Foothold placement planning with a hexapod crawling robot

In this work, we concern the problem of motion planning for a hexapod walking robot crawling in a semi-structured environment where a precise foot-tip positioning is necessary. We propose pipelined approach utilizing an RGB-D camera to perceive and map the forthcoming terrain in 2.5 D which is then processed for available foot-tip positions. The robot motion control is based on sampling-based planning to determine the most suitable leg supporting configurations for the individual body positions in the created terrain map. The individual body positions are connected into a roadmap with taking into account a feasibility of the robot transition between the individual configurations. The resulting trajectory is then planned in the created roadmap using a standard A* planner. The proposed method has been experimentally evaluated in the on-line and onboard setup with a real hexapod crawling robot. The herein reported results support feasibility of the proposed approach for a precise motion planning of small hexapod crawling robot in a semi-structured environment.