Optimal force control of elastic robot with contact motion to environment

This paper presents a control method for the contact motion of the one link flexible arm. Our purpose is to accomplish the smooth transition from the free space to the constraint space without changing control laws at a collision. We design the controller based on the model following servo system with two additional compensators: one is the stabilizing compensation based on a strain feedback, and the other is the approaching velocity compensation based on an angle feedback. In order to improve the force tracking performance, we determine the angle feedback gain so as to minimize the performance index. Some experimental results are presented to show the effectiveness of the proposed controller.