Feedback Control Based on a Sequential Observer-predictor for Systems with Unknown Actuator Delay

The present work is devoted to the stabilization of linear systems with input delay, where the delay value can be arbitrarily long with respect to the system response. The time-delay is considered unknown or incorrectly modeled. A sequential observer with variable time-delays is designed in order to predict the system states before the delay occurs. The delays in the sequential observer-predictor are updated by means of a delay estimation in order to obtain an accurate state prediction. The stability of the closed-loop system and the convergence of the observers are analyzed by considering the separation principle. Numerical simulations are performed to evaluate the proposed sequential observer-controller under different scenarios.