Hybrid output controller for parametrically uncertain systems with matching harmonic disturbances rejection

We cope with the task of output feedback stabilization of a parametrically uncertain linear plants of arbitrary relative degree under the matching harmonic disturbances of unknown frequency ω. Advancing the previously obtained results for the hybrid “consecutive compensator” controller, we present two different event-based switching algorithms incorporating only current measurements of the system output. These algorithms are needed for iterative substitution of the disturbance frequency estimations ω(t) to the feedback. It was shown that the proposed controller guarantees system invariance with respect to the external disturbance for ω(t) = ω. Simulation results bring out provided advantages of the proposed approach.