In a multi-sensor fusion system composed of cameras and LiDAR, precise extrinsic calibration contributes to the system's long-term stability and accurate perception of the environment. However, methods based on extracting and registering corresponding points still face challenges in terms of automation and precision. This paper proposes a novel fully automatic extrinsic calibration method for LiDAR-camera systems that circumvents the need for corresponding point registration. In our approach, a novel algorithm to extract required LiDAR correspondence point is proposed. This method can effectively filter out irrelevant points by computing the orientation of plane point clouds and extracting points by applying distance- and density-based thresholds. We avoid the need for corresponding point registration by introducing extrinsic parameters between the LiDAR and camera into the projection of extracted points and constructing co-planar constraints. These parameters are then optimized to solve for the extrinsic. We validated our method across multiple sets of LiDAR-camera systems. In synthetic experiments, our method demonstrates superior performance compared to current calibration techniques. Real-world data experiments further confirm the precision and robustness of the proposed algorithm, with average rotation and translation calibration errors between LiDAR and camera of less than 0.05 degree and 0.015m, respectively. This method enables automatic and accurate extrinsic calibration in a single one step, emphasizing the potential of calibration algorithms beyond using corresponding point registration to enhance the automation and precision of LiDAR-camera system calibration.

翻译：在由相机与激光雷达构成的多传感器融合系统中，精确的外参标定对系统长期稳定性和环境感知准确性至关重要。然而，基于提取与配准对应点的方法在自动化程度与精度方面仍面临挑战。本文提出一种新颖的激光雷达-相机系统全自动外参标定方法，无需进行对应点配准。本方法提出一种创新的激光雷达对应点提取算法，通过计算平面点云方向并应用基于距离与密度的阈值提取点云，可有效滤除无关点。通过将激光雷达与相机间的外参引入提取点的投影过程并构建共面约束，避免了对应点配准需求，进而通过优化这些参数求解外参。我们在多组激光雷达-相机系统上验证了本方法。合成实验表明，相较于现有标定技术，本方法展现出更优性能。真实数据实验进一步证实了所提算法的精度与鲁棒性，激光雷达与相机间的平均旋转标定误差小于0.05度，平均平移标定误差小于0.015米。该方法通过单步操作即可实现自动化高精度外参标定，彰显了超越对应点配准的标定算法在提升激光雷达-相机系统标定自动化与精度方面的潜力。