Rough Terrain Motion Planning for Actuated, Tracked Robots

Traversing challenging structures like boulders, rubble, stairs and steps, mobile robots need a special level of mobility. Robots with reconfigurable chassis are able to alter their configuration to overcome such structures. This paper presents a two-stage motion planning scheme for reconfigurable robots in rough terrain. First, we consider the robot’s operating limits rather than the complete states to quickly find an initial path in a low dimensional space. Second, we identify path segments which lead through rough areas of the environment and refine those segments using the entire robot state including the actuator configurations. We present a roadmap and a RRT* method to perform the path refinement. Our algorithm does not rely on any detailed structure/terrain categorization or on any predefined motion sequences. Hence, our planner can be applied to urban structures, like stairs, as well as rough unstructured environments.