Adaptive internal model control with reference input predictor for time-delay systems

A new adaptive two degrees-of-freedom internal model control (IMC) with reference input predictor is presented for systems with unknown time delay. The proposed controller consists of a reference input predictor, a model reference controller, a disturbance rejection controller and an internal model predictor. The unknown time-delay and the rational transfer function of continuous-time systems are simultaneously estimated by using the modified least-squares with projection. One feature of the proposed algorithm is that its structure is integrated with an online parameter estimation algorithm to form an adaptive IMC with a reference input predictor. Simulation results demonstrate the effectiveness of the proposed control scheme.