A Design Method of Model Reference Adaptive Control System Using Relay Elements

Abstract

This paper proposes a design scheme of a model reference adaptive control system (MRACS) using relay elements for single-input single-output linear systems. So far, many papers have been reported concerning MRACS. However, we still do not have “good” parameter adjusting law from the practical view point. For example, an adjusting law with simple structure has extremely bad converging properties and a good converging adaptive law is very complex. The aim of the proposal of MRACS method using relay elements is to improve these situations. The method essentially depends on the characteristics of the relay control systems, which have fast responses and simple structures.
The scheme proposed here uses relay elements to generate the identifying error signal and input signal. The advantage is that the scheme does not necessarily require a priori knowledge of the range of unknown parameters. In addition, the proposed system has the robust performance to the presence of external disturbances.
The boundedness of signals and convergence of the output error are proved. Computer simulation results are presented to illustrate the effect of this design method in Chapter 4.