Internal force control for cooperating manipulators in consideration for parameters of a grasped object

This paper describes an internal force control scheme for cooperating manipulators under consideration of parameters of a grasped object. In the proposed approach, the parameters of the grasped object are first estimated by using the internal force that is computed from the detected force at each end-effector. Then, the authors also introduce the impedance control and the position command is determined based on the parameters of the grasped object. This makes it possible to realize the position control of the grasped object and the internal force control independently of the unknown parameters of the object. This is one of the remarkable points of this approach. Several numerical results are also shown to confirm the validity of the proposed controller.