抄録
This paper discusses the stability of a discrete type of model reference adaptive control system based on the augmented error signal concept and proves that even the simple parameter adjustment law with constant adaptive gain guarantees the asymptotic stability of the output error between the plant and the reference model.
In this paper, first the design method for an adaptive control system to be considered here is explained and it is shown that the parameter adjustment law is described as a nonlinear difference equation. It is then proved that the solution of this equation converges to its equilibrium point with an exponential rate regardless of the magnitude of the plant input and output signals. This fact ensures the plant without zero lying outside the unit circle that the plant input and output signals will become bounded at the steady state and that consequently the plant output will follow the model output. The validity of the above theoretical results has been ascertained by the computer simulation studies carried out for a second order plant.
