Reduced‐order robust nonlinear sliding mode fault‐tolerant control for linear systems with disturbances: A prescribed practical sliding surface approach

This article studies the fault‐tolerant control for linear systems with disturbances through sliding mode scheme. Compared with the existing results, by means of a nonlinear sliding function with an exponential term, a reduced‐order sliding motion can be obtained while the reaching phase of conventional sliding mode control is eliminated. On the other side, with the help of an exponentially decaying barrier Lyapunov functions, a continuous sliding mode algorithm is established. Within the proposed framework, the trajectories of closed‐loop systems can be forced to a prescribed practical sliding surface, and then, both the transient as well as steady‐state performances are guaranteed despite the occurrence of abrupt actuator faults. Under the Lyapunov direct method, a sufficient condition is derived such that the sliding motion is uniformly bounded with time‐varying performance constraints. Finally, an electric amplidyne system is considered to demonstrate the theoretical results.