Indoor Passive Visible Light Positioning System Based on Perovskite Battery and Its Implementation Method

Abstract

The present invention discloses an indoor passive visible light positioning system based on a perovskite battery and an implementation method thereof, which relates to the technical field of visible light positioning. In the present invention, a PWM modulation method for digitally encoding the analog signal level is adopted during modulation, which can ensure the stable output power of the transmitter and prevent the lamp from flickering due to data transmission. When solving the coordinates at the receiving terminal, calculating the wave frequency by means of a counter, immediately stopping the counter after obtaining the wave frequency, and immediately stopping the low-frequency analog-to-digital conversion module after obtaining the sampling mean value all reduce the power consumption of the system operation to a certain extent and ensure the long-term operation of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of visible light positioning, and particularly to an indoor passive visible light positioning system based on a perovskite battery and an implementation method thereof. By using ordinary lighting LED lamps, perovskite batteries, a filtering power supply comparator circuit, and a low-power microcontroller, a self-powered real-time positioning service is realized. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Since the Global Navigation Satellite System (GNSS), including the Beidou Navigation Satellite System (BDS), the Global Positioning System (GPS), etc., cannot provide satisfactory performance in indoor environments, indoor positioning technologies that use indoor wireless signals to replace GNSS signals have developed rapidly in recent years.

[0004] In recent years, a new type of indoor positioning system - a visible light positioning system based on light-emitting diodes (LEDs) - has emerged. This system uses visible light signals instead of radio frequency (RF) signals, so it has higher positioning accuracy and stability. In addition, it can reuse existing LED lighting facilities, thus reducing the deployment cost. Because of these advantages, visible light positioning systems have received extensive attention from academia and industry. The positioning terminal of existing traditional visible light positioning systems uses a photo-diode (PD), and its positioning accuracy can reach the centimeter level or even the millimeter level. However, it cannot be ignored that in actual application scenarios, this positioning terminal needs an external power supply to work for a long time, and users need to carry a large-capacity mobile battery, which brings inconvenience to users and seriously restricts the practical application of visible light positioning systems. Summary of the Invention

[0005] The purpose of the present invention is to provide an indoor passive visible light positioning system based on a perovskite battery and an implementation method thereof to solve the above problems in view of the problems existing in the prior art.

[0006] The technical solution of the present invention is as follows:

[0007] An indoor passive visible light positioning system based on a perovskite battery includes: a transmitter and a receiving terminal; the transmitter is used for modulating an optical signal and emitting the modulated light into free space; the receiving terminal is used for receiving the modulated light in free space and performing real-time positioning;

[0008] The receiving terminal includes: a perovskite battery, a low-frequency analog-to-digital conversion module, a filter power supply comparator circuit module, and a digital signal processing unit;

[0009] The perovskite battery serves as an optical receiver, which is used to receive modulated light carrying information in free space, convert the optical signal into an electrical signal, and then output the electrical signal to the low-frequency analog-to-digital conversion module and the filter power supply comparator circuit module; it should be noted that as an optical receiver, the perovskite battery can receive optical information and collect energy simultaneously;

[0010] The low-frequency analog-to-digital conversion module can collect the electrical signal from the perovskite battery according to the set sampling interval, convert the electrical signal into a digital signal, and output it to the digital signal processing unit;

[0011] The filter power supply comparator circuit module can output a corresponding level signal based on the high-frequency alternating current signal in the electrical signal through a comparator, and can also provide stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit based on the low-frequency direct current signal in the electrical signal; that is, the filter power supply comparator circuit module has a function of storing energy through the electrolytic capacitor - voltage regulator tube branch with a low-frequency direct current signal and providing stable energy through the voltage regulator tube branch, and a function of extracting the high-frequency alternating current signal in the electrical signal to the decoupling capacitor - comparator branch and outputting a level signal after it passes through the comparator;

[0012] The digital signal processing unit can count the level signal, calculate the current wave frequency, set the sampling interval of the low-frequency analog-to-digital conversion module according to the wave frequency, and start the low-frequency analog-to-digital conversion module. After the low-frequency analog-to-digital conversion module samples continuously for N times, it takes the average value of the sampling values and substitutes the average value into the coordinate equation corresponding to the wave frequency to complete the coordinate output and realize real-time positioning.

[0013] Furthermore, the filter power supply comparator circuit module is used to perform two operations in parallel: (1) Use a decoupling capacitor to extract the high-frequency alternating current signal in the electrical signal to the decoupling capacitor - comparator branch, and output a corresponding 0 / 1 level signal to the digital signal processing unit after it passes through the comparator; at the same time, the remaining low-frequency direct current signal is output to the electrolytic capacitor - voltage regulator tube branch. The electrolytic capacitor is used to store energy, and the voltage regulator tube branch provides stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit in parallel with the electrolytic capacitor.

[0014] Furthermore, the digital signal processing unit is a microcontroller, and in the present invention, a low-power microcontroller of the STM32L0 series is adopted.

[0015] Furthermore, the low-frequency analog-to-digital conversion module is an analog-to-digital converter built in the microcontroller.

[0016] Further, the transmitter includes: an information forward modulation module and an LED array emission front end;

[0017] The information forward modulation module uses a PWM modulation method that digitally encodes the analog signal level to generate a digital control signal. The digital control signal directly controls the LED array emission front end to emit modulated light with a specific frequency and brightness, realizing the direct conversion and information transmission between digital signals and optical signals. That is, the information forward modulation module is used to perform a PWM modulation method that digitally encodes the analog signal level on the optical signal emitted by the LED to generate a digital control signal and realize information transmission. The LED array emission front end is used to receive the previous digital signal and directly generate modulated light with a specific brightness and frequency, realizing the direct conversion and information transmission between digital signals and optical signals.

[0018] Further, the LED array emission front end is an illumination LED lamp.

[0019] Further, the number of transmitters is one or more. When multiple transmitters cooperate, a frequency division multiple access scheme is adopted, that is, the transmission frequencies of each transmitter are different;

[0020] Further, the number of receiving terminals is one, which is a fixed or mobile receiving terminal.

[0021] Further, when the low-frequency analog-to-digital conversion module samples continuously 3 times, the average value of the sampled values is taken.

[0022] An implementation method of an indoor passive visible light positioning system based on a perovskite battery includes:

[0023] Step A: The information forward modulation module sets a fixed duty cycle and frequency of the PWM wave in the program and burns the program into the module. The information forward modulation module generates a digital control signal to control the LED array emission front end to generate modulated light with a specific brightness and frequency;

[0024] Step B: The perovskite battery in the receiving terminal acts as a photoelectric receiver to receive the optical signal in free space and output an electrical signal;

[0025] Step C: The filtering power supply comparator circuit module receives the electrical signal output by the perovskite battery module. The decoupling capacitor-comparator branch inside it extracts the high-frequency alternating current signal in the electrical signal to the decoupling capacitor-comparator branch and outputs a 0 / 1 level signal after passing through the comparator. At the same time, the remaining low-frequency direct current signal is output to the electrolytic capacitor branch. The electrolytic capacitor continuously stores energy, and the voltage regulator tube branch provides stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit by being connected in parallel with the electrolytic capacitor;

[0026] Step D: The digital signal processing unit first uses an internal counter to count the level signal. When the counting ends, the wave frequency information is calculated, and the sampling interval of the low-frequency analog-to-digital conversion module is set according to the wave frequency, and the low-frequency analog-to-digital conversion module is started.

[0027] Step E: The low-frequency analog-to-digital conversion module collects the electrical signal from the perovskite battery according to the set sampling interval and converts it into a digital signal and outputs it to the digital signal processing unit.

[0028] Step F: The digital signal processing unit takes the average value of the sampling values output by the low-frequency analog-to-digital conversion module and substitutes it into the coordinate equation corresponding to the wave frequency to complete the coordinate output and realize real-time positioning.

[0029] Compared with the existing technology, the beneficial effects of the present invention are:

[0030] 1. The present invention has strong practicability, low power consumption and low cost; specifically:

[0031] (1) Through the PWM modulation method, the light intensity and light frequency of the LED lamp can be conveniently controlled directly by the digital signal without affecting the lighting function of the LED.

[0032] (2) The perovskite battery is used as a photoelectric receiver, combined with the filter power supply comparator circuit module, outputs an electrical signal to the low-frequency analog-to-digital conversion module and a level signal to the digital signal processing unit, and at the same time provides stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit, realizing a low-power self-powered optical positioning terminal and a visible light positioning system, and improving the practicability of the system.

[0033] (3) The digital signal processing unit uses a microcontroller, reducing the power consumption of the system operation.

[0034] (4) The digital signal processing unit can write a low-power algorithm program internally, further reducing the power consumption of the system.

[0035] 2. The present invention adopts the PWM modulation method of digitally encoding the analog signal level during modulation, which can ensure the stable output power of the transmitter and prevent the lamp from flickering due to data transmission; while when solving the coordinates at the receiving terminal, by calculating the wave frequency through the counter method, immediately stopping the counter after obtaining the wave frequency and immediately stopping the low-frequency analog-to-digital conversion module after obtaining the sampling average value, both reduce the power consumption of the system operation to a certain extent and ensure the long-term operation of the system. Description of the Drawings

[0036] Figure 1 It is a structural block diagram of an embodiment of the present invention;

[0037] Figure 2Schematic diagram of the control of the LED array emission front end by the information forward modulation module involved in the present invention;

[0038] Figure 3 Internal equivalent schematic diagram of the perovskite battery involved in the present invention;

[0039] Figure 4 Circuit design schematic diagram of the filter power supply comparator circuit involved in the present invention;

[0040] Figure 5 Experimental determination structure schematic diagram of the coordinate equation involved in the present invention;

[0041] Figure 6 Flow schematic diagram of the digital signal processing unit for solving the coordinates of a certain position involved in the present invention.

[0042] Reference numerals: 1 - transmitter, 2 - receiving terminal, 10 - information forward modulation module, 11 - LED array emission front end, 20 - perovskite battery, 21 - low - frequency analog - to - digital conversion module, 22 - filter power supply comparator circuit module, 23 - digital signal processing unit, 200 - photosensitive part circuit, 201 - first branch, 202 - second branch, 220 - electrical signal access signal output part, 221 - decoupling capacitor - comparator part, 222 - electrolytic capacitor - voltage regulator tube part. Detailed implementation manners

[0043] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non - exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0044] The features and performance of the present invention will be further described in detail below in conjunction with embodiments.

[0045] Embodiment 1

[0046] Aiming at the disadvantages of poor portability, weak practicability and difficult deployment of the existing traditional visible - light positioning system due to using PD as the photoelectric receiver, in this embodiment, a solar cell that can simultaneously receive optical information and collect energy is used to replace PD as the photoelectric receiver to improve the performance of the visible - light positioning system.

[0047] Common solar cells on the market currently include crystalline silicon solar cells (monocrystalline silicon, polycrystalline silicon), thin-film solar cells (amorphous silicon (a-Si), cadmium telluride (CdTe), gallium arsenide (GaAs), copper indium gallium selenide (CIGS) and other thin-film cells), and perovskite solar cells. Among them, perovskite solar cells have the following advantages compared with other cells: (1) Higher energy conversion efficiency (PCE), lower production cost, and relatively simple preparation process. Currently, the certified efficiency of its single-junction cells has reached 26.1%; (2) Since the present invention adopts indoor photovoltaic technology, the bandgap and high parallel resistance are the keys to obtaining high-efficiency indoor photovoltaic cells. In emerging photovoltaic technologies, perovskite photovoltaic materials have adjustable bandgaps, high light absorption coefficients, and are insensitive to impurities. Therefore, the corresponding solar cells have a high tolerance for defects, and the above characteristics ensure that they can obtain a high indoor low-light conversion efficiency; (3) Compared with the outdoor environment, perovskite solar cells can effectively avoid harsh outdoor environmental conditions such as high temperature and humidity, uneven solar irradiance intensity, etc.

[0048] Based on the comparison between the above perovskite solar cells and other types of cells, perovskite solar cells have high energy conversion efficiency, low production cost, simple preparation process, and excellent performance in the indoor environment. Therefore, in this embodiment, perovskite solar cells (hereinafter referred to as perovskite cells) are used as the photoelectric receiver.

[0049] Specifically, as Figures 1 to 5 shown, the indoor passive visible light positioning system based on perovskite cells includes:

[0050] Two parts: a transmitter 1 and a receiving terminal 2;

[0051] Among them, the transmitter is mainly composed of an information forward modulation module 10 and an LED array emission front end 11;

[0052] The receiving terminal is mainly composed of a perovskite cell 20, a low-frequency analog-to-digital conversion module 21, a filtering power supply comparator circuit module 22, and a digital signal processing unit 23;

[0053] The information forward modulation module 10 is used to use the PWM modulation method of digitally encoding the analog signal level for the optical signal emitted by the LED to generate a digital control signal to realize the transmission of information;

[0054] The LED array emission front end 11 is used to receive the previous digital control signal and directly generate a modulated light with a specific brightness and frequency to realize the direct conversion of the digital signal and the optical signal and the transmission of information;

[0055] Figure 2It shows the control of the information forward modulation module related to the present invention over the LED array emission front end; the perovskite battery 20 is used to receive visible light in free space, convert the optical signal into an electrical signal, and then output the electrical signal to the low-frequency analog-to-digital conversion module 21 and the filter power supply comparator circuit module 22;

[0056] The low-frequency analog-to-digital conversion module 21 is used to collect the electrical signal from the perovskite battery 20 according to the set sampling interval, and convert it into a digital signal and output it to the digital signal processing unit 23;

[0057] The filter power supply comparator circuit module 22 is used to perform two operations in parallel: (1) Use a decoupling capacitor to extract the high-frequency alternating current signal in the electrical signal to the decoupling capacitor-comparator branch, and output the corresponding 0 / 1 level signal to the digital signal processing unit 23 after it passes through the comparator;

[0058] (2) The remaining low-frequency direct current signal is output to the electrolytic capacitor-zener diode branch. The electrolytic capacitor is used to store energy, and the zener diode branch provides stable energy for the low-frequency analog-to-digital conversion module 21 and the digital signal processing unit 23 by being connected in parallel with the electrolytic capacitor;

[0059] The digital signal processing unit 23 is used to first use an internal counter to count the level signal output by the filter power supply comparator circuit module 22 and calculate the current wave frequency, then set the sampling interval of the low-frequency analog-to-digital conversion module 21 according to the wave frequency and start the module. When the low-frequency analog-to-digital conversion module 21 samples three times continuously, take the average value of the sampling values and substitute the average value into the coordinate equation corresponding to the wave frequency to complete the coordinate output and realize real-time positioning.

[0060] The photoelectric receiver in the visible light positioning system generally uses a photodiode (PD), which requires an external power supply to work and has a high power consumption. If the receiving terminal works for a long time, it needs to carry a large-capacity power supply and needs to be charged frequently, which seriously restricts the practical application; in order to improve the practicality and convenience of the visible light positioning system, the present invention uses the perovskite battery 20 as the photoelectric receiver, Figure 3 Specifically, it shows the internal equivalent schematic diagram of the perovskite battery;

[0061] The perovskite battery receives visible light in free space, and its photosensitive part circuit 200 will generate a photocurrent containing a DC component and an AC component; the DC component of the photocurrent is blocked by the capacitor on the second branch 202, so it will only flow through the first branch 201 and generate a direct current signal on the resistor, making it have an energy collection function; the AC component of the photocurrent is blocked by the inductor on the first branch 201, so it will only flow through the second branch 202 and generate an alternating current signal, making it have a light information receiving function;

[0062] However, due to the low voltage stability of perovskite cells and the excessive power consumption of the digital signal processing unit when running the high-frequency analog-to-digital converter for a long time, the present invention designs a filter power supply comparator circuit module 22 to achieve the purpose of stabilizing the voltage of the system and reducing the operating time of the analog-to-digital conversion module and setting its lower sampling frequency according to the wave frequency, so that the digital processing unit can perform coordinate calculation with lower power consumption.

[0063] Figure 4 Specifically, it shows the circuit design schematic diagram of the filter power supply comparator circuit; the filter power supply comparator circuit connects the electrical signal output by the perovskite cell to the signal output part 220. When the electrical signal passes through the branch circuit, the decoupling capacitor-comparator part 221 extracts the high-frequency alternating current signal in the electrical signal to this branch, and then the alternating current signal finally outputs the corresponding level signal at the signal output end through the subsequent comparator. If its value is greater than the reference voltage, a high-level signal is output, otherwise a low-level signal is output; at the same time, the remaining low-frequency direct current signal enters the electrolytic capacitor-zener diode part 222. The electrolytic capacitor collects the energy of the direct current signal and generates a voltage across its two ends. In order to further improve the stability of power supply, the present invention connects a zener diode branch in parallel with the electrolytic capacitor to play a role in providing more stable energy for the low-frequency analog-to-digital conversion module 21 and the digital signal processing unit 23.

[0064] In order to achieve practical and low-power visible light real-time positioning, the present invention adopts a positioning method based on received signal strength, which is characterized in that the relationship between the distance between the LED array emission front end 11 and the perovskite cell 20 and the received signal strength of the perovskite cell 20 at this distance can be measured in advance, so as to obtain the coordinate equation and store it in the digital signal processing unit 23, thus accelerating the process of the digital signal processing unit solving the coordinates and reducing the system power consumption.

[0065] Such as Figure 5 In the structural schematic diagram, set the fixed vertical height of the LED array emission front end 11, and move the perovskite cell 20 equidistantly along the arrow direction in the figure, and record the received signal strength of the perovskite cell 20 at each position and the distance from the LED array emission front end 11 during this process. Furthermore, in order to obtain a more accurate coordinate equation, this data is fitted into a linear coordinate equation through computer software.

[0066] As described above, the digital signal processing unit 23 in the receiving terminal 2 of the present invention is responsible for processing the digital signal output by the low-frequency analog-to-digital conversion module 21 and the level signal output by the filter power supply comparator circuit module. Figure 6 Specifically, it shows the working flow chart of the digital signal processing unit, and the specific steps are as follows:

[0067] The digital signal processing unit first initializes the counter, sets the counting preset value and the counting mode.

[0068] Receive the level signal output by the receiving filter power supply comparator circuit module and count. If the count value is equal to the preset value, stop the counter and calculate the wave frequency. Otherwise, the counter keeps running and continues to count;

[0069] Set the sampling interval according to the wave frequency and start the low-frequency analog-to-digital conversion module. If continuous sampling has been completed three times, stop the low-frequency analog-to-digital conversion module and calculate the average value of the three sampling values. Otherwise, continue sampling;

[0070] Substitute the average value into the coordinate equation corresponding to the wave frequency, output the coordinates, complete the real-time positioning, and end this positioning.

[0071] As can be seen from the above steps, in the present invention, the PWM modulation method of digitally encoding the level of the analog signal is adopted during modulation, which can ensure the stable output power of the transmitter and prevent the lamp from flickering due to data transmission. When solving the coordinates at the receiving terminal, calculating the wave frequency by the counter method, immediately stopping the counter after obtaining the wave frequency, and immediately stopping the low-frequency analog-to-digital conversion module after obtaining the sampling average value all reduce the power consumption of the system operation to a certain extent and ensure the long-term operation of the system.

[0072] Embodiment 2

[0073] In this embodiment, a low-power algorithm program can be written inside the digital signal processing unit to further reduce the power consumption of the system. Specifically:

[0074] First, initialize the preset value of the counter to , the counting method is rising edge counting and counting up;

[0075] Subsequently, start the counter to count. When the level signal output by the comparator changes from low to high, the count value of the counter is incremented by 1. If the count value is equal to the preset value after seconds, the counting ends. Then the calculation formula for the wave frequency is , and stop the counter;

[0076] In order to further reduce the power consumption of the system in this article, set the sampling interval of the low-frequency analog-to-digital conversion module to times the wave frequency, that is, sample once every time, start the low-frequency analog-to-digital conversion module to sample continuously 3 times and take the average value of the times as the final sampling value , and stop sampling;

[0077] Finally, substitute this sampling value into the coordinate equation corresponding to the wave frequency , and finally obtain the central distance between the receiving terminal and the transmitter and the horizontal distance .

[0078] For the coordinate equation, where is the sampling value at the wave frequency of and and are the slope and intercept parameters of the coordinate equation obtained after fitting, respectively.

[0079] The above-described embodiments merely represent the specific implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the protection scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the present application.

[0080] This background art section is provided to generally present the context of the present invention. The work of the currently named inventors, to the extent described in this background art section, and aspects of the work that are not prior art at the time of filing this application are neither expressly nor impliedly admitted to be prior art to the present invention.

Claims

1. Indoor passive visible light positioning system based on perovskite cells, characterized in that: include: Transmitter and receiving terminals; The transmitter is used to modulate the optical signal and transmit the modulated light into free space; The receiving terminal is used to receive modulated light in free space and perform real-time positioning; The receiving terminal includes: a perovskite battery, a low-frequency analog-to-digital conversion module, a filter power supply comparator circuit module and a digital signal processing unit; The perovskite cell is used as a photoelectric receiver to receive modulated light in free space and convert the optical signal into an electrical signal; The low-frequency analog-to-digital conversion module can collect electrical signals from the perovskite battery according to a set sampling interval and convert the electrical signals into digital signals; The filtering and energy supply comparator circuit module can output a corresponding level signal through a comparator based on the high-frequency AC signal in the electrical signal, and can also provide stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit based on the low-frequency DC signal in the electrical signal; The digital signal processing unit can count the level signal and calculate the current wave frequency, and set the sampling interval of the low-frequency analog-to-digital conversion module according to the wave frequency and start the low-frequency analog-to-digital conversion module. After the low-frequency analog-to-digital conversion module samples N times continuously, it takes the average of the sampling values ​​and substitutes the average into the coordinate equation corresponding to the wave frequency to complete the coordinate output and realize real-time positioning.

2. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: The filtering energy supply comparator circuit module is used to perform two operations in parallel: using a decoupling capacitor to extract the high-frequency AC signal in the electrical signal to the decoupling capacitor-comparator branch, and outputting the corresponding 0 / 1 level signal to the digital signal processing unit after it passes through the comparator; at the same time, the remaining low-frequency DC signal is output to the electrolytic capacitor-voltage regulator branch, the electrolytic capacitor is used to store energy, and the voltage regulator branch provides stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit by being connected in parallel with the electrolytic capacitor.

3. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: The digital signal processing unit is a microcontroller.

4. The indoor passive visible light positioning system based on perovskite cells according to claim 3 is characterized in that: The low-frequency analog-to-digital conversion module is an analog-to-digital converter built into the microcontroller.

5. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: The transmitter comprises: an information forward modulation module and an LED array transmission front end; The information forward modulation module adopts a PWM modulation method for digitally encoding the analog signal level to generate a digital control signal. The digital control signal directly controls the LED array to emit modulated light from the front end, thereby realizing direct conversion of digital signals and optical signals and information transmission.

6. The indoor passive visible light positioning system based on perovskite cells according to claim 5, characterized in that: The LED array emission front end is a lighting LED lamp.

7. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: The number of the transmitters is one or more, and when multiple transmitters cooperate, a frequency division multiple access scheme is adopted.

8. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: The number of the receiving terminal is one, which is a fixed or mobile receiving terminal.

9. The indoor passive visible light positioning system based on perovskite cells according to claim 1, characterized in that: After the low-frequency analog-to-digital conversion module samples three times in succession, the sampled values ​​are averaged.

10. A method for realizing an indoor passive visible light positioning system based on perovskite cells, characterized in that: include: Step A: The information forward modulation module sets the fixed PWM wave duty cycle and wave frequency in the program, and burns the program into the module; The information forward modulation module generates a digital control signal to control the LED array emission front end to generate modulated light; Step B: The perovskite cell in the receiving terminal acts as a photoelectric receiver to receive the optical signal in free space and output an electrical signal; Step C: The filter power supply comparator circuit module receives the electrical signal output by the perovskite battery module, and the decoupling capacitor-comparator branch inside it extracts the high-frequency AC signal in the electrical signal to the decoupling capacitor-comparator branch and outputs a 0 / 1 level signal after passing through the comparator; at the same time, the remaining low-frequency DC signal is output to the electrolytic capacitor branch, the electrolytic capacitor continuously stores energy, and the voltage regulator branch provides stable energy for the low-frequency analog-to-digital conversion module and the digital signal processing unit by being connected in parallel with the electrolytic capacitor; Step D: The digital signal processing unit first uses an internal counter to count the level signal. When the counting is completed, the wave frequency information is calculated, and the sampling interval of the low-frequency analog-to-digital conversion module is set according to the wave frequency and the low-frequency analog-to-digital conversion module is started; Step E: The low-frequency analog-to-digital conversion module collects the electrical signal from the perovskite battery according to the set sampling interval, and converts it into a digital signal and outputs it to the digital signal processing unit; Step F: The digital signal processing unit takes the average of the sampled values ​​output by the low-frequency analog-to-digital conversion module and substitutes it into the coordinate equation corresponding to the wave frequency to complete the coordinate output and realize real-time positioning.

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