A Design Method of Digital MRACS for Attenuating the Effect of Disturbance
Yoh YONEZAWA, Yukio NISHIMURA, Chen SHUMING
In this paper, a design method of MRACS (Model Reference Adaptive Control System) is propose& for continuous time plants in the presence of slowly-varying disturbance, by which it is possible to make the output error arbitrarily small. Considered that the control law of MRACS is easy to be realized by digital controller, the structure of this paper is composed as follows : First, the continuous time system is transformed to discrete time system by using sampler and zero-order holder, where the effect of disturbance on the plant output is described by a convolution integral.
Next, in order to reduce the effect of disturbance, an integral precompensator is introduced to the sampled system, and an adaptive adjustment law with dead-zone is utilized. as analyzed theoretically, for any reference signals this reaches the results that if a small sampling period is chosen, the influence of disturbance on output can be controlled small.
Finally, that the control system is stable and that the signals of the system are bounded are proved. The effectiveness of the proposed method is illustrated by computer simulations.