抄録
Compliance control is one of the most effective control methods for manipulators in contact with their environments. In the present paper, we argue that kinematic redundancy of the manipulators should be positively utilized in terms of the compliance control. Although it is widely recognized that redundancy represents a key towards design, control and task planning of more versatile manipulators, no previous investigations of the compliance control have taken account of advantages of kinematic redundancy.
This paper proposes a new method called multi-point compliance control which is able to regulate the compliance of several points on the manipulator's links as well as the end-point compliance utilizing kinematic redundancy. First of all, we define those points on the manipulator's links as vitrual end-points, and formalize kinematic relationships between the joint compliance and the virtual end-point compliance. We then point out that the joint redundancy of the manipulator decreases as the number of the virtual end-points is increased, and the manipulator finally becomes over-constrained. The method presented here can give the optimal solution for both the redundant and over-constrained cases and can assign the order of priority to each end-point according to the given task. Finally, it is shown that the multi-point compliance control can regulate compliance of the virtual end-points for obstacle avoidance while controlling the actual end-point compliance for the given task.
