Identification and adaptive control of delayed unstable systems

In this paper, we develop a multimodel adaptive control strategy to be applied to delay compensation schemes for unstable systems. The strategy is based on intelligent control and the only requirement about the system is that the delay is unknown but bounded. The proposed approach can be used on any delay compensation scheme increasing the robustness of the system with respect to delay uncertainty. In particular, this paper considers the modified Smith Predictor (SP) for unstable and integrating systems with time-delay proposed by S. Majhi and D. P. Atherton. Simulation examples show the usefulness of implementing this strategy when the delay is unknown, showing that the scheme is capable of stabilizing the system with large delay and the good results obtained in the identification of the delay.