Dual impedance control with variable object stiffness for the dual-arm cooperative manipulators

This paper proposed the two-loop impedance controllers with variable stiffness (DIVS) for dual-arm cooperative robot grasping a common object interacting with the environment. This approach could be employed to improve force and position tracking performance when dual-arm cooperative robot grasping a common object interacts with the environment. Firstly the couple dynamic mode between the object and dual-arm cooperative robot is constructed to analysis the kinematic and dynamic among them. Secondly the force acted on the object can be decomposed as external force and the internal force based on smallest energy consumption. Moreover the two-loop object impedance with variable stiffness is designed to regulate the external force and internal force. Finally the effectiveness of the proposed strategy and theoretical discussion are proved by simulation results on dual-arm cooperative robot with two 7-DOF manipulators.