On the position/force control of robot manipulators with model uncertainty and random disturbances

This paper first investigates the force tracking performance by impedance control subjecting to model uncertainties and random external disturbances. A simple joint impedance/direct control structure is then proposed. The resulted controller has higher robustness to the environment and model uncertainties, and external disturbances. Furthermore, it does not require to switch the control modes for all task executions. Therefore, the proposed control structure combines the advantages of both the hybrid position/force control and the impedance control. Computer simulations are performed to verify the analysis of the impedance control and the effectiveness of the proposed control structure.