A parking lot positioning method and system

Abstract

The application discloses a parking lot positioning method, comprising: obtaining initial coordinates of a plurality of reference anchor point devices, and establishing an initial coordinate system; determining pre-configuration coordinates of a plurality of locators based on the initial coordinate system; obtaining a first distance set of the plurality of reference anchor point devices; obtaining current coordinates of each reference anchor point device based on the first distance set and the initial coordinate set; obtaining a second distance between a target locator and a target reference anchor point device; and obtaining a corrected coordinate of the target locator based on the second distance, the current coordinate of the target reference anchor point device and the pre-configuration coordinate of the target locator, wherein the corrected coordinate is used for positioning of a vehicle in the parking lot. Through automatic calibration of the coordinate system by the reference anchor point, real-time updating of the coordinates by the locator and intelligent adaptation of the vehicle end, the burden and cost of operation and maintenance are reduced, the problem of precision decay caused by environmental changes in the traditional scheme is solved, and a solid foundation is provided for parking and precise navigation and the like.

Description

Technical Field

[0001] This invention relates to the field of communication positioning, and more particularly to a parking lot positioning method and system. Background Technology

[0002] Parking lots are typically located in places without GPS signals, such as underground parking lots. By using Ultra Wideband (UWB) technology, UWB locators are installed in the parking lot, and receivers are installed in the vehicles. The UWB locators send location information to the receivers in the vehicles, enabling them to guide the vehicles to a precise location in environments without GPS signals.

[0003] Traditional UWB positioning relies on a fixed coordinate system and is susceptible to cumulative errors caused by changes in the physical environment of the parking lot (such as ground subsidence and equipment displacement), resulting in poor UWB positioning accuracy. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a parking lot positioning method and system that can resolve the problem of decreased parking positioning accuracy caused by structural deformation of the parking lot and displacement of positioning equipment in environments without GPS, achieving centimeter-level positioning across all scenarios.

[0005] A parking lot positioning method, applied to a positioning system, the positioning system including multiple reference anchor point devices and multiple locators installed in the parking lot, includes the following steps:

[0006] Obtain the initial coordinates of the multiple reference anchor point devices, and establish an initial coordinate system based on the initial coordinates of the multiple reference anchor point devices;

[0007] Based on the initial coordinate system, the pre-configured coordinates of the multiple locators are determined;

[0008] Obtain a first distance set of multiple reference anchor point devices, wherein the first distance set includes the actual distance values ​​between each pair of the multiple reference anchor point devices within a first preset period;

[0009] Based on the first distance set and the initial coordinate set, the current coordinates of each of the reference anchor point devices are obtained, wherein the initial coordinate set includes the initial coordinates of multiple reference anchor point devices;

[0010] Obtain a second distance between the target locator and the target reference anchor device, wherein the target locator is any one of the plurality of locators, and the target reference anchor device is a reference anchor device that communicates with the target locator;

[0011] Based on the second distance, the current coordinates of the target reference anchor point device, and the pre-configured coordinates of the target locator, the corrected coordinates of the target locator are obtained, and the corrected coordinates are used for the positioning of the vehicle in the parking lot.

[0012] Furthermore, the current coordinates of each of the reference anchor point devices, obtained based on the first distance set and the initial coordinate set, include:

[0013] Based on the first distance set and the initial coordinate set, a first correction value set is calculated, wherein the first correction value set includes the translation amount and rotation angle of each of the reference anchor point devices;

[0014] The initial coordinate set is corrected based on the first set of correction values ​​to obtain the current coordinates of each of the reference anchor point devices.

[0015] Furthermore, the aforementioned target reference anchor point device is the reference anchor point device that is closest to the target locator among the plurality of reference anchor point devices.

[0016] Furthermore, the above-mentioned method of obtaining the corrected coordinates of the target locator based on the second distance, the current coordinates of the target reference anchor point device, and the pre-configured coordinates of the target locator includes:

[0017] A second correction value is determined based on the second distance and the current coordinates of the target reference anchor point device, wherein the second correction value includes the translation amount and rotation angle of the target locator;

[0018] Based on the second correction value and the pre-configured coordinates of the target locator, the corrected coordinates of the target locator are obtained.

[0019] Furthermore, the aforementioned target locator is a locator among the plurality of locators whose distance from at least one of the plurality of reference anchor devices is less than a first preset value.

[0020] After obtaining the corrected coordinates of the target locator based on the second correction value and the pre-configured coordinates of the target locator, the method further includes:

[0021] Based on the corrected coordinates and the second corrected value, the corrected coordinates of a plurality of nearby locators are determined, wherein the nearby locators are those whose distance from the target locator is less than a second preset value, and the corrected coordinates of the nearby locators are used for the positioning of the vehicle in the parking lot.

[0022] Furthermore, the second distance between the target locator and the target reference anchor device mentioned above includes:

[0023] The first transmission time when the target reference anchor point device sends the first calibration information to the target locator is obtained;

[0024] The second transmission time of the second calibration information sent by the target locator to the target reference anchor device is obtained;

[0025] The second distance is determined based on the first transmission time and the second transmission time.

[0026] Furthermore, the above methods also include:

[0027] Real-time monitoring of the position of each of the aforementioned reference anchor point devices;

[0028] When there is an abnormal reference anchor device among the multiple reference anchor devices whose daily displacement exceeds a preset value, the abnormal reference anchor device is temporarily calibrated and an abnormal alarm is issued.

[0029] Furthermore, the second distance between the target locator and the target reference anchor device mentioned above includes:

[0030] The second distance between the target locator and the target reference anchor device is obtained within a second preset period, wherein the second preset period is less than the first preset period.

[0031] A parking lot cooperative positioning system, comprising:

[0032] The system includes multiple reference anchor devices, a control unit, and multiple positioners. The control unit is communicatively connected to the multiple reference anchor devices and the multiple positioners. The control unit is used to perform the method described in any of the above embodiments.

[0033] The beneficial effects of this invention are as follows: This application reduces the burden and cost of operation and maintenance by automatically calibrating the coordinate system with reference anchor points, updating the coordinates in real time with the locator, and intelligently adapting to the vehicle. It also solves the problem of accuracy decay caused by environmental changes in traditional solutions, providing a solid foundation for applications such as parking and precise navigation. Attached Figure Description

[0034] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0035] Figure 1 This is an exemplary system architecture diagram to which this application can be applied;

[0036] Figure 2 This is a flowchart illustrating the steps of the parking lot positioning method provided in this application;

[0037] Figure 3This is a schematic diagram of the layout of reference anchor points and locators for a parking lot provided in this application; Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. Although the accompanying drawings and specific embodiments describe exemplary embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0039] The terms "first," "second," and similar words used in this application do not indicate any order, quantity, or importance, but are merely used for distinction. The terms "including," and similar words used in this application mean that the element preceding the word encompasses the elements listed after the word, and do not exclude the possibility of including other elements. The technical solutions of this application are not limited to the execution order described in the embodiments. The steps in the execution order can be combined, broken down, or their order can be changed, as long as the logical relationship of the execution content is not affected.

[0040] All terms used in this application (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein. Technologies and equipment known to one of ordinary skill in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0041] First, the relevant terms involved in the application embodiments will be explained.

[0042] Ultra-wideband (UWB) technology is a wireless carrier communication technology that uses frequency bandwidths above 1 GHz. Instead of using sinusoidal carriers, it transmits data using nanosecond-level non-sinusoidal narrow pulses, thus occupying a large spectrum. Although it uses wireless communication, its data transmission rate can reach hundreds of megabits per second or more. In locations with severe multipath effects, such as parking lots, UWB technology can effectively overcome signal attenuation and interference problems, ensuring the accuracy and reliability of data transmission.

[0043] UWB locators are devices that utilize ultra-wideband (UWB) technology to achieve high-precision positioning. They determine the target's location by measuring the time difference of signal propagation, achieving centimeter-level accuracy. UWB positioning works by sending extremely short pulse signals (nanosecond-level), with the receiver measuring the time difference of signal propagation along different paths. Combined with algorithms, the distance difference between the target and multiple receivers is calculated to ultimately determine the location. This technology can penetrate obstacles and is suitable for complex indoor environments.

[0044] UWB-TOF (Ultra-Wideband Time-of-Flight) is a ranging method based on UWB technology. It calculates distance by measuring the time of flight of a signal, achieving centimeter-level accuracy. UWB-TOF emits ultra-narrow pulse signals (nanosecond-level pulse width) and calculates the distance by multiplying the signal's time of flight by the speed of light. Due to the extremely high pulse time resolution of UWB (picosecond-level), the ranging accuracy can reach millimeter-level, far exceeding the meter-level error of traditional Bluetooth and Wi-Fi.

[0045] V2I (Vehicle-to-Infrastructure) refers to communication technology between vehicles and infrastructure. Through real-time data interaction between vehicles and road facilities (such as traffic lights and roadside units), it optimizes traffic management and improves driving safety and efficiency. V2I is a key technology of Intelligent Transportation Systems (ITS), with its core being the realization of two-way communication between vehicles and surrounding infrastructure. For example, vehicles can receive traffic light countdown information to adjust their speed, or send location and speed data to roadside equipment, helping traffic management centers dynamically optimize traffic light timing and issue road warnings.

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0047] like Figure 1 As shown, system architecture 100 may include terminal devices 101, 102, and 103, a network 104, and a server 105. Network 104 serves as the medium for providing communication links between terminal devices 101, 102, and 103 and server 105. Network 104 may include various connection types, such as wired or wireless communication links, or fiber optic cables, etc.

[0048] Users can use terminal devices 101, 102, and 103 to interact with server 105 via network 104 to receive or send messages, etc. Terminal devices 101, 102, and 103 can be hardware positioning terminals (reference anchor devices, locators, and communication units, etc.), vehicle-mounted terminals (vehicle positioning receivers and autonomous driving controllers, etc.), user interaction terminals (mobile apps and parking lot control screens, etc.), and other intelligent terminals, such as intelligent robots, AGVs, and other terminal equipment. Server 105 can be a server providing various services, such as a backend server supporting the pages displayed on terminal devices 101, 102, and 103.

[0049] It should be noted that the parking lot positioning method provided in this application embodiment is generally executed by a server, and correspondingly, the device for the parking lot positioning method is generally located in the server.

[0050] The lack of GPS navigation in parking lots can cause numerous inconveniences. These drawbacks not only affect users' parking efficiency and experience but can also trigger a series of chain reactions. Without GPS guidance, drivers can only rely on experience or visual observation to find available spaces after entering the parking lot, often requiring them to repeatedly drive around various areas. Especially in high-traffic parking lots such as large shopping malls and airports, it can take tens of minutes to find a parking space during peak hours, severely impacting travel efficiency. Parking spaces in parking lots may be scattered, with some vacant spaces hidden around corners, behind pillars, or in relatively remote areas. Due to the lack of navigation prompts, drivers can easily miss these vacant spaces and continue searching in vain in already saturated areas.

[0051] The time spent searching for parking spaces and locating vehicles significantly increases vehicle dwell time in parking lots, further reducing traffic efficiency. In congested environments, vehicles are closer together, parking lot GPS systems are inaccurate, and drivers may be distracted while searching for parking spaces or their cars, significantly increasing the probability of minor collisions and other traffic accidents, causing unnecessary losses for both drivers and parking lot management. The lack of GPS navigation makes it impossible to monitor parking space occupancy in real time, hindering parking lot management from accurately guiding vehicles to vacant areas and reducing overall parking space utilization. To alleviate parking chaos, parking lots may need to increase the number of human guides. However, human guidance is not only inefficient but also increases management costs and may still be insufficient during peak hours.

[0052] Traditional UWB positioning technology relies on a fixed coordinate system and cannot dynamically adapt to changes in the physical environment of a parking lot, such as ground subsidence and equipment displacement, causing positioning errors to accumulate over time (up to 10-15cm). It lacks a global dynamic calibration mechanism, requiring periodic manual recalibration, resulting in high maintenance costs. Calibration of a single node is insufficient to cover the entire scenario, and positioning jumps are prone to occur during signal switching across regions. Furthermore, the pre-configured coordinates of the locator cannot track benchmark changes in real time, failing to meet the long-term centimeter-level positioning accuracy requirements in GPS-free environments.

[0053] To address the aforementioned issues, this application provides a parking lot positioning method. By deploying a self-calibrating reference anchor point network in the parking lot, a dynamically updated positioning coordinate system is constructed. Combined with the real-time calibration mechanism of the locator and the vehicle-side coordinate adaptation algorithm, the method solves the problem of decreased parking positioning accuracy caused by parking lot structural deformation and equipment displacement in environments without GPS, achieving centimeter-level positioning in all scenarios.

[0054] like Figure 2 As shown, Figure 2 This is a schematic diagram of the overall steps of the method described in this invention. An embodiment of this application provides a parking lot positioning method that may include the following steps S01-S06.

[0055] S01: Obtain the initial coordinates of the multiple reference anchor point devices, and establish an initial coordinate system based on the initial coordinates of the multiple reference anchor point devices.

[0056] The core of a positioning system is the unified quantification of spatial location. Without an initial coordinate system, the positions of the reference anchor points and the locators will lack a unified reference, and subsequent distance measurements and coordinate corrections cannot be converted into effective spatial positioning information. Therefore, it is necessary to collect initial spatial location data from multiple reference anchor points within the parking lot, and use this data as a basis to construct the initial spatial reference framework for the entire positioning system, defining the spatial location quantification standards for all positioning devices (reference anchor points and locators).

[0057] In this embodiment, a spatially stable carrier (such as a load-bearing column, load-bearing wall, ceiling mounting bracket, or ground base) is selected within the parking lot, and at least three or more reference anchor point devices are deployed (meeting the geometric constraints for constructing a spatial coordinate system). High-precision position measurement equipment (including but not limited to total stations, high-precision GNSS receivers, laser rangefinders, and 3D scanners) can be used to collect three-dimensional or two-dimensional position data for each reference anchor point, forming an initial coordinate set. Based on the initial coordinate set, a general coordinate system construction logic can be used (such as establishing a rectangular coordinate system, polar coordinate system, or geodetic coordinate system with a reference anchor point as the origin and the line connecting any two anchor points as the coordinate axis direction) to generate initial coordinate system parameters; these parameters are then stored in the system control unit or locally on the reference anchor point.

[0058] Example, reference Figure 3 , Figure 3 This is a schematic diagram of the layout of reference anchor points and locators in a parking lot. At least three reference anchor point devices are selected, equipped with fiber optic gyroscopes (for monitoring their own attitude changes) and lidar modules (for measuring distances between anchor points). These are installed in structurally stable areas such as the tops of load-bearing columns and corners of load-bearing walls in the parking lot, ensuring that the straight-line distance between any two anchor points covers more than 80% of the parking lot area. UWB locators are installed at locations such as parking space lines or both sides of lanes. Each locator has a built-in UWB transceiver module and communication unit, completes pre-configured coordinates based on an initial coordinate system (e.g., locator A is pre-configured as (10m, 5m, 0.5m)), and connects to a communication network centered on the reference anchor points.

[0059] S02: Determine the pre-configured coordinates of multiple locators based on the initial coordinate system.

[0060] The locator is a positioning node that directly interacts with the vehicle. Without pre-configured coordinates, it cannot convert its own measurement data (such as distance to the vehicle) into valid position information in the system coordinate system, and the vehicle cannot obtain its specific location in the parking lot through the locator. Therefore, it is necessary to assign an initial theoretical spatial coordinate to each locator based on the established initial coordinate system, as the original reference for its subsequent coordinate correction, and to clarify the initial position of the locator in the system coordinate system.

[0061] Based on the functional layout of the parking lot, such as parking space distribution, lane orientation, blind spots, and entrance / exit locations, plan the installation location of the locator (ensuring signal coverage of all areas requiring positioning). Using an initial coordinate system, determine the locator's pre-configured coordinates using either of the following methods: extracting coordinates from the parking lot layout drawing, or measuring the relative position of the locator to the reference anchor point using measuring tools (such as a tape measure or laser rangefinder) and converting it to coordinates in the initial coordinate system. Finally, input the pre-configured coordinates into the locator's local memory or system control unit, ensuring the locator can access these coordinates in real time for subsequent calibration.

[0062] For example, in the underground parking lot of a shopping mall, based on the parking space layout (120 parking spaces in total, lane width 4 meters), ordinary UWB locators are installed 0.5 meters inside each parking space line and every 5 meters on both sides of the lane. Based on the initial coordinate system established in step 1, the theoretical positions of each locator are extracted from the parking lot CAD drawings. The pre-configured coordinates of locator No. 1 in area A are determined to be (5m, 3m, 0.4m), and those of locator No. 2 in area A are (10m, 3m, 0.4m). The pre-configured coordinate settings for all 150 locators are completed in sequence, and the coordinates are entered into the local memory of each locator.

[0063] S03: Obtain a first distance set of the plurality of reference anchor point devices, wherein the first distance set includes the actual distance values ​​between each pair of the plurality of reference anchor point devices within a first preset period.

[0064] The location of the reference anchor points is not permanently fixed. Changes in the parking lot environment (such as ground subsidence, structural deformation, slight equipment loosening, and material expansion and contraction due to temperature changes) can cause the anchor points to shift, rendering the initial coordinates invalid. Therefore, it is necessary to periodically collect the actual distance between anchor points and compare it with the theoretical distance corresponding to the initial coordinates to identify whether the anchor points have shifted and the degree of shift, providing core data support for subsequent correction of the current coordinates of the anchor points.

[0065] Based on the specific conditions of the parking lot environment (e.g., new / old parking lot, ground material, surrounding construction), a first preset cycle is set (e.g., weekly, monthly, quarterly, or adjusted as needed). At the first preset cycle (e.g., weekly), the actual physical distance between all pairs of reference anchor points is collected. Each reference anchor point sends a distance measurement request to other anchor points via a LiDAR module. The actual distance between anchor points can be measured using built-in or external distance measurement devices, including but not limited to laser ranging modules, wireless ranging modules, ultrasonic rangefinders, and radio frequency ranging devices. The measured distance values ​​between all anchor points are then compiled to form a first distance set (containing distance data for multiple anchor point pairs).

[0066] For example, in the underground parking lot of the aforementioned shopping mall, the first preset cycle is set to once a week. Every Sunday at 2:00 AM, the system control unit automatically triggers the benchmark anchor point mutual calibration process. Benchmark anchor point 1 sends a distance measurement request to anchor points 2 and 3 via the LiDAR module. After receiving the request, anchor points 2 and 3 provide distance measurement responses, measuring the actual distances between anchor points 1 and 2 as 60.01m, 1 and 3 as 40.005m, and 2 and 3 as 50.008m, respectively. These three sets of actual distance values ​​are summarized to form the first distance set for the week and transmitted to the system control unit.

[0067] S04: Based on the first distance set and the initial coordinate set, obtain the current coordinates of each of the reference anchor point devices, wherein the initial coordinate set includes the initial coordinates of multiple reference anchor point devices.

[0068] The initial coordinates only reflect the initial position coordinates of the reference anchor points during installation. If the initial coordinates are used for a long time, the offset of the anchor points will be transmitted to the locator through the coordinate system, resulting in the accumulation of positioning errors in the entire system (a core pain point of traditional solutions). Therefore, it is necessary to calculate the current actual spatial coordinates of each reference anchor point by comparing the actual distances in the first distance set with the theoretical distances corresponding to the initial coordinate set, so as to achieve dynamic updates of the reference anchor point coordinates.

[0069] Specifically, the stored initial coordinate set of reference anchor points is retrieved, and the theoretical distance between any two reference anchor points is calculated based on the initial coordinates. The first distance set (measured distance) is compared with the initial coordinate set (theoretical distance), and the distance deviation between the two is analyzed (e.g., if the actual distance is 2cm longer than the theoretical distance, it indicates that the anchor point is moving away). Coordinate calculation algorithms (including but not limited to polygonal positioning algorithms, coordinate transformation algorithms, least squares methods, iterative approximation algorithms, etc.) can be used to solve the current actual coordinates of each reference anchor point based on the distance deviation and the initial coordinate set, and the local coordinate system parameters and version number (e.g., V1.0 → V1.1) are updated synchronously.

[0070] S05: Obtain the second distance between the target locator and the target reference anchor device, wherein the target locator is any one of the plurality of locators, and the target reference anchor device is a reference anchor device that communicates with the target locator.

[0071] It should be noted that if all locators are calibrated synchronously, the high device density (e.g., one locator per 5m) will lead to congestion of the reference anchor point communication bandwidth and exhaustion of computing resources. Selecting a small number of target locators can significantly reduce the number of initial ranging requests, avoid system overload, and quickly stitch together the entire field basic coordinate system by selecting key area nodes, thus meeting the emergency positioning needs during system startup and restart.

[0072] In this embodiment, it is necessary to collect the actual physical distance between the target locator and the target reference anchor point with which it can establish effective communication, as the second distance for correcting the target locator coordinates, and to provide direct data for subsequent calculation of the corrected coordinates.

[0073] Specifically, the target locator to be calibrated can be selected from multiple locators. The selection logic can include periodic polling, vehicle location request triggering, locator detecting anomalies (such as signal fluctuations), and core locators in key areas marked by the system. Currently, the locator scans for reference anchor points with which it can establish effective communication (signal strength and transmission delay meet requirements) and identifies these as target reference anchor points (single or multiple).

[0074] A second distance is obtained by measuring the actual distance between the target locator and the target reference anchor point using a distance measuring device (including but not limited to wireless ranging modules, signal time-of-flight measurement devices, optical ranging equipment, etc.). For example, the second distance can be obtained using the spatial coordinate formula. Finally, the second distance is transmitted to the system control unit or the target locator for subsequent coordinate correction calculations.

[0075] For example, in the underground parking lot of the aforementioned shopping mall, the system filters locators hourly. When locator number 1 in area A is selected, it is identified as the target locator. Locator number 1 in area A scans the reference anchor points within its communication range and finds that the signal strength of reference anchor point 1 is -65dBm (meeting communication requirements), thus identifying it as the target reference anchor point. The target locator sends a ranging request to the target reference anchor point, measures the signal time of flight using UWBTOF technology, calculates the actual distance between the two as 4.98m, which is the second distance, and feeds it back to the system control unit.

[0076] S06: Based on the second distance, the current coordinates of the target reference anchor point device, and the pre-configured coordinates of the target locator, the corrected coordinates of the target locator are obtained, and the corrected coordinates are used for the positioning of the vehicle in the parking lot.

[0077] It should be noted that since the reference anchor point has been updated from its initial coordinates to its current coordinates, and the coordinate system has been updated to a new coordinate system, the coordinates of the target locator in the new coordinate system are offset from the pre-configured coordinates. Directly using these coordinates would distort the vehicle's location information, for example, displaying the vehicle as being in a parking space when its actual location is still within the lane. Therefore, it is necessary to fuse the second distance, the current coordinates of the target reference anchor point, and the locator's pre-configured coordinates. By calculating the locator's translation and rotation angle (the second correction value), the pre-configured coordinates are corrected to obtain the corrected coordinates used for vehicle positioning.

[0078] Specifically, the current coordinates of the target reference anchor point and the pre-configured coordinates of the target locator are first obtained from the system storage. The three types of data are then input into a coordinate correction algorithm (including but not limited to the spatial two-point distance formula, triangulation method, spatial interpolation algorithm, weighted average algorithm, coordinate deviation compensation algorithm, etc.) to solve for the actual position offset of the target locator, thereby obtaining the corrected coordinates.

[0079] For example, it can be achieved through two points in space ( , , )and( , , The distance formula for ) The actual position offset is then obtained by subtracting the theoretical distance from the second distance, and the corrected coordinates are stored locally on the target locator or in the system control unit. When the vehicle enters the positioning range, the locator sends a positioning signal related to the corrected coordinates to the vehicle to achieve vehicle positioning.

[0080] For example, in the underground parking lot of the aforementioned shopping mall, the pre-configured coordinates (5m, 3m, 0.4m) of locator No. 1 in area A and the current coordinates (0.005, 0.003, 3.5m) of reference anchor point No. 1 are retrieved. Combined with the second distance of 4.98m, the actual coordinates of the locator are approximately (4.985, 3.003, 0.4m). Comparing these with the pre-configured coordinates (5m, 3m, 0.4m), the translation amounts ΔX and ΔY are calculated (Z remains unchanged, so no translation amount needs to be calculated):

[0081] ΔX = 4.985 - 5 = -0.015m (approximately -0.02m, taking an approximate value)

[0082] ΔY = 3.003 - 3 = +0.003m (approximately +0.01m, taking an approximate value)

[0083] With ΔX = -0.02m and ΔY = 0.01m obtained, and based on the pre-configured coordinates and translation correction, the corrected coordinates of locator 1 in area A are (4.98, 3.01, 0.4m). When a vehicle enters area A, this locator sends the UWB positioning signal related to the corrected coordinates to the vehicle receiver for precise parking positioning.

[0084] In some optional implementations of this embodiment, obtaining the current coordinates of each reference anchor device based on the first distance set and the initial coordinate set includes:

[0085] Based on the first distance set and the initial coordinate set, a first correction value set is calculated, wherein the first correction value set includes the translation and rotation angle of each reference anchor point device; the initial coordinate set is corrected based on the first correction value set to obtain the current coordinates of each reference anchor point device.

[0086] To eliminate system-level errors caused by overall deformation of the parking lot, such as ground settlement, the translation (ΔX, ΔY, ΔZ) and rotation angle (α, β, γ) that need to be corrected for all reference anchor points are calculated based on the first distance set and the initial coordinates, and then the current coordinates are updated.

[0087] Specifically, for example, in a parking lot of a coastal commercial center, underground seawater erosion causes uneven settlement of the foundation (annual settlement of 8cm). The initial coordinate sets are: 1 (0,0,3.5m), 2 (60m,0,3.5m), and 3 (30m,40m,3.5m). The first distance set (obtained through weekly cross-calibration) shows the actual distances between 1 and 2 as follows: 60.02m; between 1 and 3 as follows: 40.01m; and between 2 and 3 as follows: 50.015m. The theoretical distances (calculated from the initial coordinates) are: 60m between 1 and 2; 40m between 1 and 3; and 50m between 2 and 3.

[0088] Due to ground subsidence, the parking lot's coordinate system has shifted along the X-axis and rotated slightly around the Z-axis. The formula for calculating the current coordinates is: ,in These are the initial coordinates.

[0089] The error can be calculated iteratively using the least squares method. Assuming ΔX=0, ΔY=0, and θ=0 (initial state), calculate the error at this point. Then, gradually adjust the values ​​of ΔX, ΔY, and θ, recalculating the error after each adjustment, until the error decreases below a threshold (e.g., 0.001mm). The resulting translation ΔX=+0.01m, ΔY=+0.005m, and rotation angle θ=0.06° are the optimal correction parameters, forming the first set of correction values. Based on the first set of correction values ​​and the initial coordinate set, we obtain:

[0090] The current coordinates of point 1 are X = (0 + 0.01)cos0.06° - (0 + 0.005)sin0.06° ≈ 0.01m, Y ≈ 0.005m, which is (0.01, 0.005, 3.5m);

[0091] The current coordinates of point 2 are X = (60 + 0.01)cos0.06° - (0 + 0.005)sin0.06° ≈ 60.01m, Y ≈ 0.063m, that is, (60.01, 0.063, 3.5m);

[0092] The current coordinates of point 3 are X = (30 + 0.01)cos0.06° - (40 + 0.005)sin0.06° ≈ 29.97m, Y ≈ 40.03m, which is (29.97, 40.03, 3.5m).

[0093] This application addresses overall parking lot deformation, such as ground settlement and structural micro-rotation, by using a first set of correction values ​​to achieve global coordinate system calibration, avoiding reference confusion caused by independent calibration of individual anchor points. By dynamically generating reference anchor point coordinates, system-level errors are reduced, preventing lane navigation deviation accidents.

[0094] In some optional implementations of this embodiment, the target reference anchor device is the reference anchor device that is closest to the target locator among the plurality of reference anchor devices.

[0095] To shorten the ranging distance, avoid signal blockage, and improve calibration accuracy, the target reference anchor point is designated as the anchor point closest to the target locator. Specifically, for a parking space locator A, anchor point 3, which is 2 meters away in a straight line, is preferred over anchor point 1, which is 8 meters away, to ensure that the locator signal strength is greater.

[0096] By prioritizing the nearest reference anchor point, environmental interference is reduced, signal attenuation is minimized, and calibration time response is shortened.

[0097] In some optional implementations of this embodiment, obtaining the corrected coordinates of the target locator based on the second distance, the current coordinates of the target reference anchor point device, and the pre-configured coordinates of the target locator includes:

[0098] A second correction value is determined based on the second distance and the current coordinates of the target reference anchor device, wherein the second correction value includes the translation amount and rotation angle of the target locator; the corrected coordinates of the target locator are obtained based on the second correction value and the pre-configured coordinates of the target locator.

[0099] To address issues such as localized equipment displacement, including locator shifting due to vehicle traffic or partial ground subsidence in parking lots, the translation and rotation angles of the locator are calculated based on a second distance and the current coordinates of the reference anchor point. Using the current coordinates of the target reference anchor point as a fixed point, and based on the principle that the second distance equals the distance from the locator's actual position to the current coordinates of the anchor point, a correction model is used. The translation amounts ΔXp and ΔYp, and the rotation angle θp are then calculated using the least squares method to form a second correction value. This second correction value is then substituted into the correction model to perform translation and rotation transformations on the pre-configured coordinates of the target locator, yielding the corrected coordinates. For example, the correction model can be set as follows:

[0100] Translation:

[0101] Rotation:

[0102]

[0103] This application addresses the issue of local device displacement by using current coordinates, translation, and rotation angle, thereby improving the accuracy of locator-level calibration and the consistency of cluster synchronization. For individual locator offsets (such as displacement caused by loose installation or vehicle vibration), a second correction value is used to achieve precise calibration, resolving the pain point of fixed locator coordinates in traditional solutions.

[0104] In some optional implementations of this embodiment, the target locator is a locator among the plurality of locators whose distance from at least one of the plurality of reference anchor devices is less than a first preset value.

[0105] After obtaining the corrected coordinates of the target locator based on the second correction value and the pre-configured coordinates of the target locator, the method further includes:

[0106] Based on the corrected coordinates and the second corrected value, the corrected coordinates of a plurality of nearby locators are determined, wherein the nearby locators are those whose distance from the target locator is less than a second preset value, and the corrected coordinates of the nearby locators are used for the positioning of the vehicle in the parking lot.

[0107] Specifically, based on the effective communication distance (e.g., 10m) between the locator and the reference anchor point and the required ranging accuracy, a first preset value (e.g., 10m) is set. This means that when the distance between the locator and at least one reference anchor point is less than or equal to the first preset value, calibration is possible. Preliminary ranging measurements are performed between all locators and surrounding reference anchor points, and the distance between each locator and a reference anchor point is recorded. The distance between each locator and a reference anchor point is then assessed. If the distance to at least one reference anchor point is less than or equal to the first preset value, that locator is marked as the target locator; otherwise, it is temporarily excluded from calibration (to avoid insufficient ranging accuracy).

[0108] Based on the deployment density of the locators (e.g., 5m / locator), a second preset value (e.g., 5m) is set. When the distance between two locators is less than this second preset value, they are considered neighboring locators. After the target locator completes its correction, it can broadcast a correction information packet to its surroundings via the Mesh network. This packet includes its own corrected coordinates, the second correction value (translation amount, rotation angle), and the coordinate system version number. Each locator receives the broadcast and calculates its distance from the target locator. If the distance is less than the second preset value, it is considered a neighboring locator. Based on the target locator's correction trend (e.g., all locators in the same area translate along the X-axis by +0.01m), combined with its own pre-configured coordinates and its relative position to the target locator, the neighboring locator adjusts its own correction parameters and calculates and updates its own corrected coordinates.

[0109] For example, in a shopping mall parking lot scenario, the first preset value is set to 10m, and the second preset value is set to 5m. The distance to the reference anchor point is measured for all locators in the parking lot, and target locators are filtered out. Locators with a distance greater than the first preset value are not calibrated. Specifically, locators 1-4 in area A are 4.98m away from the reference anchor point in area A; locators 1-5 in area B are 6.5m away from the reference anchor point in area B; and locators 1-3 in area C are more than 15m away from all reference anchor points. The filtering results show that locators 1-4 in area A and 1-5 in area B are marked as target locators, while locator 3 is not calibrated.

[0110] Taking the locator in area A as an example, collaborative calibration of nearby locators is performed. Locator No. 2 in area A (corrected coordinates (9.98, 8.01, 0.4m), second correction value ΔXp=-0.02m, ΔYp=+0.01m) is selected, and a correction information packet is broadcast. Locator No. 1 in area A is 4.5m away from locator No. 2 in area A, and locator No. 3 in area A is 4.8m away from locator No. 2 in area A, and are therefore identified as nearby locators. Locator No. 4 in area A is 5.2m away from locator No. 2 in area A, which is greater than the second preset value, and is not identified as a nearby locator.

[0111] Finally, collaborative correction is performed. Locator No. 1 in Area A (pre-configured coordinates (5m, 8m, 0.4m)) adjusts its own ΔXp = -0.018m based on the correction trend of locator No. 2 in Area A, resulting in corrected coordinates of (4.982, 8.009, 0.4m). Locator No. 3 in Area A (pre-configured coordinates (15m, 8m, 0.4m)) adjusts its ΔXp = -0.022m, resulting in corrected coordinates of (14.978, 8.011, 0.4m). Locator No. 4 in Area A is not considered a nearby locator, so no collaborative correction is performed.

[0112] By selecting target locators that meet the calibration conditions using a first preset value, calibration failures caused by inaccurate long-distance ranging are avoided, thus improving calibration efficiency. By addressing the issue of inconsistent coverage areas that single-point calibration cannot cover, the update speed of coordinate synchronization is improved, regional positioning errors are reduced, and the communication load on anchor points is decreased.

[0113] In some optional implementations of this embodiment, obtaining the second distance between the target locator and the target reference anchor device includes:

[0114] The first transmission time of the target reference anchor device sending the first calibration information to the target locator is obtained; the second transmission time of the target locator sending the second calibration information to the target reference anchor device is obtained; and the second distance is determined based on the first transmission time and the second transmission time.

[0115] To overcome clock synchronization issues and improve short-range measurement accuracy, the signal flight time is calculated using transmitted timestamps to accurately determine the second distance. For example, the reference anchor sends the first calibration information at time t1 (the first transmission time). The locator receives the first calibration information at t1 and sends the second calibration information at t2 (the second transmission time). The reference anchor receives the second calibration information at t3. The distance can then be obtained using the following simplified formula:

[0116]

[0117] in, The time at which the reference anchor point receives the reply signal. The time when the locator replies with a message. The signal is sent at the reference anchor point, and the speed of light is the speed of electromagnetic waves in a vacuum (299,792,458 m / s). The distance is derived by calculating the round-trip time difference of the electromagnetic wave and combining it with the speed of light.

[0118] This application reduces ranging errors by introducing two-way ranging, meeting the requirements of automatic parking and improving resistance to multipath interference. The combination of UWB signal and time difference calculation effectively distinguishes between direct and reflected signals (multipath interference), improving the stability of ranging data.

[0119] In some optional implementations of this embodiment, the method further includes:

[0120] The position of each of the aforementioned reference anchor points is monitored in real time. When there is an abnormal reference anchor point among the multiple reference anchor point devices whose daily displacement exceeds a preset value, the abnormal reference anchor point device is temporarily calibrated and an abnormal alarm is issued.

[0121] To address sudden structural changes, such as equipment displacement due to construction impacts or other non-human-caused coordinate movements, the system monitors anchor point displacement in real time. If the displacement exceeds 3mm in a single day, a temporary calibration is triggered and an alarm is issued. For example, if the fiber optic gyroscope detects an anchor point displacement of 3.5mm in a single day, an emergency mutual calibration is automatically initiated, sending a code alarm to the management platform via V2I.

[0122] By adding anomaly detection and emergency response mechanisms, the speed of fault response has been improved, preventing the cumulative error from erupting and causing major accidents.

[0123] In some optional implementations of this embodiment, obtaining the second distance between the target locator and the target reference anchor device includes:

[0124] The second distance between the target locator and the target reference anchor device is obtained within a second preset period, wherein the second preset period is less than the first preset period.

[0125] To balance system load and accuracy requirements, locators are more susceptible to local disturbances. The locator calibration cycle (30 minutes / time) is shorter than the anchor point mutual calibration cycle (once a week). For example, an anchor point in a shopping mall undergoes mutual calibration every Monday at 2 AM, and the locator requests calibration every 30 minutes.

[0126] By using differentiated calibration cycles and low-frequency communication at anchor points, network bandwidth usage is reduced, and the displacement of the locator can be captured in real time.

[0127] In some optional implementations of this embodiment, a parking lot collaborative positioning system is also included. The system includes multiple reference anchor point devices, a control unit, and multiple locators. The control unit is communicatively connected to the multiple reference anchor point devices and the multiple locators. The control unit is used to execute the method described in any of the above embodiments or implementations.

[0128] It should be noted that the control unit in the embodiments of this application may be a microcontroller unit (MCU), microprocessor unit (MPU), system-on-chip (SOC), digital signal processor (DSP), graphics processing unit (GPU), or other integrated circuits used to execute program instructions, process data, and control the operation of the system.

[0129] For example, in a large smart factory material transfer center, covering an area of ​​over 20,000 square meters, including storage, loading and unloading, and charging areas, thirty automated guided vehicles (AGVs) need to be dispatched across areas. Traditional UWB positioning suffers from excessive cumulative errors due to ground vibrations, and the coordinates of multiple areas are independent. When AGVs cross areas, the positioning system needs to be restarted.

[0130] In the smart factory material transfer center scenario, the control unit achieves centimeter-level dynamic positioning through a closed-loop system of environmental perception, strategy decision-making, and real-time calculation: the server cluster gathers vibration data every 100ms and dynamically formulates calibration strategies (anchor points are mutually calibrated every 6 hours, and locators are updated every 5 minutes); when the AGV crosses zones, the coordinate system transformation matrix (from storage T1 to loading / unloading T2) is calculated in real time, and 200 locators are synchronized through 5G broadcast commands (latency <20ms); the vibration sensor triggers a fault self-healing mechanism, and when the locator is offline, it automatically starts the collaborative recalculation of coordinates of equipment within 3m, ultimately enabling 30 AGVs to achieve continuous positioning in a 20,000㎡ factory area.

[0131] The control unit upgrades discrete positioning devices into an intelligent collaborative network through a closed loop of environmental perception, strategy decision-making, and real-time calculation, reducing communication load and improving positioning accuracy compared to traditional solutions.

[0132] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Furthermore, the embodiments of this invention are not directed to any particular programming language.

[0133] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. Similarly, for the sake of brevity and to aid in understanding one or more aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the embodiments are sometimes grouped together in a single embodiment, figure, or description thereof. The claims, which follow the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0134] Those skilled in the art will understand that the modules in the apparatus of the embodiments can be adaptively modified and placed in one or more apparatuses different from those of the embodiments. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components, except that at least some of such features and / or processes or units are mutually exclusive.

[0135] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware.

Claims

1. A parking lot positioning method characterized by, The application is applied to a positioning system, the positioning system comprises a plurality of reference anchor point devices and a plurality of locators arranged in a parking lot, and the method comprises: obtaining initial coordinates of the plurality of reference anchor point devices, and establishing an initial coordinate system based on the initial coordinates of the plurality of reference anchor point devices; determining preconfigured coordinates of the plurality of locators based on the initial coordinate system; obtaining a first distance set of the plurality of reference anchor point devices, wherein the first distance set comprises actual distance values between each two of the plurality of reference anchor point devices within a first preset period; calculating a first correction value set according to the first distance set and an initial coordinate set, wherein the first correction value set comprises a translation amount and a rotation angle of each of the reference anchor point devices, and the initial coordinate set comprises the initial coordinates of the plurality of reference anchor point devices; correcting the initial coordinate set according to the first correction value set to obtain current coordinates of each of the reference anchor point devices; obtaining a second distance between a target locator and a target reference anchor point device, wherein the target locator is any one of the plurality of locators, and the target reference anchor point device is a reference anchor point device in communication with the target locator; determining a second correction value based on the second distance and the current coordinates of the target reference anchor point device, wherein the second correction value comprises a translation amount and a rotation angle of the target locator; obtaining a corrected coordinate of the target locator based on the second correction value and the preconfigured coordinates of the target locator, wherein the corrected coordinate is used for positioning of a vehicle in the parking lot.

2. The method of claim 1, wherein, The target reference anchor point device is a reference anchor point device closest to the target locator among the plurality of reference anchor point devices.

3. The method of claim 1, wherein, The target locator is a locator among the plurality of locators, and a distance between the target locator and at least one of the plurality of reference anchor point devices is less than a first preset value. After the corrected coordinate of the target locator is obtained based on the second correction value and the preconfigured coordinates of the target locator, the method further comprises: determining corrected coordinates of a plurality of adjacent locators based on the corrected coordinate and the second correction value, wherein the adjacent locators are locators among the plurality of locators, and distances between the adjacent locators and the target locator are all less than a second preset value, and the corrected coordinates of the adjacent locators are used for positioning of a vehicle in the parking lot.

4. The method of claim 1, wherein, The obtaining of the second distance between the target locator and the target reference anchor point device comprises: obtaining a first sending time at which the target reference anchor point device sends first calibration information to the target locator; obtaining a second sending time at which the target locator sends second calibration information to the target reference anchor point device; determining the second distance based on the first sending time and the second sending time.

5. The method of claim 1, wherein, The method further comprises: monitoring positions of each of the reference anchor point devices in real time; when there is an abnormal reference anchor point device with a single-day displacement greater than a preset value among the plurality of reference anchor point devices, temporarily calibrating the abnormal reference anchor point device and issuing an abnormal alarm.

6. The method of claim 1, wherein, The obtaining of the second distance between the target locator and the target reference anchor point device comprises: acquire a second distance between the target locator and the target reference anchor device in a second preset period, wherein the second preset period is less than the first preset period.

7. A parking lot cooperative positioning system characterized by comprising: The system comprises a plurality of reference anchor devices, a control unit and a plurality of locators, the control unit is in communication connection with the plurality of reference anchor devices and the plurality of locators, and the control unit is used for executing the method in any one of claims 1-6.

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