Coordinated Motion Control of Robot Arms Based on the Virtual Internal Model

This paper proposes an alternative coordinated motion control architecture of robot arms manipulating an object. The motion and the internal force of the object are resolved into the motion of each arm. Each arm is controlled based on the virtual internal model so as to operate in coordination even if geometric errors exist in the robot arms and the object. The virtual internal model is a reference model driven by sensory information implemented in the controller. The proposed architecture will keep the state of the system bounded even if the breakage of the manipulated object occurs. The control algorithm is experimentally applied to the coordinated motion control of two planar robot arms, each of which has three degrees of freedom. The results illustrate the validity of the proposed control architecture.