A method and device for determining the installation posture of a laser radar

Abstract

A method and device for determining the installation posture of a laser radar, comprising: obtaining the initial laser rays generated when each laser head of the laser radar rotates one circle in an initial posture; in response to the setting of the target posture of the laser radar, translating and rotating the initial laser rays of each laser head of the laser radar to obtain the target laser rays generated by each laser head in the target posture; obtaining the intersection of the target laser rays and a set plane to obtain the point cloud density generated by the laser radar in the set plane with the target posture; and determining whether the target posture is a suitable installation posture by the point cloud density. Through the above scheme, the installation posture of the laser radar can be determined more accurately.

Description

Technical Field

[0001] The present invention relates to the field of computer application technology, and in particular to a method and device for determining the installation posture of a laser radar. Background Art

[0002] When collecting map data, existing high-precision map collection vehicles use various sensors to collect corresponding data. The sensors include inertial navigation equipment (i.e., inertial navigation equipment) and lidar, etc. Among them, the inertial navigation equipment outputs the vehicle's driving trajectory, and the lidar uses high-speed laser to scan and measure the road environment during the vehicle's driving process to obtain point cloud data of the road environment.

[0003] Before the high-precision map collection vehicle starts working, an important task is to calibrate the installation posture of the laser radar, including the installation position and installation angle, to ensure that the point cloud density obtained by the laser radar scan meets the requirements. In the prior art, the installation posture of the laser radar installed on the collection vehicle is manually changed, and the point cloud data generated by the laser radar under different installation postures is recorded to find the best installation posture. Since this method requires manual participation, generally a limited number of posture change attempts will be made manually, which will result in the manual calibration of the best installation posture may not be the actual best, and there is also the problem of low efficiency. Therefore, a method is needed to quickly and accurately determine the installation posture of the laser radar. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for determining the installation posture of a laser radar, which can quickly obtain the point cloud density of the laser radar and accurately and efficiently determine the installation posture of the laser radar.

[0005] In order to achieve the above object, the present invention provides a method for determining the installation posture of a laser radar, the method comprising:

[0006] Obtaining the initial laser rays generated when each laser head of the laser radar rotates one circle at the initial posture;

[0007] In response to the setting of the target posture of the laser radar, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture;

[0008] Obtaining the intersection of the target laser ray and the set plane to obtain the point cloud density generated by the laser radar in the set plane with the target posture;

[0009] Whether the target posture is a suitable installation posture is determined according to the point cloud density.

[0010] Furthermore, the step of obtaining the initial laser rays generated when each laser head of the laser radar rotates one circle in the initial posture includes:

[0011] Calculate the three-dimensional coordinates of each point in the laser ray generated by each laser head rotating one circle according to the azimuth angle of each point in the laser ray generated by each laser head rotating one circle and the pitch angle of each laser head;

[0012] According to the three-dimensional coordinates of each point in the laser beam generated when each laser head rotates one circle, the initial laser beam generated when each laser head rotates one circle at its pitch angle is obtained.

[0013] Furthermore, the azimuth angle of each point in the laser beam generated by each laser head rotating one circle is obtained by the following method:

[0014] The number of points in the laser beam generated by one rotation of each laser head is calculated using the emission frequency and the rotation frequency of each laser head;

[0015] The azimuth angle of each point in the laser beam generated by each laser head rotating once is calculated based on the number of points in the laser beam generated by each laser head rotating once.

[0016] Furthermore, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture, including:

[0017] Obtaining a relationship matrix of the laser radar under the target posture relative to the vehicle coordinate system;

[0018] The relationship matrix is ​​used to translate and rotate the initial laser rays of each laser head of the laser radar to obtain the target laser rays generated by each laser head under the target posture.

[0019] Furthermore, the step of obtaining a relationship matrix of the laser radar under the target posture relative to the vehicle coordinate system includes:

[0020] Obtaining a rotation matrix of the laser radar under the target posture relative to a vehicle coordinate system based on an installation angle of the laser radar under the target posture;

[0021] Obtaining a translation vector of the laser radar relative to a vehicle coordinate system under the target posture;

[0022] Based on the rotation matrix and the translation vector, a relationship matrix of the laser radar relative to the vehicle coordinate system under the target posture is obtained.

[0023] The present invention also provides a device for determining the installation posture of a laser radar, the device comprising: an initial laser ray acquisition unit, a target laser ray acquisition unit, a point cloud density acquisition unit and an installation posture determination unit;

[0024] The initial laser ray acquisition unit is used to acquire the initial laser ray generated when each laser head of the laser radar rotates one circle in the initial posture;

[0025] The target laser ray acquisition unit is used to translate and rotate the initial laser rays of each laser head of the laser radar in response to the setting of the target posture of the laser radar, so as to obtain the target laser rays generated by each laser head under the target posture;

[0026] The point cloud density acquisition unit is used to acquire the intersection of the target laser ray and the set plane to obtain the point cloud density generated by the laser radar on the set plane with the target posture;

[0027] The installation posture determination unit is used to determine whether the target posture is a suitable installation posture according to the point cloud density.

[0028] The present invention also provides an electronic device, the device comprising:

[0029] Storage device;

[0030] one or more processors;

[0031] The storage device is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described above.

[0032] The present invention also provides a computer program product, comprising computer program instructions, which are used to implement the method as described above when the instructions are executed by a processor.

[0033] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the method described above is implemented.

[0034] Compared with the prior art, the present invention provides a method and device for determining the installation posture of a laser radar, which obtains the target laser beam at the target posture by translating and rotating the initial laser beam emitted by each laser head of the laser radar, and obtains the point cloud density of the target laser beam under the set plane. Therefore, it is possible to judge whether the setting of the target posture is appropriate based on the point cloud density, which provides a reliable theoretical basis for subsequent laser radar installation and point cloud evaluation processes, can be quickly applied to actual projects, and improves project execution efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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.

[0036] Figure 1 The present invention is a flow chart of a method for determining the installation posture of a laser radar.

[0037] Figure 2 Schematic diagram of the angle arrangement of each laser head of the laser radar according to an embodiment of the present invention.

[0038] Figure 3 It is a point cloud schematic diagram of the simulated laser level installation according to an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of a point cloud of a simulated laser installed at a 40° tilt according to an embodiment of the present invention.

[0040] Figure 5 Schematic diagram of the point cloud of a road sign obtained by simulating laser scanning according to an embodiment of the present invention.

[0041] Figure 6 This is a structural block diagram of a device for determining the installation posture of a laser radar according to Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding and implementation of the present invention by those skilled in the art, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. Embodiment 1:

[0043] See also Figure 1 Embodiment 1 of the present invention provides a method for determining the installation posture of a laser radar, the method comprising the following steps:

[0044] Step 101: Acquire the initial laser rays generated when each laser head of the laser radar rotates one circle in the initial posture.

[0045] In an initial state, the direction of the laser radar is consistent with the direction of the vehicle coordinate system.

[0046] Each frame of point cloud of the laser emitted by the laser radar is the initial laser ray generated by one rotation of the laser.

[0047] The obtaining of the initial laser rays generated when each laser head of the laser radar rotates one circle in the initial posture specifically includes:

[0048] (1) Calculate the number of points M of each laser head of the laser radar, that is, each line of laser light rotates one circle:

[0049]

[0050] Among them, V represents the emission frequency of the laser, the unit is points / second, and F represents the rotation frequency of the laser, the unit is Hz.

[0051] (2) Calculate the azimuth of the mth point of the nth laser head, i.e. the nth line laser m :

[0052]

[0053] Among them, 1≤n≤N, N is the number of laser heads of the laser radar, that is, the total number of lasers that can be emitted, and 0≤m≤M.

[0054] (3) According to the azimuth m and the pitch angle a of the nth laser head n Calculate the three-dimensional coordinates of the mth point of the nth laser head

[0055] x = length × cos(a n )×sin(azimuth m );

[0056] y=length×cos(a n )×cos(azimyth m );

[0057] z=length×sin(a n );

[0058] Where length is the maximum distance of the laser scan, in meters.

[0059] (4) According to the three-dimensional coordinates, the initial laser beam generated when each laser head rotates one circle at its pitch angle is obtained.

[0060] like Figure 2 As shown, the equipment parameters of the laser radar provide the pitch angle of each laser line. Before the above step (1), the pitch angle set A of all N laser lines of the laser radar must be obtained in advance:

[0061] A={a1,a2,a3,…,a n, …, a N};

[0062] Among them, a n represents the pitch angle of the nth laser head, N represents the number of laser heads included in the laser radar, that is, the total number of lasers that can be emitted by the laser radar. If the number of laser heads of the laser radar is 32, then N=32.

[0063] Step 102: in response to the setting of the target posture of the laser radar, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture;

[0064] In response to the setting of the target posture of the laser radar, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture, specifically:

[0065] (1) Setting the target posture of the laser radar, using the installation angle {roll, pitch, yaw} of the laser radar relative to the vehicle coordinate system as the target posture.

[0066] The rotation matrix of the laser radar relative to the vehicle coordinate system is R, and the translation vector of the laser radar relative to the vehicle coordinate system is T = {t x , t y , t z}, where t x ,t y ,t z They respectively represent the translation distance of the laser radar relative to the vehicle coordinate system in the x-, y-, and z-axis directions; the rotation matrix R of the laser radar relative to the vehicle coordinate system is obtained based on the installation angle of the laser radar.

[0067] In the initial state, the installation angle of the laser radar is {0, 0, 0}, and its rotation matrix relative to the vehicle coordinate system is the unit matrix R:

[0068]

[0069] In the present invention, the translation matrix can be T={0, 0, H}, where H is the installation height of the laser radar in meters.

[0070] (2) Obtain the relationship matrix M of the laser radar relative to the vehicle coordinate system:

[0071]

[0072] (3) Using the relationship matrix M, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture.

[0073] According to the three-dimensional coordinates of the points in all theoretical rays of each laser head of the laser radar rotating one circle in the initial state (that is, the three-dimensional coordinates of the mth point of the nth laser head calculated above) ) and the relationship matrix to calculate the three-dimensional coordinates of the points in the target laser rays generated by each laser head under the target posture x'y'z' represents the values ​​in the x, y, and z axes of the vehicle coordinate system, respectively, where:

[0074]

[0075] The set of three-dimensional coordinates of points in the target laser beam generated by each laser head in the target posture forms the target laser beam generated by each laser head in the target posture.

[0076] Step 103: Obtain the intersection point of the target laser ray and the set plane to obtain the point cloud density generated by the laser radar in the set plane with the target posture.

[0077] In step 103, the plane equation of the set plane is used to represent the external environment. The general form of the plane equation is:

[0078] Ax+By+Cz+D=0;

[0079] The ground equation is:

[0080] z=0.

[0081] Figure 3 , 4 Shown are the point clouds obtained when the LiDAR is installed horizontally and tilted 40 degrees.

[0082] For some special plane settings, such as a sign in the plane, it is necessary to define the spatial bounding volume of the sign. The spatial straight line equation is solved together with the plane equation to obtain the point of the laser radar in the set plane, such as Figure 5 This process can be handled using the method of the intersection of any spatial straight line and plane.

[0083] Step 104: Determine whether the target posture is a suitable installation posture according to the point cloud density.

[0084] The point cloud density generated in step 103 is analyzed to determine information such as the fineness of the point cloud density, so as to determine whether the set target posture is a suitable installation posture.

[0085] Embodiment 2:

[0086] See also Figure 6 Embodiment 2 of the present invention provides a device for determining the installation posture of a laser radar, the device comprising: an initial laser ray acquisition unit, a target laser ray acquisition unit, a point cloud density acquisition unit and an installation posture determination unit.

[0087] The initial laser beam acquisition unit is used to acquire the initial laser beam generated when each laser head of the laser radar rotates one circle in the initial posture.

[0088] In an initial state, the direction of the laser radar is consistent with the direction of the vehicle coordinate system.

[0089] Each frame of point cloud of the laser emitted by the laser radar is the initial laser ray generated by one rotation of the laser.

[0090] The obtaining of the initial laser rays generated when each laser head of the laser radar rotates one circle in the initial posture specifically includes:

[0091] (1) Calculate the number of points M of each laser head of the laser radar, that is, each line of laser light rotates one circle:

[0092]

[0093] Among them, V represents the emission frequency of the laser, the unit is points / second, and F represents the rotation frequency of the laser, the unit is Hz.

[0094] (2) Calculate the azimuth of the mth point of the nth laser head, i.e. the nth line laser m :

[0095]

[0096] Among them, 1≤n≤N, N is the number of laser heads of the laser radar, that is, the total number of lasers that can be emitted, and 0≤m≤M.

[0097] (3) According to the azimuth m and the pitch angle a of the nth laser head n Calculate the three-dimensional coordinates of the mth point of the nth laser head

[0098] x = length × cos(a n )×sin(azimuth m );

[0099] y=length=cos(a n )×cos(azimuth m );

[0100] z = length × sin (a n );

[0101] Where length is the maximum distance of the laser scan, in meters.

[0102] (4) According to the three-dimensional coordinates, the initial laser beam generated when each laser head rotates one circle at its pitch angle is obtained.

[0103] like Figure 2 As shown, the equipment parameters of the laser radar provide the pitch angle of each laser line. Before the above step (1), the pitch angle set A of all N laser lines of the laser radar must be obtained in advance:

[0104] A={a1,a2,a3,…,a n , …, a N};

[0105] Among them, a n represents the pitch angle of the nth laser head, N represents the number of laser heads included in the laser radar, that is, the total number of lasers that can be emitted by the laser radar. If the number of laser heads of the laser radar is 32, then N=32.

[0106] The target laser ray acquisition unit is used to translate and rotate the initial laser rays of each laser head of the laser radar in response to the setting of the target posture of the laser radar, so as to obtain the target laser rays generated by each laser head under the target posture;

[0107] In response to the setting of the target posture of the laser radar, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture; specifically:

[0108] (1) Setting the target posture of the laser radar, using the installation angle {roll, pitch, yaw} of the laser radar relative to the vehicle coordinate system as the target posture.

[0109] The rotation matrix of the laser radar relative to the vehicle coordinate system is R, and the translation vector of the laser radar relative to the vehicle coordinate system is T = {t x , t y , t z}, where t x ,t y ,t zThey respectively represent the translation distance of the laser radar relative to the vehicle coordinate system in the x-, y-, and z-axis directions; the rotation matrix R of the laser radar relative to the vehicle coordinate system is obtained based on the installation angle of the laser radar.

[0110] In the initial state, the installation angle of the laser radar is {0, 0, 0}, and its rotation matrix relative to the vehicle coordinate system is the unit matrix R:

[0111]

[0112] In the present invention, the translation matrix can be T={0, 0, H}, where H is the installation height of the laser radar in meters.

[0113] (2) Obtain the relationship matrix M of the laser radar relative to the vehicle coordinate system:

[0114]

[0115] (3) Using the relationship matrix M, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture.

[0116] According to the three-dimensional coordinates of the points in all theoretical rays of each laser head of the laser radar rotating one circle in the initial state (that is, the three-dimensional coordinates of the mth point of the nth laser head calculated above) ) and the relationship matrix to calculate the three-dimensional coordinates of the points in the target laser rays generated by each laser head under the target posture x'y'z' represents the values ​​in the x, y, and z axes of the vehicle coordinate system, respectively, where:

[0117]

[0118] The set of three-dimensional coordinates of points in the target laser beam generated by each laser head in the target posture forms the target laser beam generated by each laser head in the target posture.

[0119] The point cloud density acquisition unit is used to acquire the intersection of the target laser ray and the set plane to obtain the point cloud density generated by the laser radar in the set plane with the target posture.

[0120] The external environment is represented by a plane equation of a set plane, the general form of which is:

[0121] Ax+By+Cz+D=0;

[0122] The ground equation is:

[0123] z=0.

[0124] For some special plane settings, such as a sign in the plane, it is necessary to define the spatial bounding volume of the sign. The spatial line equation is solved together with the plane equation to obtain the point of the laser radar in the set plane. This process can be processed using the method of any spatial line and plane intersection.

[0125] The installation posture determination unit is used to determine whether the target posture is a suitable installation posture according to the point cloud density.

[0126] By judging the fineness of the point cloud density and other information, it is determined whether the set target posture is a suitable installation posture.

[0127] Compared with the prior art, the method and device for determining the installation posture of a laser radar provided by the present invention only use the parameters of the laser sensor to construct a theoretical equation for the coordinates of the laser scanning points. The method and device are applicable to any installation position and angle, and are convenient for checking whether the point cloud in the three-dimensional scene is too dense or too sparse, thereby providing a basis for setting the emission frequency and operating frequency of the laser, and providing a reliable theoretical basis for subsequent installation and point cloud evaluation processes. The method can be quickly applied to actual projects, thereby improving project execution efficiency.

[0128] In addition, an embodiment of the present invention further discloses an electronic device, which includes a storage device and one or more processors, wherein the storage device is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in Embodiment 1.

[0129] The embodiment of the present invention further discloses a computer program product, including computer program instructions, which are used to implement the method of the first embodiment when the instructions are executed by a processor.

[0130] The embodiment of the present invention further discloses a computer-readable storage medium, on which a computer program is stored. When the computer program is executed, the method of the first embodiment is implemented.

[0131] The flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the methods, devices and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart and block diagram can represent a unit, module, program segment or part of the code, including one or more computer executable instructions for implementing logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes can also occur in an order different from that marked in the accompanying drawings. It should also be noted that each box or combination of boxes in the block diagram and flowchart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0132] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including 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 device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0133] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. The above embodiments are merely examples for illustration and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications may be made based on the above description, and these changes or modifications will be obvious and fall within the scope of protection of the present invention.

Claims

1. A method for determining the installation posture of a laser radar, wherein: The method comprises: Obtaining the initial laser rays generated when each laser head of the laser radar rotates one circle at the initial posture; In response to the setting of the target posture of the laser radar, the initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture; The intersection point of the target laser ray and the set plane is obtained to obtain the point cloud density generated by the laser radar in the set plane with the target posture, and whether the target posture is a suitable installation posture is determined by the point cloud density.

2. The method of claim 1, wherein: The obtaining of the initial laser rays generated when each laser head of the laser radar rotates one circle in the initial posture includes: Calculate the three-dimensional coordinates of each point in the laser ray generated by each laser head rotating one circle according to the azimuth angle of each point in the laser ray generated by each laser head rotating one circle and the pitch angle of each laser head; According to the three-dimensional coordinates of each point in the laser beam generated when each laser head rotates one circle, the initial laser beam generated when each laser head rotates one circle at its pitch angle is obtained.

3. The method of claim 2, wherein: The azimuth angle of each point in the laser beam generated by each laser head rotating one circle is obtained in the following way: The number of points in the laser beam generated by one rotation of each laser head is calculated using the emission frequency and the rotation frequency of each laser head; The azimuth angle of each point in the laser beam generated by each laser head rotating once is calculated based on the number of points in the laser beam generated by each laser head rotating once.

4. The method according to any one of claims 1 to 3, wherein: The initial laser rays of each laser head of the laser radar are translated and rotated to obtain the target laser rays generated by each laser head under the target posture, including: Obtaining a relationship matrix of the laser radar under the target posture relative to the vehicle coordinate system; The relationship matrix is ​​used to translate and rotate the initial laser rays of each laser head of the laser radar to obtain the target laser rays generated by each laser head under the target posture.

5. The method of claim 4, wherein: The step of obtaining a relationship matrix of the laser radar under the target posture relative to the vehicle coordinate system includes: Obtaining a rotation matrix of the laser radar under the target posture relative to a vehicle coordinate system based on an installation angle of the laser radar under the target posture; Obtaining a translation vector of the laser radar relative to a vehicle coordinate system under the target posture; Based on the rotation matrix and the translation vector, a relationship matrix of the laser radar relative to the vehicle coordinate system under the target posture is obtained.

6. A device for determining the installation posture of a laser radar, wherein: The device comprises: an initial laser ray acquisition unit, a target laser ray acquisition unit, a point cloud density acquisition unit and an installation posture determination unit; The initial laser ray acquisition unit is used to acquire the initial laser ray generated when each laser head of the laser radar rotates one circle in the initial posture; The target laser ray acquisition unit is used to translate and rotate the initial laser rays of each laser head of the laser radar in response to the setting of the target posture of the laser radar, so as to obtain the target laser rays generated by each laser head under the target posture; The point cloud density acquisition unit is used to acquire the intersection of the target laser ray and the set plane to obtain the point cloud density generated by the laser radar on the set plane with the target posture; The installation posture determination unit is used to determine whether the target posture is a suitable installation posture according to the point cloud density.

7. An electronic device, wherein: The device comprises: Storage device; one or more processors; The storage device is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method according to any one of claims 1 to 5 is implemented.

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