A method, device and storage medium for positioning vehicles in a tunnel

Abstract

The present invention discloses a method, device and storable medium for positioning vehicles in tunnels, which relates to the field of traffic engineering technology, and includes the following steps: deploying roadside laser radars at tunnel entrances and inner walls of tunnels, and collecting point cloud data; based on different coordinate conversion methods, converting point cloud data in all laser radar coordinate systems to the same coordinate system; obtaining coordinates of two groups of points in the middle area of ​​the tunnel, and taking the sum and average of the values ​​obtained as the final coordinates to complete the long-distance positioning of vehicles in tunnels. The multi-roadside laser radar coordinate system in the present invention solves the problem that vehicles in tunnels cannot be positioned and cannot obtain full-course information in tunnels, and improves the accuracy of vehicle positioning.

Description

Technical Field

[0001] The present invention relates to the technical field of traffic engineering, and more particularly to a method and device for positioning a vehicle in a tunnel and a storable medium. Background Art

[0002] LiDAR works in the infrared and visible light bands, using laser as the working beam. It transmits detection signals to the target and receives signals reflected from the target, and then compares and processes the transmitted and reflected signals to obtain relevant information about the target, which is presented in the form of a point cloud, thereby realizing the detection, tracking and identification of the target. As LiDAR detection technology becomes more and more mature, it has become an integral part of the field of vehicle-road collaboration, and the installation method has also developed from traditional vehicle-mounted installation to roadside installation. It can generally be installed on roadside poles, signal light poles and other locations. If it is for temporary data collection, it can also be set up on a tripod. This type of LiDAR deployed on the roadside is collectively referred to as a roadside LiDAR.

[0003] The main function of roadside laser radar is to collect relevant information of all users on the road in real time with high precision, including acceleration, speed, vehicle position and driving trajectory, etc. The detection range of laser radar is limited, so multiple laser radars must be deployed at different locations on the roadside to obtain the trajectory information of the vehicle throughout the journey. However, the data collected by the laser radar generally establishes a local coordinate system with itself as the center. It is impossible to match the point cloud data collected by multiple laser radars on the roadside to obtain relevant information of the vehicle throughout the journey. Therefore, the data collected by multiple laser radars need to be aligned and converted to the geodetic coordinate system to achieve vehicle positioning and trajectory tracking.

[0004] At present, the coordinate transformation of multiple roadside laser radars has been realized. Laser radar can start from GPS data, introduce the principle of spatial rectangular coordinate transformation, and through the conversion relationship between laser radar and GPS data, based on the optimized conversion relationship, the laser radar can be aligned to the geodetic coordinate system, realizing the multi-roadside laser radar data alignment based on geodetic coordinate representation. However, the existing technology has the following problems: the radar used is limited to vehicle-mounted laser radar, which has low economic benefits; when removing bad and non-planar point cloud data, it is easy to make planar point cloud data also be eliminated; the point cloud alignment device is large in size, cannot be used in tunnels, and requires closed traffic.

[0005] Therefore, in view of the phenomenon that the GPS signal is lost in the tunnel and its data cannot be detected, resulting in the inability to locate the vehicle in the tunnel, how to locate the vehicle in the tunnel and achieve long-distance target tracking is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] In view of this, the present invention provides a method, device and storable medium for positioning a vehicle in a tunnel, which solves the problem that a vehicle cannot be positioned in a tunnel, improves the accuracy of vehicle positioning, and facilitates movement and disassembly.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for positioning a vehicle in a tunnel comprises the following steps:

[0009] Deploy roadside LiDAR at tunnel entrances and tunnel walls and collect point cloud data;

[0010] Based on different coordinate conversion methods, all point cloud data in the LiDAR coordinate system are converted to the same coordinate system;

[0011] The coordinates of the two sets of middle-region points of the tunnel are obtained, and the sum and average of the points are used as the final coordinates to complete the long-distance positioning of the vehicle in the tunnel.

[0012] The technical effect achieved by the above technical solution is: the fusion of multiple roadside laser radar coordinate systems solves the problem that vehicles in tunnels cannot be positioned and cannot obtain full information in the tunnel.

[0013] Optionally, when the roadside laser radar is deployed at the tunnel entrance and the inner wall of the tunnel, there is an overlapping area scanned by two adjacent laser radars during the deployment process.

[0014] Optionally, the coordinate conversion method of the laser radar deployed at the tunnel entrance specifically includes the following steps:

[0015] Based on the principle of spatial rectangular coordinate conversion, GPS data is converted into the geocentric spatial rectangular coordinate system for representation;

[0016] Solve the mapping relationship between the LiDAR data based on the Cartesian coordinate system and the geocentric rectangular coordinate system data, and align multiple LiDAR data to the geodetic coordinate system.

[0017] Optionally, the coordinate conversion method of the laser radar arranged on the inner wall of the tunnel specifically includes the following steps:

[0018] A roadside multi-laser radar coordinate conversion device is set up in the overlapping area of ​​two adjacent laser radars;

[0019] Obtaining the coordinates of the roadside multi-laser radar coordinate conversion device in two laser radar coordinate systems, and converting the coordinate systems of all laser radars in the tunnel to the same coordinate system;

[0020] The laser radar deployed on the other side of the tunnel entrance is converted into coordinates using the same method to obtain two sets of coordinates of the middle points of the tunnel. The two sets of coordinates are summed and averaged to obtain the final coordinates.

[0021] Optionally, the roadside multi-laser radar coordinate conversion device includes: a tripod, a laser, and a lithium battery. Setting up the roadside multi-laser radar coordinate conversion device specifically includes the following steps:

[0022] Fix the tripod at a certain point in the overlapping area of ​​the two laser radars, and the height can be adjusted;

[0023] The laser is mounted on a tripod by means of horizontal fixation or rotation fine adjustment; the lithium battery is installed inside the laser; the laser and the laser radar have the same frequency band;

[0024] Among them, the laser emits laser to the first laser radar, and after the first laser radar receives the signal, it collects the point cloud data of the laser in the first laser radar coordinate system, and collects the point cloud data of the laser in the second laser radar coordinate system in the same way, so that the laser obtains coordinates in two laser radar coordinate systems.

[0025] A vehicle positioning device in a tunnel, comprising a plurality of laser radars and a roadside multi-laser radar coordinate conversion device;

[0026] The laser radar is deployed at the tunnel entrance and the inner wall of the tunnel to present the relevant information of the target in the form of a point cloud;

[0027] The roadside multi-laser radar coordinate conversion device is set up in the overlapping area of ​​the two laser radars and is used to convert the coordinate systems of all laser radars into the same coordinate system.

[0028] Optionally, the roadside multi-lidar coordinate conversion device includes: a tripod, a laser with the same frequency band as the laser radar, and a lithium battery;

[0029] The tripod is set up at a certain point in the overlapping area of ​​the two laser radars in the tunnel, and the height is adjustable;

[0030] The laser is mounted on a tripod by means of horizontal fixation or rotation fine adjustment;

[0031] The lithium battery is installed inside the laser.

[0032] The present invention also discloses a computer storable medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for locating a vehicle in a tunnel are implemented.

[0033] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method, device and storable medium for positioning vehicles in tunnels. The coordinates of two laser radars are converted through the point cloud data of the overlapping area to achieve full-time positioning of vehicles in tunnels. The fusion of multiple laser radar coordinate systems on the road side solves the problems that vehicles in tunnels cannot be positioned and their full-time information in tunnels cannot be obtained. The working state of the laser design must be placed in a horizontal state, which improves the accuracy of vehicle positioning. In addition, the device is easy to move and disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0035] Figure 1 Schematic diagram of deploying LiDAR for tunnels;

[0036] Figure 2 Schematic diagram of determining the Z-axis coordinate of the laser for the laser radar;

[0037] Figure 3 This is a schematic diagram of laser radar data collection at the tunnel entrance;

[0038] Figure 4 This is a schematic diagram of the layout of lidar and lasers in the tunnel;

[0039] Figure 5 Schematic diagram of laser data collection for the laser radar in the tunnel;

[0040] Figure 6 This is a schematic diagram of data collection in the tunnel;

[0041] Figure 7 This is a schematic diagram of the laser radar coordinate transformation in the tunnel;

[0042] Figure 8 This is a schematic diagram of the laser radar collecting vehicle data throughout the tunnel. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] The embodiment of the present invention discloses a method for positioning a vehicle in a tunnel, comprising the following steps:

[0046] Deploy roadside LiDAR at tunnel entrances and tunnel walls and collect point cloud data;

[0047] Based on different coordinate conversion methods, all point cloud data in the LiDAR coordinate system are converted to the same coordinate system;

[0048] The coordinates of the two sets of middle-region points of the tunnel are obtained, and the sum and average of the points are used as the final coordinates to complete the long-distance positioning of the vehicle in the tunnel.

[0049] In this embodiment, the roadside laser radar is applied to the tunnel for vehicle detection and positioning to realize vehicle trajectory tracking. The roadside laser radar is deployed at the tunnel entrance and the inner wall of the tunnel. The installation height of the laser radar is generally 3 to 4 meters. The laser radars on the inner wall and the entrance of the tunnel are deployed as follows: Figure 1 As shown in the figure, during the deployment process, the areas scanned by two adjacent laser radars overlap. The laser radar transmits a detection signal to the target and receives the signal reflected from the target, and then compares and processes the transmitted signal and the reflected signal to obtain relevant information of the target, which is presented in the form of a point cloud to realize the positioning and tracking of vehicles in the tunnel.

[0050] Furthermore, the coordinate conversion method of the laser radar deployed at the tunnel entrance specifically includes the following steps:

[0051] Based on the principle of spatial rectangular coordinate conversion, GPS data is converted into the geocentric spatial rectangular coordinate system for representation;

[0052] Solve the mapping relationship between the laser radar data based on the Cartesian coordinate system and the data of the geocentric rectangular coordinate system, align multiple laser radar data to the geodetic coordinate system, and realize the registration of multiple roadside laser radar data based on geodetic coordinate representation.

[0053] Furthermore, the coordinate conversion method of the laser radar arranged on the inner wall of the tunnel specifically includes the following steps:

[0054] In the overlapping area of ​​two adjacent laser radars, a roadside multi-laser radar coordinate conversion device is set up, including: a tripod, a laser with the same frequency band as the laser radar (such as Figure 4 The laser 1, laser 2) and lithium battery shown in the figure are used to fix the tripod at a certain point in the overlapping area of ​​the two laser radars, and the height is adjustable; the laser is installed on the tripod by horizontal fixation or rotation fine adjustment; the lithium battery is installed inside the laser.

[0055] Therefore, a laser is set up in the overlapping area of ​​two adjacent laser radars to determine the three-dimensional coordinates of the laser under the laser radar. The specific process is as follows: the plane coordinates can be determined based on the point cloud data of the laser under the laser radar. At this time, the Z-axis coordinates also need to be determined, such as Figure 2 As shown, first, it is necessary to ensure that the two lasers are on the same vertical line. Secondly, the distance between the laser radar and the two lasers, the distance between the two lasers, and the distance between the two lasers and the horizontal plane can be directly measured. The trigonometric functions can be used in the triangle formed by the laser radar and the laser to obtain the readings of ∠α, ∠γ, and ∠β. Finally, the coordinates of the laser under the laser radar can be obtained based on the measured data.

[0056] Next, we will introduce the data collection stage. The laser radar deployed at the tunnel entrance can apply a GPS-based multi-side laser radar coordinate conversion method. First, the GPS data is converted to the geocentric rectangular coordinate system for representation. Then, the mapping relationship between the laser radar data based on the Cartesian coordinate system and the geocentric rectangular coordinate system data is solved. Multiple laser radar data can be aligned to the geodetic coordinate system, such as Figure 3 As shown;

[0057] The layout of laser radar in the tunnel Figure 4 As shown in Figure 2, the laser radar data collected in the tunnel is as follows: Figure 5 and Figure 6 As shown, Figure 5 This is a schematic diagram of data collection by a single laser radar in a tunnel. Figure 6 Collect data of lasers for two adjacent laser radars in the tunnel after the lasers emit and receive lasers;

[0058] Next is the coordinate conversion stage of the two adjacent laser radars. According to the laser radar data collected at the tunnel entrance, the detection target can be located in the geodetic coordinate system. Then, according to the data collected from the lasers in the overlapping area of ​​the two adjacent laser radars, the coordinates in the other coordinate system are converted to the coordinate system of the laser radar in the geodetic coordinate system. After completing the coordinate conversion of this process, the following can be obtained: Figure 7 The coordinate system shown;

[0059] Repeat the above steps to convert the data coordinates in all lidar coordinate systems to the same coordinate system.

[0060] In order to reduce the error generated in the coordinate fusion process, the laser radar with the same frequency band deployed on the other side of the tunnel entrance is used to realize the coordinate system conversion between the two adjacent laser radars in the same way, and then the coordinates of the two sets of points in the middle area of ​​the tunnel are obtained. The two sets of coordinates are summed and the average value is taken as the final coordinate of the area, thereby realizing the long-distance detection and positioning of vehicles in the tunnel. The complete process is as follows: Figure 8 shown.

[0061] In addition, this embodiment further discloses a computer storable medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for locating a vehicle in a tunnel are implemented.

[0062] Example 2

[0063] This embodiment discloses a vehicle positioning device in a tunnel, including multiple laser radars and a roadside multi-laser radar coordinate conversion device;

[0064] Among them, the laser radar is deployed at the tunnel entrance and the inner wall of the tunnel to present the relevant information of the target in the form of point cloud;

[0065] The roadside multi-laser radar coordinate conversion device is set up in the overlapping area of ​​the two laser radars to convert the coordinate systems of all laser radars to the same coordinate system.

[0066] Furthermore, the roadside multi-lidar coordinate conversion device includes: a tripod, a laser of the same frequency band as the laser radar, and a lithium battery;

[0067] The tripod is set up at a certain point in the overlapping area of ​​the two laser radars in the tunnel, and the height is adjustable;

[0068] The laser is mounted on a tripod by means of horizontal fixation or rotation fine adjustment; the lithium battery is installed inside the laser.

[0069] The present invention uses the point cloud data of the overlapping area to perform coordinate conversion between the two laser radars to achieve full-range positioning of the vehicle in the tunnel. The fusion of the coordinate systems of multiple laser radars on the road side solves the related problems that the vehicle in the tunnel cannot be positioned and its full-range information in the tunnel cannot be obtained. The working state of the laser design must be placed in a horizontal state, which improves the accuracy of vehicle positioning. In addition, the device is easy to move and disassemble.

[0070] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0071] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for positioning a vehicle in a tunnel, characterized in that: The following steps are involved: Deploy roadside LiDAR at tunnel entrances and tunnel walls and collect point cloud data; Based on different coordinate conversion methods, all point cloud data in the LiDAR coordinate system are converted to the same coordinate system; Obtain the coordinates of the middle points of the two sets of tunnels, and use the summed and averaged values ​​as the final coordinates to complete the long-distance positioning of the vehicle in the tunnel; The coordinate conversion method of the laser radar arranged on the inner wall of the tunnel specifically includes the following steps: A roadside multi-laser radar coordinate conversion device is set up in the overlapping area of ​​two adjacent laser radars; Obtaining the coordinates of the roadside multi-laser radar coordinate conversion device in two laser radar coordinate systems, and converting the coordinate systems of all laser radars in the tunnel to the same coordinate system; The laser radar deployed on the other side of the tunnel entrance is transformed in the same way to obtain the coordinates of two sets of points in the middle area of ​​the tunnel. The two sets of coordinates are summed and averaged to obtain the final coordinates. The coordinate conversion method of the laser radar deployed at the tunnel entrance specifically includes the following steps: Based on the principle of spatial rectangular coordinate conversion, GPS data is converted into the geocentric spatial rectangular coordinate system for representation; Solve the mapping relationship between the LiDAR data based on the Cartesian coordinate system and the geocentric rectangular coordinate system data, and align multiple LiDAR data to the geodetic coordinate system.

2. A method for positioning a vehicle in a tunnel according to claim 1, characterized in that: When the roadside laser radar is deployed at the tunnel entrance and the inner wall of the tunnel, there are overlapping areas scanned by two adjacent laser radars during the deployment process.

3. A method for positioning a vehicle in a tunnel according to claim 1, characterized in that: The roadside multi-laser radar coordinate conversion device includes: a tripod, a laser, and a lithium battery. Setting up the roadside multi-laser radar coordinate conversion device specifically includes the following steps: Fix the tripod at a certain point in the overlapping area of ​​the two laser radars, and the height can be adjusted; The laser is mounted on a tripod by means of horizontal fixation or rotation fine adjustment; the lithium battery is installed inside the laser; the laser and the laser radar have the same frequency band; Among them, the laser emits laser to the first laser radar, and after the first laser radar receives the signal, it collects the point cloud data of the laser in the first laser radar coordinate system, and collects the point cloud data of the laser in the second laser radar coordinate system in the same way, so that the laser obtains coordinates in two laser radar coordinate systems.

4. A device applied to the method for locating a vehicle in a tunnel as claimed in any one of claims 1 to 3, characterized in that: It includes multiple laser radars and a roadside multi-laser radar coordinate conversion device; The laser radar is deployed at the tunnel entrance and the inner wall of the tunnel to present the relevant information of the target in the form of a point cloud; The roadside multi-laser radar coordinate conversion device is set up in the overlapping area of ​​the two laser radars and is used to convert the coordinate systems of all laser radars into the same coordinate system.

5. The device according to claim 4, characterized in that The roadside multi-laser radar coordinate conversion device includes: a tripod, a laser with the same frequency band as the laser radar, and a lithium battery; The tripod is set up at a certain point in the overlapping area of ​​the two laser radars in the tunnel, and the height is adjustable; The laser is mounted on a tripod by means of horizontal fixation or rotation fine adjustment; The lithium battery is installed inside the laser.

6. A computer storable medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for locating a vehicle in a tunnel as claimed in any one of claims 1 to 3 are implemented.

Images