Robust Stabilization and Robust Performance Using Model Reference Control and Modeling Error Compensation

Abstract

A new robust linear controller design method is considered. The robust controller consists of two parts: (1) A conventional model matching feedback which assures that the reference signal to output signal transfer function is identical to that of a given reference model. (2) A conceptually new linear "modeling error compensator which exploits a modeling error signal (based on the plant input and output signals) to enhance both the stability and performance robustness It is shown that for linear SISO system of known order without right half plane zero and arbitrary variation of transer function coefficients within a given bounded set, a modeling error compensator can be designed which guarantees robust stability and an arbitrary small H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> -norm over a given frequency band. We show by example that modeling error compensation can be used to improve the robustness for systems with right half plane zeros as well. The examples further show that the transient response using model error compensation is much better than that using model reference adaptive control.