Decentralized control of cooperative manipulators based on virtual force transmission algorithm

This paper describes a novel approach to control the cooperative manipulators in the grasping motion. In this method, first, the grasping force and accelerating force are calculated at the end-effecters. Then the impedance controller is adopted to calculate the force. Second, the force is resolved from tip to base link so that the rotational force is changed into the torque and the others are given to the next joint. This means that the force is transmitted among joints step by step, and the desired tasks are realized asymptotically. Final, the work space observer is adopted so that the error is corrected in the tip motion response. Using this method, it is possible to realize decentralized control of plural and cooperative manipulators and the control structure is simplified. The proposed method is confirmed by several simulations and experiments