Direct pole placement adaptive control for sinusoidal signal tracking

We propose a direct pole placement adaptive control scheme for unknown but open loop stable linear plants with time delays. This controller utilizes the internal model principle to eliminate steady state tracking error for signals with known distinct frequencies. The controller order depends only on the number of frequencies in the reference input, but not on the order of the plant. It is shown that with sufficiently small loop gain, the controller can guarantee stable closed loop, and asymptotic tracking