External parameter calibration method of laser radar, computer equipment and computer storage medium

Abstract

The present application discloses a method for calibrating the external parameters of a laser radar, a computer device, and a computer storage medium, the method comprising: obtaining point cloud data collected by the laser radar to be calibrated, the point cloud data comprising first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other; according to the first point cloud data, the second point cloud data, and the third point cloud data, respectively calculating the plane parameters of the first plane, the second plane, and the third plane; according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, calibrating the external parameters of the laser radar, the external parameters comprising a rotation matrix and / or a translation vector. In this way, by using the plane point cloud data to calibrate the external parameters, the utilization rate of the point cloud data can be improved, the influence of the sparsity of the point cloud can be avoided or reduced, and the error of the external parameter calibration can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of radar calibration technology, and in particular to an external parameter calibration method, computer equipment and computer storage medium for a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. It is widely used in many fields. For example, vehicle-mounted 3D reconstruction systems and perception systems all need to work based on the detection data of LiDAR. After installing the LiDAR, the external parameters of the LiDAR need to be calibrated to improve the accuracy of the detection data. In related technologies, the external parameters of the LiDAR are generally calibrated and calculated through the corner points or feature points of the calibration plate, but this point-based calculation method is easily affected by the sparsity of the LiDAR point cloud, resulting in large errors in the external parameters obtained by calibration. Summary of the invention

[0003] In response to the above technical problems, the present application provides a laser radar external parameter calibration method, computer equipment and computer storage medium, which can avoid or reduce the influence of point cloud sparsity and reduce the error of external parameter calibration.

[0004] In order to solve the above technical problems, the present application provides an external parameter calibration method of a laser radar, the method comprising:

[0005] Acquire point cloud data collected by the laser radar to be calibrated, the point cloud data including first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other;

[0006] Calculating plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data;

[0007] According to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, the external parameters of the laser radar are calibrated, and the external parameters include a rotation matrix and / or a translation vector.

[0008] Optionally, respectively calculating the plane parameters of the first plane, the second plane, and the third plane according to the first point cloud data, the second point cloud data, and the third point cloud data includes:

[0009] Plane parameters of the first plane, the second plane, and the third plane are fitted respectively according to the first point cloud data, the second point cloud data, and the third point cloud data.

[0010] Optionally, the first plane is perpendicular to the first coordinate axis of the coordinate system where the laser radar is located, the second plane is perpendicular to the second coordinate axis of the coordinate system where the laser radar is located, the third plane is perpendicular to the third coordinate axis of the coordinate system where the laser radar is located, and the first coordinate axis, the second coordinate axis, and the third coordinate axis are perpendicular to each other.

[0011] Optionally, calibrating the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located includes:

[0012] According to the plane parameters of the first plane, the second plane, and the third plane, respectively calculate the translation amounts of the first plane, the second plane, and the third plane relative to the origin of the coordinate system where the laser radar is located;

[0013] Obtaining the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane;

[0014] The differences between the translation amounts and the vertical distances corresponding to the first plane, the second plane, and the third plane are calculated respectively to obtain the translation vector of the laser radar.

[0015] Optionally, the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane are preset values ​​or external input values.

[0016] Optionally, calibrating the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located includes:

[0017] Calculate normal vectors of the first plane, the second plane, and the third plane respectively according to plane parameters of the first plane, the second plane, and the third plane;

[0018] The rotation matrix of the laser radar is calculated according to the normal vectors of the first plane, the second plane, and the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located.

[0019] Optionally, calculating the rotation matrix of the laser radar according to the normal vectors of the first plane, the second plane, the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located includes:

[0020] Respectively calculate the angles between the normal vector of each plane in the first plane, the second plane, and the third plane and the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located, and obtain the rotation matrices corresponding to the first plane, the second plane, and the third plane;

[0021] The product of the rotation matrices corresponding to the first plane, the second plane, and the third plane is calculated to obtain the rotation matrix of the laser radar.

[0022] The present application also provides an external parameter calibration device for a laser radar, which is characterized by comprising:

[0023] A point cloud data acquisition module, used to acquire point cloud data collected by the laser radar to be calibrated, wherein the point cloud data includes first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other;

[0024] A plane parameter calculation module, used to calculate the plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data;

[0025] A calibration calculation module is used to calibrate the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, and the external parameters include a rotation matrix and / or a translation vector.

[0026] The present application also provides a computer device, comprising: a processor and a memory storing a computer program, and when the processor runs the computer program, the steps of the external parameter calibration method of the laser radar as described above are implemented.

[0027] The present application also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the steps of any of the above-described methods for calibrating external parameters of a laser radar.

[0028] As described above, the external parameter calibration method, computer device and computer storage medium of the laser radar of the present application obtain point cloud data collected by the laser radar to be calibrated, the point cloud data includes first point cloud data corresponding to the first plane, second point cloud data corresponding to the second plane and third point cloud data corresponding to the third plane, wherein the first plane, the second plane and the third plane are not parallel to each other; according to the first point cloud data, the second point cloud data and the third point cloud data, the plane parameters of the first plane, the second plane and the third plane are calculated respectively; according to the plane parameters of the first plane, the second plane and the third plane and the parameters of the coordinate system where the laser radar is located, the external parameters of the laser radar are calibrated, and the external parameters include rotation matrix and / or translation vector. In this way, by using the plane point cloud data to calibrate the external parameters, the utilization rate of the point cloud data can be improved, the influence of the sparsity of the point cloud can be avoided or reduced, and the error of the external parameter calibration can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a flow chart of an external parameter calibration method for a laser radar provided in an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of a calibration scenario provided by an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the structure of an external parameter calibration device for a laser radar provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0034] It should be noted that, in this article, the terms "include", "comprises" 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 includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0035] It should be understood that, although the terms first, second, third, etc. may be used to describe various information in this article, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this article, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination". Furthermore, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising", "including" indicate that there are described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Thus, “A, B, or C” or “A, B and / or C” means “any of the following: A; B; C; A and B; A and C; B and C; A, B, and C.” An exception to this definition will occur only when a combination of elements, functions, steps, or operations are inherently mutually exclusive in some manner.

[0036] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and it can be performed in other orders. Moreover, at least a portion of the steps in the figure may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0037] It should be noted that, in this article, step codes such as S101, S102, etc. are used for the purpose of expressing the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the sequence. When implementing the step, those skilled in the art may execute S102 first and then S101, etc., but these should all be within the scope of protection of this application.

[0038] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] In the subsequent description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present application, and have no specific meanings. Therefore, "module", "component" or "unit" can be used in a mixed manner.

[0040] Figure 1 The following is a flow chart of a method for calibrating an external parameter of a laser radar provided by an embodiment of the present invention. Figure 1 As shown, a method for calibrating external parameters of a laser radar comprises the following steps:

[0041] S101: Obtain point cloud data collected by the laser radar to be calibrated, the point cloud data including first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other.

[0042] Among them, the laser radar to be calibrated is a laser radar installed on the target device. The target device can be a vehicle, a robot, or other device that needs to use a laser radar. This embodiment takes the calibration process of a laser radar installed on a vehicle as an example to illustrate.

[0043] Please refer to Figure 2, which is a schematic diagram of a calibration scene after a laser radar (not shown) is installed on a vehicle 10. Before calibration, three non-parallel planes are first arranged, including a first plane 11, a second plane 12, and a third plane 13. The first plane 11, the second plane 12, and the third plane 13 can be three flat plates. In actual implementation, the first plane 11, the second plane 12, and the third plane 13 can be arranged first, and then the vehicle 10 is parked at a specified position and orientation according to the positions of the first plane 11, the second plane 12, and the third plane 13. Alternatively, the first plane 11, the second plane 12, and the third plane 13 can be arranged according to the position and orientation of the vehicle 10 after the vehicle 10 is parked.

[0044] In this embodiment, the first plane 11, the second plane 12, and the third plane 13 are perpendicular to each other. Preferably, the first plane 11 is perpendicular to the first coordinate axis of the coordinate system where the laser radar is located, the second plane 12 is perpendicular to the second coordinate axis of the coordinate system where the laser radar is located, and the third plane 13 is perpendicular to the third coordinate axis of the coordinate system where the laser radar is located. The first coordinate axis, the second coordinate axis, and the third coordinate axis are perpendicular to each other. Figure 2 In the example, the first coordinate axis can be the z-axis (not shown in the figure), the second coordinate axis can be the x-axis, and the third coordinate axis can be the y-axis, so as to simplify the scene arrangement and subsequent calibration calculation process. The laser radar coordinate system refers to the coordinate system of the device where the laser radar is located, such as the vehicle coordinate system. Figure 2 In the illustrated scenario, the vehicle coordinate system may select the center of the rear axle of the vehicle 10 as the coordinate origin, the x-axis and the y-axis as the coordinate axes on the horizontal plane, and the z-axis as the coordinate axis on the vertical plane (not shown in the figure), which may facilitate the arrangement of the first plane 11, the second plane 12, and the third plane 13. It is understood that the selection of the coordinate origin and the coordinate axis is not limited thereto.

[0045] After the calibration scene is arranged, the laser radar to be calibrated is turned on for detection, and the point cloud data corresponding to the first plane 11, the second plane 12 and the third plane 13 can be collected. That is, the collected point cloud data include first point cloud data corresponding to the first plane 11, second point cloud data corresponding to the second plane 12, and third point cloud data corresponding to the third plane 13.

[0046] S102: Calculating plane parameters of a first plane, a second plane, and a third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data;

[0047] The plane parameters refer to the parameters a, b, c, and d that make the plane equation aX+bY+cZ+d=0. In this embodiment, the plane parameters of the first plane, the second plane, and the third plane are fitted based on the first point cloud data, the second point cloud data, and the third point cloud data and the RANSAC algorithm (RANdom SAmple Consensus). Taking the plane parameters of the first plane as an example, the specific process is as follows:

[0048] (1) Randomly select three points in the first point cloud data: P1 = (x1, y1, z1), P2 = (x2, y2, z2), P3 = (x2, y3, z3);

[0049] (2) Calculate the plane parameters a, b, c, d through P1, P2, and P3. The formula is as follows:

[0050] a=[(y2-y1)(z3-z1)-(z2-z1)(y3-y2)]

[0051] b=[(z2-z1)(x3-x1)-(x2-x1)(z3-z2)]

[0052] c=[(x2-x1)(y3-y1)-(y2-y1)(x3-x2)]

[0053] d=-(ax+by+cz)

[0054] (3) Calculate the distances from all points in the first point cloud data to the plane where the three points are located. Assuming that the point is P4 (x4, y4, z4), the distance from point P4 to the plane where the three points are located is:

[0055]

[0056] (4) If the distance is less than the set threshold T, point P4 is considered an inlier, otherwise it is considered an outlier; wherein the threshold T refers to the maximum allowable distance difference between a point in the first point cloud data and a plane determined based on the current plane parameters, which can be set according to the error requirements, for example, 0.5 cm:

[0057] (5) Counting the number of inliers. If the number of inliers is greater than the historical maximum value, the plane parameters are saved. In each iteration, three points in the first point cloud data are randomly selected as described above to count the number of inliers. The historical maximum value refers to the maximum value of the number of inliers calculated in all previous iterations. For example, assuming that the number of inliers in the i-th iteration is Ni, and a total of 10 iterations are performed to obtain N1 to N10, the maximum value among N1 to N10 is taken as the historical maximum value.

[0058] (6) Repeat the above steps (1) to (5) until the algorithm converges, for example, the number of interior points is greater than a certain number, and the plane parameters of the first plane can be obtained.

[0059] As can be seen from the above, when calculating the plane parameters of the first plane, the second plane, and the third plane, the present application uses the point cloud data of the first plane, the second plane, and the third plane, and fits a large amount of point cloud data of multiple planes, thereby improving the utilization rate of point cloud data and avoiding or reducing the impact of point cloud sparsity. In addition, the calibration method of the present application can be completed without the need for a specially customized calibration plate, thereby reducing the cost of calibration.

[0060] S103: Calibrate the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located. The external parameters include a rotation matrix and / or a translation vector.

[0061] Among them, the plane parameters of the first plane, the second plane, and the third plane can be used to characterize the actual detection results of the laser radar. The parameters of the coordinate system where the laser radar is located correspond to the theoretical plane parameters of the first plane, the second plane, and the third plane, and can be used to characterize the theoretical detection results of the laser radar. Among them, the parameters of the coordinate system where the laser radar is located include the vertical distance between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane, as well as the direction of each coordinate axis of the coordinate system where the laser radar is located. Therefore, according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, the external parameters of the laser radar can be calibrated. In this embodiment, the external parameters include a rotation matrix and / or a translation vector.

[0062] Optionally, when calibrating the translation vector, the external parameters of the laser radar are calibrated according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, including:

[0063] According to the plane parameters of the first plane, the second plane, and the third plane, respectively calculate the translation amounts of the first plane, the second plane, and the third plane relative to the origin of the coordinate system where the laser radar is located;

[0064] Obtain the vertical distances between the origin of the laser radar coordinate system and the first plane, the second plane, and the third plane;

[0065] The differences between the translation amounts and vertical distances corresponding to the first plane, the second plane, and the third plane are calculated respectively to obtain the translation vector of the laser radar.

[0066] Among them, according to the plane parameters of the first plane, the second plane, and the third plane, the intersection of the first plane and the first coordinate axis, the intersection of the second plane and the second coordinate axis, and the intersection of the third plane and the third coordinate axis can be calculated, and the coordinate values ​​of the intersections are also the translation amounts of the corresponding planes. The vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane are preset values ​​or external input values. For example, the first plane, the second plane, and the third plane are arranged at the first designated position. When the vehicle stops at the second designated position corresponding to the first designated position in the specified direction, the vertical distance can use the preset value; or, after the vehicle is parked, a laser pen or ruler or other tool can be used to measure the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane, and the measured values ​​are input as external input values.

[0067] Afterwards, the differences between the translation amounts d1, d2, d3 corresponding to the first plane, the second plane, and the third plane and the vertical distances m1, m2, m3 are calculated respectively to obtain the translation vector T = [d1-m1, d2-m2, d3-m3] of the laser radar.

[0068] Optionally, when calibrating the rotation matrix of the laser radar, the external parameters of the laser radar are obtained by calibration according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, including:

[0069] According to the plane parameters of the first plane, the second plane and the third plane, respectively calculate the normal vectors of the first plane, the second plane and the third plane;

[0070] The rotation matrix of the laser radar is calculated according to the normal vectors of the first plane, the second plane, and the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located.

[0071] Optionally, the rotation matrix of the laser radar is calculated according to the normal vectors of the first plane, the second plane, and the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located, including:

[0072] Calculate the angles between the normal vector of each plane in the first plane, the second plane, and the third plane and the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located, and obtain the rotation matrices corresponding to the first plane, the second plane, and the third plane;

[0073] The product of the rotation matrices corresponding to the first plane, the second plane, and the third plane is calculated to obtain the rotation matrix of the laser radar.

[0074] Among them, the normal vector of each plane in the first plane, the second plane, and the third plane is a vector, and the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located all correspond to a vector. The rotation matrix between the two vectors can be calculated based on the following process:

[0075] (1) Assume that the unit vectors corresponding to the two vectors are a and b, and let v = a × b;

[0076] (2) Let s = ||v||, c = a·b;

[0077] (3) Definition Then the rotation matrix is:

[0078]

[0079] The process of calculating the angle between the normal vector of each plane in the first plane, the second plane, and the third plane and the first coordinate axis, the second coordinate axis, and the third coordinate axis direction of the coordinate system where the laser radar is located, and obtaining the rotation matrix corresponding to the first plane, the second plane, and the third plane is well known to those skilled in the art and will not be repeated here. After obtaining the rotation matrices E1, E2, and E3 corresponding to the first plane, the second plane, and the third plane, the product between E1, E2, and E3 is calculated to obtain the rotation matrix of the laser radar.

[0080] As described above, the external parameter calibration method of the laser radar of the present application obtains the point cloud data collected by the laser radar to be calibrated, and the point cloud data includes the first point cloud data corresponding to the first plane, the second point cloud data corresponding to the second plane, and the third point cloud data corresponding to the third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other; according to the first point cloud data, the second point cloud data, and the third point cloud data, the plane parameters of the first plane, the second plane, and the third plane are calculated respectively; according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located, the external parameters of the laser radar are calibrated, and the external parameters include the rotation matrix and / or the translation vector. In this way, by using the plane point cloud data to calibrate the external parameters, the utilization rate of the point cloud data can be improved, the influence of the sparsity of the point cloud can be avoided or reduced, and the error of the external parameter calibration can be reduced.

[0081] Figure 3 The following is a schematic diagram of the structure of an external parameter calibration device for a laser radar provided by an embodiment of the present invention. Figure 3 As shown, an external parameter calibration device for a laser radar comprises:

[0082] The point cloud data acquisition module 301 is used to acquire point cloud data collected by the laser radar to be calibrated, wherein the point cloud data includes first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other;

[0083] A plane parameter calculation module 302, used to calculate the plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data;

[0084] The calibration calculation module 303 is used to calibrate the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, and the third plane and the parameters of the coordinate system where the laser radar is located. The external parameters include the rotation matrix and / or the translation vector.

[0085] The working process of the above modules is detailed in the description of the above method embodiment, which will not be repeated here.

[0086] Based on the same inventive concept as the above embodiments, an embodiment of the present invention provides a computer device, such as Figure 4 As shown, the computer device includes: a processor 310 and a memory 311 storing a computer program; wherein, Figure 4 The processor 310 shown in the figure is not used to indicate that the number of the processor 310 is one, but is only used to indicate the positional relationship of the processor 310 relative to other devices. In actual applications, the number of the processor 310 may be one or more; similarly, Figure 4 The memory 311 shown in the figure has the same meaning, that is, it is only used to refer to the position relationship of the memory 311 relative to other devices. In practical applications, the number of memories 311 can be one or more. When the processor 310 runs the computer program, the external parameter calibration method of the laser radar described in the above embodiment is implemented.

[0087] The computer device may also include: at least one network interface 312. The various components in the computer device are coupled together via a bus system 313. It is understood that the bus system 313 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 313 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, the bus system 313 is not used in the following examples. Figure 4 Various buses are labeled as bus system 313.

[0088] The memory 311 may be a volatile memory or a nonvolatile memory, or may include both volatile and nonvolatile memories. The nonvolatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disk, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a disk memory or a tape memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM, SyncLink Dynamic Random Access Memory), and direct RAM bus random access memory (DRRAM, Direct Rambus Random Access Memory).The memory 311 described in the embodiments of the present invention is intended to include but is not limited to these and any other suitable types of memories.

[0089] The memory 311 in the embodiment of the present invention is used to store various types of data to support the operation of the external parameter calibration method of the laser radar. Examples of these data include computer programs, such as operating systems and applications. Among them, the operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application program may include various applications, such as a media player (Media Player), etc., which are used to implement various application services. Here, the program that implements the method of the embodiment of the present invention may be included in the application program.

[0090] Based on the same inventive concept as the above-mentioned embodiment, this embodiment further provides a computer storage medium, in which a computer program is stored. The computer storage medium may be a ferromagnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); it may also be various devices including one or any combination of the above-mentioned memories, such as a mobile phone, a computer, a tablet device, a personal digital assistant, etc. When the computer program stored in the computer storage medium is executed by the processor, the external parameter calibration method of the laser radar described in the above-mentioned embodiment is implemented. For the specific steps implemented when the computer program is executed by the processor, please refer to Figure 1 The description of the illustrated embodiment will not be repeated here.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0093] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A laser radar external parameter calibration method, characterized in that: The method comprises: Acquire point cloud data collected by the laser radar to be calibrated, the point cloud data including first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other; Calculating plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data; Calibrate the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, the third plane and the parameters of the coordinate system where the laser radar is located, and the external parameters include a rotation matrix and / or a translation vector; Among them, the first plane is perpendicular to the first coordinate axis of the coordinate system where the laser radar is located, the second plane is perpendicular to the second coordinate axis of the coordinate system where the laser radar is located, the third plane is perpendicular to the third coordinate axis of the coordinate system where the laser radar is located, and the first coordinate axis, the second coordinate axis, and the third coordinate axis are perpendicular to each other; the coordinate system where the laser radar is located refers to the coordinate system of the device where the laser radar is located; the parameters of the coordinate system where the laser radar is located include the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane, and the directions of the coordinate axes of the coordinate system where the laser radar is located; the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane are preset values ​​or external input values.

2. The method according to claim 1, characterized in that The calculating the plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data includes: Plane parameters of the first plane, the second plane, and the third plane are fitted respectively according to the first point cloud data, the second point cloud data, and the third point cloud data.

3. The method according to claim 1, characterized in that The calibrating the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, the third plane and the parameters of the coordinate system where the laser radar is located includes: According to the plane parameters of the first plane, the second plane, and the third plane, respectively calculate the translation amounts of the first plane, the second plane, and the third plane relative to the origin of the coordinate system where the laser radar is located; Obtaining the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane; The differences between the translation amounts and the vertical distances corresponding to the first plane, the second plane, and the third plane are calculated respectively to obtain the translation vector of the laser radar.

4. The method according to claim 1, characterized in that The calibrating the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, the third plane and the parameters of the coordinate system where the laser radar is located includes: Calculate normal vectors of the first plane, the second plane, and the third plane respectively according to plane parameters of the first plane, the second plane, and the third plane; The rotation matrix of the laser radar is calculated according to the normal vectors of the first plane, the second plane, and the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located.

5. The method according to claim 4, characterized in that The calculating the rotation matrix of the laser radar according to the normal vectors of the first plane, the second plane, the third plane and the directions of the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located includes: Respectively calculate the angles between the normal vector of each plane in the first plane, the second plane, and the third plane and the first coordinate axis, the second coordinate axis, and the third coordinate axis of the coordinate system where the laser radar is located, and obtain the rotation matrices corresponding to the first plane, the second plane, and the third plane; The product of the rotation matrices corresponding to the first plane, the second plane, and the third plane is calculated to obtain the rotation matrix of the laser radar.

6. An external parameter calibration device for a laser radar, characterized in that: include: A point cloud data acquisition module, used to acquire point cloud data collected by the laser radar to be calibrated, wherein the point cloud data includes first point cloud data corresponding to a first plane, second point cloud data corresponding to a second plane, and third point cloud data corresponding to a third plane, wherein the first plane, the second plane, and the third plane are not parallel to each other; A plane parameter calculation module, used to calculate the plane parameters of the first plane, the second plane, and the third plane respectively according to the first point cloud data, the second point cloud data, and the third point cloud data; A calibration calculation module, used for calibrating the external parameters of the laser radar according to the plane parameters of the first plane, the second plane, the third plane and the parameters of the coordinate system where the laser radar is located, wherein the external parameters include a rotation matrix and / or a translation vector; Among them, the first plane is perpendicular to the first coordinate axis of the coordinate system where the laser radar is located, the second plane is perpendicular to the second coordinate axis of the coordinate system where the laser radar is located, the third plane is perpendicular to the third coordinate axis of the coordinate system where the laser radar is located, and the first coordinate axis, the second coordinate axis, and the third coordinate axis are perpendicular to each other; the coordinate system where the laser radar is located refers to the coordinate system of the device where the laser radar is located; the parameters of the coordinate system where the laser radar is located include the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane, and the directions of the coordinate axes of the coordinate system where the laser radar is located; the vertical distances between the origin of the coordinate system where the laser radar is located and the first plane, the second plane, and the third plane are preset values ​​or external input values.

7. A computer device, characterized in that: include: A processor and a memory storing a computer program, which implements the steps of the external parameter calibration method of the laser radar described in any one of claims 1 to 5 when the processor runs the computer program.

8. A computer storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the steps of the external parameter calibration method of the laser radar described in any one of claims 1 to 5 are implemented.

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