Collision avoidance method of humanoid robot with arm force

This paper describes a collision avoidance method of the biped robot with the upper body. We propose the method that the robot stops in front of an obstacle by generating arm force. When the robot detects the obstacle by the arm tip, it should stop short of the obstacle in order to avoid crush. Hence, in this paper, we propose the method of trajectory planning with the arm force. The arm force is generated as a function of the distance from the robot body to the obstacle. The closer the robot approaches to the obstacle, the larger the arm force becomes. When the obstacle is unmovable, the robot can stop with exerting arm force. If it is movable, the robot continues walking with pushing motion. Linear inverted pendulum mode (LIPM) and orbital energy are introduced. We add the dynamics of the arm force to LIPM and orbital energy. The index of orbital energy implies the limit to recognize whether the robot can stop or not at the moment of contact.