Retrospective Cost Adaptive Harmonic Disturbance Rejection Using Dereverberated Target Models

The present paper focuses on adaptive feedback disturbance rejection for high-order, lightly damped systems using retrospective cost adaptive control (RCAC). RCAC requires a closed-loop target model, which captures key features of the plant dynamics. In the SISO case, this information includes knowledge of the sign of the leading numerator coefficient, relative degree, and non-minimum phase zeros. The present paper investigates the feasibility of using a deverberated transfer function (DTF) as the closed -loop target model. A dereverberated model of a lightly damped plant captures the magnitude and phase trend but ignores resonances and antiresonances, thus providing a simplified, low-order model of a lightly damped system. The present paper investigates the performance and robustness of RCAC using a dereverberated target model based on the nominal plant model.