Comparison Of Robot Force-Control Methods

Abstract

Four different methods of robot force control–explicit, implicit, stillness, and impedance–are compared quantitatively by simulation. Criteria and coat functions weighing these criteria were formulated. Three models were selected and used in the simulations: a simple, one-degree-of-freedom single rigid-link manipulator, a flexible link, and a macro-micro configuration. For all three systems, the performance of the impedance control method was most satisfying with respect to the chosen criterion. The flexible-arm system yielded better results than the rigid-arm model, owing to "softening" of the interaction with the environment. In combined tracking and force-applying tasks the macro-micro configuration with impedance control resulted in the best performance–especially for hard-to-follow surfaces–owing to the agility of the configuration and its ability to adapt itself to varying interaction conditions.