Positioning method, apparatus, device and storage medium of mobile terminal

Abstract

Embodiments of the present disclosure provide a positioning method, apparatus and device of a mobile terminal and a storage medium. The positioning method of the mobile terminal comprises: obtaining ranging distances between a plurality of UWB base stations and the mobile terminal in a current period; determining a target region in which the mobile terminal is located in the current period from a plurality of preset regions according to the plurality of ranging distances; and calculating a position coordinate of the mobile terminal in the current period according to the target region in which the mobile terminal is located in the current period and the ranging distances between the plurality of UWB base stations and the mobile terminal in the current period. By using this method, the problem of poor positioning accuracy caused by non-line-of-sight propagation when at least part of the UWB base stations communicate with the mobile terminal can be overcome.

Description

Technical Field

[0001] This disclosure relates to the field of positioning technology, and specifically to a positioning method, apparatus, device, and storage medium for a mobile terminal. Background Technology

[0002] Ultra-wideband (UWB) technology obtains ranging distance by propagating narrow pulses on the order of nanoseconds or microseconds, offering the advantage of high time resolution. Currently, UWB technology is applied in vehicles for locating mobile terminals such as vehicle keys. However, when deploying UWB base stations in vehicle scenarios, the base station's height is limited by the vehicle's height. Some UWB base stations experience severe non-line-of-sight propagation problems when communicating with mobile terminals, resulting in inaccurate ranging distances. Consequently, the mobile terminal's position coordinates calculated based on these ranging distances show significant errors compared to the actual coordinates. Summary of the Invention

[0003] To address the aforementioned technical problems, this disclosure provides a positioning method, apparatus, device, and storage medium for a mobile terminal.

[0004] In a first aspect, embodiments of this disclosure provide a positioning method for a mobile terminal, comprising:

[0005] Obtain the ranging distances between multiple UWB base stations and mobile terminals in the current period;

[0006] Based on multiple ranging distances, the target area where the mobile terminal is located in the current cycle is determined in multiple preset areas;

[0007] Based on the target area where the mobile terminal is located in the current period, and the ranging distance between the mobile terminal and multiple UWB base stations in the current period, the position coordinates of the mobile terminal in the current period are calculated.

[0008] Optionally, the preset area is a region determined based on the vehicle, and the preset area includes an external area and an internal area.

[0009] Optionally, the plurality of UWB base stations includes six, of which two UWB base stations are located on the left and right sides of the front grille of the vehicle, two UWB base stations are located on the left and right sides of the tailgate of the vehicle, and two UWB base stations are located in the middle area of ​​the vehicle roof and are staggered in the length direction of the vehicle body; the external area of ​​the vehicle includes the front external area, the rear external area, the front left external area, the rear left external area, the front right external area, and the rear right external area.

[0010] The interior areas include the front left area, the front right area, the rear left area, and the rear right area.

[0011] Optionally, determining the target area where the mobile terminal is located in the current period within multiple preset areas based on multiple ranging distances includes:

[0012] Based on the location coordinates of the mobile terminal in the previous cycle, the boundary calibration data of the target area where the mobile terminal was located in the previous cycle is determined. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0013] In response to the fact that the absolute value of the first difference between the calibration distance from each boundary calibration point to each UWB base station and the corresponding ranging distance is greater than the set value, the target area of ​​the mobile terminal in the previous cycle is taken as the target area of ​​the current cycle.

[0014] Optionally, the boundary calibration data also includes a second difference between the reference distance between the azimuth reference point on one side of each boundary calibration point and each UWB base station and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station.

[0015] The step of determining the target area where the mobile terminal is located in the current period within multiple preset areas based on multiple ranging distances further includes:

[0016] In response to the fact that the absolute values ​​of the first differences are all less than the set value, it is determined whether the first difference and the second difference corresponding to the boundary calibration point are the same as the zero value;

[0017] In response to the fact that the size relationships are all the same, the preset area where the orientation reference point is located is taken as the target area where the mobile terminal is located in the current cycle.

[0018] In response to at least one of the different size relationships, a preset area on the other side of a certain boundary calibration point that does not include the orientation reference point is taken as the target area of ​​the mobile terminal in the current cycle.

[0019] Optionally, before determining the boundary calibration data of the target area where the mobile terminal was located in the previous cycle, the method further includes:

[0020] Obtain the displacement of the mobile terminal in the current period;

[0021] The set value is determined based on the displacement of the mobile terminal in the current cycle.

[0022] Optionally, the method further includes: obtaining the ranging distance between multiple UWB base stations and the mobile terminal within a preset preceding time period, wherein the preset preceding time period includes multiple cycles;

[0023] Calculate the mean and variance of the ranging distances corresponding to each UWB base station within the preset time period;

[0024] Select the mean values ​​corresponding to at least N UWB base stations with the smallest variance, and calculate the estimated location coordinates of the mobile terminal, where N is an integer greater than or equal to 1;

[0025] Based on the estimated location coordinates, the target area corresponding to the estimated location coordinates and the boundary calibration data of the target area are determined. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0026] The step of determining the target area of ​​the mobile terminal in the current period in multiple preset areas based on multiple ranging distances includes: determining the target area of ​​the mobile terminal in the current period based on the calibration distance from each boundary calibration point to each UWB base station and the ranging distance of each UWB base station in the current period.

[0027] Optionally, calculating the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period includes:

[0028] Based on the target area where the mobile terminal is located in the current period, determine the confidence level of each UWB base station in the current period;

[0029] Based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period, the position coordinates of the mobile terminal in the current period are calculated.

[0030] Optionally, calculating the location coordinates of the mobile terminal in the current period based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period includes:

[0031] Multiply the confidence level and ranging distance of each UWB base station in the current period by the confidence level and ranging distance to obtain the corrected ranging distance from each UWB base station to the mobile terminal in the current period.

[0032] The position coordinates of the mobile terminal in the current period are calculated based on the corrected ranging distance and the position coordinates of each UWB base station.

[0033] Optionally, the method further includes: obtaining the displacement of the mobile terminal in the current period;

[0034] Based on the position coordinates of the mobile terminal in the previous cycle and its displacement in the current cycle, calculate the predicted coordinates of the mobile terminal in the current cycle.

[0035] The step of calculating the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period includes:

[0036] Based on the target area where the mobile terminal is located in the current period, and the ranging distance between the mobile terminal and multiple UWB base stations in the current period, the measurement coordinates of the mobile terminal in the current period are calculated.

[0037] The measured coordinates and the predicted coordinates are fused to obtain the position coordinates of the mobile terminal in the current period.

[0038] Optionally, before fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period, the method further includes:

[0039] Determine whether the measurement coordinates of the mobile terminal in the current period meet the set constraints; the set constraints include the height coordinate being within a set height coordinate range, and / or the horizontal coordinate being within a set horizontal coordinate range;

[0040] The step of fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period includes: in response to the measured coordinates of the mobile terminal in the current period satisfying the set constraint condition, performing the step of fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period;

[0041] The method further includes: in response to the fact that the measured coordinates of the mobile terminal in the current period do not meet the set constraint conditions, fusing the position coordinates of the mobile terminal in the previous period and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period.

[0042] Secondly, embodiments of this disclosure provide a positioning device for a mobile terminal, comprising:

[0043] The ranging distance acquisition unit is used to acquire the ranging distance between multiple UWB base stations and the mobile terminal in the current period;

[0044] The target area determination unit is used to determine the target area where the mobile terminal is located in the current period from multiple preset areas based on multiple ranging distances;

[0045] The location coordinate calculation unit is used to calculate the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period.

[0046] Thirdly, this disclosure provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the positioning method of the mobile terminal as described above.

[0047] Fourthly, embodiments of this disclosure provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the aforementioned positioning method for a mobile terminal.

[0048] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0049] The technical solution provided in this disclosure, after obtaining the ranging distances between multiple UWB base stations and the mobile terminal in the current period, determines the target area where the mobile terminal is located in the current period based on the multiple ranging distances. Then, based on the target area and the ranging distances between the multiple UWB base stations and the mobile terminal in the current period, the position coordinates of the mobile terminal in the current period are calculated. This method overcomes the problem of poor positioning accuracy caused by non-line-of-sight propagation during communication between at least some UWB base stations and the mobile terminal, thus making the position coordinates calculated based on the ranging distances more accurate. Attached Figure Description

[0050] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0051] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort, wherein:

[0052] Figure 1 This is a flowchart of a mobile terminal positioning method provided in some embodiments of this disclosure;

[0053] Figure 2 This is a schematic diagram of the layout and area division of a UWB base station provided in one embodiment of this disclosure;

[0054] Figure 3 This is a flowchart of a mobile terminal positioning method provided in some embodiments of this disclosure;

[0055] Figure 4 This is a schematic diagram of the structure of a positioning device for a mobile terminal provided in some embodiments of this disclosure.

[0056] Figure 5This is a schematic diagram of the structure of a computer device provided in an embodiment of this disclosure. Detailed Implementation

[0057] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0058] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc., used in this disclosure are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0059] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0060] This disclosure provides a method for locating a mobile terminal, which can be applied in scenarios such as vehicles and smart homes to locate mobile terminals such as smart keys. The following description uses a vehicle usage scenario as an example to illustrate the mobile terminal location method provided in this disclosure.

[0061] Figure 1 This is a flowchart of a mobile terminal positioning method provided in some embodiments of this disclosure. For example... Figure 1 As shown, the positioning method for a mobile terminal provided in this embodiment includes steps S101-S103.

[0062] It should be noted that the positioning method for mobile terminals provided in this disclosure can be executed by a mobile terminal equipped with a UWB module, such as a vehicle remote key, or by a vehicle equipped with a UWB base station or a smart house (specifically, by a computing device with data processing capabilities, such as a HU in a vehicle or a central control device in a smart house). The following description uses a mobile terminal as the execution subject to illustrate the method provided in this disclosure.

[0063] Step S101: Obtain the ranging distance between multiple UWB base stations and mobile terminals in the current period.

[0064] In this embodiment of the disclosure, a UWB module is installed in the mobile terminal. The UWB module periodically communicates with multiple UWB base stations deployed in the vehicle and determines the ranging distance between the mobile terminal and the UWB base stations based on the timestamp information transmitted during mutual communication.

[0065] In this embodiment of the disclosure, in order to determine the location coordinates of the mobile terminal based on the ranging distance, it is necessary to obtain the ranging distance between the mobile terminal and at least 4 UWB base stations collected in the current period. That is, the number of UWB base stations is at least 4.

[0066] In some embodiments of this disclosure, a non-bilateral ranging algorithm can be used to determine the ranging distance between the mobile terminal and the UWB base station. Taking communication with a UWB base station (UWB base station A) as an example, the method for the mobile terminal to determine the ranging distance with UWB base station A using an asymmetric bilateral ranging algorithm is as follows.

[0067] First, the UWB module in the mobile terminal sends a Pos1 message to UWB base station A and records the timestamp of sending the Pos1 message.

[0068] Subsequently, after receiving a Pos1 message matching its own address, UWB base station A records the timestamp of receiving the Pos1 message. After a delay, UWB base station A sends a response message RespA to the mobile terminal and records the timestamp of sending RespA. Based on the timestamps of receiving the Pos1 message and sending RespA, the time period TreplyA between receiving the Pos1 message and sending the response message can be calculated.

[0069] Subsequently, after receiving the response message RespA from UWB base station A, the mobile terminal records the timestamp of receiving the response message RespA and, after a delay of a period of time (Trepl2A), sends a Final message to UWB base station A. The Final message includes various timestamp information recorded during the communication between the mobile terminal and UWB base station A. Based on the aforementioned timestamp of receiving the response message RespA and the timestamp of sending the Pos1 message, the time period Tround1A from when the mobile terminal sends the Pos1 message to when it receives the response message RespA can be calculated.

[0070] Next, after receiving the Final message, UWB base station A records the timestamp of receiving the Final message. Based on the timestamp of receiving the Final message and the timestamp of sending RespA, the time period Tround2A between sending RespA and receiving the Final message can be calculated for UWB base station A.

[0071] Then, UWB base station A calculates Tround1A, TreplyA, Treply2A, and Tround2A based on the aforementioned timestamps, and uses the following formula (Tround1A×Tround2A- TreplyA×Treply2A) / (Tround1A+TreplyA+Treply2A+Tround2A) to obtain the time of flight (TOFA) of the message between the mobile terminal and UWB base station A.

[0072] Finally, based on the Time-of-Flight (TOFA) and the speed of electromagnetic signal transmission (i.e., the speed of light), UWB base station A can calculate the ranging distance between the mobile terminal and UWB base station A. After calculating the ranging distance, UWB base station A can send the ranging distance to the mobile terminal so that the mobile terminal can obtain the ranging distance between itself and UWB base station A.

[0073] Of course, in other embodiments of this disclosure, after receiving the Final message, UWB base station A can also send various timestamps to the mobile terminal so that the mobile terminal can calculate the aforementioned Tround1A, TreplyA, Treply2A and Tround2A, and calculate the time of flight TOFA according to the aforementioned four time periods using (Tround1A×Tround2A- TreplyA×Treply2A) / (Tround1A+TreplyA+Treply2A+Tround2A), and calculate the ranging distance between the mobile terminal and UWB base station A according to the time of flight TOFA and the electromagnetic signal propagation speed.

[0074] In this embodiment of the disclosure, the mobile terminal can communicate with multiple UWB base stations during a ranging cycle. Following the aforementioned method, this embodiment can also obtain the ranging distance between the mobile terminal and other UWB base stations in the current cycle.

[0075] The aforementioned asymmetric bilateral ranging algorithm can compensate for the clock offset between the mobile terminal and each UWB base station, ensuring high accuracy in the ranging distance. Of course, in other embodiments of this disclosure, a unilateral ranging algorithm can also be used to determine the ranging distance between the mobile terminal and each UWB base station.

[0076] Step S102: Based on multiple ranging distances, determine the target area where the mobile terminal is located in the current cycle from multiple preset areas.

[0077] In this embodiment of the disclosure, after obtaining multiple ranging distances, the mobile terminal determines the target area where the mobile terminal is located in the current cycle in multiple preset areas based on the aforementioned multiple ranging distances.

[0078] In this embodiment of the disclosure, when the usage scenario is a vehicle, the aforementioned preset area is a region determined based on the vehicle. Specifically, limited by the outer contour of the vehicle's cabin, the preset area can be divided into an interior area and an exterior area. In specific implementations, the interior area and the exterior area can be further divided into at least one preset sub-area based on the deployment of UWB base stations.

[0079] Figure 2 This is a schematic diagram of the UWB base station layout and area division provided in one embodiment of this disclosure. Figure 2 As shown in one embodiment of this disclosure, six UWB base stations are installed in the vehicle. Two UWB base stations (UWB base station 1 and UWB base station 2) are located on the left and right sides of the front grille (specifically above the two headlights), two UWB base stations (UWB base station 3 and UWB base station 4) are located on the left and right sides of the tailgate (specifically above the taillights), and two UWB base stations (UWB base station 5 and UWB base station 6) are located in the middle area of ​​the vehicle roof and are staggered along the length of the vehicle body (specifically, UWB base station 5 is located in the central area of ​​the roof, and UWB base station 6 is located above the rearview mirror).

[0080] Based on the aforementioned UWB base station layout, before implementing the method of this embodiment, the inventors measured the distance between the mobile terminal and the UWB base station at a large number of locations, and performed mathematical statistics on the accuracy of the distance measurement. Based on the mathematical statistics results, the vehicle's interior space and exterior space were divided into regions.

[0081] Specifically, based on the aforementioned UWB base station layout, the area outside the vehicle is divided into six sub-areas. These sub-areas are the front area, rear area, front left area, rear left area, front right area, and rear right area, corresponding sequentially to... Figure 2The vehicle exterior areas are defined as follows: Area 1, Area 4, Area 2, Area 3, Area 6, and Area 5. Specifically, the front and left front areas, and the front and right front areas are bounded by the line connecting UWB base station 1 and UWB base station 2; the left front and left rear areas, and the right front and right rear areas are bounded by the plane where the vehicle's B-pillar is located; and the rear and left rear areas, and the right rear areas are bounded by the line connecting UWB base station 3 and UWB base station 4.

[0082] Based on the aforementioned UWB base station layout, the vehicle interior area is divided into four sub-areas. These sub-areas are the front left, front right, rear left, and rear right areas, corresponding sequentially to... Figure 2 The vehicle interior area is divided into vehicle interior area 1, vehicle interior area 2, vehicle interior area 3, and vehicle interior area 4. Vehicle interior area 1, vehicle interior area 2, vehicle interior area 3, and vehicle interior area 4 are bounded by the vertical plane containing the line connecting UWB base station 5 and UWB base station 6, and vehicle interior area 1, vehicle interior area 3, vehicle interior area 2, and vehicle interior area 4 are bounded by the plane containing the B-pillar of the vehicle.

[0083] Of course, in other embodiments of this disclosure, when the UWB base station adopts other layout methods, the in-vehicle area and the out-of-vehicle area can also be divided in other ways.

[0084] In this embodiment of the disclosure, determining the target area where the mobile terminal is located in the current cycle means determining which segment of the vehicle area or the area between vehicle areas the mobile terminal is located in during the current cycle. The specific method for determining the target area where the mobile terminal is located in the current cycle will be explained later.

[0085] Step S103: Calculate the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period.

[0086] After determining the target area where the mobile terminal is located in the current period, the location coordinates of the mobile terminal in the current period can be calculated based on the target area and the ranging distance between each UWB base station and the mobile terminal in the current period.

[0087] Preliminary testing revealed that, due to the influence of the vehicle's cabin outline and the layout of in-vehicle equipment, the mobile terminal experiences severe non-line-of-sight propagation with UWB signals transmitted from certain UWB base stations when it is located in different target areas. This results in a significant deviation between the measured distance and the actual distance (the measured distance is greater than the actual distance). Because of this abnormal measuring distance, the positioning accuracy of the mobile terminal's location coordinates calculated based on the measuring distance obtained from the UWB base station is very poor. Furthermore, the UWB base stations experiencing non-line-of-sight propagation differ depending on the target area.

[0088] Based on the foregoing findings, the mobile terminal positioning method provided in this disclosure, after obtaining the ranging distances between multiple UWB base stations and the mobile terminal in the current period, determines the target area where the mobile terminal is located in the current period based on the multiple ranging distances, and then calculates the position coordinates of the mobile terminal in the current period based on the target area and the ranging distances between the multiple UWB base stations and the mobile terminal in the current period. This method can overcome the problem of poor positioning accuracy caused by non-line-of-sight propagation during communication between at least some UWB base stations and the mobile terminal.

[0089] In some embodiments of this disclosure, the aforementioned step S103, which calculates the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period, may specifically include steps S1031-S1032.

[0090] Step S1031: Determine the confidence level of each UWB base station in the current period based on the target area where the mobile terminal is located in the current period.

[0091] Before implementing the method of this disclosure embodiment, the inventors measured the ranging distance between the mobile terminal and UWB base stations at numerous locations and performed statistical analysis on the accuracy of the ranging distance. Based on the statistical results, when both the interior and exterior spaces of the vehicle were divided into regions, the confidence level of the ranging distance obtained by the mobile terminal communicating with each UWB base station in each preset region was determined. Table 1 shows the relationship between the region division and the confidence level of the UWB base stations.

[0092] Table 1. Relationship between regional division and confidence level of UWB base stations

[0093]

[0094] In this embodiment of the disclosure, the confidence level of each UWB base station is determined according to the target area where the mobile terminal is located in the current period. That is, the confidence level of each UWB base station is determined by querying the aforementioned relationship table.

[0095] Step S1032: Calculate the location coordinates of the mobile terminal in the current period based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period.

[0096] In some embodiments of this disclosure, step S1032 may include steps S1032A-S1032B.

[0097] Step S1032A: Multiply the confidence level and ranging distance of each UWB base station in the current period by the range, and obtain the corrected ranging distance from each UWB base station to the mobile terminal in the current period.

[0098] Step S1032B: Calculate the position coordinates of the mobile terminal in the current period based on the corrected ranging distance and position coordinates of each UWB base station.

[0099] In a specific embodiment, the position coordinates of the mobile terminal in the current cycle can be calculated using the trilateration least squares fitting method. Assuming the target area is external region 1, the position coordinates of UWB base station 1 are... The ranging distance from the mobile terminal to UWB base station 1 is The location coordinates of UWB base station 2 are The ranging distance from the mobile terminal to UWB base station 3 is The location coordinates of UWB base station 3 are The ranging distance from the mobile terminal to UWB base station 4 is The location coordinates of UWB base station 4 are The location coordinates of UWB base station 5 are The ranging distance from the mobile terminal to UWB base station 5 is The location coordinates of UWB base station 6 are The ranging distance from the mobile terminal to UWB base station 6 is According to Table 1, the confidence levels corresponding to UWB base stations 1-6 are 1, 1, 0.1, 0.1, 0.25 and 1 respectively, so the following system of equations can be constructed.

[0100]

[0101] Solving the aforementioned system of equations using the least squares method yields the measurement coordinates of the mobile terminal in the current cycle. .

[0102] Of course, in other embodiments of this disclosure, other methods can also be used to calculate the measurement coordinates based on the ranging distance between the UWB base station and the mobile terminal, and the confidence level of the target area corresponding to the UWB base station. For example, in other embodiments of this disclosure, when the target area is the vehicle exterior area 1, the following system of equations can be constructed based on the aforementioned ranging distance and confidence level, and the measurement coordinates for the current period can be obtained by solving the system of equations using the least squares method. .

[0103]

[0104] Based on the transmission characteristics of UWB signals, if non-line-of-sight propagation occurs, the propagation distance is relatively large compared to the straight-line propagation distance. Furthermore, the more severe the non-line-of-sight propagation of the UWB signal, the lower the confidence level of the corresponding ranging distance. By correcting the ranging distance using confidence level, and then using the corrected ranging distance to calculate the measurement coordinates, the accuracy of the measurement coordinate calculation is improved.

[0105] As mentioned above, in step S102 of this embodiment, it is necessary to determine the target area where the mobile terminal is located in the current cycle based on multiple ranging distances. In some embodiments of this company, the step of determining the target area where the mobile terminal is located in the current cycle based on multiple ranging distances includes steps S1021-S1026.

[0106] Step S1021: Determine the boundary calibration data of the area where the mobile terminal was located in the previous cycle based on the location coordinates of the mobile terminal in the previous cycle.

[0107] Before executing the positioning method of this embodiment, sufficient calibration work was performed on the boundaries of each region, and boundary calibration data of all boundaries were obtained. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0108] In this embodiment of the disclosure, the process of determining the boundary calibration data of the area where the mobile terminal is located in the previous cycle based on the location coordinates of the previous cycle includes the following steps: first, determining the area where the previous cycle is located based on the location coordinates of the previous cycle; then, selecting the corresponding calibration data from all the boundary calibration data based on the area where the previous cycle is located, as the boundary calibration data of the mobile terminal in the area where the previous cycle is located.

[0109] Step S1022: Determine the relationship between the absolute value of the first difference between the current period's mobile terminal and all UWB base stations and the calibration distance between each boundary calibration point and the corresponding UWB base station, and the set value.

[0110] If the first difference between the ranging distance between the current mobile terminal and any UWB base station and the calibration distance between a boundary calibration point and the corresponding UWB base station is greater than a set value, proceed to step S1023.

[0111] If the difference between the distance measured between the mobile terminal and multiple UWB base stations in the current cycle and the calibration distance between a certain boundary calibration point and each UWB base station is less than the set value, then step S1024 is executed.

[0112] Step S1023: Take the area where the mobile terminal was located in the previous cycle as the target area.

[0113] In this embodiment of the disclosure, if the difference between the ranging distance between the mobile terminal and any UWB base station in the current cycle and the ranging distance from the boundary calibration point to the corresponding UWB base station is greater than a set value, it indicates that the mobile terminal has not yet moved to the vicinity of the area boundary of the area in the previous cycle in the current cycle, and thus indicates that the mobile terminal in the current cycle is still located in the area of ​​the previous cycle. Therefore, the area where the mobile terminal was located in the previous cycle is taken as the target area of ​​the current cycle.

[0114] Step S1024: Determine whether the first difference and the second difference corresponding to a certain boundary calibration point are the same relative to the zero value; if they are the same, proceed to step S1025; if they are not the same, proceed to step S1026.

[0115] In some embodiments of this disclosure, the boundary calibration data includes not only the ranging distance from the boundary calibration point to the multiple UWB base stations, but also a second difference between the reference distance between the azimuth reference point on one side of each boundary calibration point and each UWB base station and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station.

[0116] Determining whether the first difference and the second difference are the same relative to zero involves determining whether the first difference and the second difference are both positive or both negative.

[0117] If the difference between the ranging distance between the mobile terminal and each UWB base station and the calibration distance between a certain boundary calibration point and each UWB base station in the current cycle is less than a set value, then it is determined that the mobile terminal is close to the aforementioned boundary calibration point. At this time, the mobile terminal may be located in the area of ​​the previous cycle, or it may cross the boundary calibration point and move to another nearby area. That is, the mobile terminal may cross the boundary. To ensure a more accurate determination of the mobile terminal's position at the aforementioned boundary calibration point, step S1024 is executed in this embodiment of the disclosure.

[0118] As before, the first difference is the difference between the ranging distance between the mobile terminal and a certain UWB base station and the calibration distance between the boundary calibration point and the corresponding UWB base station. The second difference is the difference between the reference distance between the azimuth reference point on one side of the boundary calibration point and each UWB and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station. If the first difference and the second difference have the same magnitude relative to zero, it proves that the mobile terminal and the azimuth reference point are located in the same area in the current cycle, so step S1025 is executed. If the first difference and the second difference have different magnitudes relative to zero, it proves that the mobile terminal and the azimuth reference point are not in the same area in the current cycle, that is, the mobile terminal is located in the area on the other side of the aforementioned boundary calibration point, so step S1026 is executed.

[0119] Step S1025: Take the area where the azimuth reference point is located as the target area.

[0120] Step S1026: Take the area on the other side of a certain boundary calibration point, excluding the azimuth reference point, as the target area.

[0121] Optionally, in some embodiments of this disclosure, before performing the aforementioned step S1021, the mobile terminal may also perform steps S1027-S1028.

[0122] Step S1027: Obtain the displacement of the mobile terminal in the current period.

[0123] In this embodiment, the mobile terminal can obtain its velocity in the current cycle by integrating the motion acceleration output by the inertial measurement unit. Specifically, the velocity of the mobile terminal in the current cycle can be an average velocity or an instantaneous velocity at various time points within the current cycle. After determining the velocity and cycle duration for the current cycle, the mobile terminal can determine its displacement in the current cycle through integration.

[0124] Step S1028: Determine the set value based on the displacement of the mobile terminal in the current cycle.

[0125] In this embodiment of the disclosure, the aforementioned set value can be determined based on the movement distance. For example, after determining the movement distance, the movement distance can be directly used as the set value, or the set value can be obtained by multiplying the movement distance by a weight value.

[0126] As mentioned above, in some embodiments of this disclosure, the mobile terminal needs to determine the target area of ​​the previous cycle based on the location coordinates of the previous cycle, and determine the target area of ​​the current cycle based on the target area of ​​the previous cycle.

[0127] In other embodiments of this disclosure, the mobile terminal may also use other methods to determine the target area where the current cycle is located.

[0128] In some embodiments of this disclosure, the positioning method for the mobile terminal further includes steps S104-S106 before performing step S102.

[0129] Step S104: Obtain the ranging distance between multiple UWB base stations and the mobile terminal within a preset time period.

[0130] The preset lead time is a preset time preceding the current cycle, and the preset lead time includes multiple UWB communication cycles. In one embodiment of this disclosure, the preset lead time is set to 1 second, and the UWB communication cycle is 50 ms, then the preset lead time includes 20 communication cycles.

[0131] In this embodiment of the present disclosure, the mobile terminal can determine the ranging distance between itself and multiple UWB base stations within a preset time period according to the non-bilateral ranging algorithm in step S101 above, or it can use a unilateral ranging algorithm to determine the ranging distance between itself and multiple UWB base stations within a preset time period, which will not be repeated here.

[0132] Step S105: Calculate the average ranging distance of each UWB base station within the preset time period.

[0133] In this embodiment of the disclosure, after obtaining multiple ranging distances corresponding to each UWB base station within a preset time period, the mobile terminal calculates the corresponding mean and variance based on the ranging distance corresponding to each UWB base station.

[0134] For example, 20 ranging distances were obtained for the aforementioned UWB base station 1. - The mean value corresponding to UWB base station 1 can be obtained. The corresponding variance is Similarly, the mean value corresponding to UWB base station 2 is The corresponding variance is , ……

[0135] Step S106: Select the mean values ​​corresponding to at least N UWB base stations with the smallest variance, and calculate the estimated location coordinates of the mobile terminal.

[0136] After calculating the mean and variance of the test distances corresponding to each UWB base station within a preset time period, the mobile terminal compares the variances corresponding to each UWB base station to determine at least N UWB base stations with the smallest variances, and calculates the estimated location coordinates of the mobile terminal based on the mean of the ranging distances corresponding to the aforementioned UWB base stations; where N is at least 1; preferably, N is at least 4.

[0137] The smaller the variance of the ranging distance, the smaller the change in the ranging distance between the mobile terminal and the corresponding UWB base station within the preset time period. This indicates that the possibility of non-line-of-sight propagation during communication between the mobile terminal and this UWB base station is small, and the higher the reliability of using the mean of the ranging distance corresponding to this UWB base station to calculate the estimated location coordinates of the mobile terminal.

[0138] In this embodiment of the disclosure, the mobile terminal selects the average of the ranging distances corresponding to four UWB base stations with the smallest variance to calculate the estimated location coordinates of the mobile terminal. In other embodiments of the disclosure, the mobile terminal may also select the average of the ranging distances corresponding to UWB base stations with variances less than a set threshold to calculate the estimated location coordinates of the mobile terminal.

[0139] Step S107: Based on the estimated location coordinates, determine the target area corresponding to the estimated location coordinates and the boundary calibration data of the target area. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0140] After determining the estimated location coordinates, the corresponding preset area can be determined based on the estimated location coordinates, and the boundary calibration data of the preset area can be determined. Then, step S102 can be executed to determine the target area where the mobile terminal is located in the current cycle among multiple preset areas based on multiple ranging distances. Specifically, step S102 includes step S1029.

[0141] Step S1029: Determine the target area of ​​the mobile terminal in the current period based on the calibration distance from each boundary calibration point to each UWB base station and the ranging distance of each UWB base station in the current period.

[0142] In a specific embodiment, step S1029 may include steps S1029A-S1029E.

[0143] S1029A: Determine the relationship between the absolute value of the first difference between the current period's mobile terminal and all UWB base stations and the calibration distance between each boundary calibration point and the corresponding UWB base station, and the set value.

[0144] If the first difference between the ranging distance between the current mobile terminal and any UWB base station and the calibration distance between a boundary calibration point and the corresponding UWB base station is greater than a set value, proceed to step S1029B.

[0145] If the difference between the distance measured between the mobile terminal and multiple UWB base stations in the current cycle and the calibration distance between a certain boundary calibration point and each UWB base station is less than the set value, then step S1029C is executed.

[0146] Step S1029B: Use the preset area corresponding to the estimated position coordinates as the target area.

[0147] In this embodiment of the disclosure, if the difference between the ranging distance between the mobile terminal and any UWB base station and the ranging distance from the boundary calibration point to the corresponding UWB base station in the current cycle is greater than a set value, it indicates that the mobile terminal has not yet moved to the vicinity of the area boundary of the preset area where the estimated position coordinates are located in the current cycle, and thus indicates that the mobile terminal is still located in the preset area where the estimated position coordinates are located in the current cycle. Therefore, the preset area where the estimated position coordinates are located is taken as the target area where the current cycle is located.

[0148] Step S1029C: Determine whether the first difference and the second difference corresponding to a certain boundary calibration point are the same relative to the zero value; if they are the same, proceed to step S1029D; if they are not the same, proceed to step S1029E.

[0149] In some embodiments of this disclosure, the boundary calibration data includes not only the ranging distance from the boundary calibration point to the multiple UWB base stations, but also a second difference between the reference distance between the azimuth reference point on one side of each boundary calibration point and each UWB base station and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station.

[0150] Determining whether the first difference and the second difference are the same relative to zero involves determining whether the first difference and the second difference are both positive or both negative.

[0151] If the difference between the ranging distance between the mobile terminal and each UWB base station and the calibration distance between a certain boundary calibration point and each UWB base station in the current cycle is less than a set value, then it is determined that the mobile terminal is close to the aforementioned boundary calibration point. At this time, the mobile terminal may be located in the area of ​​the previous cycle, or it may cross the boundary calibration point and move to another nearby area. That is, the mobile terminal may cross the boundary. To ensure a more accurate determination of the mobile terminal's position at the aforementioned boundary calibration point, step S1029C is executed in this embodiment of the disclosure.

[0152] If the first difference and the second difference are the same in magnitude relative to zero, it proves that the current cycle mobile terminal and the orientation reference point are located in the same area, so step S1029D is executed. If the first difference and the second difference are different in magnitude relative to zero, it proves that the current cycle mobile terminal and the orientation reference point are not in the same area, that is, the current cycle mobile terminal is located on the other side of the aforementioned boundary calibration point, so step S1029E is executed.

[0153] Step S1029D: Take the area where the azimuth reference point is located as the target area.

[0154] Step S1029E: Take the area on the other side of a certain boundary calibration point, excluding the azimuth reference point, as the target area.

[0155] In a specific embodiment, the aforementioned method can be used to determine the target area when the mobile terminal has just established a connection with the UWB base station; or the aforementioned method can be used to determine the target area at any time period.

[0156] Figure 3 This is a flowchart of a mobile terminal positioning method provided in some embodiments of this disclosure. For example... Figure 3 As shown, in some embodiments of this disclosure, the positioning method of the mobile terminal may include steps S108-S109 in addition to the aforementioned steps S101-S103, and the aforementioned steps S103 include steps S1033-S1034.

[0157] Step S101: Obtain the ranging distance between multiple UWB base stations and mobile terminals in the current period.

[0158] Step S102: Based on multiple ranging distances, determine the target area where the mobile terminal is located in the current cycle from multiple preset areas.

[0159] Step S108: Obtain the displacement of the mobile terminal in the current period.

[0160] In this embodiment of the disclosure, the mobile terminal is equipped with an inertial measurement unit (IMU), and the displacement of the mobile terminal in the current cycle can be determined based on the inertial signal output by the inertial measurement unit.

[0161] In practical applications, inertial measurement units typically include a three-axis accelerometer and a three-axis gyroscope. The three-axis accelerometer can measure the acceleration of a mobile terminal, and the velocity and displacement of the mobile terminal can be obtained by integrating the acceleration and velocity.

[0162] In one embodiment of this disclosure, the inertial measurement unit configured in the mobile terminal is a strapdown inertial measurement unit. The triaxial acceleration and triaxial angular velocity values ​​measured by the strapdown inertial measurement unit are relative to the carrier coordinate system. The velocity and displacement information of the mobile terminal cannot be simply obtained by integration. It is necessary to convert the acceleration value in the carrier coordinate system to the acceleration value in the geographic coordinate system where the mobile terminal is located, and then calculate the motion velocity and displacement of the mobile terminal based on the converted acceleration value.

[0163] Step S109: Calculate the predicted coordinates of the mobile terminal in the current cycle based on the position coordinates of the mobile terminal in the previous cycle and its displacement in the current cycle.

[0164] In this embodiment of the disclosure, after obtaining the position coordinates of the mobile terminal in the previous cycle, the position coordinates of the mobile terminal in the previous cycle and the position coordinates of the current cycle are added together to obtain the predicted coordinates of the mobile terminal in the current cycle.

[0165] Step S1033: Calculate the measurement coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period.

[0166] In this embodiment of the disclosure, the method of steps 1031-S1032 above can be used to calculate the measurement coordinates of the mobile terminal in the current period by using the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period.

[0167] Step S1034: The measured coordinates and predicted coordinates are fused to obtain the position coordinates of the mobile terminal in the current period.

[0168] In this embodiment, the mobile terminal exhibits nonlinear mobility. To accommodate this nonlinearity, the measured and predicted coordinates are fused. This fusion can be achieved using methods such as nonlinear Kalman filtering or particle filtering to obtain the mobile terminal's position coordinates in the current period. Specifically, the nonlinear Kalman filtering method can be either extended Kalman filtering or unscented Kalman filtering. Extended Kalman filtering is a method that approximates a stochastic nonlinear discrete system using linearization, while unscented Kalman filtering is a problem Kalman filtering method that uses unscented transformations to handle nonlinear systems.

[0169] The following describes how the extended Kalman filter method is used to explain the location coordinates of the mobile terminal in the current cycle obtained by fusing measured coordinates and predicted coordinates in the embodiments of this disclosure.

[0170] Based on experience, the system for mobile terminal positioning provided in this disclosure is a consistent, secure, measurable, and controllable nonlinear system.

[0171] Nonlinear systems can use state equations to predict the mobile terminal's coordinates at the next moment, where the displacement of the current cycle drives the state equations. Because inertial measurement units (IMUs) have inherent noise, long-term predictions of the mobile terminal's velocity, displacement, and other states can introduce significant accumulated errors. Therefore, state equations can only provide state estimates for a short period. In this embodiment, the state equations can be simplified to: .

[0172] Nonlinear systems can be described by measurement equations through direct or indirect measurement of coordinates, and errors generated during the derivation of state equations can be corrected. In this embodiment, the measurement equations can be simplified to... .

[0173] Assuming the state x(t) at time t is known, the following options are chosen:

[0174] Subtracting the two equations above from the model state equation and the measurement equation, and then using Taylor series expansion to omit higher-order terms, we obtain...

[0175] ,in, .

[0176] According to the discretization formula as well as ,Will Recorded as ,Will Recorded as Then the linear, i.e., discretized state equation can be written as: .

[0177] Applying the five formulas of the Kalman filter for iterative estimation, we can obtain the one-step prediction of the state. The prediction mean square error is The weighted calculation of the measured values ​​is as follows: The fusion measurement value is Estimate mean square error .

[0178] In this embodiment of the disclosure, the measured coordinates and predicted coordinates are fused to obtain the position coordinates of the mobile terminal in the current period, that is, by using... Calculate the position coordinates of the current cycle. ,in To predict coordinates, To measure coordinates, This is the Kalman gain.

[0179] In this embodiment of the disclosure, the predicted coordinates of the mobile terminal in the current cycle are calculated based on the position coordinates of the mobile terminal in the previous cycle and its displacement in the current cycle. The measured coordinates and predicted coordinates are then fused. The results of the attitude calculation by the inertial sensing unit can be used to correct the measured coordinates, reducing the positioning distortion caused by gross distance errors and optimizing the positioning results. In some embodiments of this disclosure, after the mobile terminal calculates the measured coordinates for the current cycle in step S1033, it can also execute step S1035.

[0180] Step S1035: Determine whether the measurement coordinates of the mobile terminal in the current period meet the preset constraints. If the preset constraints are met, proceed to step S1034; if the preset constraints are not met, proceed to step S1036.

[0181] In specific implementations of this disclosure, the calculated measurement coordinates may differ from the actual situation. For example, the calculated height coordinate may be less than the ground height, or the horizontal coordinate may exceed the UWB communication radius. Calculating the mobile terminal's coordinates at its current location using such contradictory measurement coordinates will introduce significant errors.

[0182] To avoid introducing measurement coordinates that contradict actual conditions, some embodiments of this disclosure, after obtaining the measurement coordinates of the mobile terminal in the current period, further determine whether the measurement coordinates meet set constraints. These set constraints are used to determine whether the measurement coordinates are reasonable.

[0183] In some embodiments of this disclosure, setting constraints includes setting a range of height coordinates and a range of horizontal coordinates. The set height coordinate range characterizes the range of possible height coordinates of the mobile terminal, and the set horizontal coordinate range characterizes the range of possible horizontal coordinates of the mobile terminal.

[0184] When setting constraints includes setting a range of height coordinates and a range of horizontal coordinates, the aforementioned step S1035 may include step S1035A.

[0185] Step S1035A: Determine whether the height coordinate of the mobile terminal in the measurement coordinates of the current cycle meets the set height coordinate range, and / or determine whether the horizontal coordinate of the mobile terminal in the measurement coordinates of the current cycle is within the horizontal coordinate range.

[0186] Step S1036: The position coordinates of the mobile terminal in the previous cycle and the predicted coordinates are fused to obtain the position coordinates of the mobile terminal in the current cycle.

[0187] If the measurement coordinates of the mobile terminal in the current cycle do not meet the set constraints, it proves that the measurement coordinates of the mobile terminal in the current cycle are unreliable. Therefore, the measurement coordinates of the current cycle are not used for fusion processing. Instead, the position coordinates of the previous cycle and the predicted coordinates are used for fusion processing to obtain the position coordinates of the mobile terminal in the current cycle.

[0188] As previously stated in the embodiments of this disclosure, the number of UWB base stations deployed in the vehicle is six. In other embodiments of this disclosure, the number of UWB base stations and the number of target UWB base stations may also be other numbers, but it should be ensured that the number of UWB base stations is at least four to ensure that the measurement coordinates of the mobile terminal can be obtained through at least four target UWB base stations.

[0189] Figure 4 This is a schematic diagram of the structure of a positioning device for a mobile terminal provided in some embodiments of this disclosure. The positioning device 400 of the mobile terminal can be understood as a part of the functional modules of the aforementioned vehicle controller. Figure 4 As shown, the positioning device 400 for a mobile terminal provided in this embodiment includes a ranging distance acquisition unit 401, a target area determination unit 402, and a position coordinate calculation unit 403.

[0190] The ranging distance acquisition unit 401 is used to acquire the ranging distance between multiple UWB base stations and mobile terminals in the current period.

[0191] The target area determination unit 402 is used to determine the target area where the mobile terminal is located in the current cycle from multiple preset areas based on multiple ranging distances.

[0192] The location coordinate calculation unit 403 is used to calculate the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period.

[0193] In some embodiments of this disclosure, the preset area is a region determined based on the vehicle, and the preset area includes an external area and an internal area.

[0194] In some embodiments of this disclosure, the plurality of UWB base stations includes six, wherein two UWB base stations are located on the left and right sides of the front grille of the vehicle, two UWB base stations are located on the left and right sides of the tailgate of the vehicle, and two UWB base stations are located in the middle area of ​​the vehicle roof and are staggered along the length of the vehicle body; the external area includes the external front area, external rear area, external left front area, external left rear area, external right front area, and external right rear area; the internal area includes the internal left front area, internal right front area, internal left rear area, and internal right rear area.

[0195] In some embodiments of this disclosure, the target region determination unit includes a boundary calibration data acquisition subunit and a target region determination subunit.

[0196] The boundary calibration data acquisition subunit is used to determine the boundary calibration data of the target area where the mobile terminal is located in the previous cycle based on the location coordinates of the mobile terminal in the previous cycle. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0197] The target area determination subunit is used to respond to the calibration distance from each boundary calibration point to each UWB base station. The absolute value of the first difference between the calibration distance and the corresponding ranging distance is greater than the set value. The target area of ​​the mobile terminal in the previous cycle is taken as the target area of ​​the current cycle.

[0198] In some embodiments of this disclosure, the boundary calibration data further includes a second difference between the reference distance between the azimuth reference point on one side of each boundary calibration point and each UWB base station, and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station. The target region determination subunit is further configured to, in response to the absolute value of the first difference being less than the set value, determine whether the magnitude relationship between the first difference and the second difference corresponding to a certain boundary calibration point and zero is the same; in response to the magnitude relationship being the same, designate the preset region where the azimuth reference point is located as the target region where the mobile terminal is located in the current cycle; in response to at least one of the magnitude relationships being different, designate the preset region on the other side of the boundary calibration point, excluding the azimuth reference point, as the target region of the mobile terminal in the current cycle.

[0199] In some embodiments of this disclosure, the positioning device for the mobile terminal further includes a displacement acquisition unit and a setpoint determination unit. The displacement acquisition unit is used to acquire the displacement of the mobile terminal in the current period. The setpoint determination unit is used to determine a setpoint based on the displacement of the mobile terminal in the current period.

[0200] In some embodiments of this disclosure, the positioning device of the mobile terminal further includes an initial ranging distance acquisition unit, a mean and variance calculation unit, and an estimated position coordinate calculation unit.

[0201] The initial ranging distance acquisition unit is used to acquire the ranging distance between multiple UWB base stations and mobile terminals within a preset time period, which includes multiple cycles.

[0202] The mean and variance calculation unit is used to calculate the mean and variance of the ranging distance corresponding to each UWB base station within a preset time period.

[0203] The estimated location coordinate calculation unit is used to select the mean values ​​corresponding to at least N UWB base stations with the smallest variance, calculate the estimated location coordinates of the mobile terminal, and determine the preset area corresponding to the estimated location coordinates and the boundary calibration data of the preset area based on the estimated location coordinates. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station.

[0204] Correspondingly, the target area determination unit 402 determines the target area of ​​the mobile terminal in the current period based on the calibration distance from each boundary calibration point to each UWB base station and the ranging distance of each UWB base station in the current period.

[0205] In some embodiments of this disclosure, the target area determination unit includes a confidence determination subunit and a location coordinate calculation subunit.

[0206] The confidence level determination subunit is used to determine the confidence level of each UWB base station in the current period based on the target area where the mobile terminal is located in the current period. The location coordinate calculation subunit is used to calculate the location coordinates of the mobile terminal in the current period based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period.

[0207] In some embodiments of this disclosure, the location coordinate calculation subunit first multiplies the confidence level and ranging distance of each UWB base station in the current period to obtain the corrected ranging distance from each UWB base station to the mobile terminal in the current period. Then, based on the corrected ranging distance and the location coordinates of each UWB base station, the location coordinates of the mobile terminal in the current period are calculated.

[0208] In some embodiments of this disclosure, a displacement acquisition unit and a predicted coordinate calculation unit are further included. The displacement acquisition unit is used to acquire the displacement of the mobile terminal in the current cycle. The predicted coordinate calculation unit is used to calculate the predicted coordinates of the mobile terminal in the current cycle based on the position coordinates of the mobile terminal in the previous cycle and the displacement in the current cycle.

[0209] Correspondingly, the location coordinate calculation unit includes a measurement coordinate calculation subunit and a fusion subunit. The measurement coordinate calculation subunit is used to calculate the measurement coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period. The fusion subunit is used to fuse the measurement coordinates and the predicted coordinates to obtain the location coordinates of the mobile terminal in the current period.

[0210] In some embodiments of this disclosure, the mobile terminal positioning device further includes a constraint determination unit. The constraint determination unit determines whether the measured coordinates of the mobile terminal in the current period meet set constraint conditions, including whether the height coordinate is within a set height coordinate range and / or whether the horizontal coordinate is within a set horizontal coordinate range. If the constraint determination unit determines that the measured coordinates of the mobile terminal in the current period meet the set constraint conditions, the data fusion unit performs fusion processing on the measured coordinates and predicted coordinates to obtain the position coordinates of the mobile terminal in the current period.

[0211] In some embodiments of this disclosure, when the measured coordinates of the mobile terminal in the current cycle do not meet the set constraints, the fusion subunit fuses the position coordinates of the mobile terminal in the previous cycle and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current cycle.

[0212] In some embodiments of this disclosure, the fusion subunit uses a nonlinear Kalman filter or a particle filter to fuse the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period.

[0213] Figure 5 This is a schematic diagram of the structure of a computer device provided in an embodiment of this disclosure. See below for details. Figure 5 It shows a schematic diagram of the structure suitable for implementing the computer device 500 in the embodiments of this disclosure. Figure 5 The computer device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0214] like Figure 5 As shown, the computer device 500 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory ROM 502 or a program loaded from a storage device 508 into a random access memory RAM 503. The RAM 503 also stores various programs and data required for the operation of the computer device 500. The processing unit 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0215] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 508 including, for example, magnetic tapes, hard disks, etc.; and communication devices 509. Communication device 509 allows computer device 500 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 5 A computer device 500 with various devices is shown; however, it should be understood that it is not required to implement or have all of the devices shown. More or fewer devices may be implemented or included alternatively.

[0216] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by the processing device 501, it performs the functions defined in the methods of embodiments of this disclosure.

[0217] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0218] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol such as HTTP (Hypertext Transfer Protocol) and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks), as well as any currently known or future-developed networks.

[0219] The aforementioned computer-readable medium may be included in the aforementioned computer device; or it may exist independently and not assembled into the computer device.

[0220] The aforementioned computer-readable medium carries one or more programs that, when executed by the computer device, cause the computer device to: acquire the ranging distances between multiple UWB base stations and the mobile terminal in the current period; determine the target area where the mobile terminal is located in the current period in multiple preset areas based on the multiple ranging distances; and calculate the position coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distances between the multiple UWB base stations and the mobile terminal in the current period.

[0221] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0222] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0223] The units described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units are not, in some cases, intended to limit the specific unit.

[0224] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), and so on.

[0225] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include, based on electrical connections of one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0226] This disclosure also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement the methods of any of the above method embodiments. The execution method and beneficial effects are similar, and will not be described again here.

[0227] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0228] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A positioning method for a mobile terminal, characterized in that, include: The ranging distance between multiple UWB base stations and mobile terminals in the current period is obtained, wherein the ranging distance is determined based on a non-bilateral ranging algorithm; Based on multiple ranging distances, the target area where the mobile terminal is located in the current cycle is determined in multiple preset areas; Based on the target area where the mobile terminal is located in the current period, and the ranging distance between the mobile terminal and multiple UWB base stations in the current period, calculate the position coordinates of the mobile terminal in the current period; The step of determining the target area where the mobile terminal is located in the current period within multiple preset areas based on multiple ranging distances includes: Based on the location coordinates of the mobile terminal in the previous cycle, the boundary calibration data of the target area where the mobile terminal was located in the previous cycle is determined. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station. In response to the fact that the absolute value of the first difference between the calibration distance from each boundary calibration point to each UWB base station and the corresponding ranging distance is greater than the set value, the target area of ​​the mobile terminal in the previous cycle is taken as the target area of ​​the current cycle.

2. The positioning method for a mobile terminal according to claim 1, characterized in that: The preset area is a region determined based on the vehicle, and the preset area includes the area outside the vehicle and the area inside the vehicle.

3. The positioning method for a mobile terminal according to claim 2, characterized in that: The plurality of UWB base stations includes six, of which two UWB base stations are located on the left and right sides of the front grille of the vehicle, two UWB base stations are located on the left and right sides of the tailgate of the vehicle, and two UWB base stations are located in the middle area of ​​the vehicle roof and are staggered along the length of the vehicle body; the external area of ​​the vehicle includes the front external area, the rear external area, the front left external area, the rear left external area, the front right external area, and the rear right external area. The interior areas include the front left area, the front right area, the rear left area, and the rear right area.

4. The positioning method for a mobile terminal according to claim 1, characterized in that, The boundary calibration data also includes a second difference between the reference distance between the azimuth reference point on one side of each boundary calibration point and each UWB base station and the calibration distance between the corresponding boundary calibration point and the corresponding UWB base station. The step of determining the target area where the mobile terminal is located in the current period within multiple preset areas based on multiple ranging distances further includes: In response to the fact that the absolute values ​​of the first differences are all less than the set value, it is determined whether the first difference and the second difference corresponding to the boundary calibration point are the same as the zero value; In response to the fact that the size relationships are all the same, the preset area where the orientation reference point is located is taken as the target area where the mobile terminal is located in the current cycle. In response to at least one of the different size relationships, a preset area on the other side of the boundary calibration point that does not include the orientation reference point is taken as the target area of ​​the mobile terminal in the current cycle.

5. The positioning method for a mobile terminal according to any one of claims 1 or 4, characterized in that, Before determining the boundary calibration data of the target area where the mobile terminal was located in the previous cycle, the method further includes: Obtain the displacement of the mobile terminal in the current period; The set value is determined based on the displacement of the mobile terminal in the current cycle.

6. The positioning method for a mobile terminal according to any one of claims 1-3, characterized in that, The method further includes: The ranging distances between multiple UWB base stations and the mobile terminal are obtained within a preset time period. The preset time period is a preset time before the current period and includes multiple periods. Calculate the mean and variance of the ranging distances corresponding to each UWB base station within the preset time period; Select the mean values ​​corresponding to at least N UWB base stations with the smallest variance, and calculate the estimated location coordinates of the mobile terminal, where N is an integer greater than or equal to 1; Based on the estimated location coordinates, a preset area corresponding to the estimated location coordinates is determined, as well as boundary calibration data of the preset area. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station. The step of determining the target area of ​​the mobile terminal in the current period in multiple preset areas based on multiple ranging distances includes: determining the target area of ​​the mobile terminal in the current period based on the calibration distance from each boundary calibration point to each UWB base station and the ranging distance of each UWB base station in the current period.

7. The positioning method for a mobile terminal according to any one of claims 1-4, characterized in that, The step of calculating the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period includes: Based on the target area where the mobile terminal is located in the current period, determine the confidence level of each UWB base station in the current period; Based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period, the position coordinates of the mobile terminal in the current period are calculated.

8. The positioning method for a mobile terminal according to claim 7, characterized in that, The step of calculating the position coordinates of the mobile terminal in the current period based on the confidence level of each UWB base station in the current period and the ranging distance between each UWB base station and the mobile terminal in the current period includes: Multiply the confidence level and ranging distance of each UWB base station in the current period to obtain the corrected ranging distance from each UWB base station to the mobile terminal in the current period. The position coordinates of the mobile terminal in the current period are calculated based on the corrected ranging distance and the position coordinates of each UWB base station.

9. The positioning method for a mobile terminal according to any one of claims 1-4, characterized in that, Also includes: Obtain the displacement of the mobile terminal in the current period; Based on the position coordinates of the mobile terminal in the previous cycle and its displacement in the current cycle, calculate the predicted coordinates of the mobile terminal in the current cycle. The step of calculating the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period includes: Based on the target area where the mobile terminal is located in the current period, and the ranging distance between the mobile terminal and multiple UWB base stations in the current period, the measurement coordinates of the mobile terminal in the current period are calculated. The measured coordinates and the predicted coordinates are fused to obtain the position coordinates of the mobile terminal in the current period.

10. The positioning method for a mobile terminal according to claim 9, characterized in that, Before fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period, the method further includes: Determine whether the measurement coordinates of the mobile terminal in the current period meet the set constraints, the set constraints including the height coordinate being within a set height coordinate range, and / or the horizontal coordinate being within a set horizontal coordinate range; The step of fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period includes: in response to the measured coordinates of the mobile terminal in the current period satisfying the set constraint condition, fusing the measured coordinates and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period; The method further includes: in response to the fact that the measured coordinates of the mobile terminal in the current period do not meet the set constraint conditions, fusing the position coordinates of the mobile terminal in the previous period and the predicted coordinates to obtain the position coordinates of the mobile terminal in the current period.

11. A positioning device for a mobile terminal, characterized in that, include: The ranging distance acquisition unit is used to acquire the ranging distance between multiple UWB base stations and mobile terminals in the current period, wherein the ranging distance is determined based on a non-bilateral ranging algorithm; The target area determination unit is used to determine the target area where the mobile terminal is located in the current period from multiple preset areas based on multiple ranging distances; The location coordinate calculation unit is used to calculate the location coordinates of the mobile terminal in the current period based on the target area where the mobile terminal is located in the current period and the ranging distance between the mobile terminal and multiple UWB base stations in the current period. The step of determining the target area where the mobile terminal is located in the current period within multiple preset areas based on multiple ranging distances includes: Based on the location coordinates of the mobile terminal in the previous cycle, the boundary calibration data of the target area where the mobile terminal was located in the previous cycle is determined. The boundary calibration data includes the calibration distance from the boundary calibration point to each UWB base station. In response to the fact that the absolute value of the first difference between the calibration distance from each boundary calibration point to each UWB base station and the corresponding ranging distance is greater than the set value, the target area of ​​the mobile terminal in the previous cycle is taken as the target area of ​​the current cycle.

12. A computer device, characterized in that, include: A memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the positioning method of the mobile terminal as described in any one of claims 1-10.

13. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the positioning method of the mobile terminal as described in any one of claims 1-10.

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