Improving transient performance in robotics force control using nonlinear damping

Robotics force control is increasingly being used in the manufacturing industry, to perform surface polishing, deburring, parts mating etc. However, to avoid the high impact force which could damage the workpiece, a common strategy is to command the robot to approach the workpiece slowly, which increases the overall cycle time. In this paper, we propose a nonlinear damping control scheme which reduces the force overshoot without compromising on the dynamic response. The controller design and the parameter tuning are relatively straightforward because of the clear physical meanings of the parameters. Finally, the effectiveness of the proposed controller is verified through simulation studies.