Indoor target positioning method and system based on UWB beacon and particle swarm optimization algorithm

Abstract

The invention discloses an indoor target positioning method and system based on UWB beacons and a particle swarm optimization algorithm, and belongs to the technical field of wireless communication networks. The system comprises a positioning terminal, a UWB gateway, a positioning calculation unit and UWB beacons arranged at different indoor preset positions, the UWB beacon transmits a UWB signal to be received by the positioning terminal; the positioning terminal reads all UWB beacon data in a preset range in real time according to the UWB signal, and reports the UWB beacon data to the UWB gateway; the UWB gateway reports the UWB beacon data and the positioning terminal number corresponding to the UWB beacon data to a positioning calculation unit; and the positioning calculation unit solves a nonlinear equation set formed by the UWB beacon coordinates and the target positioning terminal coordinates based on a particle swarm optimization algorithm according to the UWB beacon data and the UWB beacon installation position to obtain an optimized positioning terminal position. According to the invention, the optimal solution of the position of the target terminal is solved through the optimization algorithm, so that the problem that the positioning precision is reduced due to inaccurate ranging values is solved.

Description

Technical Field

[0001] The invention relates to an indoor target positioning method and system based on UWB beacon and particle swarm optimization algorithm, belonging to the technical field of wireless communication network. Background Art

[0002] In modern society, with the rapid development of technologies such as communications, networks, and the Global Positioning System (GPS), location-aware computing and location-based services (LBS) are becoming increasingly important in real life. The emergence of positioning technology has greatly facilitated people's lives, and its influence has extended to all aspects of people's daily lives, including military, science and technology, and people's daily lives. Indoor positioning helps people's daily lives and is increasingly favored by various fields. However, the current mainstream GPS applications are suitable for outdoor places, while the propagation environment in indoor environments is complex, and GPS signals are easily absorbed by buildings, metal coverings, etc., and the presence of obstructions causes wireless signals to refract, reflect, and attenuate energy. In addition, its high cost has seriously affected the development of GPS applications in indoor positioning. Therefore, in order to meet personal and commercial needs, various indoor positioning technologies have emerged.

[0003] Ultra-wideband (UWB) positioning technology has become the most widely used wireless communication technology for positioning due to its advantages such as high multipath resolution, strong penetration, low power consumption, easy integration, and high positioning performance. However, due to the limited indoor space and many obstructions, although UWB signals in most cases are not as severely interfered as GPS, Beidou and other satellite signals, they will also cause problems such as reduced positioning accuracy and inaccurate ranging values ​​to a certain extent. Summary of the invention

[0004] The purpose of the present invention is to provide an indoor target positioning method and system based on UWB beacon and particle swarm optimization algorithm, aiming to solve the technical drawback of insufficient indoor target positioning accuracy caused by inaccurate ranging of UWB beacon.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions: On the one hand, the present invention provides an indoor target positioning system, which includes: a positioning terminal arranged on a target to be measured, a UWB gateway, a positioning calculation unit, and a plurality of UWB beacons arranged at different preset positions indoors; The UWB beacon is used to transmit a UWB signal for reception by the positioning terminal; The positioning terminal is used to read all UWB beacon data that can be received within a preset range in real time according to the UWB signal, and report the UWB beacon data to the UWB gateway periodically; The UWB gateway is used to report the UWB beacon data and the positioning terminal number corresponding to the UWB beacon data to the positioning calculation unit; The positioning calculation unit is used to obtain the UWB beacon installation position manually entered in the database, and solve the nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates based on the particle swarm optimization algorithm according to the UWB beacon data and the UWB beacon installation position to obtain the optimized positioning terminal position.

[0006] The present invention uses the high-precision distance information provided by UWB technology to provide a reliable data basis for the particle swarm optimization algorithm, making the positioning result more accurate; at the same time, the particle swarm optimization algorithm effectively avoids interference problems caused by shielding, multipath, signal loss and other problems in the indoor environment by processing complex nonlinear optimization problems, thereby achieving high-precision and high-efficiency indoor target positioning.

[0007] Optionally, the indoor target positioning system further includes a human-computer interaction unit, and a scene map is provided in the corresponding human-computer interface for displaying the position of the positioning terminal by dotting the map, and displaying the movement trajectory of the positioning terminal according to corresponding historical data.

[0008] Optionally, the UWB beacon data includes: a UWB beacon number, a received signal strength, a signal-to-noise ratio, and a ranging value between the UWB beacon and the positioning terminal.

[0009] Optionally, the ranging value between the UWB beacon and the positioning terminal is calculated by a TOA method, and a reporting period for reporting the UWB beacon data to the UWB gateway is set to 4s-6s.

[0010] Optionally, the indoor target positioning system also includes preprocessing the UWB beacon data, including: if the signal-to-noise ratio is less than 10 dB or the received signal strength is less than -69dB, filtering the corresponding UWB beacon data, and counting the number of valid UWB beacons corresponding to the remaining UWB beacon data.

[0011] Optionally, the nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates is expressed as: ; In the formula, Indicates The three-dimensional coordinates of valid UWB beacons, Indicates the three-dimensional coordinates of the positioning terminal, Indicates The distance value between a valid UWB beacon and the positioning terminal.

[0012] Optionally, if the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the three-dimensional coordinates of the optimized positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the two-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of the valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance measurement value between the valid UWB beacon and the terminal to be positioned as the radius.

[0013] Optional, The value is set according to the height of the positioning terminal to ensure that the calculation result is close to the actual position of the positioning terminal.

[0014] Optional, person-specific The value is set to 1.5 meters, and the animal's The value is set to 0.4 meters, and the mechanical equipment corresponds to Set the value to 1 meter.

[0015] In a second aspect, the present invention further provides an indoor target positioning method applicable to the indoor target positioning system as described in the first aspect, which comprises the following steps: S1: Initialize various parameters of the particle swarm optimization algorithm and randomly generate a particle swarm with the average position of the corresponding coordinates of all UWB beacons as the center; S2: Calculate the fitness value of each particle in the particle swarm, use the fitness value of each particle to update the individual optimal value and the global optimal value of the particle swarm, and update the speed and position according to the individual optimal value and the global optimal value to obtain an updated new position; S3: Determine whether one of the following conditions is met: a preset positioning accuracy is achieved or a preset maximum number of iterations is achieved; if not, execute step S2; otherwise, execute step S4; S4: If one of the above conditions is met, the optimal solution corresponding to the latest position is output as the estimated positioning terminal position, and the indoor target positioning is completed.

[0016] Optionally, the fitness value of each particle in the particle swarm is calculated based on the installation position of the UWB beacon and the ranging value between the UWB beacon and the positioning terminal in the UWB beacon data, and the calculation formula is expressed as: ; In the formula, represents the fitness value, represents the convergence coefficient, represents the estimated location of the positioning terminal, Indicates The installation location of each UWB beacon, Indicates The distance value between the UWB beacon and the positioning terminal, Indicates the number of UWB beacons.

[0017] Optionally, the speed and position are updated according to the individual optimal value and the global optimal value, expressed as: ; ; In the formula, express The speed of time, represents the inertia weight, express The speed of time, and represents the acceleration constant, and Represents a random number between 0 and 1. represents the individual optimal value, Indicates Particles in The location of the moment, represents the global optimal value, Indicates Particles in The location of the moment.

[0018] Optionally, the UWB beacon data further includes: UWB beacon number, received signal strength and signal-to-noise ratio.

[0019] Optionally, if the signal-to-noise ratio is less than 10 dB or the received signal strength is less than -69 dB, the corresponding UWB beacon data is filtered and the number of valid UWB beacons corresponding to the remaining UWB beacon data is counted.

[0020] Optionally, if the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the three-dimensional coordinates of the optimized positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the two-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of the valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance measurement value between the valid UWB beacon and the terminal to be positioned as the radius.

[0021] Optional, The value is set according to the altitude of the positioning terminal.

[0022] Optional, person-specific The value is set to 1.5 meters, and the animal's The value is set to 0.4 meters, and the mechanical equipment corresponds to Set the value to 1 meter.

[0023] Compared with the prior art, the present invention has the following beneficial effects: Compared with the problems of reduced positioning accuracy and inaccurate ranging values ​​caused by traditional positioning technologies, the present invention introduces a particle swarm optimization algorithm to obtain the optimal solution for the target position to compensate for the problem of reduced positioning accuracy caused by inaccurate ranging values; in addition, in view of the technical drawbacks that the terminal position cannot be solved or there may be large errors due to insufficient effective beacon data, the present invention introduces dimensionality reduction means so that the positioning process can select the positioning method in a targeted manner according to the number of effective beacons, thereby achieving high-precision positioning when the number of effective beacons is sufficient, and feasibility reporting when the number of effective beacons is scarce, so that the beacon data is effectively utilized to the maximum extent, and the practicality is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown is a schematic structural diagram of the indoor target positioning system of the present invention; Figure 2 The figure shows a schematic diagram of the logical relationship between the number of effective beacons and dimensional positioning of the present invention; Figure 3 Shown is a schematic diagram of an embodiment of the indoor target positioning method of the present invention; Figure 4 FIG. 1 is a schematic diagram of another embodiment of the indoor target positioning method of the present invention; In the figure: 1-first positioning terminal; 2-second positioning terminal; 3-third positioning terminal; 4-first UWB beacon; 5-second UWB beacon; 6-third UWB beacon; 7-container. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0026] Example 1 refer to Figure 1 ,This embodiment introduces an indoor target positioning system, which includes: a plurality of UWB beacons arranged at different preset positions indoors, the UWB beacons are fixed on the wall or bracket of the positioning environment, the distance from the ground is generally no more than three meters, one is deployed every 20-50 meters, preferably one every 20 meters, for transmitting UWB signals for reception by the positioning terminal; A positioning terminal is set on the target to be measured. The positioning terminal can be placed in the work badge or helmet worn by the personnel, or on the top of the tunnel trolley, or installed in the collar when locating the animal, and is used to read all the UWB beacon data that can be received within the preset range in real time, and report the UWB beacon data to the UWB gateway periodically; The UWB gateway is used to report the UWB beacon data and the positioning terminal number corresponding to the UWB beacon data to the positioning calculation unit; The positioning calculation unit is used to obtain the UWB beacon installation position manually entered in the database, and solve the nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates based on the particle swarm optimization algorithm according to the UWB beacon data and the UWB beacon installation position to obtain the optimized positioning terminal position; wherein the beacon installation position is obtained by manual measurement by the installer using a laser rangefinder.

[0027] In the specific application of this embodiment, the positioning calculation unit is responsible for processing positioning data and calculating the position, the UWB gateway serves as a bridge connecting the UWB beacon and the positioning calculation service, the UWB beacon is the reference point of the positioning system, and transmits the UWB signal, and the positioning terminal is the device carried by the object to be located. These components together constitute a complete positioning system, providing users with accurate and real-time positioning services.

[0028] Example 2 Based on Example 1, this embodiment also has the following design: The indoor target positioning system also includes a human-computer interaction unit, and a scene map is set in its corresponding human-computer interface for displaying the position of the positioning terminal by dotting the map, and displaying the movement trajectory of the positioning terminal according to the corresponding historical data.

[0029] The positioning terminal can read all UWB beacon data within a range of 200 meters and report it to the UWB gateway at a periodicity (specifically, it can be set to 4s-6s, and preferably set to 4 seconds in this embodiment). Among them, the UWB beacon data includes: UWB beacon number, received signal strength, signal-to-noise ratio, and the ranging value between the UWB beacon and the positioning terminal. Specifically, the ranging value between the UWB beacon and the positioning terminal can be calculated by the TOA method. Due to the indoor environment, it may be interfered by shielding, multipath, signal loss and other problems. Generally speaking, the ranging accuracy is ±10cm, and the occasional maximum measurement error may reach 20-30cm.

[0030] Since the reported ranging value has too large an error and may contain invalid values ​​such as -1, 65535, it cannot participate in the positioning calculation. Therefore, after receiving the data reported by the positioning terminal through the UWB gateway, the positioning calculation unit first filters the received relevant data to remove the beacon data that is read by the positioning terminal but whose signal-to-noise ratio and received signal strength (preferably the signal-to-noise ratio is greater than 10 dB and the received signal strength is greater than -69dB) do not meet the requirements, and counts the number of valid UWB beacons corresponding to the remaining UWB beacon data.

[0031] Assume that the coordinates of a valid UWB beacon are ( ), =1, 2...N, The distance between the UWB beacon and the positioning terminal is , by solving the intersection points based on the intersection of multiple spheres, we can get a nonlinear equation group consisting of N UWB beacon coordinates and positioning terminal coordinates. However, due to the introduction of related errors such as obstructions, the spheres cannot intersect at the real coordinate position. Therefore, it is usually necessary to involve as many valid beacons as possible to estimate the optimal positioning terminal coordinates.

[0032] Specifically, the nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates is expressed as: ; In the formula, Indicates The three-dimensional coordinates of valid UWB beacons, Indicates the three-dimensional coordinates of the positioning terminal, Indicates The distance value between a valid UWB beacon and the positioning terminal.

[0033] refer to Figure 2, if the number of valid beacons is greater than 5 (such as the number of valid beacons is 6), it is impossible to obtain a unique analytical solution for solving such an overdetermined (the number of unknown variables is less than the number of equations) nonlinear equation system, but an optimal solution is obtained. Therefore, this embodiment specifically adopts a particle swarm optimization algorithm to perform three-dimensional positioning calculation (iterative optimization process) to obtain the xyz three-dimensional data of the positioning terminal, and the corresponding position coordinates will be displayed in real time on the human-machine interface for user reference.

[0034] However, due to signal problems, when only 1, 2 or 3 valid beacon data are received during the system operation, the terminal position cannot be solved or there may be a large error. That is, when the distance measurement value is inaccurate and the number of beacons is insufficient, it is easy to cause the objective function (evaluation function) to fail to converge, or the convergence result is far away from the actual terminal position. In traditional methods, it is generally chosen not to calculate the above-mentioned related data, which will cause the terminal position on the display interface to remain unchanged or jump for a long time.

[0035] In view of the above problems, this embodiment proposes a data dimension classification method to improve the user experience. By reducing the data dimension, the three-variable quadratic equation is converted into a two-variable quadratic equation or a one-variable linear equation. This measure can not only ensure the stable reporting of relevant data, but also ensure certain accuracy requirements, as described below: If the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the optimized three-dimensional coordinates of the positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the two-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance between the valid UWB beacon and the terminal to be positioned as the radius; if no valid UWB beacon is received, it means that the positioning fails, and the terminal position on the display interface is not updated, that is, the terminal position on the display interface does not move. The above ideas can effectively solve the problem of indoor signal problems, which lead to the loss of terminal position and inaccurate position.

[0036] In addition, the above mentioned The value is set according to the height of the positioning terminal to ensure that the calculation result is close to the actual position of the positioning terminal. The value is set to 1.5 meters, and the animal's The value is set to 0.4 meters, and the mechanical equipment corresponds to Set the value to 1 meter.

[0037] Example 3 This embodiment provides an indoor target positioning method applicable to the indoor target positioning system described in Embodiment 1 or Embodiment 2, which comprises the following steps: S1: Initialize various parameters of the particle swarm optimization algorithm and randomly generate a particle swarm with the average position of the corresponding coordinates of all UWB beacons as the center; S2: Calculate the fitness value of each particle in the particle swarm, use the fitness value of each particle to update the individual optimal value and the global optimal value of the particle swarm, and update the speed and position according to the individual optimal value and the global optimal value to obtain an updated new position; S3: Determine whether one of the following conditions is met: a preset positioning accuracy is achieved or a preset maximum number of iterations is achieved; if not, execute step S2; otherwise, execute step S4; S4: If one of the above conditions is met, the optimal solution corresponding to the latest position is output as the estimated positioning terminal position, and the indoor target positioning is completed.

[0038] This embodiment compares the search space for solving the problem to the flight space of birds, abstracts each bird into a particle without mass and volume, and uses it to represent a possible solution to the problem. During the search process, each particle updates its position and velocity based on its own historical optimal position and the global optimal position in the group, so that the particle gradually approaches the real position. This method based on the particle swarm optimization algorithm not only significantly improves the indoor positioning accuracy, but also effectively guarantees the dynamic performance of the positioning algorithm, such as the calculation speed, the amount of data collected for positioning, and the number of iterations.

[0039] Example 4 Based on Example 3, this embodiment also has the following design: First, it is worth noting that the UWB beacon mentioned in Example 3 is for a valid UWB beacon, for the following reasons: The UWB beacon data specifically includes: UWB beacon number, received signal strength, signal-to-noise ratio, and the ranging value between the UWB beacon and the positioning terminal. However, not all UWB beacon data can participate in the subsequent optimization calculation process. Therefore, in order to better achieve target positioning, this process will specifically remove beacon data that is read by the positioning terminal but does not meet the requirements for signal-to-noise ratio and received signal strength (preferably the signal-to-noise ratio is greater than 10 dB and the received signal strength is greater than -69dB), and count the number of valid UWB beacons corresponding to the remaining UWB beacon data.

[0040] Assume that the coordinates of a valid UWB beacon are ( ), =1, 2...N, The distance between the UWB beacon and the positioning terminal is , by solving the intersection points based on the intersection of multiple spheres, we can get a nonlinear equation group consisting of N UWB beacon coordinates and positioning terminal coordinates. However, due to the introduction of related errors such as obstructions, the spheres cannot intersect at the real coordinate position. Therefore, it is usually necessary to involve as many valid beacons as possible to estimate the optimal positioning terminal coordinates.

[0041] The nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates is expressed as: ; In the formula, Indicates The three-dimensional coordinates of valid UWB beacons, Indicates the three-dimensional coordinates of the positioning terminal, Indicates The distance value between a valid UWB beacon and the positioning terminal.

[0042] refer to Figure 2 , if the number of valid beacons is greater than 5 (such as the number of valid beacons is 6), it is impossible to obtain a unique analytical solution for solving such an overdetermined (the number of unknown variables is less than the number of equations) nonlinear equation system, but an optimal solution is solved. Therefore, for the case where the number of valid beacons is 6, this embodiment specifically uses a particle swarm optimization algorithm to perform three-dimensional positioning calculations (iterative optimization process) to obtain the xyz three-dimensional data of the positioning terminal, and the corresponding position coordinates will be displayed in real time on the human-machine interface for user reference. The specific optimization process is as follows: First, an evaluation function is established to calculate the fitness value of each particle in the particle swarm; wherein the fitness value of each particle in the particle swarm is calculated according to the installation position of the UWB beacon and the ranging value between the UWB beacon and the positioning terminal, and the calculation formula is expressed as: ; In the formula, represents the fitness value, represents the convergence coefficient, represents the estimated location of the positioning terminal, Indicates The installation location of each UWB beacon, Indicates The distance value between the UWB beacon and the positioning terminal, Indicates the number of UWB beacons.

[0043] The core of the particle swarm optimization algorithm is the selection of the evaluation function. The quality of the evaluation function determines the final result. When the distance measurement error is large, the general evaluation function may cause the optimal solution to be far away from the actual position. Therefore, the conventional evaluation function is adjusted from the square to the fourth power to expand the influence of the distance difference on the evaluation result; at the same time, the convergence coefficient k is added to adjust the convergence speed of the evaluation function. Preferably, k is 0.5.

[0044] Furthermore, an initial value is defined, and the position and velocity of the particle swarm are initialized with the initial value as the center.

[0045] Specifically, the position is a set of points (particles) randomly distributed in the space with the initial value as the center, the speed is a set of random vectors with the same number as the position, representing the adjustment direction of the position, and the initial value is The average of all coordinates in . If 6 valid beacons are received, and the installation coordinates corresponding to these 6 valid beacons are (0, 0, 0), (1, 1, 1)...(5, 5, 5), then the initial value is (2.5, 2.5, 2.5).

[0046] Furthermore, the speed and position of each particle are updated, and the updated position is evaluated by the evaluation function. The evaluation result is the fitness value of the point. The smaller the fitness value, the more accurate the position estimation. If it is 0, it means that the optimal solution has been found.

[0047] Specifically, the speed and position are updated according to the individual optimal value and the global optimal value, which can be expressed as: ; ; In the formula, express The speed of time, represents the inertia weight, express The speed of time, and represents the acceleration constant, and Represents a random number between 0 and 1. represents the individual optimal value, Indicates Particles in The location of the moment, represents the global optimal value, Indicates Particles in The location of the moment.

[0048] Furthermore, the fitness value of each particle is recalculated according to the new position, and the individual historical optimal position and the group historical optimal position are updated. If the new position is better than the historical optimal position, it is updated to the new historical optimal position.

[0049] Furthermore, the speed and position of each particle are updated repeatedly to determine whether one of the following conditions is met: a preset positioning accuracy is achieved or a preset maximum number of iterations is achieved. If one of the above conditions is met, the optimal solution corresponding to the latest position is output as the estimated positioning terminal position, and the indoor target positioning is completed.

[0050] However, due to signal problems, when only 1, 2 or 3 valid beacon data are received during the system operation, the terminal position cannot be solved or there may be a large error. That is, when the distance measurement value is inaccurate and the number of beacons is insufficient, it is easy to cause the objective function (evaluation function) to fail to converge, or the convergence result is far away from the actual terminal position. In traditional methods, it is generally chosen not to calculate the above-mentioned related data, which will cause the terminal position on the display interface to remain unchanged or jump for a long time.

[0051] In view of the above problems, this embodiment proposes a data dimension classification method to improve the user experience. By reducing the data dimension, the three-variable quadratic equation is converted into a two-variable quadratic equation or a one-variable linear equation. This measure can not only ensure the stable reporting of relevant data, but also ensure certain accuracy requirements, as described below: If the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the optimized three-dimensional coordinates of the positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the two-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance between the valid UWB beacon and the terminal to be positioned as the radius; if no valid UWB beacon is received, it means that the positioning fails, and the terminal position on the display interface is not updated, that is, the terminal position on the display interface does not move. The above ideas can effectively solve the problem of indoor signal problems, which lead to the loss of terminal position and inaccurate position.

[0052] In addition, the above mentioned The value is set according to the height of the positioning terminal to ensure that the calculation result is close to the actual position of the positioning terminal. The value is set to 1.5 meters, and the animal's The value is set to 0.4 meters, and the mechanical equipment corresponds to Set the value to 1 meter.

[0053] This embodiment solves the problem of inaccurate positioning and large errors through the particle swarm optimization algorithm, and solves the problem that the received data cannot calculate the terminal position due to equal shielding problems, or a large number of beacons are required to ensure the overall effect of the system due to the scene being too open, by dimensionality reduction. That is, when the number of beacons is sufficient, the data accuracy is emphasized, and when the number of beacons is small, a result with a certain degree of credibility can still be reported for the owner to have an overall understanding of the on-site situation, which is more practical.

[0054] In the specific application of this embodiment, first Figure 3 As shown, in a straight channel (100 meters long and 5-8 meters wide), there are one or more mobile carts (first positioning terminal 1) moving back and forth along the corridor (coal or cargo transportation channel, the owner is more concerned about the mileage position of the cart, and does not care whether it is on the left or right side of the channel). Generally speaking, at least three UWB beacons are required for position positioning. Using this patent solution, only two UWB beacons need to be installed at the beginning and end of the corridor, namely the first UWB beacon 4 and the second UWB beacon 5, and the one-dimensional positioning solution can be used to locate the position of the cart. When displayed, the cart will be displayed on the right side of the moving track gauge.

[0055] For example Figure 4 As shown, there are 8 shelves 7 and several third UWB beacons 6 in the factory, and the staff are walking in the factory. Among them, the staff (second positioning terminal 2) is in the middle channel, and the positioning signal is better. It is positioned using a three-dimensional positioning method. Since the staff (third positioning terminal 3) is between two shelves, the positioning signal is poor and cannot be positioned, or the positioning result may be inaccurate. The traditional solution is to increase the number of beacons, such as adding a beacon between each shelf, or moving out of the shelf (unrealistic). In view of the above situation, three-dimensional positioning is performed for the area where the second positioning terminal 2 is located to ensure the accuracy of the positioning data, and two-dimensional positioning is performed for the third positioning terminal 3 to ensure that the user can intuitively understand the location information of his location.

[0056] Example 5 This embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the indoor target positioning method described in Embodiment 3 or Embodiment 4 are executed.

[0057] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0058] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An indoor target positioning system, characterized in that: include: A positioning terminal, a UWB gateway, a positioning calculation unit, and a plurality of UWB beacons arranged at different preset positions indoors are arranged on the target to be measured; The UWB beacon is used to transmit a UWB signal for reception by the positioning terminal; The positioning terminal is used to read all UWB beacon data that can be received within a preset range in real time according to the UWB signal, and report the UWB beacon data to the UWB gateway periodically; The UWB gateway is used to report the UWB beacon data and the positioning terminal number corresponding to the UWB beacon data to the positioning calculation unit; The positioning calculation unit is used to obtain the UWB beacon installation position manually entered in the database, and solve the nonlinear equation group consisting of the UWB beacon coordinates and the positioning terminal coordinates based on the particle swarm optimization algorithm according to the UWB beacon data and the UWB beacon installation position to obtain the optimized positioning terminal position.

2. The indoor target positioning system according to claim 1, characterized in that: It also includes a human-computer interaction unit, and a scene map is set in its corresponding human-computer interface for displaying the position of the positioning terminal by dotting the map, and displaying the movement trajectory of the positioning terminal according to corresponding historical data.

3. The indoor target positioning system according to claim 2, characterized in that: The UWB beacon data includes: UWB beacon number, received signal strength, signal-to-noise ratio, and ranging value between the UWB beacon and the positioning terminal; The distance value between the UWB beacon and the positioning terminal is calculated by the TOA method, and the reporting period of the UWB beacon data to the UWB gateway is set to 4s-6s.

4. The indoor target positioning system according to claim 3, characterized in that: It also includes preprocessing the UWB beacon data, including: if the signal-to-noise ratio is less than 10 dB or the received signal strength is less than -69 dB, filtering the corresponding UWB beacon data, and counting the number of valid UWB beacons corresponding to the remaining UWB beacon data.

5. The indoor target positioning system according to claim 4, characterized in that: The nonlinear equation group composed of the UWB beacon coordinates and the positioning terminal coordinates is expressed as: ； In the formula, Indicates The three-dimensional coordinates of valid UWB beacons, Indicates the three-dimensional coordinates of the positioning terminal, Indicates The distance value between a valid UWB beacon and the positioning terminal; If the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the optimized three-dimensional coordinates of the positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the two-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; If the number of the valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance measurement value between the valid UWB beacon and the terminal to be positioned as the radius.

6. The indoor target positioning system according to claim 5, characterized in that: The value is set according to the altitude of the positioning terminal to ensure that the calculation result is close to the actual position of the positioning terminal; Among them, people correspond to The value is set to 1.5 meters, and the animal's The value is set to 0.4 meters, and the mechanical equipment corresponds to Set the value to 1 meter.

7. An indoor target positioning method applicable to the indoor target positioning system according to any one of claims 1 to 6, characterized in that: include: S1: Initialize various parameters of the particle swarm optimization algorithm and randomly generate a particle swarm with the average position of the corresponding coordinates of all UWB beacons as the center; S2: Calculate the fitness value of each particle in the particle swarm, use the fitness value of each particle to update the individual optimal value and the global optimal value of the particle swarm, and update the speed and position according to the individual optimal value and the global optimal value to obtain an updated new position; S3: Determine whether one of the following conditions is met: a preset positioning accuracy is achieved or a preset maximum number of iterations is achieved; if not, execute step S2; otherwise, execute step S4; S4: If one of the above conditions is met, the optimal solution corresponding to the latest position is output as the estimated positioning terminal position, and the indoor target positioning is completed.

8. The indoor target positioning method according to claim 7, characterized in that: The fitness value of each particle in the particle swarm is calculated based on the installation position of the UWB beacon and the ranging value between the UWB beacon and the positioning terminal in the UWB beacon data. The calculation formula is expressed as: ； In the formula, represents the fitness value, represents the convergence coefficient, represents the estimated location of the positioning terminal, Indicates The installation location of each UWB beacon, Indicates The distance value between the UWB beacon and the positioning terminal, Indicates the number of UWB beacons.

9. The indoor target positioning method according to claim 8, characterized in that: The speed and position are updated according to the individual optimal value and the global optimal value, which can be expressed as: ； ； In the formula, express The speed of time, represents the inertia weight, express The speed of time, and represents the acceleration constant, and Represents a random number between 0 and 1. represents the individual optimal value, Indicates Particles in The location of the moment, represents the global optimal value, Indicates Particles in The location of the moment.

10. The indoor target positioning method according to claim 9, characterized in that: The UWB beacon data also includes: UWB beacon number, received signal strength and signal-to-noise ratio; If the signal-to-noise ratio is less than 10 dB or the received signal strength is less than -69 dB, the corresponding UWB beacon data is filtered and the number of valid UWB beacons corresponding to the remaining UWB beacon data is counted; If the number of valid UWB beacons is greater than 5, a three-dimensional positioning calculation is performed to obtain the optimized three-dimensional coordinates of the positioning terminal. ; If the number of valid UWB beacons is greater than 2 and less than 6, the three-dimensional coordinates corresponding to the positioning terminal are set to Then, the particle swarm optimization algorithm is used to perform two-dimensional positioning calculation; if the number of valid UWB beacons is 2, the three-dimensional coordinates corresponding to the positioning terminal are set to After that, the one-dimensional positioning calculation is performed through the particle swarm optimization algorithm; The value is set according to the altitude of the positioning terminal; If the number of the valid UWB beacons is 1, a 0-dimensional positioning calculation is performed, and the positioning terminal is located in a circle with the valid UWB beacon as the center and the distance measurement value between the valid UWB beacon and the terminal to be positioned as the radius.

Images