A Strategy for Large Workpiece Assembly Based on Hybrid Impedance Control

This paper proposes a novel strategy for large workpieces assembly task based on hybrid impedance control algorithm. It is ineluctable for the manipulator's end-effector to track a desired trajectory with errors resulted from uncertain conditions during assembly process, so hybrid impedance control algorithm is widely used to ensure a smooth assembly. It's difficult to analyze the contact states and extra contact moment caused by contact force is not conducive to the smooth insertion for the large workpiece. In the introduced strategy both compliant motion and direct force control are achieved during insertion to ensure that the workpiece is in a uniform surface contact with the slot. Then the active compliance center is computed on-line and updated dynamically to minimize the extra contact moment. The strategy is capable of generating satisfactory compliant motion control with a stable contact state, which can also avoid an excessive force. To evaluate and verify the feasibility of proposed approach, a set of numerical experiments have been carried out by MSC ADAMS (R)/SIMULINK (R) co-simulation.