A method and system for dynamic selection of ultra-wideband positioning base stations

Abstract

The application provides a kind of dynamic selection method and system of ultra-wideband positioning base station, comprising: by mobile terminal broadcast query signal, collect the base station response message and corresponding RSSI reaching preset quantity;RSSI validity screening is carried out to the collected base station, and weak signal base station is eliminated;Effective base station is divided into odd-numbered base station group and even-numbered base station group according to the parity of its number;The strongest RSSI of the preset number of base stations is selected from the two groups respectively, and the final positioning base station combination is formed by merging, also includes smooth switching mechanism and GDOP check step.Through the staggered layout mode that odd-numbered base station is deployed on one side of scene and even-numbered base station is deployed on the other side, the application ensures that the selected base station is distributed on both sides of the tag from the mechanism, forms the positioning configuration of geometric distribution balance, effectively reduces GDOP value.At the same time, the cut-off mechanism of limiting the number of acquisition significantly shortens the positioning waiting time, improves the real-time performance of the system.

Description

Technical Field

[0001] This invention relates to the field of wireless positioning technology, and in particular to a dynamic selection method and system for ultra-wideband positioning base stations. Background Technology

[0002] Ultra-wideband (UWB) positioning technology, with its centimeter-level ranging accuracy and excellent multipath resistance, is widely used in indoor and confined space positioning. A UWB positioning system typically consists of multiple fixed-deployment base stations (Anchors) and one or more mobile terminal tags. The spatial location of the tag is calculated by measuring the signal propagation time between the tag and each base station (such as TWR two-way ranging or TDoA time difference of arrival).

[0003] In long and narrow scenarios such as tunnels and corridors, to achieve continuous and high-precision positioning of mobile tags over long distances, it is usually necessary to densely deploy a large number of UWB base stations along the longitudinal direction of the scenario. However, this dense deployment strategy brings new technical challenges.

[0004] First, there's the issue of communication efficiency. When a tag is within the coverage area of ​​numerous base stations, traditional communication protocols require the tag to receive responses from all available base stations, resulting in excessively long communication wait times. For example, in a tunnel with 20 base stations deployed, if a tag is simultaneously within the coverage area of ​​12 base stations, it needs to wait for all 12 base stations to respond one by one, significantly extending the time required for a single location check, reducing the location update frequency, and failing to meet the demands of high real-time applications.

[0005] Secondly, there is the issue of geometric configuration. Existing base station selection methods mostly employ fixed combinations or simple sorting based on RSSI (Received Signal Strength Indication), selecting the base stations with the strongest signals for positioning. However, in elongated scenarios, the base stations with the strongest signals are often concentrated on the same side near the tag, resulting in uneven spatial distribution of the selected base stations, a large geometrical factor of precision (GDOP), and a significant decrease in positioning accuracy. This problem is particularly pronounced when the tag is located at the edge or corner of the scene.

[0006] Secondly, there is the issue of system robustness. Static, fixed base station selection schemes cannot adapt to dynamic changes in tag location and real-time fluctuations in the signal environment. During tag movement, the signals of some pre-selected base stations may be drastically attenuated due to obstruction or increased distance, but the system still uses these base stations for positioning, resulting in unstable positioning accuracy.

[0007] Therefore, there is an urgent need for a dynamic selection method that can quickly and intelligently select the optimal combination of base stations with balanced geometric distribution and reliable signal quality from a large number of candidate base stations in a dense base station deployment environment, so as to simultaneously meet the multiple requirements of positioning accuracy, geometric configuration and real-time efficiency. Summary of the Invention

[0008] This invention provides a dynamic selection method and system for ultra-wideband positioning base stations to address the deficiencies in existing technologies.

[0009] In a first aspect, the present invention provides a dynamic selection method for ultra-wideband positioning base stations, comprising: The mobile terminal broadcasts a query signal to the surrounding area. Multiple base stations that receive the query signal respond with a message containing their unique number; The mobile terminal collects response messages from multiple base stations, records the unique number of each base station and the corresponding received signal strength indication value, and stops collecting information in this round when the number of base stations collected reaches the preset number. The mobile terminal performs validity screening on the received signal strength indication values ​​of each base station collected, and removes base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold, thus forming a valid base station set; The mobile terminal divides the base stations into odd-numbered base station groups and even-numbered base station groups based on the parity of the unique numbers of each base station in the effective base station set. The mobile terminal selects the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group, respectively, according to the received signal strength indication value sorted from high to low. The M base stations selected from the two groups are merged into 2M base stations to form a positioning base station combination used for ranging and positioning calculation in this round.

[0010] According to a dynamic selection method for ultra-wideband positioning base stations provided by the present invention, the mobile terminal broadcasts the query signal at a preset period; Between two adjacent cycles, the mobile terminal performs ranging and positioning calculations using the base station combination selected in the previous cycle.

[0011] According to the present invention, a dynamic selection method for ultra-wideband positioning base stations is provided. When the number of valid base stations in a certain number group is less than M after validity screening, all valid base stations are selected from that group, and base stations are added from another number group to make up the minimum total number of base stations required for positioning. When the number of effective base stations in a certain group is zero, the four base stations with the strongest signals are selected from another group, and the geometric precision factor (GDOP) is checked during subsequent positioning calculations.

[0012] According to the present invention, a dynamic selection method for ultra-wideband positioning base stations includes GDOP verification, which comprises: Construct an observation matrix composed of the direction cosines between the base station and the tag, and obtain the GDOP value from the observation matrix and the period; When the GDOP value exceeds the preset GDOP threshold, the output quality is unreliable flag is set.

[0013] The dynamic selection method for ultra-wideband positioning base stations provided by the present invention further includes a smooth switching step for positioning base station combinations, specifically including: When the selected combination of base stations in this round is different from the combination of base stations in the previous round, determine whether the difference between the average value of the received signal strength indication value of each base station in this round and the average value of the received signal strength indication value of each base station in the previous round is greater than the preset handover threshold. Base station combination handover is performed only when the difference is greater than the preset handover threshold; otherwise, the base station combination from the previous round is used.

[0014] According to the present invention, a dynamic selection method for ultra-wideband positioning base stations is provided. The method is applied to a narrow and elongated scene. The base stations of the odd-numbered base station group are deployed on one side of the narrow and elongated scene, and the base stations of the even-numbered base station group are deployed on the other side of the narrow and elongated scene. The odd-numbered base station group and the even-numbered base station group are arranged alternately along the longitudinal direction of the scene.

[0015] Secondly, the present invention also provides a dynamic selection system for ultra-wideband positioning base stations, comprising: The broadcast module is used to broadcast query signals from the mobile terminal to the surrounding area; The response module is used to receive the query signal from multiple base stations, each responding with a message containing its unique number; The collection module is used by the mobile terminal to collect response messages from multiple base stations, record the unique number of each base station and the corresponding received signal strength indication value, and stop the current round of information collection when the number of base stations collected reaches the preset collection number. The filtering module is used by the mobile terminal to filter the received signal strength indication values ​​of each base station collected, and remove base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold to form a set of valid base stations. The partitioning module is used by the mobile terminal to partition the base stations into odd-numbered base station groups and even-numbered base station groups based on the parity of the unique numbers of each base station in the effective base station set. The selection module is used by the mobile terminal to select the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group respectively, according to the received signal strength indication value sorted from high to low. The merging module is used to merge the M base stations selected from the two groups into 2M base stations, forming a positioning base station combination for this round of ranging and positioning calculation.

[0016] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the dynamic selection method for ultra-wideband positioning base stations as described above.

[0017] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the dynamic selection method for ultra-wideband positioning base stations as described above.

[0018] The dynamic selection method and system for ultra-wideband positioning base stations provided by this invention have the following beneficial effects: (1) Geometric distribution balance: By using the odd and even numbering grouping strategy and combining the staggered physical deployment of base stations on both sides of the scene, the mechanism ensures that the selected base stations are distributed in different directions of the tag, forming a polygonal geometric configuration that surrounds the tag, effectively reducing the GDOP value and avoiding the ill-conditioned problem of the solution caused by the concentration of base stations on one side in the traditional method.

[0019] (2) High real-time performance: By limiting the collection of responses from only a preset number of N base stations, the redundant time overhead of communicating with each base station individually is avoided. Taking N=8 as an example, compared with waiting for responses from all 20 base stations, the communication time for a single positioning can be reduced by more than 60%.

[0020] (3) Signal quality assurance: An RSSI threshold screening mechanism is introduced to remove base stations with weak signals before group selection, ensuring that all base stations participating in positioning have reliable ranging quality.

[0021] (4) Smooth handover: By setting a handover threshold, frequent changes in base station combinations caused by small signal fluctuations are avoided, ensuring the continuity and stability of the positioning trajectory.

[0022] (5) Fault tolerance: When there are not enough effective base stations in a certain number group, a cross-group replacement mechanism and GDOP verification are provided to enhance the robustness of the system under extreme conditions.

[0023] (6) Low computational complexity: The entire selection process only involves parity judgment and RSSI sorting, with minimal computational load, making it suitable for real-time operation on resource-constrained embedded tag platforms. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is one of the flowcharts illustrating the dynamic selection method for ultra-wideband positioning base stations provided by the present invention; Figure 2 This is a schematic diagram of the staggered deployment method of UWB base stations and the tag movement trajectory provided by the present invention; Figure 3 This is the second flowchart illustrating the dynamic selection method for ultra-wideband positioning base stations provided by the present invention. Figure 4 This is a scatter plot of RSSI signal strength of each base station provided by the present invention (before screening); Figure 5 This is a scatter plot of base station RSSI after parity grouping selection (after filtering) provided by the present invention. Figure 6 This is a structural diagram of the UWB positioning system module provided by the present invention. Figure 7 This is a schematic diagram of the structure of the dynamic selection system for ultra-wideband positioning base stations provided by the present invention; Figure 8 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] To address the shortcomings of existing technologies, the present invention aims to provide a dynamic selection method and system for ultra-wideband positioning base stations. This method employs a grouping strategy based on the parity of base station numbers, combined with a staggered physical deployment of base stations in elongated scenarios. This mechanism ensures that the selected base stations originate from different areas on both sides of the scenario, forming a geometrically balanced combination of positioning base stations. While improving positioning accuracy, it also significantly shortens positioning waiting time and enhances system real-time performance by limiting the amount of information collected.

[0028] Figure 1 This is one of the flowcharts illustrating the dynamic selection method for ultra-wideband positioning base stations provided by the present invention, such as... Figure 1 As shown, it includes: Step 100: The mobile terminal broadcasts a query signal to the surrounding area; Step 200: The multiple base stations that received the query signal responded with a message containing their unique number; Step 300: The mobile terminal collects response messages from multiple base stations, records the unique number of each base station and the corresponding received signal strength indication value, and stops the current round of information collection when the number of base stations collected reaches the preset collection number; Step 400: The mobile terminal performs validity screening on the received signal strength indication values ​​of each base station collected, and removes base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold, thus forming a valid base station set; Step 500: The mobile terminal divides the base stations into odd-numbered base station groups and even-numbered base station groups according to the parity of the unique numbers of each base station in the set of valid base stations; Step 600: The mobile terminal selects the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group, respectively, according to the received signal strength indication value sorted from high to low. Step 700: Merge the M base stations selected from the two groups into 2M base stations to form a positioning base station combination for this round of ranging and positioning calculation.

[0029] Specifically, the specific implementation steps of the embodiments of the present invention include: Initiating a query: The mobile terminal broadcasts a query signal to all UWB base stations within its coverage area. The query signal can be a standard UWB ranging request frame or a dedicated intensity query frame. The mobile terminal broadcasts the query signal at a period T, where the period T ranges from 50ms to 500ms. Between two adjacent periods, the mobile terminal performs ranging and positioning calculations using the base station combination selected in the previous period.

[0030] Base station response: Each UWB base station within the positioning area that receives the query signal independently responds to the mobile terminal with a message containing its unique number. The unique number is a pre-configured integer value, wherein base stations deployed on one side of the scene are assigned odd-numbered numbers, and base stations deployed on the other side of the scene are assigned even-numbered numbers.

[0031] Information Collection: The mobile terminal opens a receiving window to listen for and collect response messages from different base stations. The mobile terminal records the source base station number and corresponding Received Signal Strength Indicator (RSSI) value of each response message in real time. Once the mobile terminal has successfully collected information from a preset number of N different base stations, it immediately stops collecting information in this round. The preset number N ranges from 6 to 12, preferably 8. This mechanism of limiting the number of collections ensures that the mobile terminal does not wait for responses from all base stations, thereby significantly shortening the communication time for a single positioning operation.

[0032] Validity Screening: The mobile terminal performs validity screening on the RSSI values ​​of the collected N base stations, eliminating base stations with RSSI values ​​lower than a preset signal strength threshold Th_rssi, and retaining the set of valid base stations. The threshold Th_rssi ranges from -85dBm to -75dBm. The purpose of this step is to exclude remote base stations with weak signals, large ranging errors, or severely obstructed base stations, thereby improving the reliability of subsequent positioning.

[0033] Odd / Even Grouping: Based on the parity of the unique IDs of each base station in the effective base station set, the mobile terminal divides the base stations into an odd-numbered base station group (G_odd) and an even-numbered base station group (G_even). This method is applied to elongated scenarios, where the odd-numbered base stations are physically deployed on one side of the elongated scenario, and the even-numbered base stations are physically deployed on the other side, with the odd-numbered and even-numbered base stations staggered along the longitudinal direction of the scenario. The elongated scenario can be any of a tunnel, corridor, alleyway, or utility tunnel; the base stations are deployed at equal intervals (D) along the longitudinal direction of the scenario, where the interval D ranges from 2m to 20m.

[0034] Within each group, the mobile terminal sorts the base stations in both groups according to their RSSI values ​​from highest to lowest. It then selects the M base stations with the strongest signals from the odd-numbered base station group G_odd and the M base stations with the strongest signals from the even-numbered base station group G_even. The preset selection quantity M is preferably 2.

[0035] When the number of valid base stations in a group is less than M, all valid base stations are selected from that group, and base stations are added from another group to make up the minimum total number of base stations required for positioning (at least 4 for 3D positioning and at least 3 for 2D positioning). When the number of valid base stations in a group is zero, the 4 base stations with the strongest signals are selected from another group, and GDOP verification is performed during subsequent positioning calculations.

[0036] Determine the positioning combination: Combine the 2M base stations selected from the two groups to form the final positioning base station combination used for this round of ranging and positioning calculation.

[0037] Furthermore, the method also includes a smooth handover step for the positioning base station combination: when the selected positioning base station combination in this round is different from the base station combination used in the previous round, the mobile terminal calculates the difference between the average RSSI value of each base station in the current round combination and the average RSSI value of each base station in the previous round combination. Base station combination handover is only performed if the difference is greater than a preset handover threshold Th_switch (ranging from 2dB to 6dB); otherwise, the base station combination from the previous round is used. This mechanism effectively avoids frequent handovers and positioning trajectory jitter caused by signal fluctuations.

[0038] Furthermore, the method also includes a GDOP verification step: before the positioning calculation, the geometrical precision factor (GDOP) value is calculated based on the known spatial coordinates of each base station in the selected base station combination and the estimated position of the mobile terminal. The GDOP is calculated by constructing an observation matrix H composed of the direction cosines between the base station and the tag: GDOP = sqrt(trace((H^T * H)^(-1))) When the GDOP value exceeds the preset GDOP threshold (ranging from 4 to 8), a flag indicating that the positioning quality is unreliable is output, prompting the upper layer to use the positioning result with caution.

[0039] The following specific embodiments illustrate the solution of the present invention: Example 1 See Figure 2 In this embodiment, the application scenario is an indoor corridor approximately 14m long and 2m wide. Eight UWB base stations, numbered BS1 to BS8, are deployed in this corridor. Specifically: Odd-numbered base stations BS1, BS3, BS5, and BS7 are deployed on the upper side of the corridor (Y coordinate approximately +1m), and are arranged at equal intervals of approximately 2m along the longitudinal direction (X direction) of the corridor. Their specific coordinates are BS1(0, 1), BS3(2, 1), BS5(4, 1), and BS7(6, 1).

[0040] Even-numbered base stations BS2, BS4, BS6, and BS8 are deployed on the lower side of the corridor (Y coordinate approximately -1m), and are also arranged at equal intervals of approximately 2m. Their specific coordinates are BS2(0, -1), BS4(2, -1), BS6(4, -1), and BS8(6, -1).

[0041] This arrangement of odd and even numbers corresponding to the physical positions on both sides is the physical basis for the excellent geometric configuration obtained by the method of this invention.

[0042] A worker wearing a UWB tag starts from the starting point (green square, coordinates approximately (0, 0.8)) and walks along the middle of the corridor to the ending point (purple square, coordinates approximately (7, -0.05)). The tag performs positioning continuously with a period of 100ms.

[0043] See Figure 3 The dynamic base station selection method of the present invention is executed periodically at each sampling time point as the tag moves along the trajectory. The specific steps are as follows: Step (a): At each sampling time point on the trajectory, the tag actively broadcasts a query signal to the surrounding area via the UWB radio frequency module. This signal is a standard UWB frame, does not carry a destination address, and can be received by all base stations within the coverage area.

[0044] Step (b): Upon receiving the query signal, all nearby base stations BS1 to BS8 each respond to the tag with a message containing their own unique identifier. Because each base station receives the query signal at different times and has different processing delays, the order in which the response messages arrive at the tag is random. Typically, the base station closer to the tag receives its response signal first and has a higher RSSI value.

[0045] Step (c): The tag opens the receiving window. In this embodiment, the preset collection quantity N=8. The tag records the base station number and the corresponding RSSI value in the order in which the response messages arrive. After successfully collecting information from 8 different base stations, the tag immediately closes the receiving window and stops this round of information collection.

[0046] See Figure 4 This scatter plot shows the data collection results of the tag at 18 consecutive sampling time points. The horizontal axis represents the sampling point sequence number, and the vertical axis represents the RSSI value (unit: dBm). At each sampling point, the tag collected RSSI data from 8 base stations, with different colored dots representing the signal strength of different base stations. It can be observed that the RSSI values ​​of base stations closer to the tag are higher (approximately -60dBm to -65dBm), while the RSSI values ​​of base stations farther away are lower (approximately -80dBm to -90dBm).

[0047] Step (d): In this embodiment, the signal strength threshold Th_rssi is set to -82dBm. The tag checks the RSSI values ​​of the eight collected base stations and marks base stations with RSSI values ​​below -82dBm as invalid and removes them. For example, at sampling point 1, if the RSSI of BS8 is -87dBm, then BS8 is removed and will not participate in subsequent group selection.

[0048] Step (e): The base stations whose tags have passed the validity screening are divided into two groups based on the parity of their ID numbers: Odd-numbered base station group G_odd: includes valid base stations from BS1, BS3, BS5, and BS7; Even-numbered base station group G_even: includes valid base stations from BS2, BS4, BS6, and BS8.

[0049] Step (f): The tags are sorted in descending order of RSSI values ​​for the valid base stations within each of the two groups. Assuming the preset selection quantity M=2, then: Select the two base stations with the highest RSSI from G_odd. For example, at sampling point 1, if the RSSI of BS1 in G_odd is -59dBm, BS3 is -63dBm, BS5 is -68dBm, and BS7 is -82dBm (which has been removed by the threshold or has a weak signal), then BS1 and BS3 are selected. Select the two base stations with the highest RSSI from G_even. For example, if BS2 has an RSSI of -62dBm and BS4 has an RSSI of -73dBm, then BS2 and BS4 will be selected.

[0050] Step (g): The four base stations selected from the two groups are merged into the final positioning base station combination {BS1, BS3, BS2, BS4}.

[0051] See Figure 5 This scatter plot shows the results after the odd-even grouping selection. (Comparison) Figure 4 It can be clearly seen that the original 8 data points per sampling point were filtered into 4, and these 4 base stations must come from both sides of the corridor (2 odd-numbered numbers from the top and 2 even-numbered numbers from the bottom), thus forming a quadrilateral geometric configuration surrounding the label.

[0052] In this embodiment, as the tag travels from the starting point to the ending point, the optimal base station combination is dynamically updated as the tag's position changes. For example: Sampling points 1-4 (labels located near X=0 to X=1.5): Selected combination is {BS1, BS3, BS2, BS4}; Sampling points 5-9 (labels located near X=2 to X=3.5): The selected combination is changed to {BS3, BS5, BS4, BS6}; Sampling points 10-14 (labels located near X=4 to X=5.5): The selected combination is changed to {BS5, BS7, BS6, BS8}.

[0053] As can be seen, the base station combination dynamically slides with the tag's position, always selecting the base station with the closest distance and strongest signal on both sides of the tag, ensuring the positioning accuracy and geometric configuration throughout the entire process.

[0054] The specific implementation of the smooth switching step: Between sampling points 4 and 5, the tag detects a change in the optimal combination. The mean RSSI of the new combination {BS3, BS5, BS4, BS6} is calculated to be -65.5dBm, while the mean RSSI of the old combination {BS1, BS3, BS2, BS4} is -68.2dBm, with a difference of 2.7dB. In this embodiment, the switching threshold Th_switch = 2dB is set. Since 2.7dB > 2dB, the switching is performed. If the difference is less than 2dB, the old combination is used to avoid unnecessary switching due to small signal fluctuations.

[0055] The specific implementation of the GDOP verification step is as follows: Taking the base station combination {BS3, BS5, BS4, BS6} as an example, the coordinates of the four base stations are BS3(2,1), BS5(4,1), BS4(2,-1), and BS6(4,-1), respectively, and the estimated tag position is (3, 0.3). An observation matrix H is constructed, and GDOP is calculated to be 2.1. Since 2.1 < 4.0 (preset threshold), the positioning result is reliable. If the tag is in an extreme position causing GDOP > 4.0, the system will output a warning flag.

[0056] Example 2 See Figure 6 This embodiment provides a specific implementation scheme for a UWB positioning system.

[0057] The system comprises the following components: (1) UWB base station array: Consists of 8 (or more) UWB base stations. Each base station contains a UWB radio transceiver module, a microcontroller, and a power supply module. Each base station is configured with a unique integer number during system initialization; odd-numbered base stations are deployed on the upper side of the corridor, and even-numbered base stations are deployed on the lower side. The function of each base station is to receive query signals broadcast by tags and respond with a message containing its own number.

[0058] (2) Mobile terminal (tag): The hardware platform of the tag is an embedded system (such as an STM32 microcontroller) equipped with a UWB chip (such as the Decawave DW3000 series), and the software modules include: a) UWB radio frequency module: responsible for transmitting query signals and receiving base station responses; b) Signal acquisition module: Parse the received base station response message, extract the base station number and RSSI value, remove duplicates by number and store them in the current round of acquisition buffer. When the number of different base stations in the buffer reaches N, a stop acquisition signal is triggered. c) Validity screening module: Iterate through the acquisition buffer and mark records with RSSI below the threshold Th_rssi as invalid; d) Parity grouping selection module: Divide the valid base stations into two groups according to the parity of their numbers, sort each group in descending order of RSSI, take the first M, and merge them to form a positioning base station combination; e) Smooth handover module: Compares the current combination with the previous combination, and decides whether to perform the actual handover based on whether the difference in the mean RSSI exceeds the handover threshold; f) GDOP verification module: Calculates the GDOP value based on the spatial coordinates of the selected base station and the estimated location of the tag, and outputs the positioning quality indicator; g) Positioning calculation module: Using the finally selected base station combination, the distance from the tag to each base station is obtained through TWR ranging, and the weighted least squares method is used to calculate the three-dimensional or two-dimensional position.

[0059] In actual testing, the performance comparison between the method of this invention and the traditional method is as follows: Test scenario: A corridor 14m long and 2m wide, with 8 base stations deployed, and the tag moves from one end to the other.

[0060] (1) Compared with the fixed base station selection method: the fixed selection of BS1-BS4 increases the positioning error to more than 50cm when the tag moves to the far end; the method of the present invention maintains the error within the range of 10-15cm throughout the process.

[0061] (2) Compared with the pure RSSI sorting method: When the tag is located on one side of the corridor, the four selected base stations may all be located on the same side, the GDOP value can reach more than 5.0, and the positioning error is 30-40cm; the GDOP value of the method of the present invention is always lower than 2.5, and the positioning error is stable at 10-15cm.

[0062] (3) Regarding the positioning update frequency: The scheme of waiting for all 8 base stations to respond takes about 80ms / time (10Hz update rate), while the present invention, through the N=8 cutoff mechanism and fast group selection, takes about 45ms (22Hz update rate) for a single positioning, improving real-time performance by about 120%.

[0063] The following describes the dynamic selection system for ultra-wideband positioning base stations provided by the present invention. The dynamic selection system for ultra-wideband positioning base stations described below can be referred to in correspondence with the dynamic selection method for ultra-wideband positioning base stations described above.

[0064] Figure 7 This is a schematic diagram of the structure of the dynamic selection system for ultra-wideband positioning base stations provided in an embodiment of the present invention, as shown below. Figure 7 As shown, it includes: a broadcast module 71, a response module 72, a collection module 73, a filtering module 74, a division module 75, a selection module 76, and a merging module 77, wherein: The broadcast module 71 is used by the mobile terminal to broadcast a query signal to the surrounding area; the response module 72 is used by multiple base stations receiving the query signal to respond with a message containing their unique number; the collection module 73 is used by the mobile terminal to collect the response messages from multiple base stations, record the unique number of each base station and the corresponding received signal strength indication value, and stop the current round of information collection when the number of collected base stations reaches a preset collection number; the filtering module 74 is used by the mobile terminal to filter the validity of the collected received signal strength indication values ​​of each base station, and remove those with received signal strength indication values ​​lower than a preset signal strength indication value. The base stations with a threshold are used to form a valid base station set; the division module 75 is used by the mobile terminal to divide the base stations into odd-numbered base station groups and even-numbered base station groups according to the parity of the unique numbers of each base station in the valid base station set; the selection module 76 is used by the mobile terminal to select the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group respectively, according to the received signal strength indication value from high to low; the merging module 77 is used to merge the M base stations selected from the two groups into 2M base stations to form a positioning base station combination for this round of ranging and positioning calculation.

[0065] Figure 8 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 8 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call logic instructions in the memory 830 to execute a dynamic selection method for ultra-wideband positioning base stations. This method includes: a mobile terminal broadcasting a query signal to the surrounding area; multiple base stations receiving the query signal responding with messages containing their unique numbers; the mobile terminal collecting the response messages from multiple base stations, recording the unique number of each base station and its corresponding received signal strength indication value; stopping the current round of information collection when the number of collected base stations reaches a preset collection limit; the mobile terminal performing validity screening on the received signal strength indication values ​​of each collected base station, eliminating base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold, forming a valid base station set; the mobile terminal dividing the base stations into odd-numbered base station groups and even-numbered base station groups based on the parity of the unique numbers of each base station in the valid base station set; the mobile terminal selecting the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group respectively, sorting them from high to low according to the received signal strength indication values; and merging the M base stations selected from each group into 2M base stations, forming a positioning base station combination for this round of ranging and positioning calculation.

[0066] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0067] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the dynamic selection method for ultra-wideband positioning base stations provided by the above methods. This method includes: a mobile terminal broadcasting a query signal to the surrounding area; multiple base stations receiving the query signal responding with messages containing their unique numbers; the mobile terminal collecting the response messages from multiple base stations, recording the unique number of each base station and its corresponding received signal strength indication value; and stopping the current round of information collection when the number of collected base stations reaches a preset collection number. The mobile terminal performs validity screening on the received signal strength indication values ​​of each base station collected, eliminating base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold, thus forming a set of valid base stations. The mobile terminal divides the base stations into odd-numbered base station groups and even-numbered base station groups according to the parity of the unique numbers of each base station in the set of valid base stations. The mobile terminal selects the M base stations with the strongest signals from the odd-numbered base station groups and even-numbered base station groups respectively, sorting them from high to low according to the received signal strength indication values. The M base stations selected from the two groups are merged into 2M base stations to form a positioning base station combination used for ranging and positioning calculation in this round.

[0068] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements a dynamic selection method for ultra-wideband positioning base stations provided by the methods described above. This method includes: a mobile terminal broadcasting a query signal to the surrounding area; multiple base stations receiving the query signal responding with messages containing their unique identifiers; the mobile terminal collecting the response messages from the multiple base stations, recording the unique identifier of each base station and its corresponding received signal strength indication value; stopping the current round of information collection when the number of collected base stations reaches a preset collection quantity; and the mobile terminal receiving signals from each of the collected base stations... The signal strength indication value is used for validity screening, and base stations whose received signal strength indication value is lower than a preset signal strength indication threshold are removed to form a valid base station set. The mobile terminal divides the base stations into odd-numbered base station groups and even-numbered base station groups according to the parity of the unique number of each base station in the valid base station set. The mobile terminal selects the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group respectively, according to the received signal strength indication value from high to low. The M base stations selected from the two groups are merged into 2M base stations to form a positioning base station combination for this round of ranging and positioning calculation.

[0069] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0070] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic selection method for ultra-wideband positioning base stations, characterized in that, include: The mobile terminal broadcasts a query signal to the surrounding area. Multiple base stations that receive the query signal respond with a message containing their unique number; The mobile terminal collects response messages from multiple base stations, records the unique number of each base station and the corresponding received signal strength indication value, and stops collecting information in this round when the number of base stations collected reaches the preset number. The mobile terminal performs validity screening on the received signal strength indication values ​​of each base station collected, and removes base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold, thus forming a valid base station set; The mobile terminal divides the base stations into odd-numbered base station groups and even-numbered base station groups based on the parity of the unique numbers of each base station in the effective base station set. The mobile terminal selects the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group, respectively, according to the received signal strength indication value sorted from high to low. The M base stations selected from the two groups are merged into 2M base stations to form a positioning base station combination used for ranging and positioning calculation in this round.

2. The dynamic selection method for ultra-wideband positioning base stations according to claim 1, characterized in that, The mobile terminal broadcasts the query signal at a preset period; Between two adjacent cycles, the mobile terminal performs ranging and positioning calculations using the base station combination selected in the previous cycle.

3. The dynamic selection method for ultra-wideband positioning base stations according to claim 1, characterized in that, When the number of valid base stations in a certain numbered group is less than M after the validity screening, all valid base stations are selected from that group, and base stations are added from another numbered group to make up the minimum total number of base stations required for positioning. When the number of effective base stations in a certain group is zero, the four base stations with the strongest signals are selected from another group, and the geometric precision factor (GDOP) is checked during subsequent positioning calculations.

4. The dynamic selection method for ultra-wideband positioning base stations according to claim 3, characterized in that, The GDOP verification includes: Construct an observation matrix composed of the direction cosines between the base station and the tag, and obtain the GDOP value from the observation matrix and the period; When the GDOP value exceeds the preset GDOP threshold, the output quality is unreliable flag is set.

5. The dynamic selection method for ultra-wideband positioning base stations according to claim 1, characterized in that, It also includes a smooth handover process for the combined positioning base stations, specifically including: When the selected combination of base stations in this round is different from the combination of base stations in the previous round, determine whether the difference between the average value of the received signal strength indication value of each base station in this round and the average value of the received signal strength indication value of each base station in the previous round is greater than the preset handover threshold. Base station combination handover is performed only when the difference is greater than the preset handover threshold; otherwise, the base station combination from the previous round is used.

6. The dynamic selection method for ultra-wideband positioning base stations according to claim 1, characterized in that, The method is applied to a long and narrow scene. The base stations of the odd-numbered base station group are deployed on one side of the long and narrow scene, and the base stations of the even-numbered base station group are deployed on the other side of the long and narrow scene. The odd-numbered base station group and the even-numbered base station group are arranged alternately along the longitudinal direction of the scene.

7. A dynamic selection system for ultra-wideband positioning base stations, characterized in that, include: The broadcast module is used to broadcast query signals from the mobile terminal to the surrounding area; The response module is used to receive the query signal from multiple base stations, each responding with a message containing its unique number; The collection module is used by the mobile terminal to collect response messages from multiple base stations, record the unique number of each base station and the corresponding received signal strength indication value, and stop the current round of information collection when the number of base stations collected reaches the preset collection number. The filtering module is used by the mobile terminal to filter the received signal strength indication values ​​of each base station collected, and remove base stations whose received signal strength indication values ​​are lower than a preset signal strength indication threshold to form a set of valid base stations. The partitioning module is used by the mobile terminal to partition the base stations into odd-numbered base station groups and even-numbered base station groups based on the parity of the unique numbers of each base station in the effective base station set. The selection module is used by the mobile terminal to select the M base stations with the strongest signals from the odd-numbered base station group and the even-numbered base station group respectively, according to the received signal strength indication value sorted from high to low. The merging module is used to merge the M base stations selected from the two groups into 2M base stations, forming a positioning base station combination for this round of ranging and positioning calculation.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the dynamic selection method for ultra-wideband positioning base stations as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the dynamic selection method for ultra-wideband positioning base stations as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the dynamic selection method for ultra-wideband positioning base stations as described in any one of claims 1 to 6.

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