Output Control Algorithm for Unstable Plant with Input Delay and Cancellation of Unknown Biased Harmonic Disturbance

We present a new stabilization approach for a linear plant with input delay, parametric uncertainties, and an unknown harmonic disturbance. To solve this problem, we combine the well-known predictor feedback approach with the state observer and adaptive scheme that identifies the frequency of the disturbance. Compared to the existing approaches, the dynamic order of our adaptive scheme is low (equal to three) and the results apply to plants that are unstable, non-minimum phase, and have an arbitrary relative degree.