Abstract
This paper discusses the robustness of a class of continuous-time model reference adaptive control systems (MRACS) in the presence of parasitics, where transfer function of the error equation is proper, to be more specific, 1 and adaptive law is integral-proportional type.
First, the linearization and the singular perturbation techniques are introduced to analyze the robustness property and the following conclusion is led. The conventional MRACS remains locally stable in the presence of small parasitics, provided that the internal signal is persistently exciting.
Second, it is shown that above MRACS is superior to the one characterized by an error equation with strictly proper transfer function from a viewpoint of robustness property in the presence of parasitics.
Last, these results are confirmed by simple examples and simulation studies.
