A 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 systems. The feature of the proposed method is the use of H^∞ optimal theory for the 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. The proposed method was applied to motor speed control to illustrate its effectiveness. Simulation results show that a controller satisfying the specification can be designed easily