Position feedback in force control of industrial manipulators - An experimental comparison with basic algorithms

This paper investigates simple position based force control algorithms for an industrial robot. A lot of approaches to robot force control published in the previous three decades are difficult to implement in commercial robot controllers. This fact is one reason why force controlled robots rarely appear in industrial applications. On the other side force control may improve some robot tasks like automated assembling or material processing. Therefore, is seems to be necessary to concentrate on simple controller structures on the field of robot force control which are easily realizable and adjustable. For this purpose in this paper linear standard control algorithms have been selected and implemented with a real robot. One proposed structure is the proportional controller with positive position feedback which dealt probably here for the first time and shows very good control behavior. Some proposals to parameterization of different controllers are given and their performance with respect to contact detection, impact and response to setpoint changes is shown and compared by practical experiments.