On coordinated control of multiple flexible joint robots holding a constrained object

Abstract

Coordinated control of multiple flexible joint robots holding a constrained object is addressed in this paper. A combined adaptive and robust control scheme, consisting of an adaptive coordinated controller and a robust joint torque controller, is proposed to control simultaneously the motion of the object, the internal force among the robots, the contact force between the object and environment, and the joint torques. The proposed control scheme is developed assuming that all system parameters, including the joint flexibility values, are unknown except for some of their bounds. Stability analysis of the control system shows that with the proposed control scheme, asymptotic motion and force tracking is achieved. Simulation results illustrate the effectiveness of the proposed control method.