Force Control of One Link Flexible Arm with Contact Motion to Environment.

This paper considers the problem to design force control of a one-link flexible robot arm with contact motion to an environment. Our purpose is to design a controller to realize the smooth transition from the free space to the constraint space without changing controllers. The controller consists of both the force control system and the additional compensators. The force control system based on the model following servo system is designed with consideration of the arm elasticity. The additional compensators are given by a stabilizing compensator and an approach velocity compensator. The former is based on a strain feedback to suppress elastic vibration in approach motion. The latter is based on an angle feedback to control the approach velocity. Then two compensators also realize to suppress the contact force. Some experimental results show the effectiveness of the proposed controller.