Control method with improved disturbance observer
采用改进型扰动观测器的控制方法

An improved disturbance observer(DOB) is proposed for non-minimum phase systems. In this structure, both the nominal performance controller output and the feedback signal from the system output are dynamically compensated by two additional controllers. Hence, the effect of the external disturbances in low frequency and the model uncertainties in system output are eliminated. Furthermore, the capability in suppressing the high frequency measurement noise is highly improved. Finally, the internal stability and the robust stability of the whole control system are discussed.