Design method for control systems with disturbance observers using H^∞ optimal control

This paper proposes a design method for control systems with disturbance observers, and discusses a method for linearization and decoupling of nonlinear system. The feature of the proposal is use of H^∞ optimal theory for two-degrees-of-freedom controller to design control systems with disturbance observers. Therefore not only disturbance observers but also preliminary controllers are designed, and the control systems which are optimum as a whole can be attained. In order to illustrate the effectiveness of the proposed method, it was applied to motor speed control. Some simulation results showed that a controller satisfying the specification can be designed easily.