UWB positioning method based on error compensation, readable storage medium and equipment

Abstract

The invention relates to the technical field of indoor wireless positioning, in particular to a UWB positioning method based on error compensation, a readable storage medium and equipment. The UWB positioning method comprises the following four steps: deploying UWB base stations around an indoor scene, dividing the indoor scene into different areas, calculating a Tag position by using a trilateral positioning algorithm, calculating a residual error value, and carrying out weighting processing on the residual error value to obtain Tag coordinates based on error compensation, namely dividing an indoor space into a plurality of positioning areas, the coordinate estimation value of the Tag and the distance of the UWB base station are subjected to weighted fusion, weighting processing is carried out through residual values of position estimation of a plurality of positioning areas, the influence of a non-line-of-sight (NLOS) error is identified in a primary error compensation mode, a residual correction model is established to carry out secondary error compensation on a UWB positioning result, and the UWB positioning accuracy is improved. The influence of the non-line-of-sight error on UWB positioning can be effectively suppressed, and a higher-precision positioning result can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of indoor wireless positioning, and in particular to a UWB positioning method based on error compensation, a readable storage medium and a device. Background Art

[0002] Ultra-Wideband (UWB) positioning technology is a wireless carrier communication technology that uses nanosecond non-sinusoidal narrow pulses to transmit data. It has received extensive attention and research in the field of indoor positioning due to its high precision, strong anti-interference ability, and good real-time performance. In two-dimensional positioning, the principle of single UWB positioning is based on three-sided ranging, using TOF (Time of Light) or TDOA (Time Different of Arrival) to measure the distance between the UWB tag Tag and at least three UWB base station Anchors, and then solving the coordinates by a set of simultaneous equations. Due to the complexity of the indoor environment, when the Tag and the Anchor are in a non-line-of-sight (NLOS) scenario, the distance measurement error increases, resulting in deviations in the positioning results.

[0003] Therefore, the UWB positioning results are greatly affected by the NLOS scenario indoors. In order to improve the positioning performance of the UWB positioning system, the conventional practice is to add enough redundant base stations, but this will increase the cost of deploying additional base stations, or use combined positioning with other positioning methods such as WiFi, PDR, etc., which will also cause problems such as increased system complexity, large data processing volume, and additional costs.

[0004] In summary, there is an urgent need for a positioning method that can effectively suppress the impact of non-line-of-sight errors on UWB positioning to solve the problems existing in the prior art. Summary of the invention

[0005] The purpose of this utility model is to provide a UWB positioning method based on error compensation that can effectively suppress the influence of non-line-of-sight errors on UWB positioning. The specific technical scheme is as follows:

[0006] A UWB positioning method based on error compensation comprises the following steps:

[0007] The first step is to deploy n UWB base stations around the indoor scene, and people carry UWB tags to any location indoors; n is a natural number greater than or equal to 3;

[0008] The second step is to divide the indoor scene into different areas, and use the three-sided positioning algorithm to solve the tag position, which includes: Step 2.1, area division, specifically: using three-sided ranging positioning, divide the indoor scene into triangular areas; establish a list of corresponding relationships between the numbers of UWB base stations and triangular areas; step 2.2, based on the judgment condition that the tag can communicate and measure distance with the UWB base station, screen out m UWB base stations, where m is a natural number greater than or equal to 3 and less than or equal to n; obtain the corresponding p triangular areas according to the corresponding relationship list in step 2.1, where p is a natural number greater than or equal to 1 and less than or equal to natural number; solve the estimated coordinate value of the Tag in the p triangular regions; step 2.3, weighted fusion of the estimated coordinate value of the Tag obtained in step 2.2 and the distance of m UWB base stations to obtain the fused coordinate value X of the Tag Tag ;

[0009] Step 3: Calculate the distance between the coordinates of the fused tag and each UWB base station; Calculate the distance between the estimated location of the tag in each area and each UWB base station; Subtract the two distances to get the residual value E res ;

[0010] Step 4: The residual value E obtained in step 3 res Perform weighted processing to obtain the tag coordinates after error compensation.

[0011] Preferably, 3-20 UWB base stations are deployed around the indoor scene;

[0012] Set the coordinate value set of the UWB base station to A i , then we have the following expression:

[0013]

[0014] in: They represent the x-coordinate and y-coordinate of the i-th UWB base station respectively.

[0015] Preferably, the distance between the Tag and the UWB base station is calculated using the following formula:

[0016]

[0017] Where: d i,t represents the distance between the tag and the i-th UWB base station, i is a natural number greater than or equal to 1 and less than or equal to n; (x Tag ,y Tag ) indicates the coordinate position of the Tag.

[0018] Preferably, before weighted fusion of the distance between the tag obtained in step 2.2 and each UWB base station, the position of the tag is estimated in each triangle to obtain a coordinate set in: Represents the estimated position of the Tag in the Δi-th triangular region.

[0019] Preferably, the coordinate value X of the fused Tag in step 2.3 Tag Calculated using the following formula:

[0020]

[0021] in: represents the fusion weight of the Δi-th triangle area, which is calculated using the following formula:

[0022] j represents the calculation control parameter and has no practical meaning.

[0023] Preferably, in the third step:

[0024] The distance between the fused tag coordinates and the i-th UWB base station is expressed by the vector norm: ||X Tag -A i ||;

[0025] The distance between the estimated location of the tag in each area and the i-th UWB base station is expressed by the vector norm: ||X Tag,Δi -A i ||;

[0026] The residual value E corresponding to the Δi-th triangular area res (X Tag,Δi ) is calculated using the following formula:

[0027]

[0028] Preferably, the following residual weighted fusion correction model is used when performing weighted processing in the fourth step:

[0029]

[0030] in: represents the tag coordinates after error compensation, S is the total number of residual values ​​retained for fusion solution after comparison with the threshold, and W i is the weight value of the position coordinate residual solved for the Δi-th triangular area, which is calculated using the following formula:

[0031]

[0032] Applying the technical solution of the present invention, the effects are as follows:

[0033] 1. The UWB positioning method based on error compensation of the present invention includes four steps: deploying UWB base stations around indoor scenes, dividing indoor scenes into different areas and using three-sided positioning algorithm to solve Tag positions, calculating residual values, and weighted processing the residual values ​​to obtain Tag coordinates after error compensation. The indoor space is divided into multiple positioning areas, the estimated coordinate value of the Tag and the distance of the UWB base station are weightedly fused, and the residual values ​​of the position estimates of multiple positioning areas are weighted. An error compensation method is performed to identify the influence of non-line-of-sight error NLOS, and a residual correction model is established to perform secondary error compensation on the UWB positioning result, which can effectively suppress the influence of non-line-of-sight error on UWB positioning and obtain a more accurate positioning result.

[0034] 2. The present invention preferably deploys 3-20 UWB base stations around the indoor scene. The specific number is selected according to actual needs, which can maximize the advantages of UWB base stations and improve positioning accuracy.

[0035] 3. The present invention preferably estimates the position of the Tag in each triangle before weighted fusion of the distance between the obtained Tag and each UWB base station, so as to facilitate the subsequent acquisition of the coordinate value of the fused Tag, thereby facilitating the further acquisition of the residual value corresponding to the triangular area, and introducing the weight value of the position coordinate residual solved in the triangular area to compensate the coordinate, and finally obtain high-precision Tag coordinates based on error compensation.

[0036] The present invention also discloses a readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned UWB positioning method based on error compensation is implemented.

[0037] The present invention also discloses an electronic device, comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the above-mentioned UWB positioning method based on error compensation by executing the executable instructions.

[0038] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 is a schematic diagram of a UWB positioning method based on error compensation in an embodiment of the present invention;

[0041] Figure 2 It is a structural schematic diagram of indoor scene division in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0043] Example:

[0044] A UWB positioning method based on error compensation, the principle of which is as follows Figure 1 As shown, it specifically includes: deploying UWB base stations in indoor areas; dividing indoor scenes into several areas according to the number of UWB base stations (referred to as base stations); calculating the position residuals of single-area solution and multi-area fusion solution; taking the average value of the residual values ​​as the threshold; screening the residual values ​​that meet the threshold conditions; calculating the weights of the screened residual values, establishing a weighted fusion correction model, and outputting the positioning results.

[0045] In this embodiment, a UWB positioning method based on error compensation specifically includes the following steps:

[0046] The first step is to deploy n UWB base stations around the indoor scene, and people carry UWB tags to any location indoors; n is a natural number greater than or equal to 3. In this embodiment, 3-20 UWB base stations can be deployed around the indoor scene, and four UWB base stations (that is, the value of n is 4) are further preferred according to demand, specifically Anchor1 to Anchor4 UWB base stations.

[0047] Set the coordinate value set of the UWB base station to A i , then we have the following expression:

[0048]

[0049] in: They represent the x-coordinate and y-coordinate of the i-th UWB base station respectively.

[0050] The second step is to divide the indoor scene into different areas and use the three-sided positioning algorithm to solve the tag position, including:

[0051] Step 2.1: Area division: Use three-sided ranging positioning to divide the indoor scene into In this embodiment, the indoor scene can be divided into 4 triangular areas. They are represented by Δ1, Δ2, Δ3, and Δ4 respectively, see Figure 1 . Establish a list of correspondence between the UWB base station numbers and triangular areas, such as: {Δ1, uwb1, uwb2, uwb3} for easy understanding;

[0052] {Δ1, uwb4, uwb5, uwb6}

[0053] {......}

[0054] Step 2.2: Based on the condition that the tag can communicate and measure distance with the UWB base station, m UWB base stations are selected, where m is a natural number greater than or equal to 3 and less than or equal to n; and p corresponding triangular areas are obtained according to the corresponding relationship list in step 2.1, where p is a natural number greater than or equal to 1 and less than or equal to n. A natural number; solve the estimated coordinates of Tag in p triangular regions.

[0055] In this embodiment, the following formula is preferably used to calculate the distance between the tag and the UWB base station:

[0056]

[0057] Where: d i,t represents the distance between the tag and the i-th UWB base station, i is a natural number greater than or equal to 1 and less than or equal to n; (x Tag ,y Tag ) indicates the coordinate position of the Tag.

[0058] Whether it is NLOS or LOS conditions, the UWB signal can communicate with the tag through direct radiation, refraction, etc., but the indirect ranging contains errors. If communication and ranging are completely impossible, it means that the communication link between the base station and the tag is completely interrupted due to the obstruction of the indoor environment, and it needs to be abandoned. In this embodiment, the judgment condition is based on the ability of the Tag to communicate and measure distance with the base station. By screening m base stations that meet the conditions, according to the corresponding relationship list of step 2.1, the corresponding p areas in the indoor scene are obtained. In the p triangular areas, the distance between the Tag and each UWB base station in the triangular area is measured, and the coordinate estimate of the Tag in the p triangular areas is solved. The core concept is: use multiple base stations for regional positioning, obtain the residuals between multiple positioning coordinate values ​​and each base station, and judge the impact of NLOS by the size of the residuals.

[0059] Step 2.3: Perform weighted fusion of the distance between the tag obtained in step 2.2 and each UWB base station to obtain the coordinate value X of the fused tag. Tag .

[0060] In this embodiment, before weighted fusion is preferably performed, the position of the tag in each triangle is estimated to obtain a coordinate set: in: T represents the estimated position of the Tag in the Δi-th triangular area. In this embodiment, the four estimated coordinate values ​​of the Tag are:

[0061] The coordinate value X of the fused tag Tag Calculated using the following formula:

[0062]

[0063] in: represents the fusion weight of the Δi-th triangle area, which is calculated using the following formula:

[0064] j represents the calculation control parameter and has no practical meaning.

[0065] Step 3: Calculate the distance between the coordinates of the fused tag and each UWB base station; Calculate the distance between the estimated location of the tag in each area and each UWB base station; Subtract the two distances to get the residual value E res . The preferred embodiment of this invention is:

[0066] The distance between the fused tag coordinates and the i-th UWB base station is expressed by the vector norm: ||X Tag -A i ||;

[0067] The distance between the estimated location of the tag in each area and the i-th UWB base station is expressed by the vector norm: ||X Tag,Δi -A i ||;

[0068] The residual value E corresponding to the Δi-th triangular area res (X Tag,Δi ) is calculated using the following formula:

[0069]

[0070] The purpose of residual analysis in this embodiment is: when the Tag moves to any area, whether the Tag coordinates involved in the positioning solution by the UWB base station selected in the area are accurate, that is, compared with the Tag coordinates solved by fusion of multiple areas, the residual of the position estimate is obtained (the probabilistic difference between the residual and the error: the residual indicates that the two distance values ​​are both observed values / measured values; the error is the difference between the true value and the measured value). According to the size of the residual, it is determined whether the Tag is in the NLOS or LOS state in the Δi-th triangular area. If the residual of the Δi-th triangular area is large, it is determined that there is an NLOS error in this area. If the residual value is small, it is determined that this area is in the LOS situation.

[0071] Step 4: The residual value E obtained in step 3 res Perform weighted processing to obtain the tag coordinates after error compensation. In this embodiment, the following is preferred:

[0072] From the third step, we can know that when the residual is large, the tag is judged to be in NLOS in this area, indicating that the positioning result is not accurate and the confidence is not high; otherwise, it means that the positioning result is accurate and the confidence is high. To establish a residual correction model, weights must be assigned to the residual values ​​of the tag position coordinates solved in each area. The following is the weight quantitative analysis process:

[0073] According to the residual value calculation formula, according to the UWB positioning solution frequency, four sets of residual values ​​can be calculated at each positioning moment. The following formula is used to first calculate E res (X Tag,Δi ) is the arithmetic mean:

[0074]

[0075] and will As the threshold, the four groups of residual values ​​are compared with the threshold respectively, and the residual values ​​not greater than the threshold are retained to participate in the fusion solution, and S residual values ​​are retained.

[0076] The following residual weighted fusion correction model is used when performing weighted processing in the fourth step:

[0077]

[0078] in: represents the tag coordinates after error compensation, S is the total number of residual values ​​retained for fusion solution after comparison with the threshold, and W i is the weight value of the position coordinate residual solved for the Δi-th triangular area, which is calculated using the following formula:

[0079]

[0080] In this embodiment, the weight W i The allocation can be adjusted and optimized based on the results of the positioning test.

[0081] This embodiment further discloses a readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned UWB positioning method based on error compensation is implemented.

[0082] This embodiment also discloses an electronic device, including: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the above-mentioned UWB positioning method based on error compensation by executing the executable instructions.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A UWB positioning method based on error compensation, characterized in that: The following steps are involved: The first step is to deploy n UWB base stations around the indoor scene, and people carry UWB tags to any location indoors; n is a natural number greater than or equal to 3; The second step is to divide the indoor scene into different areas and use the three-sided positioning algorithm to solve the tag position, including: Step 2.1: Area division: Use three-sided ranging positioning to divide the indoor scene into A triangular area; establishing a corresponding relationship list between the number of the UWB base station and the triangular area; Step 2.2: Based on the condition that the tag can communicate and measure distance with the UWB base station, m UWB base stations are selected, where m is a natural number greater than or equal to 3 and less than or equal to n; and p corresponding triangular areas are obtained according to the corresponding relationship list in step 2.1, where p is a natural number greater than or equal to 1 and less than or equal to n. natural number; solve the estimated coordinates of Tag in p triangular regions; Step 2.3: Perform a weighted fusion of the estimated coordinate value of the tag obtained in step 2.2 and the distances of the m UWB base stations to obtain the fused coordinate value X of the tag. Tag ; Step 3: Calculate the distance between the coordinates of the fused tag and each UWB base station; Calculate the distance between the estimated location of the tag in each area and each UWB base station; Subtract the two distances to get the residual value E res ; Step 4: The residual value E obtained in step 3 res Perform weighted processing to obtain the tag coordinates after error compensation.

2. The UWB positioning method based on error compensation according to claim 1, characterized in that: Deploy 3-20 UWB base stations around indoor scenes; Set the coordinate value set of the UWB base station to A i , then we have the following expression: in: They represent the x-coordinate and y-coordinate of the i-th UWB base station respectively.

3. The UWB positioning method based on error compensation according to claim 2, characterized in that: The following formula is used to calculate the distance between the Tag and the UWB base station: Where: d i,t represents the distance between the tag and the i-th UWB base station, i is a natural number greater than or equal to 1 and less than or equal to m; (x Tag ,y Tag ) indicates the coordinate position of the Tag.

4. The UWB positioning method based on error compensation according to claim 3, characterized in that: Before weighted fusion of the distance between the tag obtained in step 2.2 and each UWB base station, the location of the tag in each triangle is estimated to obtain the coordinate set in: Represents the estimated position of the Tag in the Δi-th triangular region.

5. The UWB positioning method based on error compensation according to claim 4, characterized in that: The coordinate value X of the fused Tag in step 2.3 Tag Calculated using the following formula: in: represents the fusion weight of the Δi-th triangle area, which is calculated using the following formula: j represents the calculation control parameter and has no practical meaning.

6. The UWB positioning method based on error compensation according to claim 5, characterized in that: In the third step: the distance between the coordinates of the fused tag and the i-th UWB base station is expressed by the vector norm: ||X Tag -A i ||; The distance between the estimated location of the tag in each area and the i-th UWB base station is expressed by the vector norm: ||X Tag,Δi -A i ||; The residual value E corresponding to the Δi-th triangular area res (X Tag,Δi ) is calculated using the following formula:

7. The UWB positioning method based on error compensation according to claim 6, characterized in that: The following residual weighted fusion correction model is used when performing weighted processing in the fourth step: in: represents the tag coordinates after error compensation, S is the total number of residual values ​​retained for fusion solution after comparison with the threshold, and W i is the weight value of the position coordinate residual solved for the Δi-th triangular area, which is calculated using the following formula:

8. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the UWB positioning method based on error compensation described in any one of claims 1 to 7 is implemented.

9. An electronic device, characterized in that: include: processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the UWB positioning method based on error compensation as described in any one of claims 1 to 7 by executing the executable instructions.

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