On the implementation and performance of impedance control on position controlled robots

This paper discusses the implementation and performance of the impedance control scheme on position controlled robot manipulators. The performance of such impedance controllers is very dependent on the behavior of the underlying position controller. Three different configurations are presented and compared with respect to their ability to follow the nominal impedance equation, as well as their ease of implementation. A very simple method based on the use of additional feedback signals is also proposed as a way of significantly improving the tracking performance of these controllers. Simulation as well as experimental results demonstrating the controller behaviors are presented