WO2021017352A1 - Laser radar-camera joint calibration target and joint calibration method - Google Patents
Laser radar-camera joint calibration target and joint calibration method Download PDFInfo
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- WO2021017352A1 WO2021017352A1 PCT/CN2019/122410 CN2019122410W WO2021017352A1 WO 2021017352 A1 WO2021017352 A1 WO 2021017352A1 CN 2019122410 W CN2019122410 W CN 2019122410W WO 2021017352 A1 WO2021017352 A1 WO 2021017352A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/497—Means for monitoring or calibrating
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- the invention belongs to the technical field of multi-sensor joint calibration, and specifically relates to a lidar-camera joint calibration target, and also relates to a method for joint calibration of the lidar-camera using the joint calibration target.
- multi-sensor calibration is one of the problems that must be solved.
- Calibration is generally divided into two parts: the calibration of each sensor's own parameters and the joint calibration of multiple sensors.
- the calibration of each sensor's own parameters is to ensure the accuracy of the collected data, and the joint calibration of multiple sensors is to accurately match the data of multiple sensors.
- Lidar and camera are the main sensors of the robot. The distance information provided by Lidar and the color information provided by the camera are highly complementary. Therefore, fusion of the two information has become a research hotspot today.
- the problem of camera calibration has been better solved, such as the two-step method based on radial arrangement constraints, the calibration method based on 3D checkerboard targets, and the plane template calibration method.
- lidar For example, a thin rod is used as the calibration object surface.
- a right-angled triangular flat plate or a trapezoidal slope calibration plate is used as the target, and the line is used as a matching feature to obtain the calibration result.
- the distance information map collected by the lidar is transformed to make the natural edge of the scene more clear and prominent, and then the edge lines are extracted to match the edges detected in the photos taken by the camera; when the sensor platform moves along any track, it is aimed at a fixed target Collect data multiple times, and obtain calibration results by minimizing the Euclidean projection deviation of scene points between multiple frames taken from different perspectives.
- the sensor platform moves along any track, it is aimed at a fixed target Collect data multiple times, and obtain calibration results by minimizing the Euclidean projection deviation of scene points between multiple frames taken from different perspectives.
- its angular resolution is low, usually only 0.15°-3°, and due to the influence of mixed pixels, the edge part of the sudden distance change often cannot get an accurate distance value.
- the embodiment of the present invention provides a lidar-camera joint calibration target.
- the joint calibration of the lidar and the camera is completed under the condition that neither the sensor nor the calibration target moves, which can overcome the practical limitations of the lower angular resolution of the lidar.
- the edge part of the sudden distance change can obtain the accurate distance value, has the characteristics of simple structure, low production cost, and is suitable for batch calibration.
- the present invention provides a lidar-camera joint calibration target, which includes a checkerboard calibration board and an "L"-shaped calibration board;
- the "L"-shaped calibration board includes a first plane vertical board and a second plane A vertical board, the second plane vertical board is fixed on the first plane vertical board after a 90° angle relative to the first plane vertical board;
- the checkerboard calibration board is parallel to the first plane vertical board and is located on the first plane vertical board
- the front side of the line of sight is fixed on a first plane vertical board, and a black and white checkerboard pattern is arranged on the checkerboard calibration board.
- checkerboard calibration board is located on the first vertical vertical board below the connecting part of the first vertical vertical board and the second vertical vertical board.
- the extension line of the connecting portion of the first plane vertical plate and the second plane vertical plate is a vertical line
- the extension line of one of the black and white dividing lines of the black and white checkerboard pattern It overlaps with the extension line of the connecting part of the first plane vertical plate and the second plane vertical plate.
- the present invention provides a lidar-camera joint calibration method.
- the joint calibration target of the above structure is used to jointly calibrate the lidar and the camera, including the following steps:
- Lidar scans the "L” shaped calibration board to obtain the relative positional relationship between the lidar and the "L” shaped calibration board [R 1 ,T 1 ];
- step (1) the process of obtaining the relative positional relationship [R 1 , T 1 ] between the lidar and the "L" shaped calibration plate is:
- the lidar continuously scans the first and second vertical planes to obtain all radar points hitting the first and second vertical planes;
- step S2 the process of screening radar points is:
- N is an integer greater than 7
- L3 the screening line equation
- the boundary radar points located between the second plane vertical board and the first plane vertical board are determined, all radar points located before the boundary radar point are radar points belonging to the second plane vertical board, and the boundary The radar point and all subsequent radar points are radar points belonging to the first plane vertical plate.
- the process of determining the boundary radar point further includes:
- the N-4th radar point belongs to the radar point on the second plane vertical plate, and the N-3th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-4th radar point is the boundary radar point;
- the N-3th radar point belongs to the radar point on the second plane vertical plate, and the N-2th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-3th radar point is the boundary radar point;
- step (2) obtaining the relative positional relationship between the camera and the chessboard calibration board [R 2 , T 2 ] based on the PNP algorithm.
- the lidar-camera joint calibration target of the present invention completes the joint calibration of the lidar and the camera without moving the sensor and the calibration target, which can overcome the practical limitations of the lower angular resolution of the lidar and the edge of sudden distance change Some of them can get accurate distance values, have the characteristics of simple structure, low production cost, and are suitable for batch calibration.
- the laser mine method-camera joint calibration method of the present invention uses a joint calibration target designed with a specific structure to quickly perform joint calibration on the laser mine method and the camera, which is suitable for batch calibration and saves calibration costs. Among them, using the fitting method to calibrate the lidar has higher accuracy and is more suitable for joint calibration of low-resolution lidar.
- the joint calibration method can also be extended to the joint calibration of single scene, multiple cameras and lidar.
- Figure 1 is a schematic diagram of the structure of a joint calibration target in a preferred embodiment of the present invention
- Figure 2 is a schematic diagram of the distribution of radar points on the "L"-shaped calibration board
- Fig. 3 is a position marking diagram of the lidar camera joint calibration using the calibration target shown in Fig. 1.
- the joint calibration target includes a checkerboard calibration board 2 and an "L"-shaped calibration board;
- the above-mentioned "L"-shaped calibration board includes a first plane vertical board 4 and a second plane vertical board 6, the second plane vertical board 6 is fixed on the first plane vertical board 4 after a 90° angle relative to the first plane vertical board 4;
- the above-mentioned checkerboard calibration board 2 is parallel to the first plane vertical board 4, and located in front of the line of sight of the first plane vertical board 4 is fixed on the first plane vertical board 4, the checkerboard calibration board 2 is arranged with a black and white checkerboard pattern 8.
- the checkerboard calibration board 2 is a flat board structure on which black and white checkerboard patterns 8 are regularly arranged; in the prior art, the camera is calibrated by means of a checkerboard calibration board 2 with black and white checkerboard patterns 8, for example , Based on the checkerboard calibration method and the PNP method to obtain the posture of the camera to obtain the internal parameters of the camera and the external parameters to the checkerboard calibration board, where the external parameters are the relative position relationship between the camera coordinate system and the chessboard coordinate system (including translation and rotation relationship).
- the "L"-shaped calibration board designed by the optimized structure of this embodiment has a first plane vertical board 4 as the main calibration board and a second plane vertical board 6 as an auxiliary calibration board.
- the second plane upright board 6 is perpendicular to the first plane.
- the extension line of the vertical plate 4 where the two meet is a vertical line.
- the checkerboard calibration board 2 is located on the first plane vertical board 4 below the connecting part of the first plane vertical board 4 and the second plane vertical board 6. Wherein, the extension line of one of the black and white dividing lines of the black and white checkerboard pattern 8 overlaps with the extension line of the connecting portion of the first planar vertical plate 4 and the second planar vertical plate 6.
- the lidar-camera joint calibration target designed with the above structure can complete the joint calibration of lidar and camera without moving the sensor and the calibration target, which can overcome the practical limitations of the lower angular resolution of the lidar and the sudden distance change.
- the edge part can get the accurate distance value, has the characteristics of simple structure, low production cost, and is suitable for batch calibration.
- This embodiment discloses a lidar-camera joint calibration method.
- the lidar-camera joint calibration is performed using the joint calibration target disclosed in the first embodiment.
- the calibration target is placed in the field of view of the two cameras of the two cameras and placed At a distance of about 2 meters from the lidar (the range of the lidar is 4 meters).
- the internal parameters of the camera have been calibrated using methods in the prior art.
- the joint calibration method includes the following specific steps:
- Lidar scans the "L” shaped calibration board to obtain the relative positional relationship between the lidar and the "L” shaped calibration board [R 1 ,T 1 ].
- the lidar continuously scans the first planar vertical plate 4 and the second planar vertical plate 6, and can continuously scan from the first planar vertical plate 4 to the second planar vertical plate 6, or from the second planar vertical plate 6 to the first Continuous scanning in 4 directions on the flat vertical board.
- the lidar continuously scans from the second plane vertical plate 6 to the first plane vertical plate 4, and the light data of the lidar is sequentially hit on the second plane vertical plate 6 and the first plane vertical plate 4.
- the reason for the laser radar ranging error is that the joint shape of the dots on the calibration plate is not necessarily a straight shape, but a wave in a small area.
- the lidar continuously scans the first planar vertical plate 4 and the second planar vertical plate 6, while the second planar vertical plate 6 is vertically fixed on the first planar vertical plate 4, and the discrete radar points also present a 90-degree turn distribution.
- This application is based on the least squares straight line fitting method to fit the radar points on the first plane vertical plate 4 and the second plane vertical plate 6, and the structural design of the target is jointly calibrated so that they are distributed on the first plane vertical plate 4 and the second plane
- the straight line fitted by the off-line radar point on the vertical plate 6 intersects at the junction of the two.
- the lidar scans from the second plane vertical plate 6 to the first plane vertical plate 4, because the scanning only has an "L" shaped calibration plate, starting from the laser scanning direction, the place where there is an obstacle for the first time must be the left side of the calibration plate .
- the radar points belonging to the first planar vertical plate 4 and the radar points belonging to the second planar vertical plate 6 are filtered out based on the following methods:
- N is an integer greater than 7
- the boundary radar point located between the second planar vertical plate and the first planar vertical plate is determined based on the above-mentioned screening line, wherein the process of determining the boundary radar point is,
- the N-4th radar point belongs to the radar point on the second plane vertical plate, and the N-3th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-4th radar point is the boundary radar point;
- the N-3th radar point belongs to the radar point on the second plane vertical plate, and the N-2th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-3th radar point is the boundary radar point;
- the laser mine method-camera joint calibration method of the present invention uses a joint calibration target designed with a specific structure to quickly perform joint calibration on the laser mine method and the camera, which is suitable for batch calibration and saves calibration costs. Among them, using the fitting method to calibrate the lidar has higher accuracy and is more suitable for joint calibration of low-resolution lidar.
- the joint calibration method can also be extended to the joint calibration of single scene, multiple cameras and lidar.
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Abstract
A laser radar-camera joint calibration target and a joint calibration method, wherein the joint calibration target comprises a checkerboard calibration plate (2) and an "L" shaped calibration plate; the "L" shaped calibration plate includes a first planar vertical plate (4) and a second planar vertical plate (6), the second planar vertical plate (6) is fixed on the first planar vertical plate (4) after turning 90° relative to the first planar vertical plate (4); the checkerboard calibration plate (2) is parallel to the first planar vertical plate (4), located at the front side of the line of sight of the first planar vertical plate (4) and fixed on the first planar vertical plate (4), a black and white checkerboard pattern (8) is arranged on the checkerboard calibration plate (2), the laser radar-camera joint calibration target completes the joint calibration of the laser radar and the camera under the condition that both a sensor and the calibration target do not move, can overcome the practical use limitation of the laser radar with low angular resolution, obtain an accurate distance value of the edge portion of the distance mutation, has the characteristics of simple structure and low manufacturing cost, and is suitable for batch calibration.
Description
本发明属于多传感器联合标定技术领域，具体涉及一种激光雷达-摄像机联合标定靶，还涉及一种使用该联合标定靶对激光雷达-摄像机进行联合标定的方法。The invention belongs to the technical field of multi-sensor joint calibration, and specifically relates to a lidar-camera joint calibration target, and also relates to a method for joint calibration of the lidar-camera using the joint calibration target.
在智能机器人的视觉导航中，使用多传感器数据融合技术，可以得到关于环境更加可靠、统一、精细的描述，以便决策、规划及控制。在进行像素级别的数据融合时，多传感器的标定是必须解决的问题之一。标定一般分为2个部分：各传感器自身参数的标定以及多传感器的联合标定。各传感器自身参数的标定是为了保证所采集数据的准确性，而多传感器的联合标定是为了多传感器数据的准确匹配。激光雷达与摄像机是机器人的主要传感器，激光雷达提供的距离信息和摄像机提供的色彩信息具有很强的互补性，因此融合两者的信息成为当今的研究热点。其中，摄像机标定问题已经得到较好的解决，如，基于径向排列约束的两步法、基于3D棋盘靶标的标定法以及平面模板标定法。关于激光雷达标定问题也有研究，如采用一根细杆子作为标定物面，如，针对摄像机和2D激光雷达，采用直角三角形平板或者采用梯形斜面标定板作为靶标，采用线条作为匹配特征得到标定结果。都是将激光雷达采集的距离信息图通过变换，使场景自然边缘更清晰突出，再提取边缘线条与摄像机拍摄的照片中检测出来的边缘相匹配；在传感器平台沿任意轨道移动过程中针对固定靶标多次采集数据，通过最小化不同视角拍摄的多帧间场景点的欧式投影偏差来得到标定结果等。然而由于扫描激光雷达的特殊性，它的角分辨率较低，通常仅 为0.15°-3°，而且受混合像素的影响，距离突变的边缘部分往往得不到准确的距离值。In the visual navigation of intelligent robots, the use of multi-sensor data fusion technology can obtain a more reliable, uniform and detailed description of the environment for decision-making, planning and control. When performing pixel-level data fusion, multi-sensor calibration is one of the problems that must be solved. Calibration is generally divided into two parts: the calibration of each sensor's own parameters and the joint calibration of multiple sensors. The calibration of each sensor's own parameters is to ensure the accuracy of the collected data, and the joint calibration of multiple sensors is to accurately match the data of multiple sensors. Lidar and camera are the main sensors of the robot. The distance information provided by Lidar and the color information provided by the camera are highly complementary. Therefore, fusion of the two information has become a research hotspot today. Among them, the problem of camera calibration has been better solved, such as the two-step method based on radial arrangement constraints, the calibration method based on 3D checkerboard targets, and the plane template calibration method. There are also studies on the calibration of lidar. For example, a thin rod is used as the calibration object surface. For example, for cameras and 2D lidars, a right-angled triangular flat plate or a trapezoidal slope calibration plate is used as the target, and the line is used as a matching feature to obtain the calibration result. The distance information map collected by the lidar is transformed to make the natural edge of the scene more clear and prominent, and then the edge lines are extracted to match the edges detected in the photos taken by the camera; when the sensor platform moves along any track, it is aimed at a fixed target Collect data multiple times, and obtain calibration results by minimizing the Euclidean projection deviation of scene points between multiple frames taken from different perspectives. However, due to the particularity of scanning lidar, its angular resolution is low, usually only 0.15°-3°, and due to the influence of mixed pixels, the edge part of the sudden distance change often cannot get an accurate distance value.
发明内容Summary of the invention
本发明实施例提供一种激光雷达-摄像机联合标定靶，在传感器和标定靶均不移动的情况下完成激光雷达和摄像机的联合标定，能够克服激光雷达角分辨率较低的实际使用局限性，距离突变的边缘部分能够得到准确的距离值，具有结构简单，制作成本低的特点，并适用于批量标定。The embodiment of the present invention provides a lidar-camera joint calibration target. The joint calibration of the lidar and the camera is completed under the condition that neither the sensor nor the calibration target moves, which can overcome the practical limitations of the lower angular resolution of the lidar. The edge part of the sudden distance change can obtain the accurate distance value, has the characteristics of simple structure, low production cost, and is suitable for batch calibration.
为了解决上述技术问题，本发明提供了一种激光雷达-摄像机联合标定靶，包括棋盘标定板和“L”字形标定板；所述“L”字形标定板包括第一平面立板和第二平面立板，所述第二平面立板相对于第一平面立板转角90°后固定在第一平面立板上；所述棋盘标定板平行于第一平面立板，且位于第一平面立板的视线前侧固定于第一平面立板上，所述棋盘标定板上排布有黑白棋盘格图案。In order to solve the above technical problems, the present invention provides a lidar-camera joint calibration target, which includes a checkerboard calibration board and an "L"-shaped calibration board; the "L"-shaped calibration board includes a first plane vertical board and a second plane A vertical board, the second plane vertical board is fixed on the first plane vertical board after a 90° angle relative to the first plane vertical board; the checkerboard calibration board is parallel to the first plane vertical board and is located on the first plane vertical board The front side of the line of sight is fixed on a first plane vertical board, and a black and white checkerboard pattern is arranged on the checkerboard calibration board.
本发明一个较佳实施例中，进一步包括所述棋盘标定板在第一平面立板上位于第一平面立板和第二平面立板相接部位的下方。In a preferred embodiment of the present invention, it further includes that the checkerboard calibration board is located on the first vertical vertical board below the connecting part of the first vertical vertical board and the second vertical vertical board.
本发明一个较佳实施例中，进一步包括所述第一平面立板和第二平面立板相接部位的延长线为铅垂线，所述黑白棋盘格图案的其中一条黑白分隔线的延长线与所述第一平面立板和第二平面立板相接部位的延长线重叠。In a preferred embodiment of the present invention, it further includes that the extension line of the connecting portion of the first plane vertical plate and the second plane vertical plate is a vertical line, and the extension line of one of the black and white dividing lines of the black and white checkerboard pattern It overlaps with the extension line of the connecting part of the first plane vertical plate and the second plane vertical plate.
为了解决上述技术问题，本发明提供了一种激光雷达-摄像机联合标定方法，使用以上结构的联合标定靶对激光雷达和摄像机进行联合标定，包括以下步骤，In order to solve the above technical problems, the present invention provides a lidar-camera joint calibration method. The joint calibration target of the above structure is used to jointly calibrate the lidar and the camera, including the following steps:
(1)激光雷达扫描“L”字形标定板，获取激光雷达和“L”字形标定板之间的相对位置关系[R
1,T
1]；
(1) Lidar scans the "L" shaped calibration board to obtain the relative positional relationship between the lidar and the "L" shaped calibration board [R 1 ,T 1 ];
(2)摄像头拍摄棋盘标定板，获取摄像机和棋盘标定板之间的相对位置关 系[R
2,T
2]；
(2) The camera shoots the checkerboard calibration board to obtain the relative positional relationship between the camera and the checkerboard calibration board [R 2 ,T 2 ];
(3)根据联合标定靶的结构获取棋盘标定板和“L”字形标定板之间的相对位置关系[R
3,T
3]；
(3) Obtain the relative positional relationship between the checkerboard calibration board and the "L"-shaped calibration board according to the structure of the joint calibration target [R 3 ,T 3 ];
(4)根据激光雷达和“L”字形标定板之间的相对位置关系[R
1,T
1]、摄像机和棋盘标定板之间的相对位置关系[R
2,T
2]和棋盘标定板和“L”字形标定板之间的相对位置关系[R
3,T
3]，确定激光雷达和摄像机之间的相对位置关系[R,T]。
(4) According to the relative position relationship between the lidar and the "L"-shaped calibration board [R 1 ,T 1 ], the relative position relationship between the camera and the chessboard calibration board [R 2 ,T 2 ] and the chessboard calibration board and The relative position relationship between the "L" shaped calibration plates [R 3 ,T 3 ], determine the relative position relationship between the lidar and the camera [R,T].
本发明一个较佳实施例中，进一步包括步骤(1)中，获取激光雷达和“L”字形标定板之间相对位置关系[R
1,T
1]的过程为：
In a preferred embodiment of the present invention, further including step (1), the process of obtaining the relative positional relationship [R 1 , T 1 ] between the lidar and the "L" shaped calibration plate is:
S1，激光雷达连续扫描第一平面立板和第二平面立板，获取打在第一平面立板和第二平面立板上的所有雷达点；S1. The lidar continuously scans the first and second vertical planes to obtain all radar points hitting the first and second vertical planes;
S2，筛选出属于第一平面立板的雷达点和属于第二平面立板的雷达点；S2. Filter out the radar points belonging to the first horizontal vertical plate and the radar points belonging to the second horizontal vertical plate;
S3，基于最小二乘直线拟合法拟合属于第一平面立板的所有雷达点，获取第一条直线方程L1；基于最小二乘直线拟合法拟合属于第二平面立板的所有雷达点，获取第二条直线方程L2；S3: Fit all radar points belonging to the first plane vertical plate based on the least squares straight line fitting method to obtain the first straight line equation L1; fit all radar points belonging to the second plane vertical plate based on the least square straight line fitting method, Obtain the second linear equation L2;
S4，计算第一条直线和第二条直线的交点P；S4, calculate the intersection point P of the first straight line and the second straight line;
S5，根据激光雷达和“L”字形标定板之间的高度差确定以交点P为原点的“L”字形标定板坐标系。S5, according to the height difference between the lidar and the "L" shaped calibration plate, determine the coordinate system of the "L" shaped calibration plate with the intersection point P as the origin.
本发明一个较佳实施例中，进一步包括步骤S2中，筛选雷达点的过程为，In a preferred embodiment of the present invention, further including step S2, the process of screening radar points is:
当激光雷达自第二平面立板向第一平面立板扫描时，根据第二平面立板的长度预测打在第二平面立板上的雷达点有N(N为大于7的整数)个，基于最小二乘直线拟合法拟合第一个雷达点、第二个雷达点……第N-5个雷达点，获取筛选直线方程L3；When the lidar scans from the second vertical vertical plate to the first vertical vertical plate, according to the length of the second vertical vertical plate, it is predicted that there are N (N is an integer greater than 7) radar points on the second vertical vertical plate. Fit the first radar point, the second radar point...the N-5th radar point based on the least squares straight line fitting method, and obtain the screening line equation L3;
以所述筛选直线为基础确定位于第二平面立板和第一平面立板之间的分界雷达点，位于所述分界雷达点之前的所有雷达点为属于第二平面立板的雷达点，分界雷达点和以后的所有雷达点为属于第一平面立板的雷达点。Based on the screening straight line, the boundary radar points located between the second plane vertical board and the first plane vertical board are determined, all radar points located before the boundary radar point are radar points belonging to the second plane vertical board, and the boundary The radar point and all subsequent radar points are radar points belonging to the first plane vertical plate.
本发明一个较佳实施例中，进一步包括确定所述分界雷达点的过程为，In a preferred embodiment of the present invention, the process of determining the boundary radar point further includes:
计算并判断第N-4个雷达点到筛选直线的距离是否满足激光雷达的测距精度：Calculate and judge whether the distance from the N-4th radar point to the screening line meets the range accuracy of the lidar:
若，第N-4个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-4个雷达点属于第二平面立板上的雷达点，继续判断第N-3个雷达点到筛选直线L3的距离是否满足激光雷达的测距精度；否则，第N-4个雷达点为分界雷达点；If the distance from the N-4th radar point to the screening line L3 meets the ranging accuracy of the lidar, the N-4th radar point belongs to the radar point on the second plane vertical plate, and the N-3th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-4th radar point is the boundary radar point;
若，第N-3个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-3个雷达点属于第二平面立板上的雷达点，继续判断第N-2个雷达点到筛选直线L3的距离是否满足激光雷达的测距精度；否则，第N-3个雷达点为分界雷达点；If the distance from the N-3th radar point to the screening line L3 satisfies the range accuracy of the lidar, the N-3th radar point belongs to the radar point on the second plane vertical plate, and the N-2th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-3th radar point is the boundary radar point;
以此类推，直至筛选出位于第二平面立板和第一平面立板之间的分界雷达点。And so on, until the boundary radar point located between the second plane vertical plate and the first plane vertical plate is filtered out.
本发明一个较佳实施例中，进一步包括步骤(2)中，基于PNP算法获取摄像机和棋盘标定板之间的相对位置关系[R
2,T
2]。
In a preferred embodiment of the present invention, it further includes step (2), obtaining the relative positional relationship between the camera and the chessboard calibration board [R 2 , T 2 ] based on the PNP algorithm.
本发明的有益效果：The beneficial effects of the present invention:
本发明的激光雷达-摄像机联合标定靶，在传感器和标定靶均不移动的情况下完成激光雷达和摄像机的联合标定，能够克服激光雷达角分辨率较低的实际使用局限性，距离突变的边缘部分能够得到准确的距离值，具有结构简单，制作成本低的特点，并适用于批量标定。The lidar-camera joint calibration target of the present invention completes the joint calibration of the lidar and the camera without moving the sensor and the calibration target, which can overcome the practical limitations of the lower angular resolution of the lidar and the edge of sudden distance change Some of them can get accurate distance values, have the characteristics of simple structure, low production cost, and are suitable for batch calibration.
本发明的激光雷法-摄像机联合标定方法，使用特定结构设计的联合标定靶 以快速的对激光雷法和摄像机进行联合标定，可适用于批量标定，节约标定成本。其中，采用拟合方法标定激光雷达，准确性更高，更适合低分辨率激光雷达的联合标定。该联合标定方法还可以推广到单场景多摄像头与激光雷达的联合标定。The laser mine method-camera joint calibration method of the present invention uses a joint calibration target designed with a specific structure to quickly perform joint calibration on the laser mine method and the camera, which is suitable for batch calibration and saves calibration costs. Among them, using the fitting method to calibrate the lidar has higher accuracy and is more suitable for joint calibration of low-resolution lidar. The joint calibration method can also be extended to the joint calibration of single scene, multiple cameras and lidar.
图1是本发明优选实施例中联合标定靶的结构示意图；Figure 1 is a schematic diagram of the structure of a joint calibration target in a preferred embodiment of the present invention;
图2是“L”字形标定板上雷达点的分布示意图；Figure 2 is a schematic diagram of the distribution of radar points on the "L"-shaped calibration board;
图3是使用图1所示标定靶进行激光雷达摄像机联合标定时的位置标记图。Fig. 3 is a position marking diagram of the lidar camera joint calibration using the calibration target shown in Fig. 1.
图中标号说明：2-棋盘标定板，4-第一平面立板，6-第二平面立板，8-棋盘格图案。Explanation of labels in the figure: 2-checkerboard calibration board, 4-first plane vertical board, 6-second plane vertical board, 8-checkerboard pattern.
下面结合附图和具体实施例对本发明作进一步说明，以使本领域的技术人员可以更好地理解本发明并能予以实施，但所举实施例不作为对本发明的限定。The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the cited embodiments are not intended to limit the present invention.
实施例一Example one
本实施例公开一种激光雷达-摄像机联合标定靶，参照图1所示，该联合标定靶包括棋盘标定板2和“L”字形标定板；上述“L”字形标定板包括第一平面立板4和第二平面立板6，上述第二平面立板6相对于第一平面立板4转角90°后固定在第一平面立板4上；上述棋盘标定板2平行于第一平面立板4，且位于第一平面立板4的视线前侧固定于第一平面立板4上，上述棋盘标定板2上排布有黑白棋盘格图案8。This embodiment discloses a lidar-camera joint calibration target. As shown in FIG. 1, the joint calibration target includes a checkerboard calibration board 2 and an "L"-shaped calibration board; the above-mentioned "L"-shaped calibration board includes a first plane vertical board 4 and a second plane vertical board 6, the second plane vertical board 6 is fixed on the first plane vertical board 4 after a 90° angle relative to the first plane vertical board 4; the above-mentioned checkerboard calibration board 2 is parallel to the first plane vertical board 4, and located in front of the line of sight of the first plane vertical board 4 is fixed on the first plane vertical board 4, the checkerboard calibration board 2 is arranged with a black and white checkerboard pattern 8.
以上结构的联合标定靶，棋盘标定板2为平面板结构，其上规则排布黑白棋盘格图案8；现有技术中，借助具有黑白棋盘格图案8的棋盘标定板2对摄像机进行标定，比如，基于棋盘标定法和PNP求姿态法求得摄像机的内参数与 到棋盘标定板的外参数，此处的外参数为摄像机坐标系到棋盘坐标系之间的相对位置关系(包括平移关系和旋转关系)。For the joint calibration target of the above structure, the checkerboard calibration board 2 is a flat board structure on which black and white checkerboard patterns 8 are regularly arranged; in the prior art, the camera is calibrated by means of a checkerboard calibration board 2 with black and white checkerboard patterns 8, for example , Based on the checkerboard calibration method and the PNP method to obtain the posture of the camera to obtain the internal parameters of the camera and the external parameters to the checkerboard calibration board, where the external parameters are the relative position relationship between the camera coordinate system and the chessboard coordinate system (including translation and rotation relationship).
本实施例优化结构设计的“L”字形的标定板，具有作为主标定板的第一平面立板4和辅标定板的第二平面立板6，第二平面立板6垂直于第一平面立板4，两者相接部位的延长线为铅垂线。棋盘标定板2在第一平面立板4上位于第一平面立板4和第二平面立板6相接部位的下方。其中，上述黑白棋盘格图案8的其中一条黑白分隔线的延长线与上述第一平面立板4和第二平面立板6相接部位的延长线重叠。The "L"-shaped calibration board designed by the optimized structure of this embodiment has a first plane vertical board 4 as the main calibration board and a second plane vertical board 6 as an auxiliary calibration board. The second plane upright board 6 is perpendicular to the first plane. The extension line of the vertical plate 4 where the two meet is a vertical line. The checkerboard calibration board 2 is located on the first plane vertical board 4 below the connecting part of the first plane vertical board 4 and the second plane vertical board 6. Wherein, the extension line of one of the black and white dividing lines of the black and white checkerboard pattern 8 overlaps with the extension line of the connecting portion of the first planar vertical plate 4 and the second planar vertical plate 6.
以上结构设计的激光雷达-摄像机联合标定靶，在传感器和标定靶都不移动的情况下完成激光雷达和摄像机的联合标定，能够克服激光雷达角分辨率较低的实际使用局限性，距离突变的边缘部分能够得到准确的距离值，具有结构简单，制作成本低的特点，并适用于批量标定。The lidar-camera joint calibration target designed with the above structure can complete the joint calibration of lidar and camera without moving the sensor and the calibration target, which can overcome the practical limitations of the lower angular resolution of the lidar and the sudden distance change. The edge part can get the accurate distance value, has the characteristics of simple structure, low production cost, and is suitable for batch calibration.
实施例二Example two
本实施例公开一种激光雷达-摄像机联合标定方法，使用实施例一公开的联合标定靶对激光雷达-摄像机进行联合标定，标定靶放在两台摄像机的两个摄像头的视野范围内，并放在距离激光雷达2米左右的距离(激光雷达的测距范围为4米)。此处，摄像机的内参数已经使用现有技术中的方法标定好。This embodiment discloses a lidar-camera joint calibration method. The lidar-camera joint calibration is performed using the joint calibration target disclosed in the first embodiment. The calibration target is placed in the field of view of the two cameras of the two cameras and placed At a distance of about 2 meters from the lidar (the range of the lidar is 4 meters). Here, the internal parameters of the camera have been calibrated using methods in the prior art.
该联合标定方法包括以下具体步骤：The joint calibration method includes the following specific steps:
(1)激光雷达扫描“L”字形标定板，获取激光雷达和“L”字形标定板之间的相对位置关系[R
1,T
1]。
(1) Lidar scans the "L" shaped calibration board to obtain the relative positional relationship between the lidar and the "L" shaped calibration board [R 1 ,T 1 ].
该步骤的具体实施过程如下：The specific implementation process of this step is as follows:
S1，激光雷达连续扫描第一平面立板4和第二平面立板6，可以自第一平面立板4向第二平面立板6方向连续扫描，或者自第二平面立板6向第一平面立板4方向连续扫描。如图2所示，激光雷达自第二平面立板6向第一平面立 板4方向连续扫描，激光雷达的光线数据依次打在第二平面立板6和第一平面立板4上，由于激光雷达测距误差的原因，点打在标定板上的联合形状不一定是直线的形状，而是在小区域内成波浪状。激光雷达扫描后在第一平面立板4和第二平面立板6上有多个离散的雷达点，获取打在第一平面立板4和第二平面立板6上的所有雷达点。S1, the lidar continuously scans the first planar vertical plate 4 and the second planar vertical plate 6, and can continuously scan from the first planar vertical plate 4 to the second planar vertical plate 6, or from the second planar vertical plate 6 to the first Continuous scanning in 4 directions on the flat vertical board. As shown in Figure 2, the lidar continuously scans from the second plane vertical plate 6 to the first plane vertical plate 4, and the light data of the lidar is sequentially hit on the second plane vertical plate 6 and the first plane vertical plate 4. The reason for the laser radar ranging error is that the joint shape of the dots on the calibration plate is not necessarily a straight shape, but a wave in a small area. After the lidar is scanned, there are a plurality of discrete radar points on the first planar vertical plate 4 and the second planar vertical plate 6, and all the radar points hit on the first planar vertical plate 4 and the second planar vertical plate 6 are acquired.
激光雷达连续扫描第一平面立板4和第二平面立板6，而第二平面立板6垂直固定在第一平面立板4上，离散的雷达点整体也呈现拐弯90度分布。本申请基于最小二乘直线拟合法来拟合第一平面立板4和第二平面立板6上的雷达点，联合标定靶的结构设计，使得分布在第一平面立板4和第二平面立板6上离线雷达点拟合后的直线在两者的相接部处相交。在拟合直线前，需要对待拟合的点做预处理，利于阈值判断两条相交直线上的“归属点”问题，即哪些雷达点属于第一平面立板，哪些雷达点属于第二平面立板。当激光雷达自第二平面立板6向第一平面立板4扫描时，因为扫描只有“L”字形标定板，故从激光扫描方向开始，初次有障碍物的地方一定是标定板的左侧。具体基于以下方式筛选出属于第一平面立板4的雷达点和属于第二平面立板6的雷达点：The lidar continuously scans the first planar vertical plate 4 and the second planar vertical plate 6, while the second planar vertical plate 6 is vertically fixed on the first planar vertical plate 4, and the discrete radar points also present a 90-degree turn distribution. This application is based on the least squares straight line fitting method to fit the radar points on the first plane vertical plate 4 and the second plane vertical plate 6, and the structural design of the target is jointly calibrated so that they are distributed on the first plane vertical plate 4 and the second plane The straight line fitted by the off-line radar point on the vertical plate 6 intersects at the junction of the two. Before fitting a straight line, it is necessary to preprocess the points to be fitted, which is conducive to the threshold judgment of the "attribution point" problem on two intersecting straight lines, that is, which radar points belong to the first plane vertical plate and which radar points belong to the second plane vertical plate. board. When the lidar scans from the second plane vertical plate 6 to the first plane vertical plate 4, because the scanning only has an "L" shaped calibration plate, starting from the laser scanning direction, the place where there is an obstacle for the first time must be the left side of the calibration plate . Specifically, the radar points belonging to the first planar vertical plate 4 and the radar points belonging to the second planar vertical plate 6 are filtered out based on the following methods:
根据第二平面立板6的长度预测打在第二平面立板6上的雷达点有N(N为大于7的整数)个，基于最小二乘直线拟合法拟合第二平面立板6上的第一个雷达点、第二个雷达点……第N-5个雷达点，获取筛选直线方程L3；According to the length of the second plane vertical plate 6, it is predicted that there are N (N is an integer greater than 7) radar points hitting the second plane vertical plate 6, and the second plane vertical plate 6 is fitted based on the least squares straight line fitting method The first radar point, the second radar point...the N-5th radar point, obtain the screening linear equation L3;
以上述筛选直线为基础确定位于第二平面立板和第一平面立板之间的分界雷达点，其中，确定所述分界雷达点的过程为，The boundary radar point located between the second planar vertical plate and the first planar vertical plate is determined based on the above-mentioned screening line, wherein the process of determining the boundary radar point is,
计算并判断第N-4个雷达点到筛选直线的距离是否满足激光雷达的测距精度：Calculate and judge whether the distance from the N-4th radar point to the screening line meets the range accuracy of the lidar:
若，第N-4个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-4个雷达点属于第二平面立板上的雷达点，继续判断第N-3个雷达点到筛 选直线L3的距离是否满足激光雷达的测距精度；否则，第N-4个雷达点为分界雷达点；If the distance from the N-4th radar point to the screening line L3 meets the ranging accuracy of the lidar, the N-4th radar point belongs to the radar point on the second plane vertical plate, and the N-3th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-4th radar point is the boundary radar point;
若，第N-3个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-3个雷达点属于第二平面立板上的雷达点，继续判断第N-2个雷达点到筛选直线L3的距离是否满足激光雷达的测距精度；否则，第N-3个雷达点为分界雷达点；If the distance from the N-3th radar point to the screening line L3 satisfies the range accuracy of the lidar, the N-3th radar point belongs to the radar point on the second plane vertical plate, and the N-2th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-3th radar point is the boundary radar point;
以此类推，直至筛选出位于第二平面立板和第一平面立板之间的分界雷达点，位于所述分界雷达点之前的所有雷达点为属于第二平面立板的雷达点，分界雷达点和以后的所有雷达点为属于第一平面立板的雷达点。By analogy, until the boundary radar points located between the second plane vertical board and the first plane vertical board are filtered out, all radar points located before the boundary radar point are radar points belonging to the second plane vertical board, and the boundary radar The point and all subsequent radar points are radar points belonging to the first plane vertical plate.
S3，基于最小二乘直线拟合法拟合属于第一平面立板的所有雷达点，获取第一条直线方程L1；基于最小二乘直线拟合法拟合属于第二平面立板的所有雷达点，获取第二条直线方程L2。基于最小二乘直线拟合法对多个离散点进行拟合获取拟合直线方程为现有技术，此处不再赘述。S3: Fit all radar points belonging to the first plane vertical plate based on the least squares straight line fitting method to obtain the first straight line equation L1; fit all radar points belonging to the second plane vertical plate based on the least square straight line fitting method, Obtain the second linear equation L2. Fitting multiple discrete points based on the least squares straight line fitting method to obtain the fitted straight line equation is the prior art, and will not be repeated here.
S4，计算第一条直线和第二条直线的交点P。获取两条直线的方程后，通过解方程组的方式获取两条直线交点坐标为现有技术，此处不再赘述。S4, calculate the intersection point P of the first straight line and the second straight line. After obtaining the equations of the two straight lines, obtaining the coordinates of the intersection point of the two straight lines by solving the equation group is the prior art, and will not be repeated here.
S5，如图3所示，根据激光雷达和“L”字形标定板之间的高度差确定以交点P为原点的“L”字形标定板坐标系。此处，“L”字形标定板相对于地面的高度，以及激光雷达相对于地面的高度已知，即两者之间的高度差已知，交点P的坐标已知，激光雷达的内参数坐标系已知，基于以上三个已知量，可以唯一确定“L”字形标定板以交点P为原点的坐标系，以此可以唯一确定激光雷达和“L”字形标定板之间的相对位置关系[R
1,T
1]。
S5, as shown in Fig. 3, determine the coordinate system of the “L”-shaped calibration plate with the intersection point P as the origin according to the height difference between the lidar and the “L”-shaped calibration plate. Here, the height of the "L" shaped calibration board relative to the ground and the height of the lidar relative to the ground are known, that is, the height difference between the two is known, the coordinates of the intersection point P are known, and the internal parameter coordinates of the lidar The system is known. Based on the above three known quantities, the coordinate system of the "L"-shaped calibration board with the intersection point P as the origin can be uniquely determined, so that the relative position relationship between the lidar and the "L"-shaped calibration board can be uniquely determined [R 1 ,T 1 ].
(2)摄像头拍摄棋盘标定板，获取摄像机和棋盘标定板之间的相对位置关系[R
2,T
2]。此处，基于现有技术中的PNP算法获取摄像机和棋盘标定板之间的相对位置关系[R
2,T
2]。
(2) The camera shoots the checkerboard calibration board to obtain the relative positional relationship between the camera and the checkerboard calibration board [R 2 ,T 2 ]. Here, the relative positional relationship [R 2 , T 2 ] between the camera and the checkerboard calibration board is obtained based on the PNP algorithm in the prior art.
(3)根据联合标定靶的结构设计获取棋盘标定板和“L”字形标定板之间的相对位置关系[R
3,T
3]。此处，基于联合标定靶的结构设计，棋盘标定板的原点O位于交点P的正下方，两者之间的高度差ΔH
2唯一确定；即棋盘标定板和“L”字形标定板之间的相对位置关系[R
3,T
3]唯一确定。
(3) Obtain the relative positional relationship between the checkerboard calibration board and the "L"-shaped calibration board according to the structural design of the joint calibration target [R 3 ,T 3 ]. Here, based on the structural design of the joint calibration target, the origin O of the checkerboard calibration board is located directly below the intersection point P, and the height difference ΔH 2 between the two is uniquely determined; that is, the gap between the checkerboard calibration board and the "L"-shaped calibration board The relative position relationship [R 3 ,T 3 ] is uniquely determined.
(4)根据以上确定的激光雷达和“L”字形标定板之间的相对位置关系[R
1,T
1]、摄像机和棋盘标定板之间的相对位置关系[R
2,T
2]和棋盘标定板和“L”字形标定板之间的相对位置关系[R
3,T
3]，确定激光雷达和摄像机之间的相对位置关系[R,T]；以此，完成激光雷达和摄像机的联合标定。
(4) According to the relative positional relationship between the lidar and the "L" shaped calibration board determined above [R 1 ,T 1 ], the relative positional relationship between the camera and the chessboard calibration board [R 2 ,T 2 ] and the chessboard The relative positional relationship between the calibration board and the "L"-shaped calibration board [R 3 ,T 3 ], determine the relative positional relationship between the lidar and the camera [R,T]; in this way, complete the combination of the lidar and the camera Calibration.
本发明的激光雷法-摄像机联合标定方法，使用特定结构设计的联合标定靶能够快速的对激光雷法和摄像机进行联合标定，可适用于批量标定，节约标定成本。其中，采用拟合方法标定激光雷达，准确性更高，更适合低分辨率激光雷达的联合标定。该联合标定方法还可以推广到单场景多摄像头与激光雷达的联合标定。The laser mine method-camera joint calibration method of the present invention uses a joint calibration target designed with a specific structure to quickly perform joint calibration on the laser mine method and the camera, which is suitable for batch calibration and saves calibration costs. Among them, using the fitting method to calibrate the lidar has higher accuracy and is more suitable for joint calibration of low-resolution lidar. The joint calibration method can also be extended to the joint calibration of single scene, multiple cameras and lidar.
以上所述实施例仅是为充分说明本发明而所举的较佳的实施例，本发明的保护范围不限于此。本技术领域的技术人员在本发明基础上所作的等同替代或变换，均在本发明的保护范围之内。本发明的保护范围以权利要求书为准。The above-mentioned embodiments are only preferred embodiments for fully explaining the present invention, and the protection scope of the present invention is not limited thereto. The equivalent substitutions or changes made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.
Claims (8)
- 一种激光雷达-摄像机联合标定靶，其特征在于：包括棋盘标定板和“L”字形标定板；所述“L”字形标定板包括第一平面立板和第二平面立板，所述第二平面立板相对于第一平面立板转角90°后固定在第一平面立板上；所述棋盘标定板平行于第一平面立板，且位于第一平面立板的视线前侧固定于第一平面立板上，所述棋盘标定板上排布有黑白棋盘格图案。A lidar-camera joint calibration target, characterized in that it comprises a checkerboard calibration board and an "L"-shaped calibration board; the "L"-shaped calibration board includes a first plane vertical board and a second plane vertical board. The two plane vertical boards are fixed on the first plane vertical board after a 90° angle relative to the first plane vertical board; the checkerboard calibration board is parallel to the first plane vertical board, and is located in front of the line of sight of the first plane vertical board. On the first plane vertical board, a black and white checkerboard pattern is arranged on the checkerboard calibration board.
- 如权利要求1所述的激光雷达-摄像机联合标定靶，其特征在于：所述棋盘标定板在第一平面立板上位于第一平面立板和第二平面立板相接部位的下方。The lidar-camera joint calibration target according to claim 1, wherein the checkerboard calibration board is located on the first vertical vertical board below the joint of the first vertical vertical board and the second vertical vertical board.
- 如权利要求2所述的激光雷达-摄像机联合标定靶，其特征在于：所述第一平面立板和第二平面立板相接部位的延长线为铅垂线，所述黑白棋盘格图案的其中一条黑白分隔线的延长线与所述第一平面立板和第二平面立板相接部位的延长线重叠。The lidar-camera joint calibration target according to claim 2, wherein the extension line of the connecting part of the first plane vertical plate and the second plane vertical plate is a vertical line, and the black and white checkerboard pattern The extension line of one of the black and white dividing lines overlaps with the extension line of the connecting part of the first plane vertical board and the second plane vertical board.
- 一种激光雷达-摄像机联合标定方法，使用权利要求1或2或3所述的联合标定靶对激光雷达和摄像机进行联合标定，其特征在于：包括以下步骤，A lidar-camera joint calibration method, which uses the joint calibration target of claim 1 or 2 or 3 for joint calibration of lidar and camera, characterized in that it comprises the following steps:(1)激光雷达扫描“L”字形标定板，获取激光雷达和“L”字形标定板之间的相对位置关系[R 1,T 1]； (1) Lidar scans the "L" shaped calibration board to obtain the relative positional relationship between the lidar and the "L" shaped calibration board [R 1 ,T 1 ];(2)摄像头拍摄棋盘标定板，获取摄像机和棋盘标定板之间的相对位置关系[R 2,T 2]； (2) The camera shoots the checkerboard calibration board to obtain the relative positional relationship between the camera and the checkerboard calibration board [R 2 ,T 2 ];(3)根据联合标定靶的结构获取棋盘标定板和“L”字形标定板之间的相对位置关系[R 3,T 3]； (3) Obtain the relative positional relationship between the checkerboard calibration board and the "L"-shaped calibration board according to the structure of the joint calibration target [R 3 ,T 3 ];(4)根据激光雷达和“L”字形标定板之间的相对位置关系[R 1,T 1]、摄像机 和棋盘标定板之间的相对位置关系[R 2,T 2]和棋盘标定板和“L”字形标定板之间的相对位置关系[R 3,T 3]，确定激光雷达和摄像机之间的相对位置关系[R,T]。 (4) According to the relative position relationship between the lidar and the "L"-shaped calibration board [R 1 ,T 1 ], the relative position relationship between the camera and the chessboard calibration board [R 2 ,T 2 ] and the chessboard calibration board and The relative position relationship between the "L" shaped calibration plates [R 3 ,T 3 ], determine the relative position relationship between the lidar and the camera [R,T].
- 如权利要求4所述的激光雷达-摄像机联合标定方法，其特征在于：步骤(1)中，获取激光雷达和“L”字形标定板之间相对位置关系[R 1,T 1]的过程为： The lidar-camera joint calibration method according to claim 4, characterized in that: in step (1), the process of obtaining the relative positional relationship [R 1 , T 1 ] between the lidar and the "L" shaped calibration plate is :S1，激光雷达连续扫描第一平面立板和第二平面立板，获取打在第一平面立板和第二平面立板上的所有雷达点；S1. The lidar continuously scans the first and second vertical planes to obtain all radar points hitting the first and second vertical planes;S2，筛选出属于第一平面立板的雷达点和属于第二平面立板的雷达点；S2. Filter out the radar points belonging to the first horizontal vertical plate and the radar points belonging to the second horizontal vertical plate;S3，基于最小二乘直线拟合法拟合属于第一平面立板的所有雷达点，获取第一条直线方程L1；基于最小二乘直线拟合法拟合属于第二平面立板的所有雷达点，获取第二条直线方程L2；S3: Fit all radar points belonging to the first plane vertical plate based on the least squares straight line fitting method to obtain the first straight line equation L1; fit all radar points belonging to the second plane vertical plate based on the least square straight line fitting method, Obtain the second linear equation L2;S4，计算第一条直线和第二条直线的交点P；S4, calculate the intersection point P of the first straight line and the second straight line;S5，根据激光雷达和“L”字形标定板之间的高度差确定以交点P为原点的“L”字形标定板坐标系。S5, according to the height difference between the lidar and the "L" shaped calibration plate, determine the coordinate system of the "L" shaped calibration plate with the intersection point P as the origin.
- 如权利要求5所述的激光雷达-摄像机联合标定方法，其特征在于：步骤S2中，筛选雷达点的过程为，The lidar-camera joint calibration method according to claim 5, characterized in that: in step S2, the process of screening radar points is:当激光雷达自第二平面立板向第一平面立板扫描时，根据第二平面立板的长度预测打在第二平面立板上的雷达点有N(N为大于7的整数)个，基于最小二乘直线拟合法拟合第一个雷达点、第二个雷达点……第N-5个雷达点，获取筛选直线方程L3；When the lidar scans from the second vertical vertical plate to the first vertical vertical plate, according to the length of the second vertical vertical plate, it is predicted that there are N (N is an integer greater than 7) radar points on the second vertical vertical plate. Fit the first radar point, the second radar point...the N-5th radar point based on the least squares straight line fitting method, and obtain the screening line equation L3;以所述筛选直线为基础确定位于第二平面立板和第一平面立板之间的分界雷达点，位于所述分界雷达点之前的所有雷达点为属于第二平面立板的雷达点，分界雷达点和以后的所有雷达点为属于第一平面立板的雷达点。Based on the screening straight line, the boundary radar points located between the second plane vertical board and the first plane vertical board are determined, all radar points located before the boundary radar point are radar points belonging to the second plane vertical board, and the boundary The radar point and all subsequent radar points are radar points belonging to the first plane vertical plate.
- 如权利要求6所述的激光雷达-摄像机联合标定方法，其特征在于：确定所述分界雷达点的过程为，The lidar-camera joint calibration method according to claim 6, wherein the process of determining the boundary radar point is,计算并判断第N-4个雷达点到筛选直线的距离是否满足激光雷达的测距精度：Calculate and judge whether the distance from the N-4th radar point to the screening line meets the range accuracy of the lidar:若，第N-4个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-4个雷达点属于第二平面立板上的雷达点，继续判断第N-3个雷达点到筛选直线L3的距离是否满足激光雷达的测距精度；否则，第N-4个雷达点为分界雷达点；If the distance from the N-4th radar point to the screening line L3 meets the ranging accuracy of the lidar, the N-4th radar point belongs to the radar point on the second plane vertical plate, and the N-3th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-4th radar point is the boundary radar point;若，第N-3个雷达点到筛选直线L3的距离满足激光雷达的测距精度，则第N-3个雷达点属于第二平面立板上的雷达点，继续判断第N-2个雷达点到筛选直线L3的距离是否满足激光雷达的测距精度；否则，第N-3个雷达点为分界雷达点；If the distance from the N-3th radar point to the screening line L3 satisfies the range accuracy of the lidar, the N-3th radar point belongs to the radar point on the second plane vertical plate, and the N-2th radar is continued to be judged Whether the distance from the point to the screening line L3 meets the ranging accuracy of the lidar; otherwise, the N-3th radar point is the boundary radar point;以此类推，直至筛选出位于第二平面立板和第一平面立板之间的分界雷达点。And so on, until the boundary radar point located between the second plane vertical plate and the first plane vertical plate is filtered out.
- 如权利要求4所述的激光雷达-摄像机联合标定方法，其特征在于：步骤(2)中，基于PNP算法获取摄像机和棋盘标定板之间的相对位置关系[R 2,T 2]。 The lidar-camera joint calibration method according to claim 4, characterized in that: in step (2), the relative positional relationship [R 2 , T 2 ] between the camera and the chessboard calibration board is obtained based on the PNP algorithm.
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