Sensor-less torque control considering contact phase for two-mass system

Abstract

This paper considers the contact phase in a sensorless torque control system for a two-mass system. A plant system is a two mass system with an environmental switch. The environmental switch is used for considering unstable contact behavior. The state observer (SOB) and zero-order disturbance observer (ZODOB) are used to estimate the state variable of a plant system. In sensor-less torque control system, the ZODOB has better performance than the SOB. When plant system is not in contact with the environment the estimated value using the SOB is not good for control system. It makes control system becomes instability in some cases. When the ZODOB is fed back to torque control system, the stability of control system is preserved. Experiments are performed to confirm the effectiveness of using the ZODOB in sensor-less torque control system.