Frequency domain design conditions for robust direct model reference adaptive controllers

Presents the design of a robust direct model reference adaptive control (DMRAC) algorithm with focus on the satisfaction of an almost strictly positive real (ASPR) condition in the presence of plant unmodeled dynamics. These unmodeled dynamics are represented as either additive or multiplicative norm bounded perturbations in the transfer function. Frequency domain design conditions for a feedforward compensator have been developed utilizing the so-called Q parameterization. Illustrative examples are presented to validate the algorithm´s use and applicability to control systems with unmodeled dynamics