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.