Positioning method and positioning device and positioning system based on visible light communication

Abstract

This invention relates to a positioning method, device, and system based on visible light communication, belonging to the field of positioning technology, and particularly to wireless communication positioning technology. The positioning method controls the distance between two visible light communication devices, records the received power, and obtains the relationship between the distance and the corresponding power. The visible light communication devices are mounted on an underwater moving target; one device transmits an optical signal, and the other receives and processes the signal to obtain a photoelectric analog signal. Based on the photoelectric analog signal and the relationship between the distance and the corresponding power, the relative position of the two devices is calculated. The positioning method, device, and system based on visible light communication provided by this invention can achieve high-speed, efficient, and highly secure communication and positioning functions, and can be applied to scenarios such as marine exploration, underwater operations, and tunnel exploration, solving the problem of establishing a stable transmission link between underwater moving targets.

Description

Technical Field

[0001] This invention belongs to the field of positioning technology, and particularly relates to wireless communication positioning technology, specifically to a positioning method, positioning device, and positioning system based on visible light communication. Background Technology

[0002] Underwater positioning technology has significant applications in marine exploration, underwater operations, and marine conservation. Commonly used underwater positioning technologies include those based on wireless signals such as sound waves, electromagnetic waves, and lasers, as well as those based on sensors such as inertial, pressure, and magnetic fields. Each of these technologies has its advantages and disadvantages, but they generally suffer from problems such as low positioning accuracy, low communication bandwidth, high system cost, and susceptibility to interference. Visible light communication (VLC) technology, as a novel communication technology, offers advantages such as abundant spectrum resources, no electromagnetic interference, strong confidentiality, and high transmission rates. Utilizing visible light technology for positioning can effectively improve positioning efficiency.

[0003] In the prior art, there have been some studies on positioning methods based on visible light communication technology. For example, Chinese invention patent CN108363052A discloses an indoor positioning system and method based on visible light communication. It provides a method for indoor positioning using visible light. In practical applications, one of the signal transmitter and the signal receiver is a fixed end, and the other end is a mobile end. Multiple fixed ends need to be set up to identify different locations, forming a positioning mode of one transmitter and multiple receivers or multiple transmitters and one receiver. This greatly increases the complexity and overhead of communication and positioning. Furthermore, this patent uses monochromatic LEDs to emit light signals, and the emission wavelength of monochromatic LEDs is affected by the absorption and scattering characteristics of seawater. Therefore, the positioning system provided by this patent is only suitable for indoor environments and not for underwater environments.

[0004] Therefore, how to provide a positioning method and device based on visible light communication technology suitable for underwater positioning is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a positioning method, device, and system based on visible light communication. It achieves a one-to-one positioning mode through a visible light communication device, solving the problem of establishing a stable transmission link between underwater moving targets.

[0006] This invention provides a positioning method based on visible light communication, comprising the following steps:

[0007] S1, Obtain the relationship between the distance and the corresponding power: One visible light communication device transmits an optical signal, and another visible light communication device receives the optical signal. The location of the receiving visible light communication device is taken as the origin O, and the three detection directions of the photodetector module of the receiving visible light communication device are the x-axis, y-axis, and z-axis, respectively. The distance between the two visible light communication devices is controlled to be 0m and a maximum communication distance. The initial power and maximum power received by the receiving visible light communication device along one of the x-axis, y-axis, or z-axis are recorded when the distance is 0m and the maximum communication distance, respectively. This yields the relationship between the distance between the two visible light communication devices and the corresponding power.

[0008] S2, Establish a transmission link between underwater moving targets: Two visible light communication devices are mounted on the underwater moving targets respectively. The two visible light communication devices move underwater with the underwater moving targets. One visible light communication device transmits light signals, and the other visible light communication device receives and processes the light signals through a photodetector module to obtain photoelectric analog signals along the x-axis, y-axis, and z-axis respectively.

[0009] S3, Obtain the relative position of the underwater moving target: Based on the photoelectric analog signal obtained in step S2, combined with the relationship between the spacing and the corresponding power change obtained in step S1, as well as the initial power and initial position, calculate the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis directions, respectively, thereby obtaining the relative position between the underwater moving targets.

[0010] In some embodiments, the specific method for calculating the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis is as follows: based on the photoelectric analog signal obtained in step S2, the received optical power received by the visible light communication devices along the x-axis, y-axis, and z-axis is calculated and inverted. The difference between the received optical power and the initial power is used to obtain the optical power loss of the optical signal between the two visible light communication devices along the x-axis, y-axis, and z-axis, respectively. Based on the received optical power of the visible light communication devices and the optical power loss of the optical signal in the x-axis, y-axis, and z-axis directions, the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis, respectively, are calculated.

[0011] In some embodiments, the specific method for calculating and retrieving the received optical power of the visible light communication device along the x-axis, y-axis, and z-axis directions is as follows: The visible light communication device amplifies the photoelectric analog signals along the x-axis, y-axis, and z-axis directions respectively through the positioning module. Based on the amplified photoelectric analog signals along the x-axis, y-axis, and z-axis directions, combined with the photoelectric conversion efficiency of the photodetector module and the amplification factor of the positioning module, the optical power of the photoelectric analog signals along the x-axis, y-axis, and z-axis directions is retrieved respectively, thereby obtaining the received optical power of the visible light communication device along the x-axis, y-axis, and z-axis directions respectively.

[0012] In some embodiments, step S1 further includes storing the obtained relationship between the spacing and the corresponding power in the storage module of the visible light communication device.

[0013] In addition, the present invention also provides a positioning device based on visible light communication, applied to the above-mentioned positioning method based on visible light communication, including a visible light communication unit, which includes:

[0014] The transmitting circuit is used to amplify the data source signal to be transmitted.

[0015] The transmitting diode, which is connected to the transmitting circuit, is used to convert the amplified data source signal into an optical signal and then transmit the optical signal.

[0016] The photodetector module is used to receive light signals emitted by an external light source and convert them into photoelectric analog signals along the x-axis, y-axis, and z-axis, respectively.

[0017] The storage module is used to store the signals that need to be saved and the relationship between the spacing and the corresponding power changes;

[0018] The positioning module, which is connected to the photodetector module and the storage module, is used to calculate the relative position of the transmitter and receiver based on the photoelectric analog signal and the relationship between the spacing and the corresponding power.

[0019] The receiving circuit, which is connected to the photodetector module, is used to receive photoelectric analog signals and convert them into photoelectric digital signals.

[0020] The signal processing module is communicatively connected to the transmitting circuit to convert the raw data signal into a data source signal and provide it to the transmitting circuit. The signal processing module is also communicatively connected between the receiving circuit and the storage module to process the photoelectric digital signal output by the receiving circuit to obtain a communication signal. The signal processing module is also communicatively connected to the positioning module to receive and process the relative position output by the positioning module to obtain a positioning signal, and to output the positioning signal to the storage module for storage.

[0021] In some embodiments, the positioning device based on visible light communication also includes a signal transmitter that is communicatively connected to the signal processing module for outputting raw data signals to the signal processing module.

[0022] In some embodiments, the positioning device based on visible light communication also includes a signal display, which is communicatively connected to the signal processing module for displaying communication signals or positioning signals.

[0023] In some embodiments, the positioning module includes:

[0024] The amplification unit, which is connected to the photodetector module, is used to receive and amplify photoelectric analog signals;

[0025] The analog-to-digital converter unit, whose communication connection is to the amplifier unit, is used to convert the amplified photoelectric analog signal into a photoelectric digital signal;

[0026] The main control unit, which is connected to the analog-to-digital conversion unit, the storage module, and the signal processing module, is used to obtain the optical power loss and distance from the external light source to the location of the visible light communication device based on the linear relationship between the optical power attenuation of the photoelectric digital signal and the distance. It also calculates the positioning data of the transmitter by combining the relationship between the spacing and the corresponding power change stored in the storage module.

[0027] In some embodiments, the photodetector module includes three photodetectors, namely a first photodetector, a second photodetector, and a third photodetector, which are arranged at 90° to each other; wherein the detection direction of the first photodetector is parallel to the x-axis, the detection direction of the second photodetector is parallel to the y-axis, and the detection direction of the third photodetector is parallel to the z-axis.

[0028] In addition, the present invention also provides a positioning system based on visible light communication, including the above-mentioned positioning device based on visible light communication, wherein a transmission link for communication and positioning is formed between two positioning devices based on visible light communication.

[0029] Based on the above scheme, the positioning method, positioning device and positioning system based on visible light communication in the embodiments of the present invention can realize bidirectional communication and positioning process, and can improve the flexibility and stability of communication and positioning, and are suitable for communication and positioning of moving targets in underwater environment. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0031] Figure 1 A flowchart illustrating a positioning method based on visible light communication provided in an embodiment of the present invention;

[0032] Figure 2 A structural block diagram of a positioning device based on visible light communication provided in an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of signal transmission for a positioning device based on visible light communication provided in an embodiment of the present invention;

[0034] Figure 4 This is a structural block diagram of a visible light communication device provided in an embodiment of the present invention;

[0035] Figure 5 A structural block diagram of a positioning system based on visible light communication provided in an embodiment of the present invention;

[0036] Figure 6 This is a structural block diagram of the positioning module in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of signal transmission of the positioning module in an embodiment of the present invention.

[0038] In the picture:

[0039] 1. Visible light communication device; 2. Signal transmitter; 3. Signal display;

[0040] 11. Signal processing module; 12. Transmitting circuit; 13. Emitter diode; 14. Photodetector module;

[0041] 15. Receiving circuit; 16. Positioning module; 17. Storage module;

[0042] 161. Amplification unit; 162. Analog-to-digital conversion unit; 163. Main control unit. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances.

[0046] The terms “system,” “unit,” and “module” used in this article are methods for distinguishing different components, elements, parts, sections, or assemblies at different levels. These terms may be replaced by other expressions that achieve the same purpose.

[0047] like Figure 1 As shown, in one embodiment of the positioning method based on visible light communication provided by the present invention, the following steps are included:

[0048] S1, Obtain the relationship between the spacing and the corresponding power: One visible light communication device 1 transmits an optical signal, and another visible light communication device 1 receives the optical signal. Taking the location of the receiving visible light communication device 1 as the origin O, and the three detection directions of the photodetector module 14 of the receiving visible light communication device 1 as the x-axis, y-axis, and z-axis, a positioning coordinate system O-xyz is established. The spacing between the two visible light communication devices 1 is controlled to be 0m and the limit communication distance. The initial power and the limit power received by the receiving visible light communication device 1 along one of the coordinate axes (x-axis, y-axis, z-axis) when the spacing is 0m and the limit communication distance are recorded respectively, thus obtaining the relationship between the spacing between the two visible light communication devices 1 and the corresponding power. It can be understood that in this step, according to the attenuation law of the optical signal, the attenuation of the optical signal along the x-axis, y-axis, and z-axis is the same. Therefore, it is only necessary to record the initial power and the limit power along one of the coordinate axes (x-axis, y-axis, z-axis). This record can be applied to all three directions (x-axis, y-axis, z-axis).

[0049] S2, establish a transmission link between underwater moving targets: two visible light communication devices 1 are mounted on the underwater moving targets respectively, and the two visible light communication devices 1 move underwater with the underwater moving targets respectively. One visible light communication device 1 transmits light signals, and the other visible light communication device 1 receives and processes the light signals through the photodetector module 14 to obtain photoelectric analog signals along the x-axis, y-axis and z-axis respectively.

[0050] S3, Obtain the relative position of the underwater moving target: Based on the photoelectric analog signal obtained in step S2, combined with the relationship between the spacing and the corresponding power change obtained in step S1, as well as the initial power and initial position, calculate the relative positions of the two visible light communication devices 1 along the x-axis, y-axis, and z-axis directions, respectively, thereby obtaining the relative position between the underwater moving targets.

[0051] It should be noted that in step S3, the specific method for calculating the relative positions of the two visible light communication devices 1 along the x-axis, y-axis, and z-axis is as follows: based on the photoelectric analog signal obtained in step S2, the received optical power of the visible light communication device 1 along the x-axis, y-axis, and z-axis is calculated and inverted. The difference between the received optical power and the initial power is used to obtain the optical power loss of the optical signal between the two visible light communication devices 1 along the x-axis, y-axis, and z-axis. Based on the received optical power of the visible light communication device 1 and the optical power loss of the optical signal along the x-axis, y-axis, and z-axis, the relative positions of the two visible light communication devices 1 along the x-axis, y-axis, and z-axis are calculated.

[0052] It should be noted that the specific method for calculating and retrieving the received optical power of the visible light communication device 1 along the x-axis, y-axis, and z-axis is as follows: The visible light communication device 1 amplifies the photoelectric analog signals along the x-axis, y-axis, and z-axis respectively through the positioning module 16. Based on the amplified photoelectric analog signals along the x-axis, y-axis, and z-axis, combined with the photoelectric conversion efficiency of the photodetector module 14 and the amplification factor of the positioning module 16, the optical power of the photoelectric analog signals along the x-axis, y-axis, and z-axis is retrieved respectively, thereby obtaining the received optical power of the visible light communication device 1 along the x-axis, y-axis, and z-axis respectively.

[0053] It should be noted that step S1 also includes storing the obtained relationship between the spacing and the corresponding power change in the storage module 17 of the visible light communication device 1. It is understood that new positioning signals generated during the positioning process can also be stored in the storage module 17 of the visible light communication device 1 for reference in subsequent positioning processes. This step, by storing the signals that need to be saved in the visible light communication device 1, enables adjustments to be made based on the stored data to address problems that arise during the positioning process, eliminating errors and interference.

[0054] In addition, such as Figure 2 As shown, the present invention also provides a positioning device based on visible light communication, applied to the above-mentioned positioning method based on visible light communication, including a visible light communication unit 1, as shown in the figure. Figure 4 As shown, the visible light communication device 1 includes:

[0055] The transmitting circuit 12 is used to amplify the data source signal to be transmitted;

[0056] The emitting diode 13 is communicatively connected to the transmitting circuit 12 and is used to convert the amplified data source signal into an optical signal and transmit the optical signal.

[0057] The photodetector module 14 is used to receive light signals emitted by an external light source and convert them into photoelectric analog signals along the x-axis, y-axis and z-axis directions respectively;

[0058] Storage module 17 is used to store the signals that need to be saved and the relationship between the spacing and the corresponding power changes;

[0059] The positioning module 16 is communicatively connected to the photodetector module 14 and the storage module 17, and is used to calculate the relative position of the transmitter and receiver based on the photoelectric analog signal and the relationship between the spacing and the corresponding power.

[0060] The receiving circuit 15 is communicatively connected to the photodetector module 14 and is used to receive photoelectric analog signals and convert them into photoelectric digital signals.

[0061] The signal processing module 11, communicatively connected to the transmitting circuit 12, converts the raw data signal into a data source signal and provides it to the transmitting circuit 12. The signal processing module 11 is also communicatively connected between the receiving circuit 15 and the storage module 17, processing the photoelectric digital signal output by the receiving circuit 15 to obtain a communication signal. The signal processing module 11 is also communicatively connected to the positioning module 16, receiving and processing the relative position output by the positioning module 16 to obtain a positioning signal, and outputting the positioning signal to the storage module 17 for storage. It can be understood that the signal stored in the storage module 17 is the positioning signal.

[0062] In the above embodiments, the positioning device based on visible light communication abandons the traditional indoor optical positioning mode of one transmitter and multiple receivers or one receiver and multiple transmitters. The visible light communication device 1 can transmit optical signals as a transmitter and receive optical signals as a receiver, realizing a one-to-one positioning mode. At the same time, it can realize high-speed, high-efficiency, and high-security communication and positioning functions, and can be applied to underwater detection, navigation, monitoring and other fields, solving the problem of establishing a stable transmission link between underwater moving targets.

[0063] It should be noted that in the structure of the visible light communication device 1 described above, the transmission drive of the transmitting circuit 12 can be a MOSFET driver, a DC bias driver, etc., to convert the data source signal into a level that matches the transmitting diode 13. Specifically, the transmission drive power varies depending on the distance and speed requirements, thus selecting different IC chips, with typical values ​​of 30W and 10Mbps. The transmitting diode 13 can be a light-emitting diode chip of different bands (different colors), different powers, and different numbers, which can be selected as needed, requiring only the transmitting circuit 12 to drive and match it. The array of light-emitting diodes 13 adopts a wide-angle transceiver structure array to improve the communication coverage and sensitivity, especially when applied in underwater environments, it can cope with optical path fluctuations caused by seawater turbulence and movement, improving the stability of communication and positioning. The core of the signal processing module 11 is a microprocessor (MCU). When converting the raw data signal into a data source signal, it performs cross-clock processing, data conversion, and modulation encoding on the raw data signal, and then outputs the raw data signal (voltage) conforming to the CMOS or TTL standard to the transmitting circuit 12. When processing the photoelectric digital signal output from the receiving circuit 15, the signal processing module 11 performs digital filtering, synchronization, decoding, demodulation, data conversion, and cross-clock transformation on the photoelectric digital signal, and then outputs it to the signal display 3 for display. The receiving circuit 15 adopts a closed-loop gain circuit to perform transimpedance amplification, filtering, two-stage amplification, and comparison output on the photoelectric analog signal, converting the photoelectric analog signal into a photoelectric digital signal that the signal processing module 11 can recognize. The storage module 17 can be selected from ROM, EEPROM, FLAS, USB flash drive, etc., as needed.

[0064] It should also be noted that, such as Figure 2 As shown, the positioning device based on visible light communication also includes a signal transmitter 2, which is communicatively connected to the signal processing module 11 and is used to output raw data signals to the signal processing module 11. It is understood that the raw data signals can be from various data sources, including video, audio, sensors, byte streams, network ports, etc., and their interfaces can be serial ports, network ports, or other similar interfaces.

[0065] like Figure 2 As shown, the positioning device based on visible light communication also includes a signal display 3, which is communicatively connected to the signal processing module 11 and used to display communication signals or positioning signals. It is understood that the signal display 3 can be a device with display capabilities, such as a computer, and can be selected as needed. The signal display 3 provides a clear and intuitive display of communication signals or positioning signals, facilitating operation and management.

[0066] like Figure 6As shown, the positioning module 16 includes an amplification unit 161, an analog-to-digital converter 162, and a main control unit 163. The amplification unit 161 is communicatively connected to the photodetector module 14 and is used to receive and amplify the photoelectric analog signal. The analog-to-digital converter 162 is communicatively connected to the amplification unit 161 and is used to convert the amplified photoelectric analog signal into a photoelectric digital signal. The main control unit 163 is communicatively connected to the analog-to-digital converter 162, the storage module 17, and the signal processing module 11. It is used to obtain the optical power loss and distance from the external light source to the visible light communication device 1 based on the linear relationship between the optical power attenuation of the photoelectric digital signal and the distance, and to calculate the positioning data of the transmitting end by combining the distance and corresponding power change relationship stored in the storage module 17. By processing the photoelectric analog signal through the amplification unit 161 and the analog-to-digital converter 162, the signal quality and stability are improved, and the influence of noise and errors is reduced. The main control unit 163 simplifies the complexity and difficulty of positioning by utilizing the linear relationship between optical power attenuation and distance.

[0067] It is important to note that the photodetector module 14 includes three photodetectors—a first photodetector, a second photodetector, and a third photodetector—set at 90° angles to each other. The detection direction of the first photodetector is parallel to the x-axis, the second photodetector is parallel to the y-axis, and the third photodetector is parallel to the z-axis. This arrangement of three photodetectors at 90° angles enables the reception of light signals in three-dimensional space, improving the sensitivity of the photodetector module 14 and allowing it to adapt to different signal intensities and directions. Furthermore, the three photodetectors at 90° angles are suitable for triangulation-based algorithms, reducing the computational difficulty of positioning data. It is understood that the three photodetectors can be photosensitive devices such as photodiodes (PDs), avalanche photodiodes (APDs), or photomultiplier tubes (PMTs).

[0068] Furthermore, this invention also provides a positioning system based on visible light communication, comprising two of the aforementioned visible light communication-based positioning devices, with a transmission link between the two devices for communication and positioning. It is understood that by employing a one-to-one transmission and one-to-reception positioning mode between the two visible light communication devices, bidirectional communication and positioning functions are achieved, improving the flexibility and practicality of the visible light communication positioning system and meeting diverse communication and positioning needs.

[0069] The positioning methods based on visible light communication in the above embodiments can achieve both bidirectional visible light communication and positioning functions, while also improving the flexibility and stability of communication and positioning. They are suitable for communication and positioning of moving targets in underwater environments and can be applied to scenarios such as marine exploration, underwater operations, and tunnel exploration. Other positive technical effects of the positioning methods based on visible light communication in the above embodiments are also applicable to positioning devices and systems based on visible light communication, and will not be elaborated upon here.

[0070] Example 1

[0071] This embodiment provides a specific application based on a visible light communication device. It is understood that this device can be mounted on an underwater moving target, such as an underwater vehicle. The working process of Embodiment 1 is described below with reference to the accompanying drawings:

[0072] 1. Function to transmit optical signals

[0073] like Figure 3 As shown, the signal transmitter 2 outputs the raw data signal; the signal processing module 11 receives the raw data signal, and after cross-clock processing, data conversion, and modulation encoding, converts the raw data signal into a data source signal; the transmitting circuit 12 receives the data source signal and converts it into a level that matches the transmitting diode 13, and outputs the amplified data source signal; the transmitting diode 13 receives the amplified data source signal and converts it into an optical signal for transmission, thus realizing the function of transmitting optical signals.

[0074] 2. Communication Function

[0075] like Figure 3 As shown, the photodetector module 14 receives optical signals and outputs photoelectric analog signals; the receiving circuit 15 receives the photoelectric analog signals and performs transimpedance amplification, filtering, two-stage amplification, and comparison output to obtain photoelectric digital signals; the signal processing module 11 receives the photoelectric digital signals and outputs communication signals after digital filtering, synchronization, decoding, demodulation, data conversion, and cross-clock conversion; the signal display 3 receives the communication signals and displays them to realize the communication function.

[0076] 3. Location function

[0077] First, based on the aforementioned step S1, the relationship between the spacing and the corresponding power is obtained and stored in storage module 17. It can be understood that the change in spacing and the corresponding power is linear, from which the linear attenuation coefficient of light in the medium can be derived; for example... Figure 3As shown, the photodetector module 14 receives optical signals and outputs photoelectric analog signals (including photoelectric analog signals output by the first photodetector along the x-axis, photoelectric analog signals output by the second photodetector along the y-axis, and photoelectric analog signals output by the third photodetector along the z-axis); as Figure 7 As shown, the amplification unit 161 in the positioning module 16 receives and amplifies the photoelectric analog signal, outputting the amplified photoelectric analog signal. The analog-to-digital conversion unit 162 receives and processes the amplified photoelectric analog signal, outputting the photoelectric digital signal. The main control unit 163 obtains the relative position and corresponding power between the two visible light communication devices based on the photoelectric digital signal and the relationship between the distance and the corresponding power. The signal processing module 11 receives and processes the relative position, outputting the positioning signal. The signal display 3 receives and displays the positioning signal, thus realizing the positioning function. During the positioning process, the obtained relative position and corresponding power can be transmitted to the storage module 17 via the signal processing module 11 for storage, so as to calibrate and adjust the positioning data.

[0078] The calculation process by which the main control unit 163 obtains the relative position and corresponding power between the two visible light communication devices is as follows:

[0079] 1) Based on the photoelectric analog signal output by the photodetector module 14 and the second-stage amplification factor of the amplification unit 161, calculate and inversely determine the received optical power of the photodetector module 14; wherein, the calculation method for the received optical power of the first photodetector along the x-axis is as follows:

[0080]

[0081] In equation (1), E x I represents the received optical power of the first photodetector. px R is the current of the photoelectric analog signal of the first photodetector. x G represents the photoelectric conversion efficiency of the first photodetector, and G is the second-order amplification factor of the receiving circuit 15.

[0082] The method for calculating the received optical power of the second photodetector along the y-axis is as follows:

[0083]

[0084] In equation (2), E y I represents the received optical power of the second photodetector. py R is the current of the photoelectric analog signal of the second photodetector. y The photoelectric conversion efficiency of the second photodetector;

[0085] The method for calculating the received optical power of the third photodetector along the z-axis is as follows:

[0086]

[0087] In equation (3), E z I represents the received optical power of the third photodetector. pz R is the current of the photoelectric analog signal of the third photodetector. z The photoelectric conversion efficiency of the third photodetector;

[0088] 2) Based on the received optical power of the photodetector module 14 and the initial power in the relationship between spacing and corresponding power, the optical power loss from emission to reception is calculated; wherein, the calculation method for the optical power loss along the x-axis is as follows:

[0089] ΔE x =E0-E x (4);

[0090] In equation (4), ΔE x E0 represents the optical power loss of the optical signal along the x-axis from emission to reception, and E0 is the initial power when the distance between the two visible light communication devices is 0m.

[0091] The method for calculating optical power loss along the y-axis is as follows:

[0092] ΔE y =E0-E y (5);

[0093] In equation (5), ΔE y This represents the optical power loss of the optical signal along the y-axis from emission to reception.

[0094] The method for calculating optical power loss along the z-axis is as follows:

[0095] ΔE z =E0-E z (6);

[0096] In equation (6), ΔE z This represents the optical power loss of the optical signal along the z-axis from emission to reception.

[0097] 3) Based on the optical power loss of the optical signal and the received optical power of the photodetector module 14, and combined with the correspondence between spacing and power, the distance between the two visible light communication devices is calculated, thereby obtaining the relative position of the two visible light communication devices; wherein, the method for calculating the distance between the two visible light devices along the x-axis is as follows:

[0098]

[0099] In equation (7), d xLet be the distance between the two visible light communication devices along the x-axis, and μ be the linear attenuation coefficient of light in the medium in the relationship between the spacing and the corresponding power obtained in step S1.

[0100] The method for calculating the distance between two visible light devices along the y-axis is as follows:

[0101]

[0102] In equation (8), d y The distance between the two visible light communication devices along the y-axis;

[0103] The method for calculating the distance between two visible light devices along the z-axis is as follows:

[0104]

[0105] In equation (9), d z The distance between the two visible light communication devices along the z-axis;

[0106] Therefore, the coordinates of the visible light communication device that receives the optical signal in the spatial rectangular coordinate system O-xyz can be derived as (d x d y d z The coordinates can be displayed as a relative position via the signal display 3; the power corresponding to this relative position is the received optical power E of the photodetector module 14. x E y E z .

[0107] Through the description of several embodiments of the positioning method, positioning device, and positioning system based on visible light communication of the present invention, it can be seen that the embodiments of the positioning method, positioning device, and positioning system based on visible light communication of the present invention have at least one or more of the following advantages:

[0108] 1. The positioning method based on visible light communication provided by this invention provides stable and reliable positioning data through a visible light communication positioning system, realizes the establishment of a stable transmission link between underwater moving targets, and can be applied to scenarios such as marine exploration, underwater operations, and tunnel exploration;

[0109] 2. The positioning device based on visible light communication provided by the present invention can realize bidirectional visible light communication and positioning functions by setting up a visible light communication device, which improves the flexibility and practicality of the system and meets different communication and positioning needs.

[0110] 3. The positioning system based on visible light communication provided by the present invention can realize high-speed, high-efficiency and high-security transmission and reception of optical signals through the visible light communication device 1. It is suitable for underwater environment, can cope with optical path fluctuations caused by seawater turbulence and turbulence, and improve the stability of communication and positioning.

[0111] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A positioning method based on visible light communication, characterized in that, Includes the following steps: S1, Obtain the relationship between the distance and the corresponding power: One visible light communication device transmits an optical signal, and another visible light communication device receives the optical signal. The location of the receiving visible light communication device is taken as the origin O, and the three detection directions of the photodetector module of the receiving visible light communication device are the x-axis, y-axis, and z-axis, respectively. The distance between the two visible light communication devices is controlled to be 0m and a maximum communication distance. The initial power and maximum power received by the receiving visible light communication device along one of the x-axis, y-axis, or z-axis are recorded when the distance is 0m and the maximum communication distance, respectively. This yields the relationship between the distance between the two visible light communication devices and the corresponding power. S2, Establish a transmission link between underwater moving targets: Two visible light communication devices are mounted on the underwater moving targets respectively. The two visible light communication devices move underwater with the underwater moving targets. One visible light communication device transmits light signals, and the other visible light communication device receives and processes the light signals through a photodetector module to obtain photoelectric analog signals along the x-axis, y-axis, and z-axis respectively. S3, Obtain the relative position of the underwater moving target: Based on the photoelectric analog signal obtained in step S2, combined with the relationship between the spacing and the corresponding power change obtained in step S1, as well as the initial power and initial position, calculate the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis directions, respectively, thereby obtaining the relative position between the underwater moving targets. 2.The method of claim 1, wherein, In step S3, the specific method for calculating the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis is as follows: Based on the photoelectric analog signal obtained in step S2, the received optical power received by the visible light communication devices along the x-axis, y-axis, and z-axis is calculated and inverted. The difference between the received optical power and the initial power is used to obtain the optical power loss of the optical signal between the two visible light communication devices along the x-axis, y-axis, and z-axis. Based on the received optical power of the visible light communication devices and the optical power loss of the optical signal along the x-axis, y-axis, and z-axis, the relative positions of the two visible light communication devices along the x-axis, y-axis, and z-axis are calculated.

3. The method of claim 2, wherein, The specific method for calculating and retrieving the received optical power of a visible light communication device along the x-axis, y-axis, and z-axis is as follows: The visible light communication device amplifies the photoelectric analog signals along the x-axis, y-axis, and z-axis respectively through the positioning module. Based on the amplified photoelectric analog signals along the x-axis, y-axis, and z-axis, combined with the photoelectric conversion efficiency of the photodetector module and the amplification factor of the positioning module, the optical power of the photoelectric analog signals along the x-axis, y-axis, and z-axis is retrieved respectively, thereby obtaining the received optical power of the visible light communication device along the x-axis, y-axis, and z-axis respectively.

4. The positioning method based on visible light communication according to claim 1, characterized in that, Step S1 also includes storing the obtained relationship between the spacing and the corresponding power in the storage module of the visible light communication device.

5. A positioning device based on visible light communication, characterized in that, The positioning method based on visible light communication as described in any one of claims 1-4 includes a visible light communication device, which comprises: The transmitting circuit is used to amplify the data source signal to be transmitted. The transmitting diode, which is connected to the transmitting circuit, is used to convert the amplified data source signal into an optical signal and then transmit the optical signal. The photodetector module is used to receive light signals emitted by an external light source and convert them into photoelectric analog signals along the x-axis, y-axis, and z-axis, respectively. The storage module is used to store the signals that need to be saved and the relationship between the spacing and the corresponding power changes; The positioning module, which is connected to the photodetector module and the storage module, is used to calculate the relative position of the transmitter and receiver based on the photoelectric analog signal and the relationship between the spacing and the corresponding power. The receiving circuit, which is connected to the photodetector module, is used to receive photoelectric analog signals and convert them into photoelectric digital signals. The signal processing module is communicatively connected to the transmitting circuit to convert the raw data signal into a data source signal and provide it to the transmitting circuit. The signal processing module is also communicatively connected between the receiving circuit and the storage module to process the photoelectric digital signal output by the receiving circuit to obtain a communication signal. The signal processing module is also communicatively connected to the positioning module to receive and process the relative position output by the positioning module to obtain a positioning signal, and to output the positioning signal to the storage module for storage.

6. The positioning device based on visible light communication according to claim 5, characterized in that, The positioning device based on visible light communication also includes a signal transmitter, which is communicatively connected to the signal processing module and is used to output raw data signals to the signal processing module. 7.The visible light communication based positioning apparatus of claim 5, wherein, The positioning device based on visible light communication also includes a signal display, which is communicatively connected to the signal processing module to display communication signals or positioning signals. 8.The visible light communication based positioning apparatus of claim 5, wherein, The positioning module includes: The amplification unit, which is connected to the photodetector module, is used to receive and amplify photoelectric analog signals; The analog-to-digital converter unit, whose communication connection is to the amplifier unit, is used to convert the amplified photoelectric analog signal into a photoelectric digital signal; The main control unit, which is connected to the analog-to-digital conversion unit, the storage module, and the signal processing module, is used to obtain the optical power loss and distance from the external light source to the location of the visible light communication device based on the linear relationship between the optical power attenuation of the photoelectric digital signal and the distance. It also calculates the positioning data of the transmitter by combining the relationship between the spacing and the corresponding power change stored in the storage module. 9.The visible light communication based positioning apparatus of claim 5, wherein, The photodetector module includes three photodetectors, namely a first photodetector, a second photodetector, and a third photodetector, which are set at 90° to each other. The detection direction of the first photodetector is parallel to the x-axis, the detection direction of the second photodetector is parallel to the y-axis, and the detection direction of the third photodetector is parallel to the z-axis.

10. A positioning system based on visible light communication, characterized in that, It includes two positioning devices based on visible light communication as described in any one of claims 5-9, wherein a transmission link for communication and positioning is formed between the two positioning devices based on visible light communication.

Images