IJCAS

In this paper, an adaptive fault tolerant controller is developed for a class of linear state delay systems against actuator failures. To design the controller, all parameters of the system are considered to be unknown, but the time delay value is assumed to be known. Actuator failures are characterized by some unknown system inputs are stuck at some unknown fixed values and at unknown time instants. The adaptive controller is designed based on SPR-Lyapunov approach for the cases with the relative degrees of one and two. Closed-loop system stability and asymptotic output tracking are proved using a suitable Lyapunov-Krasovskii functional for each case and the effectiveness of the proposed results has been illustrated through simulation studies.

Keywords: Actuator failure compensation, adaptive control, output feedback, time delay systems.