An online gait planner of hexapod robot to safely pass through crowded environment based on tactile sense and virtual dynamic model

A major problem for a mobile robot aiming to work with people is how to move safely in a crowded environment where the robot-human contact is inevitable. However, most existing solutions focus on finding a collision-free path. Moreover, few of them considers the legged robots, which are believed to find wide applications in human daily life due to their superior mobility in complex artificial environments. In this paper, we propose a novel tactile-based gait planning method for a hexapod robot to pass through crowds in a safe and stable manner. Firstly, we developed a body trajectory generator based on a virtual dynamic model with actual contact force feedback. Then, we developed a leg trajectory planner by taking into account the ZMP stability criterion. In such a way, the contact force can be actively controlled and the stable tripod walking can be realized. We verify our method in simulations and then implement it on the real robot, HexbotIII, for experiments. The experimental results show that with our method the robot can effectively bypass moving humans while regulating the contact force in a safe range.