Improving disturbance-rejection performance based on an equivalent-input-disturbance approach

This paper presents a new method of improving the disturbance-rejection performance of a servo system based on the estimation of an equivalent,input disturbance (EID). First, the concept of EID is defined. Next, the configuration of an improved servo system employing the new disturbance-estimation method is described. Then, a method of designing a control law employing a disturbance estimate is explained. Finally, the speed control of a rotational control system is used to demonstrate the validity of the method, and some design guidelines are presented.