二维激光雷达与可见光相机外参标定方法研究

Research on extrinsic parameter calibration method of 2D laser rangefinder (LRF) and visible light camera

针对目前二维激光雷达和可见光相机外参标定精度低、步骤冗杂等问题,结合移动机器人实际应用,提出了一种基于镂空标定板的高效标定方法。通过计算激光雷达扫描镂空标定板形成的点云线段的长度,求得雷达扫描线在标定板上的坐标方程,在此基础上使用显示器绘制出雷达扫描线并在相机图像中提取对应特征点,进而定位激光雷达数据点在图像中的具体位置,最后利用两种传感器在不同位姿下的测量数据,以特征点对拟合参数的方式求取对应关系。实验结果表明,该方法的平均旋转误差为1.73°,平均平移误差为28.621 mm。所提方法无需多视角观测,只需要采集两次数据就能够实现标定过程,标定精度、效率和可操作性能够满足移动机器人实用性的需求。

Aiming at the problems of low extrinsic parameter calibration accuracy and tedious steps of 2 D laser rangefinder(LRF)and visible light camera,considering the practical application of mobile robot,this paper proposes a high efficient calibration method based on hollow calibration plate.Through calculating the length of the point cloud line segment formed by the LRF scanning the hollow calibration plate,this method can obtain the coordinate equation of the LRF scanning line on the calibration plate.On this basis,the display monitor is used to visualize the LRF scanning line and the corresponding feature points in the camera image are extracted,thus the positions of the LRF data points in the image can be located.Finally,the measurement data of the two sensors in different poses are used to obtain the corresponding relationship in the manner of feature points versus parameters.Experiment results show that the average rotation error and translation error of the proposed method are 1.73°and 28.621 mm,respectively.The proposed method does not need multi-perspective observation;it only needs to collect data twice to achieve the calibration process.The calibration accuracy,efficiency and operability can meet the practicability requirements of mobile robots.