Abstract
A linear servo system of the present can let the output of the controlled object follow to the desired value stably in case that the desired values and disturbances belong to the output of linear time invariant system by using the internal model principle. But the desired values are limited to the output of the invariant system, and the modes of the system must be known previously. So there is the great limitation for following signals in a linear servo system of the present. On the other hand, it is possible for MRACS (model reference adaptive control system) which has developed in recent years to let the output of the controlled object follow to the output of the reference model which has an arbitrary input signal. But there is no enough countermeasure for disturbances in MRACS. In this way the advantage and the disadvantage of a linear servo system and MRACS are compensated with each other. So this paper presents the design of the linear servo system which can let the output of the controlled object follow stably to the output of the following model to have an arbitrary input signal in the case that unknown step disturbances enter into the controlled object by using advantages of a linear servo system and MRACS. In the proposed method to separate the whole system into a steady state system and a transient system, state variable filters are used for the steady state system in order to nill the stationary error, and the augmented system is set for the transient system in order to take off the influences of step disturbances and initial values by the stabilization of the augmented system.
