Friction free bilateral robot based on twin drive control system considering resonant frequency

This paper proposes a new friction free bilateral robot based on twin drive control system considering resonant frequency. The twin drive system consists of two motors, which are coupled by the differential gear. The output torque becomes a different torque of both motors. The nonlinear friction torque of twin drive system can be easily compensated. However, as this system is constructed by the planetary gear and the differential gear, this system has the mechanical resonant frequency. Hence, it often has the tensional vibration. In order to overcome this problem, this paper proposes a new two-mass-model of twin drive system, and identifies these mechanical parameters and the friction torque. Moreover, this paper realizes a fine friction free bilateral control system considering its resonant frequency.