A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF IMPACT CONTROL FOR MANIPULATORS

This article describes a simple control strategy for stable hard-on-ha rd contact of a manipulator with the environment. The strategy is moti vated by recognition of the equivalence of proportional gain explicit force control and impedance control. It is shown that negative proport ional force gains, or impedance mass ratios less than unity, can equiv alently provide excellent impact response without bouncing. This resul t is indicated by an analysis performed with an experimentally determi ned arm/sensor/environment model. The results are corroborated by expe rimental data from implementation of the control algorithms on the CMU DD Arm II system. The results confirm that manipulator impact against a stiff environment without bouncing can be readily handled by this n ovel control strategy.