Abstract
This paper describes the development of a waist of a human friendly robot. The waist that has 3DOFs installs a collision force suppression mechanism every joint. Also, the whole robot body is covered by air cushion bag. When a collision between an object and the robot occurs, collision force is suppressed passively by the collision force suppression mechanism and the air cushion. Using the robot, collision experiments are conducted and the effectiveness of the collision force suppression mechanism is confirmed.