Wave-based load disturbance observer for robust enhancement of reflected wave rejection-based vibration control

The researches have been ongoing on various vibration control methods for resonant system. Reflected wave rejection-based vibration control is one of the vibration control for resonant system which considers high order resonances owing to the wave equation. However, the conventional reflected wave rejection-based vibration control does not consider the modeling error in the propagation time of the wave and the effect of the external torque acting on the load side. This paper proposes a wave-based load disturbance observer (WLDOB) for improving robustness against modeling error and the external load torque. The WLDOB is a generalized structure of the arm (load) disturbance observer for a two-mass resonant system which was already proposed in conventional research. Because the load disturbance rejection based on wave-based load disturbance observer includes an inverse system of time delay, the approximated WLDOB is used in this paper for actual implementation. The validity of the proposed method is verified by the simulation and experimental results.