Indoor positioning system and positioning method based on electromagnetic grid

Abstract

The present invention discloses an indoor positioning system and method based on an electromagnetic grid. The positioning system includes an on-board power transmission coil assembly, which includes two power transmission coils with different vibration frequencies, and the power transmission coils are powered by the on-board terminal. A roadside power receiving coil assembly includes a coil grid formed by the power receiving coils, a receiver, a decoder, and a data transmission device, and the positions of the power receiving coils are calibrated. The receiver is used to analyze the induced current and the magnetic field vibration resonance frequency. The decoder is used to obtain the xy coordinates of the power receiving coils. The data transmission device receives the xy coordinate information. The data receiving device is used to receive the coordinate position of the power receiving coils and the corresponding vibration frequency, determine the coordinate position of the two power transmission coils, and obtain the position of the center of gravity of the on-board terminal based on the weighted distance between the two power transmission coils and the center of gravity of the on-board terminal. The heading of the on-board terminal is calculated based on the coordinate position of the two power transmission coils. Utilizing the electromagnetic induction effect and the magnetic field resonance principle, high-precision and reliable positioning is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of indoor positioning, and in particular relates to an indoor positioning system and a positioning method based on an electromagnetic grid. Background Art

[0002] With the advancement of automotive intelligence, autonomous driving technology is booming. Positioning and high-precision maps, as sensory inputs for autonomous driving systems, play a vital role in perception, decision-making, and control, and are an indispensable part of autonomous driving solutions.

[0003] Currently, commonly used indoor positioning technologies include ultra-wideband (UWB) indoor positioning technology, radio frequency identification (RFID) technology, Wi-Fi technology, Bluetooth indoor positioning technology, and ultrasonic indoor positioning technology. Compared with Wi-Fi, Bluetooth, RFID and other positioning technologies, UWB technology has a relatively high positioning accuracy of up to 10cm, but the cost is basically more than 10 times that of other positioning technologies. The higher the accuracy requirements of UWB technology, the higher the cost of deploying base stations. For example, if the coverage area is 50*50 meters, the total cost is 2500m. 2 To achieve this, four UWB positioning points are required, with a base station costing approximately 40,000 yuan and an average positioning accuracy of around 20cm. Other positioning technologies, including radio frequency identification, Wi-Fi, and Bluetooth, all suffer from positioning drift, which translates to low positioning accuracy.

[0004] Autonomous AGVs (Automated Guided Vehicles) have high positioning requirements (10 cm or less) when transporting goods indoors and loading and unloading goods at fixed locations. Therefore, it is necessary to develop a low-cost, highly accurate, and reliable indoor positioning system to address the positioning issues currently faced by autonomous AGVs during indoor cargo transport. Summary of the Invention

[0005] In response to the above-mentioned technical problems, the present invention provides an indoor positioning system and positioning method based on an electromagnetic grid, which utilizes the electromagnetic induction effect and the magnetic field resonance principle to achieve high-precision and reliable positioning effects, and solve the problems of high cost and positioning drift in the existing indoor positioning technology.

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

[0007] An object of the present invention is to provide an indoor positioning system based on an electromagnetic grid, comprising:

[0008] The vehicle-mounted power transmission coil assembly includes two power transmission coils with different vibration frequencies, which are respectively provided at the front and rear of the vehicle-mounted terminal, and the two power transmission coils are powered by the vehicle-mounted terminal;

[0009] A roadside power receiving coil assembly comprising a coil grid formed by a plurality of power receiving coils arranged on the indoor floor at intervals of vertical and horizontal spacing, a receiver, a decoder and a data transmission device, wherein the position of any of the power receiving coils is pre-calibrated;

[0010] When supplying power, the two power transmission coils respectively form electromagnetic induction with the power receiving coils at the position where the vehicle-mounted terminal is located, and generate induced current in the corresponding power receiving coils;

[0011] The receiver is configured to analyze the induced current and magnetic field vibration resonance frequency; the decoder is configured to respectively obtain the corresponding xy coordinates of the power receiving coil that generates electromagnetic induction; the data sending device is configured to receive the xy coordinate information sent by the decoder;

[0012] When the vehicle-mounted terminal automatically passes a certain location indoors, the control module determines the coordinate positions of the two power transmission coils based on different vibration frequencies, and obtains the position of the center of gravity of the vehicle-mounted terminal by weighting the distances from the two power transmission coils to the center of gravity of the vehicle-mounted terminal, and calculates the heading of the vehicle-mounted terminal based on the coordinate positions of the two power transmission coils.

[0013] Preferably, the vehicle-mounted power transmission coil assembly further includes:

[0014] a data receiving device configured to receive the coordinate position of the power receiving coil generating electromagnetic induction and the corresponding vibration frequency sent by the data transmitting device;

[0015] The control module is built in the data receiving device or the data receiving device is electrically connected to the control module.

[0016] Preferably, it also includes an oscillator connected to the corresponding circuits of the two power transmission coils.

[0017] Preferably, the distances between the two power transmission coils and the center of gravity of the vehicle-mounted terminal are L1 and L2 respectively;

[0018] When the vehicle-mounted terminal passes a certain position, the positions of the two receiving coils that generate electromagnetic induction with the two transmitting coils are set to and , then:

[0019] The weighted position P of the center of gravity of the vehicle-mounted terminal is: ;in, , .

[0020] Preferably, the positions of the two receiving coils generating electromagnetic induction with the two transmitting coils are and , then:

[0021] The heading of the vehicle terminal is .

[0022] Preferably, the data receiving device is provided on the vehicle-mounted terminal.

[0023] Preferably, the intervals between all the power receiving coils in the roadside power receiving coil group are equal.

[0024] Preferably, when the vehicle-mounted terminal is started, both power transmission coils in the vehicle-mounted power transmission coil group are powered.

[0025] Another object of the present invention is to provide a positioning method for the indoor positioning system based on the electromagnetic grid, comprising the following steps:

[0026] S1. Lay the roadside power receiving coil group on the indoor floor and calibrate each power receiving coil to determine the position of each power receiving coil;

[0027] S2. When the vehicle terminal automatically passes a certain position,

[0028] S21, obtaining the xy coordinates of the power receiving coil generating the induced current at the location;

[0029] S22. Calculate the position and heading of the center of gravity of the vehicle-mounted terminal at the position to achieve indoor positioning of the vehicle-mounted terminal.

[0030] Preferably, in step S21:

[0031] The receiver analyzes the induced current and magnetic field vibration frequency of the receiving coil that generates electromagnetic induction, and obtains the corresponding xy coordinates of the receiving coil through the decoder.

[0032] Preferably, in step S22:

[0033] S221: The data receiving device receives the position of the power receiving coil generating electromagnetic induction and the corresponding vibration frequency, and determines the positions of the two power transmitting coils;

[0034] S222. Obtain the position of the center of gravity of the vehicle-mounted terminal at that position by weighting the distances between the two power transmission coils and the center of gravity of the vehicle-mounted terminal; and obtain the heading of the vehicle-mounted terminal according to the positions of the two corresponding power transmission coils.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] The electromagnetic grid-based indoor positioning system of the present invention achieves high-precision and reliable positioning by arranging a power transmission coil at the front and rear of the vehicle, respectively, and laying a power receiving coil group forming an electromagnetic grid on the indoor floor. It utilizes the electromagnetic induction effect and the principle of magnetic field resonance to achieve a high-precision and reliable positioning effect, solving the problems of high cost and positioning drift in the existing indoor positioning technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0038] Figure 1 Schematic diagram of the structure of an indoor positioning system based on electromagnetic grid according to an embodiment of the present invention;

[0039] Figure 2 Schematic diagram of the structure of a vehicle-mounted power transmission coil assembly of an indoor positioning system based on an electromagnetic grid according to an embodiment of the present invention.

[0040] Among them: 1. Vehicle-mounted power transmission coil group; 10. Vehicle-mounted terminal; 11. Power transmission coil; 12. Data receiving device; 13. Oscillator; 2. Roadside power receiving coil group; 21. Power receiving coil; 22. Receiver; 23. Decoder; 24. Data sending device. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0042] Example:

[0043] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, first, second, front, back, etc.), the directional indications are only used to explain the relative relationship and movement status of the various components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0044] In addition, if the present invention involves descriptions such as "first" and "second", the descriptions such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] See also Figures 1 to 2An electromagnetic grid-based indoor positioning system according to an embodiment of the present invention includes an on-board power transmission coil assembly 1, a roadside power receiving coil assembly 2, and a control module (not shown). The on-board power transmission coil assembly 1 includes two power transmission coils 11 and a data receiving device 12. The roadside power receiving coil assembly 2 includes several power receiving coils 21, a receiver 22, a decoder 23, and a data transmission device 24.

[0046] One of the two power transmission coils 11 of the vehicle-mounted power transmission coil group 1 is arranged at the vehicle-mounted end 10, such as the front of an existing conventional AGV vehicle used for indoor transportation, and the other is arranged at the rear of the vehicle-mounted end 10. Both power transmission coils 11 are powered by the vehicle-mounted end 10. Preferably, each power transmission coil 11 is circuit-connected to an oscillator 13, and the vibration frequencies of the two power transmission coils 11 are different. According to the principle of electromagnetic field resonance, it is convenient to distinguish and judge the power receiving coils 21 corresponding to the two power transmission coils 11 in the future, thereby facilitating the calculation and confirmation of the positioning position of the vehicle-mounted end 10. Specifically, as Figure 2 As shown, one power transmission coil 11 is located in the center of the bottom front of the vehicle-mounted terminal 10, and the other power transmission coil 11 is located in the center of the bottom rear of the vehicle-mounted terminal 10. Both power transmission coils 11 are electrically connected to the vehicle-mounted terminal 10. Specifically, when the vehicle-mounted terminal 10 is powered on, both power transmission coils 11 are powered. In other words, both power transmission coils 11 only operate when the vehicle-mounted terminal 10 is powered on, ensuring high efficiency and safety.

[0047] The roadside power receiving coil group 2 includes a plurality of power receiving coils 21. The specific number is not limited or described, and is determined according to the indoor floor area where it is arranged. Specifically, a plurality of power receiving coils 21 are arranged on the indoor floor in a vertical and horizontal manner to form a coil grid. It should be noted that in order to facilitate the subsequent calculation to confirm the position and heading of the center of gravity of the vehicle-mounted terminal 10 in order to achieve accurate positioning of the vehicle-mounted terminal 10, after the roadside power receiving coil group 2 on the ground is installed, the position of each power receiving coil 21 needs to be calibrated to determine the specific position of each power receiving coil 21 and save it in the file. Use P m，n = (x, y) (natural numbers where m ≥ 1 and n ≥ 1) represents the position of any receiving coil 21. In this embodiment, 100 receiving coils 21 are arranged horizontally and 150 are arranged vertically, for a total of 15,000 receiving coils (i.e., 1 ≤ m ≤ 150, 1 ≤ n ≤ 100). Thus, the positions of all the receiving coils 21 in the roadside receiving coil group 2 can be expressed as follows:

[0048] .

[0049] There is no special limit on the spacing of each receiving coil 21, which mainly depends on the area of ​​the indoor floor, such as 10cm, 20cm, etc. In some embodiments of the present invention, assuming that the floor area of ​​a factory is 30m*20m and the electromagnetic field grid accuracy is 20cm, the number of receiving coils 21 in the roadside receiving coil group 2 is )indivual.

[0050] In the positioning system of an embodiment of the present invention, when the two power transmitting coils 11 in the vehicle-mounted power transmitting coil assembly 1 are powered, the two power transmitting coils 11 respectively form electromagnetic induction with the corresponding power receiving coils 21 at the position of the vehicle-mounted terminal 10, specifically, the position closest to the power transmitting coils 11, based on the electromagnetic induction effect, and generate induced current in the power receiving coils 21.

[0051] The receiver 22 is a conventional receiving device in the prior art, configured to be electrically connected, such as by circuit connection, to all of the receiving coils 21 to analyze the induced current and magnetic field vibration resonant frequency. The decoder 23 is similarly a conventional decoder in the prior art and can be a component of the receiver 22 or a separate decoder. In the embodiment of the present invention, the decoder and receiver are separate devices, electrically connected, such as by circuit connection or wireless communication connection, and configured to obtain the corresponding positions, i.e., xy coordinates, of the receiving coils 21 generating electromagnetic induction. The data transmitter 24 is, for example, a conventional wireless data transmitter or electromagnetic data transmitter in the prior art. It is connected, such as by wireless communication connection, to the decoder 23 and configured to receive the xy coordinate information of the receiving coils 21 transmitted by the decoder 23 and transmit it to the data receiver 12. The data receiver 12 is, for example, a conventional wireless data receiver in the prior art, wirelessly connected to the data transmitter 24 and configured to receive the coordinate positions of the receiving coils generating electromagnetic induction and the corresponding vibration frequency of the magnetic needle. The data receiving device 12 has a built-in control module (for example, the control module is a built-in control chip of the data receiving device 12), or the data receiving device 12 is electrically connected to a controller of the vehicle-mounted terminal 10 (the controller is the aforementioned control module) (in this case, the data receiving device 12 can be provided on the vehicle-mounted terminal), or the control module is an external device and wirelessly connected to the data transmitting module 24 (in this case, the data receiving device 12 may not be provided). The control module or controller can store the calibrated positions of the receiving coils 21 of the roadside receiving coil group 2. The control module can determine the coordinate positions of the two transmitting coils 11, i.e., the front and rear of the vehicle, based on the received coordinate positions and resonance frequencies of the receiving coils 21 (because the two transmitting coils 11 are respectively provided at the front and rear of the vehicle and have different frequencies, according to the principle of electromagnetic field resonance, the transmitting coils 11 corresponding to the two receiving coils 21 can be determined based on the difference in vibration frequencies. Combined with the positions of the receiving coils 21 obtained by the decoder 23, the positions of the front and rear of the vehicle-mounted terminal 10 can be accurately determined). The position of the center of gravity of the vehicle-mounted terminal 10 when the vehicle-mounted terminal 10 passes a certain position indoors is obtained by weighting the distance from the two power transmission coils 11 to the center of gravity of the vehicle-mounted terminal 10, and the heading of the vehicle-mounted terminal 10 is calculated based on the coordinate positions of the two power transmission coils 11. Based on the electromagnetic induction effect and the principle of electromagnetic resonance, the precise positioning of the vehicle-mounted terminal 10 indoors is achieved by obtaining and confirming the position and heading of the center of gravity of the vehicle-mounted terminal 10. In a preferred embodiment of the present invention, the data receiving device 12 is arranged on the vehicle-mounted terminal 10. The specific structure and working principle of the receiver 22, decoder 23, data sending device 24 and data receiving device 12 are not specifically limited or described here, and are all existing conventional equipment. According to some embodiments of the present invention, the vehicle-mounted power transmission coil group 1 does not include the data receiving device 12.

[0052] More specifically, let the distances between the two power transmission coils 11 and the center of gravity of the vehicle terminal 10 be L1 and L2 respectively, where L1 and L2 are known. When the vehicle terminal 10 passes a certain position, let the positions of the two power receiving coils 21 that generate electromagnetic induction with the two power transmission coils 11 be and , then:

[0053] The weighted position P of the center of gravity of the vehicle-mounted terminal 10 is: ;in, , , 0≤K1≤1, 0≤K2≤1. Since L1 and L2 are known, and the positions of the two power receiving coils 21 are also calibrated in advance, they are also known. Therefore, the position of the center of gravity of the vehicle-mounted terminal 10 can be calculated by directly substituting them. It should be noted that L1 and L2 can be equal or unequal. In a preferred embodiment, L1 and L2 are equal, then the coefficients K1 and K2 are both 0.5, then .

[0054] According to some embodiments of the present invention, the positions of the two power receiving coils 21 that generate electromagnetic induction with the two power transmitting coils 11 are and , then:

[0055] The heading of the vehicle terminal 10 is Since the positions of the two power receiving coils 21 are calibrated in advance, the values ​​of x1, x2, y1 and y2 in the heading are all known. Therefore, the heading of the vehicle terminal 10 can be calculated by simply substituting them.

[0056] The indoor positioning system of the embodiment of the present invention is based on an electromagnetic grid and achieves high-precision and high-reliability positioning of the vehicle-mounted terminal indoors through the electromagnetic induction effect and the magnetic field resonance principle, solving the problems of high indoor positioning cost or positioning drift, that is, low positioning accuracy, in the existing technology. The indoor positioning system of the embodiment of the present invention is low-cost, has high positioning accuracy, and is efficient and safe. It only works when the vehicle-mounted terminal is started.

[0057] An embodiment of the present invention further provides a positioning method of the indoor positioning system in the above embodiment, comprising the following steps:

[0058] S1. Lay the roadside power receiving coil group 2 on the indoor floor and calibrate each power receiving coil 21 to determine the position of each power receiving coil 21;

[0059] S2. When the vehicle terminal 10 automatically passes a certain position,

[0060] S21, obtaining the xy coordinates of the power receiving coil 21 generating the induced current at the position;

[0061] S22 : Calculate the position and heading of the center of gravity of the vehicle-mounted terminal 10 at the location, and realize indoor positioning of the vehicle-mounted terminal 10 .

[0062] Specifically, in step S21:

[0063] The receiver 22 analyzes the induced current and magnetic field vibration frequency of the power receiving coil 21 that generates electromagnetic induction, and obtains the corresponding xy coordinates of the power receiving coil 21 through the decoder 23. The specific description is the same as the above embodiment and will not be repeated here.

[0064] Specifically, in step S22:

[0065] S221: The data receiving device 12 receives the position of the power receiving coil 21 generating electromagnetic induction and the corresponding vibration frequency, and determines the positions of the two power transmitting coils 11;

[0066] S222: Based on the distances between the two power transmission coils 11 and the center of gravity of the vehicle-mounted terminal, the center of gravity of the vehicle-mounted terminal 10 at that location is weighted and the heading of the vehicle-mounted terminal 10 is obtained based on the positions of the two corresponding power transmission coils 11. The detailed description is the same as in the above embodiment and will not be repeated here.

[0067] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. An indoor positioning system based on electromagnetic grid, characterized in that: include: An on-board power transmission coil assembly includes two power transmission coils with different vibration frequencies, respectively located at the front and rear of the vehicle, and a data receiving device configured to receive the coordinate position and corresponding vibration frequency of the power receiving coil generating electromagnetic induction from a data transmitting device; a control module is built into the data receiving device or the data receiving device is electrically connected to the control module, and the two power transmission coils are powered by the on-board terminal; A roadside power receiving coil assembly comprising a coil grid formed by a plurality of power receiving coils arranged on the indoor floor at intervals of vertical and horizontal spacing, a receiver, a decoder and a data transmission device, wherein the position of any of the power receiving coils is pre-calibrated; When supplying power, the two power transmission coils respectively form electromagnetic induction with the power receiving coils at the position where the vehicle-mounted terminal is located, and generate induced current in the corresponding power receiving coils; The receiver is configured to analyze the induced current and magnetic field vibration resonance frequency; the decoder is configured to respectively obtain the corresponding xy coordinates of the power receiving coil that generates electromagnetic induction; the data sending device is configured to receive the xy coordinate information sent by the decoder; When the vehicle-mounted terminal automatically passes a certain location indoors, the control module determines the coordinate positions of the two power transmission coils based on the different vibration frequencies, and obtains the position of the center of gravity of the vehicle-mounted terminal based on the weighted distances between the two power transmission coils and the center of gravity of the vehicle-mounted terminal. The heading of the vehicle-mounted terminal is calculated based on the coordinate positions of the two power transmission coils. The distances between the two power transmission coils and the center of gravity of the vehicle-mounted terminal are L1 and L2 respectively; When the vehicle-mounted terminal passes a certain position, the positions of the two receiving coils that generate electromagnetic induction with the two transmitting coils are set to and , then: The weighted position P of the center of gravity of the vehicle-mounted terminal is: ;in, , ; Let the positions of the two receiving coils that generate electromagnetic induction with the two transmitting coils be and , then: the heading of the vehicle-mounted terminal is .

2. The indoor positioning system based on electromagnetic grid according to claim 1, characterized in that: It also includes an oscillator connected to the corresponding circuits of the two power transmission coils.

3. The indoor positioning system based on electromagnetic grid according to claim 1, characterized in that: The intervals between all the power receiving coils in the roadside power receiving coil group are equal.

4. The indoor positioning system based on electromagnetic grid according to claim 1, characterized in that: When the vehicle-mounted terminal is started, both power transmission coils in the vehicle-mounted power transmission coil group are powered.

5. A positioning method of an indoor positioning system based on an electromagnetic grid according to any one of claims 1 to 4, characterized in that: The steps include: S1. Lay the roadside power receiving coil group on the indoor floor and calibrate each power receiving coil to determine the position of each power receiving coil; S2. When the vehicle terminal automatically passes a certain position, S21, obtaining the xy coordinates of the power receiving coil generating the induced current at the position; S22. Calculate the position and heading of the center of gravity of the vehicle-mounted terminal at the position to achieve indoor positioning of the vehicle-mounted terminal.

6. The positioning method according to claim 5, characterized in that: In step S21: The receiver analyzes the induced current and magnetic field vibration frequency of the receiving coil that generates electromagnetic induction, and obtains the corresponding xy coordinates of the receiving coil through the decoder.

7. The positioning method according to claim 5, characterized in that: In step S22: S221: The data receiving device receives the position of the power receiving coil generating electromagnetic induction and the corresponding vibration frequency, and determines the positions of the two power transmitting coils; S222. Obtain the position of the center of gravity of the vehicle-mounted terminal at that position by weighting the distances between the two power transmission coils and the center of gravity of the vehicle-mounted terminal; and obtain the heading of the vehicle-mounted terminal according to the positions of the two corresponding power transmission coils.

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