High-order estimator for model reference adaptive control of linear time-varying systems

This paper is concerned with a new adaptive tilter design for a linear time-varying systems based on a robust high-order estimator. In order to attain the parametric representation of system, the derivatives of the time-varying plant parameters are needed in unknown parameters of the model. These derivatives are not available in standard estimators. This difficulty is overcome by using the high-order estimator. The sigma-modified high-order estimator ensures that all the estimated parameters are uniformly bounded. Furthermore, a new model reference adaptive control system(MRACS) is also proposed. Finally, the effectiveness of the presented approach is shown in the numerical examples.