In this paper, an application of disturbance observers to high speed synchronization of two motion axes is considered. The proposed system consists of two motion axes coupled with a synchronizing controller and two disturbance observers.
First, the effects of disturbance input on the responses of two motion axes coupled with the only synchronizing controller are investigated. Based on the results of investigation, an in-phase disturbance observer and anti-phase disturbance observer are designed and introduced to achieve sufficient robustness and high speed synchronization. Furthermore, a feedforward controller is used to improve the tracking performance. Experimental results demonstrate the effectiveness of the proposed disturbance observers and the feedforward controller for faster removal of the tracking and synchronizing errors.