Coordinated path planning for autonomous ground vehicles in off-Road environments with 3D rigid terrain and obstacles

Generating safe, smooth, and efficient path is a fundamental and difficult task for autonomous ground vehicles (AGVs) in off-road environments with 3D rigid terrain and obstacles. In this paper, a coordinated path planning approach is proposed to deal with the influence of off-road terrains and obstacles systematically for the path planning of AGVs. The proposed approach consists of integrated traversable area assessment (ITAA) layer and path planning and path optimization (PPPO) layer. In the ITAA layer, a hierarchical map model is established to solve the problem of difficult off-road terrain evaluation in path planning. Based on the hierarchical map, we evaluated the slope, maximum height difference, and roughness of the off-road terrain. In addition, we also model the vehicle's motion capabilities on off-road roads, including off-road vehicle pose estimation, longitudinal stability analysis, and static stability analysis. For the PPPO layer, a reference path generation method considering terrain is proposed to generate a passable reference path that meets the vehicle's kinematic constraints and static stability requirements. Based on the generated reference path, a path optimization method based on a differential flat model is proposed to generate the optimal path, where a safe driving corridor method is established to ensure the safety of the vehicle. Finally, the proposed coordinated path planning approach is validated in both simulations and real-vehicle, and experimental results demonstrate that the proposed system can plan a feasible path fast with the constraints from vehicle kinematics, obstacle avoidance and off-road terrains.