device orientation under dynamic conditions, sensor fusion solutions sometimes are used to combine the accelerometer measurements with measurements from other devices such as a gyroscope or

magnetometer. A gyroscope, for example, can provide an additional dimension to the information supplied by the accelerometer by tracking rotation or twist. A gyroscope, however, tends to consume a relatively large amount of power, which can quickly drain the device’s battery or other power source.

SUMMARY

[0005] The present disclosure describes moveable apparatuses operable to determine the orientation of the apparatus using multiple pressure sensors in or on the moveable apparatus.

[0006] In one aspect, for example, the disclosure describes a moveable apparatus including multiple pressure sensors in or on the moveable apparatus, each of the pressure sensors being operable to generate a respective output signal indicative of pressure. The moveable apparatus also includes one or more processors operable to determine an orientation of the moveable apparatus based, at least in part, on the output signals from the multiple pressure sensors.

[0007] Some implementations include one or more of the following features. For example, in some instances, the one or more processors are operable to determine at least one of tilt or inclination of the moveable apparatus based, at least in part, on the output signals from the pressure sensors. In some instance, the one or more processors are operable to determine an angle of a plane of the moveable apparatus with respect to a predetermined reference plane (e.g., a horizontal plane parallel to the ground) based, at least in part, on the output signals from the pressure sensors. In some cases, the one or more processors are operable to generate a control signal to adjust a feature of the moveable apparatus in response to the determined orientation of the device. For example, a control signal can be generated to switch between a portrait orientation and a landscape orientation of a display screen in response to the determined orientation of the moveable apparatus.

[0008] Each of the pressure sensors can be implemented, for example, as a capacitive pressure sensor. Other types of pressure sensors may be appropriate for some implementations. In some instances, there are at least three pressure sensors.

[0009] The techniques can be integrated into a wide range of moveable apparatuses, including mobile devices, vehicles, drones, game console controllers, wearable devices, and others.

[0010] The disclosure also describes a method of determining an orientation of a moveable apparatus. The method includes obtaining output signals from multiple pressure sensors in the moveable apparatus, and determining an orientation of the moveable apparatus based, at least in part, on the output signals from the multiple pressure sensors. In some implementations, the method also includes generating a control signal to adjust a feature of the moveable apparatus in response to the determined orientation.

[0011] Some implementations include one or more of the following advantages. For example, the use of two or more pressure sensors can enable the determination of relative height differences, and thus the device’s tilt, independently of ambient pressure. Pressure sensors tend to be less expensive than some other sensors such as accelerometers and gyroscopes. Thus, overall costs can be reduced. Further, the power consumption of capacitive pressure sensors tends to be significantly smaller than that of gyroscopes.

Thus, by using capacitive pressure sensors to determine the orientation of the moveable apparatus, the pressure sensors can be operated in a continuous mode in which the pressure sensors remain on, thereby enabling high-output data rates without draining the power source (e.g., battery) in the moveable apparatus. The techniques described here can, in some cases, facilitate determination of the orientation of the apparatus (e.g., its inclination, tilt, and/or rotation) with relative high accuracy and low latency. [0012] Other aspects, features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 illustrates an example of part of a moveable apparatus including multiple pressure sensors.

[0014] FIG. 2 illustrates an example of how the tilt angle of a moveable apparatus can be determined based on measurements obtained from two pressure sensors.

[0015] FIG. 3 illustrates an example of a mobile device that includes multiple pressure sensors.

[0016] FIG. 4 illustrates an example of a vehicle that includes multiple pressure sensors.

[0017] FIG. 5 illustrates an example of a wearable device that includes multiple pressure sensors.

[0018] FIG. 6 illustrates an example of a game control console that includes multiple pressure sensors.

[0019] FIG. 7 illustrates an example of a garage door that includes multiple pressure sensors.

[0020] FIG. 8 is a flow chart of a method according to as aspect of the disclosure.

[0021] FIG. 9 illustrates an example of a combination package that includes a microphone and a pressure sensor.

DETAIFED DESCRIPTION

[0022] As mentioned above, the present disclosure describes a moveable apparatus operable to determine the orientation of the apparatus (e.g., its inclination, tilt, and/or rotation) using multiple pressure sensors disposed in or on the moveable apparatus. As shown in FIG. 1, for example, the pressure sensors 20 can be disposed on a printed circuit board or other substrate 22 within the moveable apparatus. More generally, the pressure sensors 20 can be disposed elsewhere within or on the moveable apparatus and need not be disposed on the same surface as one another. The pressure sensors 20, however, should have sufficient sensitivity and accuracy, and should be located at positions sufficiently separated from one another such that, when the moveable apparatus is rotated, the difference in pressure at the positions of the pressure sensors 20 can be measured. Thus, for example, in some cases, the pressure sensors 20 are located at, or near, the comers of the moveable apparatus so as to maximize the distances between the sensors. In some cases, the pressure sensors 20 are located at, or near, opposite edges of the moveable apparatus. Although FIG. 1 illustrates four pressure sensors 20, other implementations may include as few as two pressure sensors, and some implementations may include three or more pressure sensors in or on the moveable apparatus. Although two sensors 20 can be sufficient to measure one angle, at least three sensors 20 may be provided for measuring two angles (e.g., the inclination of a plane in three-dimensional space). Some implementations can include a further pressure sensor 20’ disposed on a platform 26 so as to permit distinguishing between a rotation, for example, of 180° degrees around either the x axis or the y axis. Also, increasing the number of pressure sensors 20 can, in some instances, improve accuracy.

[0023] Various types of sensors can be used as the pressure sensors 20. In some instances, barometric sensors can be used to measure ambient pressure levels at the multiple locations within the moveable apparatus. Preferably, the pressure sensors 20 have a short measurement time, low noise, low power consumption, high accuracy, a small form factor, and a fast output frequency to facilitate fast readout. For example, in some cases, in order to resolve height differences of less than 1 cm, the pressure noise of the difference signal should be less than 0.12 Pa rms, with an output data rate larger than 20 Hz. Different applications may require different resolution settings and/or data output rates. Thus, other pressure noise and or altitude resolution requirements may be appropriate for different output data rates. For example, some implementations may require 1 Pa rms resolution (8 cm) with higher output data rate (e.g., at least 100 Hz) or 0.1 Pa rms resolution with output data rate of at least 5 Hz. In some instances, the pressure sensors 20 advantageously are implemented as capacitive, microelectro- mechanical systems (MEMS) type pressure sensors, in which pressure is measured via deflection of a membrane caused by external (e.g., ambient) pressure. In some cases, each of the capacitive pressure sensors 20 includes a suspended tensile membrane over a cavity that is at a certain gauge pressure. The external pressure can be measured because the pressure difference between the external pressure and the gauge pressure generates a force on the membrane, which causes the membrane to deflect. This deflection then can be measured by capacitive measurement. Other types of pressure sensors can be used as well.

[0024] As further shown in FIG. 1, the pressure sensors 20 are operable to generate output signals indicative of pressure. The pressure sensors 20 are coupled to a signal processing unit 24 in the moveable apparatus. The signal processing unit 24 is operable to obtain (e.g., read) the pressure values generated by the pressure sensors 20, to convert the pressure values to relative height values, and to compute a best fitting plane that includes the positions of the pressure sensors 20, thus yielding the orientation of the moveable apparatus (e.g., its inclination with respect to a predetermined plane such as the horizontal plane).

[0025] FIG. 2 illustrates an example of how the tilt angle of the moveable apparatus can be determined by the signal processing unit 24 based on measurements obtained from two pressure sensors 20 A and 20B. The tilt Q of the moveable apparatus causes a difference in height for the respective positions of the pressure sensors, and thus a difference in pressure. Straight-forward calculations lead to the following equation for the tilt angle Q:

where h is the difference in height between the locations of the two pressure sensors (20 A, 20B), d is the distance between the sensors, pi and p2 are the values of pressure measured, respectively, by the sensors, and k indicates the change in pressure per unit distance (e.g., in some cases, k = 12 Pa/m). The foregoing implementation allows for measurement of tilt for -90° < Q < 90°. [0026] In some implementations, the tilt angle of the moveable apparatus can be determined by the signal processing unit 24 using output signals from three pressure sensors (20A, 20B, 20C) located, respectively, at different positions in or on the moveable apparatus. The tilt angle Q can be found by passing a line or a plane through the positions of the pressure sensors (20A, 20B, 2C) and a predetermined reference plane (e.g., the horizontal plane). Assuming that the positions of the pressure sensors in three- dimensional space are (0, 0, 0) for the first sensor 20A, (x₂, 0, 0) for the second sensor 20B, and (x₃, y₃, 0) for the third sensor 20C, the tilt angle Q can be determined by the following equation:

where pi, p2, p3 are the values of pressure measured, respectively, by the sensors 20A, 20B, 20C, and where k indicates the change in pressure per unit distance.

[0027] In the foregoing examples, it is assumed that the relative positions of the pressure sensors are known by the signal processing unit 24. For example, the position

information can be stored in memory accessible by the signal processing unit 24 or can be hardwired into code executable by the signal processing unit.

[0028] In some implementations, a control unit in the moveable apparatus is operable to generate a control signal to adjust a feature of the mobile device in response to the determined orientation of the device. The control unit can be implemented as the same or different processor(s) as the signal processing unit 24.

[0029] The foregoing techniques can be incorporated in a wide range of different types of moveable apparatus. Thus, the pressure sensors 20 and signal processing unit 24 can be integrated, for example, into a mobile device such as a smart phone, cellular phone, tablet computer, notebook computer, laptop computer, personal data assistant, and other such hand-held or portable computing devices. FIG. 3 illustrates an example of a mobile device, in this case a smart phone 30, that includes pressure sensors 20 whose measurements can be used to determine the orientation (e.g., tilt) of the device. In some implementations, a control unit in the smart phone is operable to use the orientation to determine whether the device is in a portrait or landscape orientation, and in some cases, can cause a display screen 32 on the device to switch from the portrait orientation to the landscape orientation, or vice-versa. Signals form the pressure sensors 20 also can be used, for example, to determine tilt, which can be in the. control of video games on the mobile device or to navigate in a three-dimensional (e.g., 360°) photograph or video displayed on the mobile device.

[0030] The techniques described here also can be integrated into various types of vehicles, including automobiles, bicycles, motorcycles, motorbikes, trucks, trailers, caravans, airplanes, trains, boats, and drones, among others. FIG. 4 illustrates an example of a vehicle, in this case an automobile 40, that includes pressure sensors 20 whose measurements can be used to determine the orientation (e.g., pitch or tilt) of the vehicle. In some implementations, a control unit in the vehicle is operable to use the orientation to control an automatic parking brake system, a hill start system, an antitheft system, an automatic headlight control system, or other systems of the vehicle. For example, if the orientation indicates the vehicle’s pitch, the control unit can use the vehicle’s orientation to adjust a direction of the vehicle’s headlight(s) and/or can enable hill-start functionality.

[0031] The techniques described here can be integrated into various types of wearable devices as well. Wearable devices refers to electronic and/or computing technologies incorporated into items of clothing and accessories which can be worn on the body. In some instances, the wearable device is operable to perform various computing tasks and may provide sensory and/or scanning features such as biofeedback or tracking of physiological function(s). Examples of wearable devices include smart watches, smart eyeglasses, fitness trackers, smart fabrics, smart jewelry such as bracelets, and virtual reality headsets, among others. The wearable device can be coupled wirelessly for communication with a smartphone or other computing device. FIG. 5 illustrates an example of a wearable device, in this case smart eyeglasses 50, that includes pressure sensors 20 whose measurements can be used to determine the orientation (e.g., tilt) of the wearable device.

[0032] In addition, the techniques described here can be integrated into game controllers of the type in which the position and orientation in space of the game controller is used to provide control of the game functions. FIG. 6 illustrates an example of a game controller 60 that includes pressure sensors 20 whose measurements can be used to determine the orientation (e.g., tilt) of the game controller. When a player plays the game, the game controller 60 moves up and down. The difference in pressure measured by the pressure sensors 20 is translated by a signal processing unit to the corresponding difference in height. Subsequently this information is used by a control unit to control the game (e.g., to control the position and/or orientation of an item on a display screen).

[0033] The techniques described here also can be integrated into stationary or partially stationary objects that include a moveable apparatus as a component or part of the object. An example of such objects includes a garage or other building that includes an automatic door. Another example is a bridge that includes a moveable deck. Other examples of such objects include industrial equipment and playground equipment having a moveable component. Pressure sensors can be integrated into the moveable apparatus and used as described above. FIG. 7 illustrates an example of a building 70 that has an automatic garage door 72 including pressure sensors 20 whose measurements can be used to determine the orientation (e.g., tilt) of the door.

[0034] In some applications, space in the moveable apparatus is at a premium. For example, smart phones are compact hand-held devices that typically have limited space for additional components because a relatively small foot print is desirable. In such instances, it can be advantageous to integrate one or more of the pressure sensors with other components of the moveable apparatus. For example, at least one pressure sensor 20 can be integrated with read-out circuitry. In some implementations, a capacitive pressure sensor can be integrated on top of a CMOS read-out circuit. For example, the pressure sensor 20 can include a bottom electrode formed on top of the final passivation layer of the CMOS read-out circuit. Further details of such implementations are described, for example, is U.S. Patent No. 9,340,412, which is incorporated herein by reference in its entirety.

[0035] As illustrated in FIG. 8, a method of determining an orientation of a moveable apparatus includes obtaining output signals from multiple pressure sensors in or on the moveable apparatus (202) and determining an orientation of the moveable apparatus based, at least in part, on the output signals from the pressure sensors (204). In some implementations, the method also includes generating a control signal to adjust a feature of the moveable apparatus in response to the determined orientation (206).

[0036] In some instances, a pressure sensor 20 can be integrated with some other component (e.g., a microphone ASIC die) in the moveable apparatus. As microphones require an acoustic port at the bottom and top of the device in which they are disposed, these device positions are particularly suited for a combination package that includes a microphone and a pressure sensor. An example is illustrated in FIG. 9, which shows a package 300 that includes a pressure sensor chip 302 integrated with, and stacked on, a microphone ASIC 304 that is coupled to the microphone MEMS element 306. Such an implementation can be advantageous for some smart phones, which already include one or more microphones (e.g., for cancellation of environment noise).

[0037] In some implementations, the moveable apparatus includes one or more additional sensors, such as an accelerometer, a gyroscope, a magnetometer, and/or a location determining device that uses, for example, GPS, WiFi or 4G technology. The signal processing unit 24 can be operable to determine the orientation of the moveable apparatus based, at least in part, on the output signals from the pressure sensors 20 and at least one of the additional sensors. [0038] Various aspects of the subject matter and the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them.

Embodiments of the subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine -readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more of them.

[0039] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows also can be performed by, and apparatus also can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). [0040] Various modifications can be made to the foregoing implementations. Further, features from different implementations described above can, in some instances, be combined in the same implementation. Accordingly, other implementations are within the scope of the claims.

Claims

1. A moveable apparatus comprising:

a plurality of pressure sensors in or on the moveable apparatus, each of the pressure sensors being operable to generate a respective output signal indicative of pressure; and

one or more processors operable to determine an orientation of the moveable apparatus based, at least in part, on the output signals from the plurality of pressure sensors.

2. The moveable apparatus of claim 1 wherein the one or more processors are operable to determine at least one of tilt or inclination of the moveable apparatus based, at least in part, on the output signals from the plurality of pressure sensors.

3. The moveable apparatus of any one of the previous claims wherein the one or more processors are operable to determine an angle of a plane of the moveable apparatus with respect to a predetermined reference plane based, at least in part, on the output signals from the plurality of pressure sensors.

4. The moveable apparatus of claim 3 wherein the predetermined reference plane is a horizontal plane parallel to ground.

5. The moveable apparatus of any one of the previous claims wherein the one or more processors are operable to generate a control signal to adjust a feature of the moveable apparatus in response to the determined orientation.

6. The mobile device of claim 5 wherein the moveable apparatus includes a display having a portrait orientation and a landscape orientation, and wherein the one or more processors are operable to generate a control signal to switch between the portrait orientation and the landscape orientation in response to the determined orientation.

7. The moveable apparatus of any one of the previous claims wherein each of the pressure sensors is a capacitive pressure sensor.

8. The moveable apparatus of claim 7 wherein a difference signal between pressure sensors has a pressure noise less than 0.12 Pa rms, and the pressure sensors have an output data rate greater than 20 Hz.

9. The moveable apparatus of claim 7 wherein the one or more processors are operable to resolve height differences of less than 1 cm based on the output signals from the pressure sensors.

10. The moveable apparatus of any one of the previous claims wherein the plurality of pressure sensors includes at least three pressure sensors.

11. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a mobile device.

12. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a vehicle.

13. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a drone.

14. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a game console controller.

15. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a wearable device.

16. The moveable apparatus of any one of claims 1-10 wherein the moveable apparatus is a subcomponent of a stationary object.

17. The moveable apparatus of any one of claims 1-16 wherein at least two of the pressure sensors are disposed adjacent opposite sides of the moveable apparatus from one another.

18. The moveable apparatus of any one of claims 1-16 wherein at least two of the pressure sensors are disposed at opposite edges of the moveable apparatus.

19. The moveable apparatus of any one of claims 1-18 further including CMOS read-out circuitry, wherein at least one of the pressure sensors is integrated with the CMOS readout circuitry.

20. The moveable apparatus of claim 19 wherein the at least one of the pressure sensors is integrated on top of the CMOS readout circuitry.

21. The moveable apparatus of any one of claims 1-18 further including a package containing a microphone circuit and at least one of the pressure sensors.

22. The moveable apparatus of any one of claims 1-21 further including at least one additional sensor of a type different from the plurality of pressure sensors, wherein the one or more processors are operable to determine the orientation of the moveable apparatus based, at least in part, on the output signals from the plurality of pressure sensors and an output signal from the at least one additional sensor.

23. A method of determining an orientation of a moveable apparatus, the method comprising:

obtaining output signals from a plurality of pressure sensors in or on the moveable apparatus; and determining an orientation of the moveable apparatus based, at least in part, on the output signals from the plurality of pressure sensors.

24. The method of claim 23 including determining at least one of tilt or inclination of the moveable apparatus based, at least in part, on the output signals from the plurality of pressure sensors.

25. The method of claim 23 including determining an angle of a plane of the moveable apparatus with respect to a predetermined reference plane based, at least in part, on the output signals from the plurality of pressure sensors.

26. The method of any one of claims 23-25 including generating a control signal to adjust a feature of the moveable apparatus in response to the determined orientation.

27. The method of claim 26 including generating a control signal to switch between a portrait orientation and a landscape orientation of a display in response to the determined orientation of the moveable apparatus.