Path and posture planning for walking robots by artificial potential field method

Most of studies on path planning assume a wheeled robot as the vehicle. However, the robot is allowed to only make a detour for obstacle avoidance that often includes inefficiency. This research focuses that a walking robot has a high adaptation on irregular terrain and ability to transform the robot posture during walk. Therefore, the walking robot follows an efficient path in a three-dimensional complex environment in which a wheeled robot cannot do. In order to obtain an efficient path, we notice that the appearance of obstacles depends on the robot's body height and lateral foot breadth. For example, the walking robot avoids under overhead obstacles by crouching and pass as if there are no low level obstacles. When crouching, the robot should react to low-level obstacles as if they are high-level obstacles because the maximum lift of robot's foot is restricted by the crouch position. At the same time, low obstacles should be taken up as though higher obstacle because maximum lift of foot is restricted by the crouching posture. By such property, virtual obstacle, which is defined depended on robot posture, is defined. This paper presents path and posture planning method with the virtual obstacle. Finally, the method is verified by some experiments.