On the influence of Filter Choice in Output-Feedback MRAC during Adaptation Transients

The choice of the filter in output feedback MRAC (with plant order greater or equal to two) is considered. This choice is shown to have a potentially significant effect on the performance of the adaptive control loop before adaptation has finished. Thus, a good choice of the filter dynamics in MRAC is beneficial for transient performance. This paper proposes an assessment of a given filter choice based on an L2-gain analysis, using known results from the robust control literature. The assessment of different filter dynamics is thus achieved, and a comparison between filter dynamics is made possible. This approach is applied to the adaptive position control of a throttle plate.