Adaptive Robust Impedance Control of Haptic Systems for Skill Transfer

This paper aims to develop the impedance control structure of a dual-user haptic training system for the application of surgical training. Through the proposed structure, the process of skill transfer from the trainer to the trainee is considered through automatic transformation of impedance coefficients, based on the evaluation of the trainee’s performance and its adaptation to the trainer’s behavior. The similarities between the position of the trainer and the trainee are examined in a time window to generate the base structure for varying impedance coefficients. In presence of modeling uncertainties, the proposed impedance controller is capable to enforce two reference impedance dynamics for the trainer and the trainee. In the proposed control structure, a high-gain observer is used to satisfy force demands without requiring expensive sensors. The input-to-state stability (ISS) of the dual-user haptic training system is analyzed in details. Finally, verification of the effectiveness of the presented structure is reported through computer simulations.