Friction free force-reflecting type bilateral control based on twin drive system considering 2nd resonant frequency and unbalance friction

This paper proposes a new friction free bilateral system based on twin drive control system considering it's resonant frequency. The twin drive system consists of two motors that are coupled by the differential gear. The output torque becomes a differential torque of both motors. The nonlinear friction torque of the twin drive system is easily compensated. However, this system has the resonant frequencies and the anti-resonant frequencies which are caused by the torsional vibration. This paper proposes a new three-inertial-model of twin drive system, and identifies the resonant frequencies and it's friction torque. The proposed controller can suppress the torsional vibration without high order control design. Therefore, the operationality of bilateral teleoperation is improved by the proposed system.