CN118316520A - Safety performance testing method based on sensor - Google Patents

Abstract

The invention discloses a safety performance testing method based on a sensor, which comprises the following steps: step one: setting up a simulation model of a visible light communication system, and testing the communication function of a full communication area; step two: based on the inclination angle of the image sensor, testing the indoor positioning accuracy of the inclined image sensor according to the inclination angle and the geometric relation of the LED image generated on the inclined image sensor by the LEDs; step three: establishing a physical layer security architecture test method based on an indoor visible light communication system in an intelligent home environment; step four: adopting zero forcing beam forming technology to make simulation judgment in the radio frequency and visible light communication heterogeneous network under multi-user; step five: aiming at the channel characteristics of visible light communication, the visible light power distribution is optimized to protect the safety of the visible light communication in the home from the physical layer.

Description

A sensor-based safety performance testing method

Technical Field

The present invention relates to the technical field of safety performance testing, and in particular to a sensor-based safety performance testing method.

Background technique

As a powerful supplement to traditional radio frequency communication, visible light communication uses existing white light emitting diodes for data transmission. That is, in actual visible light communication systems, white light LEDs can not only provide lighting sources, but also realize communication functions. Its related parameters will greatly affect the communication performance of the communication system on the receiving plane. Generally, these LED lights are usually placed in the center of the roof, which will cause the received optical power, signal-to-noise ratio and illumination on the receiving plane to be very uneven. Even some corners with poor performance will have communication blind spots, which will affect the fairness of user communication. At the same time, because it is not sensitive to security vulnerabilities, there is also a security problem of being eavesdropped. Therefore, it is necessary to design a sensor-based security performance testing method to improve communication security performance and reduce the risk of eavesdropping.

Summary of the invention

The purpose of the present invention is to provide a sensor-based safety performance testing method to solve the problems raised in the above background technology.

In order to solve the above technical problems, the present invention provides the following technical solutions: a sensor-based safety performance testing method, comprising the following steps:

Step 1: Build a simulation model of the visible light communication system to test the communication function of the entire communication area;

Step 2: Based on the tilt angle of the image sensor, the indoor positioning accuracy of the tilt image sensor is tested according to the tilt angle and the geometric relationship between the LED image generated by the LED on the tilted image sensor;

Step 3: Establish a physical layer security architecture test method for indoor visible light communication systems in smart home environments;

Step 4: Use zero-forcing beamforming technology to conduct simulation and judgment in a multi-user RF and visible light communication heterogeneous network;

Step 5: Based on the channel characteristics of visible light communication, optimize the visible light power distribution to protect the security of visible light communication in the home from the physical layer.

According to the above technical solution, the step of building a simulation model of the visible light communication system includes:

Build a visible light communication system consisting of an LED transmitter and a photodetector receiver. Set up the transmitter, channel and receiver in the visible light communication system. The transmitter first encodes and modulates the input data, and then drives the LED to emit a specific light signal through the driving circuit. The light signal carrying the data is transmitted to form a visible light communication channel. The light signal is transmitted to the photosensitive element of the photoelectric conversion device. The photoelectric conversion device converts the received light signal into an electrical signal. After subsequent signal processing, demodulation and decoding, the data transmitted at the beginning is obtained, and the application scenario of the system is set in the field of smart home.

The LED transmitter is installed on the ceiling in the home environment, and the photodetectors are randomly placed on the receiving plane as receivers. The receivers are used to detect the signals from the transmitters. In the simulation model of the visible light communication system, the channel links of the visible light communication system are divided into line-of-sight links and non-line-of-sight links according to the relative directionality between transceivers. The line-of-sight links mainly involve short-distance indoor visible light communications, and the visible light is concentrated in a narrow beam for directional transmission.

According to the above technical solution, the specific operation steps of the simulation test method by adding the tilt angle of the image sensor include:

Step 21: Use the LED light source as the signal transmitter to continuously send visible light signals with modulated LED position information to the nearby indoor environment, use the camera to shoot the surrounding environment, obtain image information, and then use image processing technology to identify the LED position information and calculate the position for positioning;

Step 22: The image sensor is used to shoot the LED light source through a rolling shutter to generate a black and white stripe image. There is a specific quantitative relationship between the flashing frequency of the LED light source and the width of the black and white stripes. The frequency of the LED light source is modulated using this specific quantitative relationship, and different frequencies are set to represent different position information.

Step 23: The receiving end uses a mobile terminal with a front camera to obtain image information of the LED light source and its home environment through the camera, selects the nearest LED light source to measure the width of its black and white stripes and obtains the corresponding position information, and calculates the position coordinates of the camera according to the position coordinates of the camera.

Step 24: When there is a part of the area between two adjacent groups of LED light sources with positioning information where the image with the LED light source cannot be obtained, the positioning function will stop working; when the light source is in a blank area, the sensor is used for auxiliary positioning, and when entering the system working area again, the visible light imaging positioning is performed again to calibrate the position in real time;

Step 25: Use multiple LED lights to send visible light information with time information, test the information transmission performance from the vertical distance and angle between the transmitting and receiving ends, test the indoor positioning performance based on the tilt image sensor, use the receiver to receive the light signal containing time information, and obtain the time information of the receiving time while receiving the signal;

Step 26: By calculating the difference between the sending time and the receiving time, and then multiplying it by the speed of light signal propagation, we can get the distance between the LED light and each receiver. Then, we can subtract the distance between each LED light and the receiver to obtain the actual positioning result data. According to the positioning prediction, we can determine the positioning error and record the positioning effect.

According to the above technical solution, the specific test method steps include:

Step 31: adopt a general visible light communication channel model to establish a heterogeneous transmission network for downlink visible light communication based on multiple inputs and single outputs in home rooms;

Step 32: setting a radio frequency access point equipped with multiple antennas and a visible light communication access point equipped with multiple LED arrays, wherein the radio frequency access point is embedded in the LED lamp and fixed on the ceiling of the room;

Step 33: Consider the scene where each LED is located as a circle with a fixed radius, where the projection of the LED light is located at the center of the circle. In this scene, it is set to include multiple legitimate users and one eavesdropper, all of which are equipped with a radio frequency receiving antenna and a visible light communication receiving antenna;

Step 34: It is assumed that there are a group of illegal eavesdroppers who attempt to eavesdrop on the information transmission between the LED light and the legal receiver in the same place, and it is established that the legal receiver and the eavesdropping device use photodiodes for data communication, and at the same time, the legal receiver positions are set to meet the uniform distribution within the circle;

Step 35: The heterogeneous network adopts a parallel RF and VLC hybrid model, that is, both RF and VLC access points transmit confidential information to users at the same time, and all users and eavesdroppers have the ability to aggregate information, that is, they can aggregate information from RF access points and VLC access points;

Step 36: Set each legitimate user as a potential internal eavesdropper. When it is determined that there is an eavesdropper in the heterogeneous network, synchronously determine whether to eavesdrop on the information transmitted by the sender to multiple legitimate users.

According to the above technical solution, the step of performing simulation judgment includes:

When it is determined that there is an eavesdropper in the heterogeneous network, and when the information transmitted by the transmitter to multiple legitimate users is eavesdropped, the zero-forcing beamforming technology is used to perform simulation in the RF and visible light communication heterogeneous network with multiple users to test whether the beamforming technology can reduce the signal received by the eavesdropper to zero in the eavesdropping channel. If so, it means that the zero-forcing beamforming technology can ensure the security of internal and external eavesdropping in the system, and prevent the confidential information of legitimate users from being leaked to other legitimate users and eavesdroppers.

According to the above technical solution, the step of optimizing visible light power distribution to protect the security of visible light communication in the home from the physical layer includes:

Different parameters are set for different LED arrays and optimization algorithms, and the location of the target receiver is set, and a power adjustment factor vector is set using the optimization algorithm;

Calculate the direct channel gain obtained by superimposing the LED array adjusted by the adjustment factor at each receiver and convert it into received optical power;

Analyze and calculate the point with the largest absolute value of direct channel gain in the safe area, record its direct channel gain, subtract the absolute value of the direct channel gain of the point with the largest absolute value of direct channel gain in the safe area from the absolute value of the direct channel gain of the receiver, save it as the fitness value and return it to the optimization algorithm;

The node sends out key update prompts and one-time passwords at regular intervals or after receiving certain signals. The legitimate user receives the prompts and one-time passwords and sends them back for confirmation. Then the one-time password is replaced together to continue communication under the new key encryption mode. The node LED will generate a new key and enter the key update phase, complete the key exchange with the legitimate user, and then start the next information transmission.

According to the above technical solution, the safety performance testing system includes:

A visible light communication unit, used to establish simulation for a visible light communication system;

Performance test unit, used to test the indoor positioning performance and safety performance of the visible light communication system;

The communication security optimization unit is used to optimize the security performance in the visible light communication process based on the analysis and judgment results.

Compared with the prior art, the beneficial effects achieved by the present invention are:

1. By setting the application scenario as the smart home field, the LED transmitter is installed on the ceiling in the home environment, and the photodetector is randomly placed on the receiving plane as a receiver. The receiver is used to detect the signal from the transmitter. In the simulation model of the visible light communication system, the visible light is concentrated in a narrow beam for directional transmission, and the transmission power and light intensity in this scenario are tested;

2. Test the positioning and security performance of the visible light communication system, determine whether there are eavesdroppers in the heterogeneous network and whether there is any behavior of eavesdropping on the information transmitted by the sender to multiple legitimate users, and prevent the confidential information of legitimate users from being leaked to other legitimate users and eavesdroppers;

3. By reducing the half-power half-angle of LED in the visible light communication system, the sum security rate of the RF and visible light communication heterogeneous network is gradually increased. As the half-power half-angle of LED becomes smaller, its radiation beam becomes narrower, and the user's received signal power becomes greater. Under the same noise power, the user's received signal-to-noise ratio also increases. When the LED's transmission beam becomes narrower, the probability of information being eavesdropped is reduced, thereby improving the overall security of the heterogeneous system.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

FIG1 is a flow chart of a sensor-based safety performance testing method provided in Embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of the module composition of a sensor-based safety performance testing system provided in Embodiment 2 of the present invention.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Embodiment 1: FIG. 1 is a flow chart of a sensor-based safety performance testing method provided in Embodiment 1 of the present invention. This embodiment can be applied to the scenario of indoor visible light communication safety performance testing. This method can be performed by a sensor-based safety performance testing system provided in this embodiment. As shown in FIG. 1 , this method specifically includes the following steps:

Step 1: Build a simulation model of the visible light communication system to test the communication function of the entire communication area;

In an embodiment of the present invention, a visible light communication system consisting of an LED transmitter and a photodetector receiver is constructed, and a transmitter, a channel and a receiver are set up in the visible light communication system. The transmitter first encodes and modulates the input data, and then drives the LED to emit a specific light signal through a driving circuit. The light signal carrying the data is transmitted to form a visible light communication channel. The light signal is transmitted to the photosensitive element of the photoelectric conversion device. The photoelectric conversion device converts the received light signal into an electrical signal. After subsequent signal processing, demodulation and decoding processes, the data initially transmitted is obtained, and the application scenario of the system is set to the smart home field. Therefore, the LED transmitter is installed on the ceiling in the home environment, and the photodetector is randomly placed on the receiving plane as a receiver. The receiver is used to detect the signal from the transmitter. In the simulation model of the visible light communication system, according to the relative directivity between the transceivers, the channel link of the visible light communication system is divided into a line-of-sight link and a non-line-of-sight link. The line-of-sight link mainly involves the situation of indoor short-distance visible light communication. The visible light is concentrated in a narrow beam for directional transmission, saving transmission power and improving light intensity.

Exemplarily, the line-of-sight exit angle of the transmitter and the line-of-sight incident angle of the receiver are set. At the transmitting end, the input electrical signal is intensity modulated and enters the driving circuit, and then the LED light-emitting diode is dimmed and controlled. Then, the visible light is freely emitted to the outer space through the LED array and the optical lens, and the visible light is captured by the optical concentrator and the optical filter. The received optical signal is converted into an electrical signal by the photodiode, and then amplified step by step by the optical amplifier. Finally, the information is decoded by the direct detection technology at the demodulation circuit end, and the original signal is restored.

Exemplarily, the LED in the visible light communication system is used to meet the needs of lighting and communication. By mathematically defining the light intensity index of the LED, analyzing the channel and security characteristics of the visible light communication, the LED incoherent light source is regarded as a Lambertian radiator, that is, the LED lamp is regarded as a point light source. Therefore, the brightness of the LED is expressed by the light intensity, the total energy radiated by the LED is expressed by the transmitted light power, and the luminous flux is expressed by the light intensity.

Step 2: Based on the tilt angle of the image sensor, the indoor positioning accuracy of the tilt image sensor is tested according to the tilt angle and the geometric relationship between the LED image generated by the LED on the tilted image sensor;

In the embodiment of the present invention, a camera system consisting of a camera, a photosensitive sensor, an analog-to-digital converter, an image sensor and a storage is configured, light is gathered onto the photosensitive sensor through a lens, the photosensitive sensor converts the light signal into an analog signal, the analog signal is converted into a digital signal through the analog-to-digital converter, and after adjustment and processing by the image sensor, the formed image information is stored in the storage;

Exemplarily, the specific operating steps of the simulation test method by adding the tilt angle of the image sensor are as follows:

Step 21: Use the LED light source as the signal transmitter to continuously send visible light signals with modulated LED position information to the nearby indoor environment, use the camera to shoot the surrounding environment, obtain image information, and then use image processing technology to identify the LED position information and calculate the position for positioning;

Step 22: The image sensor is used to shoot the LED light source through a rolling shutter to generate a black and white stripe image. There is a specific quantitative relationship between the flashing frequency of the LED light source and the width of the black and white stripes. The frequency of the LED light source is modulated using this specific quantitative relationship, and different frequencies are set to represent different position information.

Step 23: The receiving end uses a mobile terminal with a front camera to obtain image information of the LED light source and its home environment through the camera, selects the nearest LED light source to measure the width of its black and white stripes and obtains the corresponding position information, and calculates the position coordinates of the camera according to the position coordinates of the camera.

Step 24: When there is a part of the area between two adjacent groups of LED light sources with positioning information where the image with the LED light source cannot be obtained, the positioning function will stop working; when the light source is in a blank area, the sensor is used for auxiliary positioning, and when entering the system working area again, the visible light imaging positioning is performed again to calibrate the position in real time;

Step 25: Use multiple LED lights to send visible light information with time information, test the information transmission performance from the vertical distance and angle between the transmitting and receiving ends, test the indoor positioning performance based on the tilt image sensor, use the receiver to receive the light signal containing time information, and obtain the time information of the receiving time while receiving the signal;

Step 26: By calculating the difference between the sending time and the receiving time, and then multiplying it by the speed of light signal propagation, we can get the distance between the LED light and each receiver. Then, we can subtract the distance between each LED light and the receiver to obtain the actual positioning result data. According to the positioning prediction, we can determine the positioning error and record the positioning effect.

Step 3: Establish a physical layer security architecture test method for indoor visible light communication systems in smart home environments;

In the embodiment of the present invention, the specific testing method is:

Step 31: adopt a general visible light communication channel model to establish a heterogeneous transmission network for downlink visible light communication based on multiple inputs and single outputs in home rooms;

Step 32: setting a radio frequency access point equipped with multiple antennas and a visible light communication access point equipped with multiple LED arrays, wherein the radio frequency access point is embedded in the LED lamp and fixed on the ceiling of the room;

Step 33: Consider the scene where each LED is located as a circle with a fixed radius, where the projection of the LED light is located at the center of the circle. In this scene, it is set to include multiple legitimate users and one eavesdropper, all of which are equipped with a radio frequency receiving antenna and a visible light communication receiving antenna;

Step 34: It is assumed that there are a group of illegal eavesdroppers who attempt to eavesdrop on the information transmission between the LED light and the legal receiver in the same place, and it is established that the legal receiver and the eavesdropping device use photodiodes for data communication, and at the same time, the legal receiver positions are set to meet the uniform distribution within the circle;

Step 35: The heterogeneous network adopts a parallel RF and VLC hybrid model, that is, both RF and VLC access points transmit confidential information to users at the same time, and all users and eavesdroppers have the ability to aggregate information, that is, they can aggregate information from RF access points and VLC access points;

Step 36: Set each legitimate user as a potential internal eavesdropper. When it is determined that there is an eavesdropper in the heterogeneous network, synchronously determine whether to eavesdrop on the information transmitted by the sender to multiple legitimate users.

Step 4: Use zero-forcing beamforming technology to conduct simulation and judgment in a multi-user RF and visible light communication heterogeneous network;

In an embodiment of the present invention, when it is determined that there is an eavesdropper in the heterogeneous network, and when the information transmitted by the transmitter to multiple legitimate users is simultaneously eavesdropped, a zero-forcing beamforming technology is used to perform simulation in a multi-user RF and visible light communication heterogeneous network to test whether the beamforming technology can reduce the signal received by the eavesdropper to zero in the eavesdropping channel. If so, it means that the zero-forcing beamforming technology can ensure the security of internal and external eavesdropping in the system, and prevent the confidential information of legitimate users from being leaked to other legitimate users and eavesdroppers.

Step 5: Based on the channel characteristics of visible light communication, optimize the visible light power distribution to protect the security of visible light communication in the home from the physical layer.

In the embodiment of the present invention, different parameters are set for different LED arrays and optimization algorithms, and the position of the target receiver is set. A power adjustment factor vector is set using the optimization algorithm. The direct channel gain obtained by superimposing the LED array adjusted by the adjustment factor at each receiver is calculated and converted into received optical power. The point with the largest absolute value of the direct channel gain in the safe area is analyzed and calculated, and its direct channel gain is recorded. The absolute value of the direct channel gain of the point with the largest absolute value of the direct channel gain in the safe area is subtracted from the absolute value of the direct channel gain of the receiver, and the difference is saved as a fitness value and returned to the optimization algorithm. Then, the LED half-power half-angle is reduced, so that the sum security rate of the heterogeneous network of radio frequency and visible light communication is gradually increased. As the LED half-power half-angle is smaller, its radiation beam is narrower, and the user's received signal power is greater. Under the same noise power, the user's received signal-to-noise ratio is also increased. When the LED's transmission beam becomes narrower, the probability of information being eavesdropped is reduced, and the overall security of the heterogeneous system is improved.

Exemplarily, a new key encryption mode is adopted in which the node sends out a key update prompt and a one-time password regularly or receives certain signals. The legitimate user receives the prompt and the one-time password and sends them back for confirmation. Then, the one-time password is replaced together to continue communication. The node LED will generate a new key and enter the key update phase, complete the key exchange with the legitimate user, and then start the next information transmission. While effectively ensuring that the legitimate user successfully obtains the issued key, the security of visible light communication is guaranteed to the greatest extent.

Embodiment 2: Embodiment 2 of the present invention provides a sensor-based safety performance testing system. FIG. 2 is a schematic diagram of the module composition of a sensor-based safety performance testing system provided by Embodiment 2 of the present invention. As shown in FIG. 2 , the system includes:

A visible light communication unit, used to establish simulation for a visible light communication system;

Performance test unit, used to test the indoor positioning performance and safety performance of the visible light communication system;

The communication security optimization unit is used to optimize the security performance in the visible light communication process based on the analysis and judgment results.

In some embodiments of the present invention, the visible light communication unit includes:

A simulation model building module is used to build a simulation model of a visible light communication system to test the communication function of the entire communication area;

An application scenario setting module, used to set the application scenario of the visible light communication system to the field of smart home;

The channel and security characteristics analysis module is used to analyze the characteristics of the channel and communication security characteristics of the optical signal carrying data for transmission to form visible light communication.

In some embodiments of the present invention, the performance testing unit includes:

An image sensor module, which is used to focus light through a lens onto a photosensitive sensor and convert the light signal into an analog signal;

A simulation test running module, used for performing simulation test running by adding a tilt angle of the image sensor;

Security architecture test module, used to establish physical layer security architecture test of indoor visible light communication system in smart home environment;

The heterogeneous transmission network establishment module is used to establish a heterogeneous transmission network for downlink visible light communication based on multiple inputs and single outputs in the home.

In some embodiments of the present invention, the communication security optimization unit includes:

Zero-forcing beamforming module, used to simulate and emulate the use of zero-forcing beamforming technology in multi-user RF and visible light communication heterogeneous networks;

A simulation judgment module is used to test and judge whether the beamforming technology reduces the signal received by the eavesdropper to zero in the eavesdropping channel;

A channel characteristic analysis module is used to calculate the direct channel gain characteristic obtained by superimposing the LED array adjusted by the adjustment factor at each receiver;

The communication security assurance module is used to ensure that users can safely obtain and send key information in visible light communication.

It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A sensor-based safety performance testing method, characterized in that the method comprises the following steps: Step 1: Build a simulation model of the visible light communication system to test the communication function of the entire communication area; Step 2: Based on the tilt angle of the image sensor, the indoor positioning accuracy of the tilt image sensor is tested according to the tilt angle and the geometric relationship between the LED image generated by the LED on the tilted image sensor; Step 3: Establish a physical layer security architecture test method for indoor visible light communication systems in smart home environments; Step 4: Use zero-forcing beamforming technology to conduct simulation and judgment in a multi-user RF and visible light communication heterogeneous network; Step 5: Based on the channel characteristics of visible light communication, optimize the visible light power distribution to protect the security of visible light communication in the home from the physical layer. 2. A sensor-based safety performance testing method according to claim 1, characterized in that: the step of building a simulation model of a visible light communication system comprises: Build a visible light communication system consisting of an LED transmitter and a photodetector receiver. Set up the transmitter, channel and receiver in the visible light communication system. The transmitter first encodes and modulates the input data, and then drives the LED to emit a specific light signal through the driving circuit. The light signal carrying the data is transmitted to form a visible light communication channel. The light signal is transmitted to the photosensitive element of the photoelectric conversion device. The photoelectric conversion device converts the received light signal into an electrical signal. After subsequent signal processing, demodulation and decoding, the data transmitted at the beginning is obtained, and the application scenario of the system is set in the field of smart home. The LED transmitter is installed on the ceiling in the home environment, and the photodetectors are randomly placed on the receiving plane as receivers. The receivers are used to detect the signals from the transmitters. In the simulation model of the visible light communication system, the channel links of the visible light communication system are divided into line-of-sight links and non-line-of-sight links according to the relative directionality between transceivers. The line-of-sight links mainly involve short-distance indoor visible light communications, and the visible light is concentrated in a narrow beam for directional transmission. 3. A sensor-based safety performance testing method according to claim 2, characterized in that: the specific operation steps of the simulation testing method by adding the tilt angle of the image sensor include: Step 21: Use the LED light source as the signal transmitter to continuously send visible light signals with modulated LED position information to the nearby indoor environment, use the camera to shoot the surrounding environment, obtain image information, and then use image processing technology to identify the LED position information and calculate the position for positioning; Step 22: The image sensor is used to shoot the LED light source through a rolling shutter to generate a black and white stripe image. There is a specific quantitative relationship between the flashing frequency of the LED light source and the width of the black and white stripes. The frequency of the LED light source is modulated using this specific quantitative relationship, and different frequencies are set to represent different position information. Step 23: The receiving end uses a mobile terminal with a front camera to obtain image information of the LED light source and its home environment through the camera, selects the nearest LED light source to measure the width of its black and white stripes and obtains the corresponding position information, and calculates the position coordinates of the camera according to the position coordinates of the camera. Step 24: When there is a part of the area between two adjacent groups of LED light sources with positioning information where the image with the LED light source cannot be obtained, the positioning function will stop working; when the light source is in a blank area, the sensor is used for auxiliary positioning, and when entering the system working area again, the visible light imaging positioning is performed again to calibrate the position in real time; Step 25: Use multiple LED lights to send visible light information with time information, test the information transmission performance from the vertical distance and angle between the transmitting and receiving ends, test the indoor positioning performance based on the tilt image sensor, use the receiver to receive the light signal containing time information, and obtain the time information of the receiving time while receiving the signal; Step 26: By calculating the difference between the sending time and the receiving time, and then multiplying it by the speed of light signal propagation, we can get the distance between the LED light and each receiver. Then, we can subtract the distance between each LED light and the receiver to obtain the actual positioning result data. According to the positioning prediction, we can determine the positioning error and record the positioning effect. 4. A sensor-based safety performance testing method according to claim 3, characterized in that: the specific testing method steps include: Step 31: adopt a general visible light communication channel model to establish a heterogeneous transmission network for downlink visible light communication based on multiple inputs and single outputs in home rooms; Step 32: setting a radio frequency access point equipped with multiple antennas and a visible light communication access point equipped with multiple LED arrays, wherein the radio frequency access point is embedded in the LED lamp and fixed on the ceiling of the room; Step 33: Consider the scene where each LED is located as a circle with a fixed radius, where the projection of the LED light is located at the center of the circle. In this scene, it is set to include multiple legitimate users and one eavesdropper, all of which are equipped with a radio frequency receiving antenna and a visible light communication receiving antenna; Step 34: It is assumed that there are a group of illegal eavesdroppers who attempt to eavesdrop on the information transmission between the LED light and the legal receiver in the same place, and it is established that the legal receiver and the eavesdropping device use photodiodes for data communication, and at the same time, the legal receiver positions are set to meet the uniform distribution within the circle; Step 35: The heterogeneous network adopts a parallel RF and VLC hybrid model, that is, both RF and VLC access points transmit confidential information to users at the same time, and all users and eavesdroppers have the ability to aggregate information, that is, they can aggregate information from RF access points and VLC access points; Step 36: Set each legitimate user as a potential internal eavesdropper. When it is determined that there is an eavesdropper in the heterogeneous network, synchronously determine whether to eavesdrop on the information transmitted by the sender to multiple legitimate users. 5. A sensor-based safety performance testing method according to claim 4, characterized in that: the step of performing simulation judgment comprises: When it is determined that there is an eavesdropper in the heterogeneous network, and when the information transmitted by the transmitter to multiple legitimate users is eavesdropped, the zero-forcing beamforming technology is used to perform simulation in the RF and visible light communication heterogeneous network with multiple users to test whether the beamforming technology can reduce the signal received by the eavesdropper to zero in the eavesdropping channel. If so, it means that the zero-forcing beamforming technology can ensure the security of internal and external eavesdropping in the system, and prevent the confidential information of legitimate users from being leaked to other legitimate users and eavesdroppers. 6. A sensor-based safety performance testing method according to claim 5, characterized in that: the step of optimizing visible light power distribution to protect the visible light communication security in the home from the physical layer comprises: Different parameters are set for different LED arrays and optimization algorithms, and the location of the target receiver is set, and a power adjustment factor vector is set using the optimization algorithm; Calculate the direct channel gain obtained by superimposing the LED array adjusted by the adjustment factor at each receiver and convert it into received optical power; Analyze and calculate the point with the largest absolute value of direct channel gain in the safe area, record its direct channel gain, subtract the absolute value of the direct channel gain of the point with the largest absolute value of direct channel gain in the safe area from the absolute value of the direct channel gain of the receiver, save it as the fitness value and return it to the optimization algorithm; The node sends out key update prompts and one-time passwords at regular intervals or after receiving certain signals. The legitimate user receives the prompts and one-time passwords and sends them back for confirmation. Then the one-time password is replaced together to continue communication under the new key encryption mode. The node LED will generate a new key and enter the key update phase, complete the key exchange with the legitimate user, and then start the next information transmission. 7. A safety performance testing system for executing the sensor-based safety performance testing method according to claim 1, characterized in that the system comprises: A visible light communication unit, used to establish simulation for a visible light communication system; Performance test unit, used to test the indoor positioning performance and safety performance of the visible light communication system; The communication security optimization unit is used to optimize the security performance in the visible light communication process based on the analysis and judgment results. 8. The safety performance testing system according to claim 7, characterized in that: the visible light communication unit comprises: A simulation model building module is used to build a simulation model of a visible light communication system to test the communication function of the entire communication area; An application scenario setting module, used to set the application scenario of the visible light communication system to the field of smart home; The channel and security characteristics analysis module is used to analyze the characteristics of the channel and communication security characteristics of the optical signal carrying data for transmission to form visible light communication. 9. The safety performance testing system according to claim 8, characterized in that: the performance testing unit comprises: An image sensor module, which is used to focus light through a lens onto a photosensitive sensor and convert the light signal into an analog signal; A simulation test running module, used for performing simulation test running by adding a tilt angle of the image sensor; Security architecture test module, used to establish physical layer security architecture test of indoor visible light communication system in smart home environment; The heterogeneous transmission network establishment module is used to establish a heterogeneous transmission network for downlink visible light communication based on multiple inputs and single outputs in the home. 10. The safety performance testing system according to claim 9, characterized in that: the communication security optimization unit comprises: Zero-forcing beamforming module, used to simulate and emulate the use of zero-forcing beamforming technology in multi-user RF and visible light communication heterogeneous networks; A simulation judgment module is used to test and judge whether the beamforming technology reduces the signal received by the eavesdropper to zero in the eavesdropping channel; A channel characteristic analysis module is used to calculate the direct channel gain characteristic obtained by superimposing the LED array adjusted by the adjustment factor at each receiver; The communication security assurance module is used to ensure that users can safely obtain and send key information in visible light communication.