Indoor optical space positioning method and system

Abstract

The application provides an indoor optical space positioning method and system, which comprises a transmitting unit, a receiving unit and a solving unit, the transmitting unit modulates the ID information of each laser beam by using lasers of different wavelengths, the laser signals are distinguished by using the differentiation of laser light intensity under different wavelengths, the laser can emit laser beams of red, green and blue wavelengths, a beam splitter emits the three light beams to different directions, the receiving unit arranges the three-color laser light rays by a matrix arrangement of optical fibers, transmits the three-color laser light rays to a receiving end through the optical fibers, converts the three-color laser light rays into electrical signals for signal processing, inputs the processed electrical signals into a neural network, and calculates the pose of the transmitting unit based on the known optical fiber plate position and the light intensity information of the three-color laser light rays. The application provides an efficient, accurate and flexible method for pose solving, makes the positioning error controllable, is simple and efficient, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of indoor spatial positioning technology, and in particular to an indoor optical spatial positioning method and system. Background Technology

[0002] GPS and BDS positioning technologies are widely used in aerospace, autonomous driving, and other fields. However, due to the complex topology of indoor spaces and interference from factors such as ephemeris errors, multipath fading, and Earth's rotation, the positioning performance of these two methods is not ideal. To address this issue, various platforms and solutions have emerged, including ultrasonic technology, geomagnetic technology, and radio frequency identification (RFID) technology, to compensate for the shortcomings of GPS and BDS in indoor positioning. However, these indoor positioning solutions suffer from drawbacks such as operational complexity, high cost, and low positioning accuracy.

[0003] Optical positioning technology, as an emerging indoor positioning solution, offers unique advantages compared to other positioning technologies. Utilizing optical principles, optical spatial positioning achieves precise spatial location, featuring high data acquisition speed and density, as well as strong resistance to multipath effects. Furthermore, optical spatial positioning is unaffected by electromagnetic interference, providing higher real-time performance and more accurate spatial location information. In the field of indoor positioning, laser-based optical spatial positioning systems are not only simpler and lower in cost, but also have broader application prospects.

[0004] However, existing laser-based optical spatial positioning systems typically use single-frequency lasers as the transmitting unit and photodetectors or high-speed cameras as the receiving unit, which results in high costs. Furthermore, in these systems, the receiving unit infers the transmitter's attitude by detecting information such as time of arrival (TOA), time difference of arrival (TDOA), and angle of arrival (AOA). While these techniques offer advantages such as high accuracy, good stability, and wide measurement range, they also place high demands on optical signal processing algorithms and hardware circuits, and attitude calculation in complex scenarios remains a challenge. Summary of the Invention

[0005] The purpose of this invention is to provide an indoor optical spatial positioning method and system to solve the problems of high cost, poor anti-interference capability, and high requirements for optical signal processing algorithms and hardware circuits in existing laser optical spatial positioning systems. The specific technical solution is as follows:

[0006] An indoor optical spatial positioning system includes a transmitting unit, a receiving unit, and a solving unit. The transmitting unit includes a laser driving module, a laser connected to the output of the laser driving module, and a beam splitter connected to the output of the laser. The receiving unit includes an optical fiber positioning plate, a photoelectric detection module connected to the end of the optical fiber of the optical fiber positioning plate, a digital-to-analog converter circuit and a filtering circuit connected to the output of the photoelectric detection module, and a data acquisition card connected to the output of the digital-to-analog converter circuit and the filtering circuit. The output of the data acquisition card is connected to the solving unit. The optical fiber positioning plates are arranged perpendicularly to each other in a three-dimensional coordinate system. The transmitting unit and the receiving unit transmit laser signals in indoor free space.

[0007] The laser driving module converts electrical signals into laser signals. The laser emits laser signals of different wavelengths. The beam splitter simultaneously emits laser signals from different angles into the indoor free space. The fiber optic positioning board receives laser signals from multiple points in the space and transmits them to the photoelectric detection module. The photoelectric detection module converts the laser signals into electrical signals. The digital-to-analog converter and filtering circuit process the electrical signals to obtain laser intensity array information. The data acquisition card reads the laser intensity array information and transmits it to the calculation unit. The calculation unit performs positioning coordinate calculation and outputs the coordinate data of the positioning point.

[0008] Furthermore, the calculation unit includes a processor and an intelligent positioning algorithm, wherein the processor is a programmable controller or a microcontroller.

[0009] Furthermore, the laser is an array laser composed of multiple laser diodes, and the beam splitters are arranged in a triangular pyramid shape with an included angle of 15-90° between them.

[0010] Furthermore, the optical fibers in the optical fiber positioning plate are arranged in a matrix, and the photoelectric detection module is a photodiode or a photoresistor.

[0011] Furthermore, the transmitting unit also includes a threaded connection structure, which is disposed at one end near the laser driving module.

[0012] The present invention also provides an indoor optical spatial positioning method, which is based on the above-mentioned indoor optical spatial positioning system and specifically includes the following steps:

[0013] S1. Collect data to build a fingerprint database and train a neural network model;

[0014] S2. The transmitting unit emits a tri-color laser beam in the indoor space;

[0015] S3. The three-color laser beam enters the receiving unit, which converts and processes the laser signal and transmits the obtained laser intensity information to the calculation unit.

[0016] S4. The calculation unit uses the laser intensity information to calculate and predict the position coordinates of the transmitting unit.

[0017] Furthermore, step 1 specifically includes:

[0018] S11. When the system is offline, it collects wireless signal characteristics from different locations in the indoor space to form a fingerprint database.

[0019] S12. Record the coordinate information mapped onto the fiber optic positioning board when the transmitting unit is in different positions in the indoor space in an Excel table to form positioning point number data.

[0020] S13. Use fingerprint data and location point number data to train a neural network model.

[0021] Furthermore, step 2 specifically includes: when the system is online, the transmitting unit moves freely in the indoor space. In order to determine the positioning target point of the transmitting unit, the laser driving module converts the electrical signal into a laser signal. The laser emits laser signals of different wavelengths simultaneously from different angles through the beam splitter, emitting red, green and blue laser beams.

[0022] Furthermore, step 3 specifically includes:

[0023] S31. The three-color laser beam is transmitted through the indoor three-dimensional free space. The fiber optic positioning plate receives laser signals from multiple points in the space. The received laser signals are transmitted to the photoelectric detection module through the internal fiber optic cable.

[0024] S32, the photoelectric detection module converts the laser signal into an electrical signal. The converted electrical signal enters the digital-to-analog converter circuit and the filter circuit. After processing and conversion, the laser intensity array information is obtained.

[0025] S33, the data acquisition card acquires laser intensity array information and transmits it to the calculation unit.

[0026] Furthermore, step 4 specifically includes:

[0027] S41. The processor of the solution unit acquires the laser intensity array information, performs matrix transformation, and calculates the coordinates of the maximum element of the laser on the fiber positioning plate.

[0028] S42. Input the fingerprint features of this point into the neural network model. The model will predict the location of this point based on the fingerprint features, thereby achieving accurate indoor positioning.

[0029] The indoor optical spatial positioning method and system provided by this invention have the following advantages compared with the prior art:

[0030] 1. This invention proposes an indoor optical spatial positioning method and system, which effectively suppresses ambient light interference through a special darkroom and photoelectric detector, thereby improving positioning accuracy and precision.

[0031] 2. This invention proposes an indoor optical spatial positioning method and system, which uses a matrix-type fiber optic positioning board and laser diodes of different wavelengths to effectively combine actual coordinate parameters and received signal strength information, thus solving the problems of multipath effect and nonlinear error in indoor optical positioning.

[0032] 3. This invention proposes an indoor optical spatial positioning method and system. It utilizes a fingerprint database positioning method based on a BP neural network, applies deep learning technology to the positioning algorithm, and deploys the algorithm in the host computer, reducing redundant calculations in the lower-level computer and improving overall performance and real-time performance. Attached Figure Description

[0033] Figure 1 This invention presents a schematic diagram of the structure of an indoor optical spatial positioning system.

[0034] Figure 2 This invention provides a front view and a top view of the transmitting unit of an indoor optical spatial positioning system;

[0035] Figure 3 This is a partial structural diagram of the receiving unit of an indoor optical spatial positioning system proposed in this invention;

[0036] Figure 4 This is a partial structural diagram of the receiving unit of an indoor optical spatial positioning system proposed in this invention;

[0037] Figure 5 This is a flowchart illustrating an indoor optical spatial positioning method proposed in this invention.

[0038] Figure 6 This invention presents a laser transmission model diagram for an indoor optical spatial positioning system. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0040] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connection" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] In the description of this invention, terms such as "upper," "lower," "left," "right," "front," "back," "center," "horizontal," "vertical," "top," "bottom," "inner," and "outer," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Example 1: This example provides an indoor optical spatial positioning system, see reference. Figure 1 The diagram shown is a structural connection block diagram of the system. The system includes a transmitting unit 100, a receiving unit 200, and a processing unit 300. The transmitting unit 100 includes a laser driving module 110, a laser 120, and a beam splitter 130. The receiving unit includes a fiber optic positioning plate 210, a photoelectric detection module 220, a digital-to-analog converter and filtering circuit 230, and a data acquisition card 240. The processing unit 300 includes a processor and an intelligent positioning algorithm within the processor. The output of the laser driving module 110 in the transmitting unit 100 is connected to the input of the laser 120, and the output of the laser 120... The input end of the beam splitter is connected to the transmitting unit 100. The laser signal is transmitted between the transmitting unit 100 and the receiving unit 200 through free space. The end of the optical fiber in the optical fiber positioning plate 210 in the receiving unit 200 is connected to the photoelectric detection module 220. The output end of the photoelectric detection module 220 is connected to the digital-to-analog converter circuit and the filtering circuit 230. The output end of the digital-to-analog converter circuit and the filtering circuit 230 is connected to the input end of the data acquisition card 240. The output end of the data acquisition card 240 is connected to the processor 320 of the calculation unit 300. The processor 320 is a programmable controller, a microcontroller, or a PC.

[0043] The laser driving module 110 converts electrical signals into laser signals, generating resonance in the laser 120. The laser 120 transmits laser signals of different wavelengths into free space via the beam splitter 130. The laser signals are transmitted to the receiving unit 200 through the indoor three-dimensional free space. The fiber optic positioning plate 210 in the receiving unit 200 can simultaneously receive laser signals from multiple points in the space and transmit the laser signals to the photoelectric detection module 220. The photoelectric detection module 220 converts the laser signals into electrical signals. The digital-to-analog converter circuit and the filtering circuit 230 process the electrical signals, filter out noise, and convert them into digital quantities to obtain laser intensity array information. The information is read by the data acquisition card 240 and transmitted to the calculation unit 300. The intelligent positioning algorithm in the processor calculates the positioning coordinates and finally predicts the coordinate data of the positioning point where the transmitting unit is located.

[0044] See Figure 2 The diagram shows the physical device of the transmitting unit 100. The transmitting unit 100 is also equipped with a battery compartment 121 and a threaded connection structure 122. The battery compartment 121 is used to deploy the laser driving module 110, and the threaded connection structure 122 is used to connect an external free-moving device. The external free-moving device can drive the transmitting unit 100 to move freely in the indoor positioning space. The output end of the laser 120 is connected to a beam splitter 130. The beam splitters 130 are arranged in a triangular pyramid shape, and the included angle between each pair of beam splitters is 15-90°. The laser 120 uses laser diodes of different wavelengths.

[0045] See Figure 3 As shown, the fiber optic positioning plate 210 is arranged in a three-dimensional coordinate system, including the positioning plate YOZ plane 211, the positioning plate XOZ plane 212, and the positioning plate XOY plane 213. Three light rays of different intensities emitted by the transmitting unit 100 are transmitted to the fiber optic positioning plate 120 through free space. (See reference...) Figure 4 As shown, the optical fibers in the optical fiber positioning plate 210 are arranged in a matrix, which can realize the simultaneous reception of multiple points in space and reduce the number of signals collected. The end of each optical fiber is connected to a photoelectric detection module 220, which is a photodiode or a photoresistor. The output end of the photoelectric detection module 220 is connected in sequence to a digital-to-analog converter circuit, a filter circuit 230, and a data acquisition card 240.

[0046] Example 2: See Figure 5 As shown, this embodiment provides an indoor optical spatial positioning method, which specifically includes the following steps:

[0047] S1. Collect data to build a fingerprint database and train a neural network model;

[0048] Specifically, when the system is offline, it utilizes the spatial differences in wireless signals across different environments to treat the wireless signal characteristics at specific locations within the indoor space as fingerprints for those locations. This allows for the collection of wireless signal characteristics from different locations within the indoor space. The coordinates of these locations and their corresponding wireless signal characteristics form a fingerprint feature database. The coordinate information mapped onto the fiber optic positioning board when the transmitting unit is in different indoor locations is recorded in an Excel spreadsheet, forming a positioning point number, which is then stored in the fingerprint database. Simultaneously, a BP neural network model containing an input layer, hidden layers, and an output layer is constructed. The collected fingerprint features and positioning point numbers are used to train the BP neural network model, enabling it to compare the fingerprint feature data with the signal characteristics actually collected when the system is online, correctly predicting the positioning point number, and thus determining the location of the positioning point.

[0049] S2. The transmitting unit emits a tri-color laser beam in the indoor space;

[0050] Specifically, when the system is online, the transmitting unit can move freely within the positioning area, and its location is set as the positioning target point. In order to determine the position and direction of the target point, the laser driving module converts the electrical signal into a laser signal. The laser signal resonates in the laser, and the laser emits laser signals of different wavelengths from different angles simultaneously through the beam splitter. The laser beams emitted at the same time include red, green and blue laser beams.

[0051] S3. The three-color laser beam enters the receiving unit, which converts and processes the laser signal and transmits the obtained laser intensity information to the calculation unit.

[0052] Specifically, the laser signals from the three-color laser beams are transmitted through the indoor three-dimensional free space to the fiber optic positioning plate of the receiving unit. The fiber optic positioning plate is arranged according to a three-dimensional coordinate system, and the optical fibers in the positioning plate are arranged in a matrix. Therefore, the fiber optic positioning plate can simultaneously receive laser signals from multiple points in the space. The fiber optic positioning plate transmits the received laser signals to the photoelectric detection module through internal optical fibers. The photoelectric detection module converts the laser signals into electrical signals. The converted electrical signals enter the digital-to-analog converter circuit and the filtering circuit. The filtering circuit filters out noise in the electrical signals, and the digital-to-analog converter circuit converts the electrical signals from analog quantities to digital quantities to obtain laser intensity array information. The data acquisition card collects the laser intensity array information and transmits it to the calculation unit.

[0053] S4. The calculation unit uses the laser intensity information to calculate and predict the position coordinates of the transmitting unit.

[0054] Specifically, the processor of the calculation unit obtains the laser intensity array information transmitted by the data acquisition card through serial communication, performs matrix transformation, calculates the coordinates of the fiber matrix board, i.e. the coordinates of the maximum element, loads and runs the BP neural network model, inputs the fingerprint features of the point into the BP neural network model, and the model will predict the position of the point based on the fingerprint features, thereby achieving precise indoor positioning.

[0055] See Figure 6 The diagram shows the laser transmission model in the above process. This model can be simplified as follows: after the laser source passes through the gain of the transmitting unit, it is attenuated by the free-space optical channel and interfered with by ambient light before being modulated by the receiving unit. Finally, it is transmitted to the calculation unit for intelligent positioning and calculation to obtain coordinate data. The laser intensity transmitted from the receiving unit to the calculation unit can be expressed as:

[0056] I RX =I TX +G TX -I L -N+G RX

[0057] I RX It is the received light intensity, I TX It is the transmitted light intensity, G TX It is the transmitter gain, I L It represents channel fading, N is ambient light noise, and G is channel fading. RX It is the receiver gain.

[0058] When a laser signal is incident perpendicularly into an optical fiber in a fiber optic plate, the intensity of the laser light in the fiber will undergo a first attenuation. This attenuation is related to the distance between the incident light and the photoelectric detection module, and we call this relationship radial attenuation.

[0059] I Fiber =-951.678+6415.92e -0.0667539x (R = 0.966269)

[0060] I Fiber It measures the light intensity, and x is the distance between the incident light and the photoelectric detection module.

[0061] When two beams of light superimpose in space, interference occurs, causing a redistribution of light energy. For ease of calculation, the combined intensity of the two beams must equal the sum of their individual intensities. Light intensity can be understood as the average of the squares of the electric field strength amplitudes.

[0062]

[0063] A1 represents the amplitude of the first optical column, A2 represents the amplitude of the second optical column, and A represents the combined amplitude. It is the first light phase. It is the second optical phase. It's the phase difference.

[0064] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the invention. Any changes or modifications made by those skilled in the art based on the embodiments of the present invention and the above disclosure shall fall within the protection scope of the claims.

Claims

1. An indoor optical spatial positioning system, characterized in that: The system includes a transmitting unit, a receiving unit, and a processing unit. The transmitting unit includes a laser driving module, a laser connected to the output of the laser driving module, and a beam splitter connected to the output of the laser. The receiving unit includes an optical fiber positioning plate, a photoelectric detection module connected to the end of the optical fiber of the optical fiber positioning plate, a digital-to-analog converter circuit and a filtering circuit connected to the output of the photoelectric detection module, and a data acquisition card connected to the output of the digital-to-analog converter circuit and the filtering circuit. The output of the data acquisition card is connected to the processing unit. The optical fiber positioning plates are arranged perpendicularly to each other in a three-dimensional coordinate system. The transmitting unit and the receiving unit transmit laser signals in indoor free space. The laser driving module converts electrical signals into laser signals. The laser emits laser signals of different wavelengths. The beam splitter simultaneously emits laser signals from different angles into the indoor free space. The fiber optic positioning board receives laser signals from multiple points in the space and transmits them to the photoelectric detection module. The photoelectric detection module converts the laser signals into electrical signals. The digital-to-analog converter and filtering circuit process the electrical signals to obtain laser intensity array information. The data acquisition card reads the laser intensity array information and transmits it to the calculation unit. The calculation unit performs intelligent positioning calculations and outputs the coordinate data of the positioning point.

2. The indoor optical spatial positioning system according to claim 1, characterized in that: The calculation unit includes a processor and an intelligent positioning algorithm, wherein the processor is a programmable controller or a microcontroller.

3. The indoor optical spatial positioning system according to claim 1, characterized in that: The laser is an array laser composed of multiple laser diodes, and the beam splitters are arranged in a triangular pyramid shape with an included angle of 15-90° between them.

4. The indoor optical spatial positioning system according to claim 1, characterized in that: The optical fibers in the optical fiber positioning plate are arranged in a matrix, and the photoelectric detection module is a photodiode or a photoresistor.

5. The indoor optical spatial positioning system according to claim 1, characterized in that: The transmitting unit also includes a threaded connection structure, which is located at one end near the laser driving module.

6. An indoor optical spatial positioning method, characterized in that: The method, based on the indoor optical spatial positioning system according to any one of claims 1-5, specifically includes the following steps: S1. Collect data to build a fingerprint database and train a neural network model; S2. The transmitting unit emits a tri-color laser beam in the indoor space; S3. The three-color laser beam enters the receiving unit, which converts and processes the laser signal and transmits the obtained laser intensity information to the calculation unit. S4. The calculation unit uses the laser intensity information to calculate and predict the position coordinates of the transmitting unit.

7. The indoor optical spatial positioning method according to claim 6, characterized in that: Step 1 specifically includes: S11. When the system is offline, it collects wireless signal characteristics from different locations in the indoor space to form a fingerprint database. S12. Record the coordinate information mapped onto the fiber optic positioning board when the transmitting unit is in different positions in the indoor space in an Excel spreadsheet to form positioning point number data; S13. Use fingerprint data and location point number data to train a neural network model.

8. The indoor optical spatial positioning method according to claim 6, characterized in that: Step 2 specifically includes: when the system is online, the transmitting unit moves freely in the indoor space. In order to determine the positioning target point of the transmitting unit, the laser driving module converts the electrical signal into a laser signal. The laser emits laser signals of different wavelengths from different angles simultaneously through the beam splitter, emitting red, green and blue laser beams.

9. The indoor optical spatial positioning method according to claim 6, characterized in that: Step 3 specifically includes: S31. The three-color laser beam is transmitted through the indoor three-dimensional free space. The fiber optic positioning plate receives laser signals from multiple points in the space. The received laser signals are transmitted to the photoelectric detection module through the internal fiber optic cable. S32, the photoelectric detection module converts the laser signal into an electrical signal. The converted electrical signal enters the digital-to-analog converter circuit and the filter circuit. After processing and conversion, the laser intensity array information is obtained. S33, the data acquisition card acquires laser intensity array information and transmits it to the calculation unit.

10. The indoor optical spatial positioning method according to claim 6, characterized in that: Step 4 specifically includes: S41. The processor of the solution unit acquires the laser intensity array information, performs matrix transformation, and calculates the coordinates of the maximum element of the laser on the fiber positioning plate. S42. Input the fingerprint features of this point into the neural network model. The model will predict the location of this point based on the fingerprint features, thereby achieving accurate indoor positioning.

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