Optimal Fault-Tolerant Control for Large-Scale Interconnected Systems With State Constraints

Abstract

Guaranteed system performance under various circumstances continues to be a challenge in technique and practice. Based on this, this article investigates the optimal fault-tolerant control strategy for a large-scale interconnected system with the intermittent actuator faults. Since the subsystem state is enforced to a restricted range, an asymmetric integral barrier Lyapunov function is incorporated into the principle of Bellman optimality to avoid the violation of state constraints. Also, it can conquer a conservative limitation that the bounds of the transformed error-constraints are known. Subsequently, the critic-actor–identifier framework is constructed in the backstepping step to evaluate the objective function, control behavior and unknown dynamic, respectively, wherein the decentralized controller derived from the learning process and the fault-tolerant controller are separated by introducing an intermediate controller. Meanwhile, it is illustrated that the trajectory tracking errors will approach to a small region nearby the origin, and the system states may not beyond the given asymmetric constraint bounds, even in the presence of faults. Finally, results are presented to exhibit the effectiveness and the advantage of the optimal approach through appropriate comparative simulations.