An attitude calibration method and device for multiple lidar installations

Abstract

The present application provides a posture calibration method and device for the installation of multiple laser radars, wherein the method includes: obtaining point cloud data of the road surface to be detected through the first laser radar, selecting point cloud data of the flat area of the road surface from the point cloud data of the road surface as a calibration point cloud set, rotating the first spatial rectangular coordinate system around the coordinate axis multiple times within a preset angle range with a preset step size, performing posture calibration on the first laser radar according to the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation, and performing posture calibration on the second laser radar according to the second spatial rectangular coordinate system. The technical solution of the present application has the following beneficial effects: it improves the efficiency of the installation of multiple laser radars, reduces the installation standards of the laser radars, and solves the problem of slow installation efficiency during the existing laser radar installation process when multiple laser radars are calibrated because the coordinate systems of the multiple laser radars are difficult to unify.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a posture calibration method and device for installing multiple laser radars. Background Art

[0002] LiDAR needs to be installed before use. When using LiDAR in the field of automatic measurement of vehicle exterior dimensions, it is generally necessary to calibrate information such as the radar installation position, detection target position, and installation angle during installation. The shortcomings and deficiencies of existing installation calibration methods require related auxiliary tools to perform various precise calibration tasks, resulting in low efficiency on the construction site of LiDAR installation. At the same time, when installing multiple LiDARs, it is difficult to unify the coordinate systems of multiple LiDARs, resulting in slow installation efficiency.

[0003] It can be seen that how to provide a posture calibration method and device for the installation of multiple lidars has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The embodiments of the present application provide a posture calibration method and device for the installation of multiple laser radars to solve the problem of slow installation efficiency during the existing laser radar installation process when multiple laser radars are calibrated because the coordinate systems of the multiple laser radars are difficult to unify.

[0005] In a first aspect, according to an embodiment of the present application, a method for attitude calibration of multiple laser radar installations is provided, comprising:

[0006] Establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin;

[0007] Acquire point cloud data of the road surface to be detected by the first laser radar;

[0008] Selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set;

[0009] Obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around a coordinate axis within a preset angle range and with a preset step size;

[0010] Performing attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation;

[0011] Establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin;

[0012] The second laser radar is calibrated according to the second spatial rectangular coordinate system.

[0013] The step of calibrating the attitude of the second laser radar according to the second spatial rectangular coordinate system specifically includes the following steps:

[0014] Rotating the second rectangular coordinate system around the y-axis within a preset angle range and at a preset step size multiple times so that the second rectangular coordinate system coincides with the x-axis and the z-axis of the first rectangular coordinate system;

[0015] Converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into coordinates in the second space rectangular coordinate system;

[0016] The second laser radar is calibrated according to the coordinates of the calibration point in the second spatial rectangular coordinate system after each rotation.

[0017] There are multiple second laser radars.

[0018] Optionally, the coordinate axis is at least one of an x-axis, a y-axis, and a z-axis.

[0019] Optionally, before performing attitude calibration on the first laser radar according to the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation, the method further includes: changing the origin of the first rectangular coordinate system.

[0020] Changing the origin of the first rectangular coordinate system specifically includes the following steps:

[0021] The intersection of the first laser radar and the road surface is used as the second origin;

[0022] The coordinates of the calibration point in the first space rectangular coordinate system after each rotation are transformed according to the coordinates of the second origin.

[0023] The coordinates of the calibration point in the first space rectangular coordinate system after each rotation are transformed according to the coordinates of the second origin, and the transformation formula is:

[0024] X=(x-x0)*cosA+(y-y0)*sinA

[0025] Y=(x-x0)*(-sinA)+(y-y0)cosA

[0026] Among them, (x, y) is the coordinate value of the calibration point in the first rectangular coordinate system, (X, Y) is the coordinate value of the calibration point (x, y) transformed to the corresponding position in the rectangular coordinate system with the second origin, A is the rotation angle, x0 is the displacement that the y coordinate axis needs to move, and y0 is the displacement that the x coordinate axis needs to move.

[0027] In a second aspect, the present application provides a posture calibration device for installing multiple laser radars, comprising:

[0028] A first acquisition module: establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin, and acquiring point cloud data of the road surface to be detected through the first laser radar;

[0029] Selection module: selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set;

[0030] Rotation module: obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around the coordinate axis within a preset angle range and with a preset step size;

[0031] A first calibration module is configured to perform attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation;

[0032] Second acquisition module: establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin;

[0033] The second calibration module is used to calibrate the attitude of the second laser radar according to the second spatial rectangular coordinate system.

[0034] The second calibration module includes:

[0035] Rotation unit: rotates the second rectangular coordinate system around the y-axis multiple times within a preset angle range and with a preset step size, so that the second rectangular coordinate system coincides with the x-axis and z-axis of the first rectangular coordinate system;

[0036] A conversion unit: converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into the coordinates in the second space rectangular coordinate system;

[0037] Calibration unit: performs attitude calibration on the second laser radar according to the coordinates of the calibration point in the second spatial rectangular coordinate system after each rotation.

[0038] As can be seen from the above technical solutions, the embodiment of the present application provides a posture calibration method and device for the installation of multiple laser radars, wherein the method includes: establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin, obtaining point cloud data of the road surface to be detected through the first laser radar, selecting point cloud data of the flat road surface area in the point cloud data of the road surface as a calibration point cloud set, and obtaining the coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system around the coordinate axis multiple times within a preset angle range with a preset step size, calibrating the posture of the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation, establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin, and calibrating the posture of the second laser radar according to the second spatial rectangular coordinate system. The technical solution of the embodiment of the present application does not use a chain neural network with complex parameters, so the training effect is greatly accelerated. To sum up, the technical solution provided by the embodiment of the present application has the following beneficial effects: it improves the efficiency of installing multiple laser radars, lowers the installation standards of laser radars, and solves the problem of difficulty in unifying the coordinate system and slow installation efficiency when calibrating multiple laser radars during the existing laser radar installation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0040] Figure 1 This is a flow chart of a method for attitude calibration of multiple laser radar installations shown in this application;

[0041] Figure 2 is a flow chart of a method in an embodiment shown in the present application;

[0042] Figure 3 is a method flow chart of another embodiment shown in the present application;

[0043] Figure 4 This is a schematic structural diagram of a posture calibration device for multiple laser radar installations shown in this application;

[0044] Figure 5 It is a structural diagram of the second calibration module shown in this application. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0046] LiDAR needs to be installed before use. When using LiDAR in the field of automatic measurement of vehicle exterior dimensions, it is generally necessary to calibrate information such as the radar installation position, detection target position, and installation angle during installation. The shortcomings and deficiencies of existing installation calibration methods require related auxiliary tools to perform various precise calibration tasks, resulting in low efficiency on the construction site of LiDAR installation. At the same time, when installing multiple LiDARs, it is difficult to unify the coordinate systems of multiple LiDARs, resulting in slow installation efficiency.

[0047] In order to solve the above problems, the embodiments of the present application provide a posture calibration method and device for the installation of multiple laser radars, so as to solve the problem of slow installation efficiency during the existing laser radar installation process when multiple laser radars are calibrated because the coordinate systems of multiple laser radars are difficult to unify.

[0048] join Figure 1 In a first aspect, the present application provides a posture calibration method for multiple laser radar installations, comprising:

[0049] S110: Establishing a first spatial rectangular coordinate system with the position of the first laser radar as the origin;

[0050] S120: Acquire point cloud data of the road surface to be detected by the first laser radar;

[0051] S130: Selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set;

[0052] S140: Obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around a coordinate axis within a preset angle range and with a preset step size;

[0053] S150: Performing attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation;

[0054] S160: Establishing a second spatial rectangular coordinate system with the position of the second laser radar as the origin;

[0055] S170: Perform attitude calibration on the second laser radar according to the second spatial rectangular coordinate system.

[0056] See also Figure 2 , Figure 2 This is a flow chart of a method according to an embodiment of the present application, wherein the attitude calibration of the second laser radar according to the second spatial rectangular coordinate system specifically includes the following steps:

[0057] S171: rotating the second rectangular coordinate system around the y-axis within a preset angle range and with a preset step size for multiple times, so that the second rectangular coordinate system coincides with the x-axis and the z-axis of the first rectangular coordinate system;

[0058] S172: Converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into coordinates in the second space rectangular coordinate system;

[0059] S173: Perform attitude calibration on the second laser radar according to the coordinates of the calibration point in the second spatial rectangular coordinate system after each rotation.

[0060] In one embodiment of the present application, there are multiple second laser radars.

[0061] Optionally, the coordinate axis is at least one of an x-axis, a y-axis, and a z-axis.

[0062] Specifically, when the first spatial rectangular coordinate system is rotated about the z-axis, the attitude calibration of the first laser radar based on the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation includes: calculating the coordinates of the calibration rod in the spatial rectangular coordinate system before each rotation and the preset step size, and calibrating the heading angle of the first laser radar based on the vertical coordinate of the calibration point in the spatial rectangular coordinate system after each rotation and the corresponding rotation angle after each rotation. When the first spatial rectangular coordinate system is rotated about the y-axis, the attitude calibration of the first laser radar based on the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation includes: calculating the coordinates of the calibration point in the spatial rectangular coordinate system after each rotation based on the coordinates of the calibration point in the first spatial rectangular coordinate system before each rotation and the preset step size, and calibrating the pitch angle of the first laser radar based on the vertical coordinate of the calibration point in the spatial rectangular coordinate system after each rotation and the corresponding rotation angle after each rotation. When the spatial rectangular coordinate system is rotated around the x-axis, the attitude calibration of the first laser radar is performed according to the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation, including: calculating the coordinates of the calibration point in the spatial rectangular coordinate system after each rotation according to the coordinates of the calibration point in the first spatial rectangular coordinate system before each rotation and the preset step size; calibrating the roll angle of the first laser radar according to the vertical coordinate of the calibration point in the spatial rectangular coordinate system after each rotation and the rotation angle corresponding to each rotation.

[0063] In one embodiment of the present application, before performing attitude calibration on the first laser radar according to the coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation, the method further includes: changing the origin of the first rectangular coordinate system.

[0064] See also Figure 3 , the changing of the origin of the first rectangular coordinate system specifically includes the following steps:

[0065] S210: Taking the intersection of the first laser radar and the road surface as the second origin;

[0066] S210: transforming the coordinates of the calibration point in the first space rectangular coordinate system after each rotation according to the coordinates of the second origin.

[0067] In one embodiment of the present application, the second origin is set at the junction of the first laser radar and the road surface directly below, so that a more intuitive radar detection image can be obtained, which is convenient for operators to observe and improve efficiency.

[0068] The coordinates of the calibration point in the first space rectangular coordinate system after each rotation are transformed according to the coordinates of the second origin, and the transformation formula is:

[0069] X=(x-x0)*cosA+(y-y0)*sinA

[0070] Y=(x-x0)*(-sinA)+(y-y0)cosA

[0071] Among them, (x, y) is the coordinate value of the calibration point in the first rectangular coordinate system, (X, Y) is the coordinate value of the calibration point (x, y) transformed to the corresponding position in the rectangular coordinate system with the second origin, A is the rotation angle, x0 is the displacement that the y coordinate axis needs to move, and y0 is the displacement that the x coordinate axis needs to move.

[0072] Second, see Figure 4 The present application provides a posture calibration device for multiple laser radar installations, comprising:

[0073] A first acquisition module 310 is configured to establish a first spatial rectangular coordinate system based on the position of the first laser radar as the origin, and acquire point cloud data of the road surface to be inspected through the first laser radar;

[0074] Selection module 320: selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set;

[0075] Rotation module 330: Obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around the coordinate axis within a preset angle range and with a preset step size;

[0076] A first calibration module 340 is configured to perform attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation;

[0077] The second acquisition module 350 is used to establish a second spatial rectangular coordinate system based on the position of the second laser radar as the origin;

[0078] The second calibration module 360 performs attitude calibration on the second laser radar according to the second spatial rectangular coordinate system.

[0079] See also Figure 5 , the second calibration module 360 includes:

[0080] Rotation unit 3601: rotates the second spatial rectangular coordinate system multiple times around the coordinate y-axis within a preset angle range and with a preset step size, so that the second rectangular coordinate system coincides with the coordinate x-axis and the coordinate z-axis of the first rectangular coordinate system;

[0081] Converting unit 3602: Converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into coordinates in the second space rectangular coordinate system;

[0082] Calibration unit 3603: performs attitude calibration on the second laser radar according to the coordinates of the calibration points in the second spatial rectangular coordinate system after each rotation.

[0083] As can be seen from the above technical solutions, the embodiment of the present application provides a posture calibration method and device for the installation of multiple laser radars, wherein the method includes: establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin, obtaining point cloud data of the road surface to be detected through the first laser radar, selecting point cloud data of the flat road surface area in the point cloud data of the road surface as a calibration point cloud set, and obtaining the coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system around the coordinate axis multiple times within a preset angle range with a preset step size, calibrating the posture of the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation, establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin, and calibrating the posture of the second laser radar according to the second spatial rectangular coordinate system. The technical solution of the embodiment of the present application does not use a chain neural network with complex parameters, so the training effect is greatly accelerated. To sum up, the technical solution provided by the embodiment of the present application has the following beneficial effects: it improves the efficiency of installing multiple laser radars, lowers the installation standards of laser radars, and solves the problem of difficulty in unifying the coordinate system and slow installation efficiency when calibrating multiple laser radars during the existing laser radar installation process.

[0084] The present application can be used in a wide variety of general-purpose or specialized computing system environments or configurations, such as personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments that include any of the above.

[0085] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communications network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0086] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0087] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0088] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for attitude calibration of multiple laser radar installations, characterized in that: include: Establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin; Acquire point cloud data of the road surface to be detected by the first laser radar; Selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set; Obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around a coordinate axis within a preset angle range and with a preset step size; Performing attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation; Establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin; Performing attitude calibration on the second laser radar according to the second spatial rectangular coordinate system specifically includes the following steps: Rotating the second rectangular coordinate system around the y-axis within a preset angle range and at a preset step size multiple times so that the second rectangular coordinate system coincides with the x-axis and the z-axis of the first rectangular coordinate system; Converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into coordinates in the second space rectangular coordinate system; Performing attitude calibration on the second laser radar according to the coordinates of the calibration points in the second spatial rectangular coordinate system after each rotation; Before performing attitude calibration on the first laser radar according to the coordinates of the calibration point in the first space rectangular coordinate system after each rotation, the method further includes: changing the origin of the first space rectangular coordinate system; Changing the origin of the first spatial rectangular coordinate system specifically includes the following steps: The intersection of the first laser radar and the road surface is used as the second origin; The coordinates of the calibration point in the first spatial rectangular coordinate system after each rotation are transformed according to the coordinates of the second origin, and the transformation formula is: X=(x-x0)*cosA+(y-y0)*sinA Y=(x-x0)*(-sinA)+(y-y0)cosA Among them, (x, y) is the coordinate value of the calibration point in the first spatial rectangular coordinate system, (X, Y) is the coordinate value of the calibration point (x, y) transformed to the corresponding position in the rectangular coordinate system with the second origin, A is the rotation angle, x0 is the displacement that the y coordinate axis needs to move, and y0 is the displacement that the x coordinate axis needs to move.

2. The attitude calibration method for multiple laser radar installations according to claim 1, characterized in that: There are multiple second laser radars.

3. The attitude calibration method for multiple laser radar installations according to claim 1, characterized in that: The coordinate axis is at least one of an x-axis, a y-axis, and a z-axis.

4. A posture calibration device for multiple laser radar installations, characterized in that: include: A first acquisition module: establishing a first spatial rectangular coordinate system based on the position of the first laser radar as the origin, and acquiring point cloud data of the road surface to be detected through the first laser radar; Selection module: selecting point cloud data of a flat road surface area from the point cloud data of the road surface as a calibration point cloud set; Rotation module: obtaining coordinates corresponding to a certain number of calibration points in the calibration point cloud set according to the first spatial rectangular coordinate system; rotating the first spatial rectangular coordinate system multiple times around the coordinate axis within a preset angle range and with a preset step size; A first calibration module is configured to perform attitude calibration on the first laser radar according to the coordinates of the calibration points in the first spatial rectangular coordinate system after each rotation; Second acquisition module: establishing a second spatial rectangular coordinate system based on the position of the second laser radar as the origin; A second calibration module is used to calibrate the attitude of the second laser radar according to the second spatial rectangular coordinate system; The second calibration module includes: Rotation unit: rotates the second rectangular coordinate system around the y-axis within a preset angle range and with a preset step size multiple times so that the second rectangular coordinate system coincides with the x-axis and z-axis of the first rectangular coordinate system; A conversion unit: converting the coordinates of the calibration point in the first space rectangular coordinate system after each rotation into the coordinates in the second space rectangular coordinate system; Calibration unit: performs attitude calibration on the second laser radar according to the coordinates of the calibration point in the second spatial rectangular coordinate system after each rotation.

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