Search

This paper studies the problem of robust sliding mode control (SMC) for a class of nonlinear systems subject to actuator failures and disturbances. By employing a novel integral sliding function constructed with an nested sliding mode controller "ν(t)$$ \nu (t) $$," a dual‐layer sliding mode control is established. The first layer is an integral sliding mode generated by the actuator output, the second one is a linear sliding mode generated by "ν(t)$$ \nu (t) $$." Indeed, the linear sliding mode is nested to the integral sliding mode for the system under consideration. Compared with the state‐of‐the‐art integral sliding mode controls (ISMCs), not only the inherent robustness of ISMC is retained, but also the time derivative of integral sliding function in integral sliding motion dynamics can be compensated by "ν(t)$$ \nu (t) $$," so that the robustness of integral sliding motion is further enhanced. Furthermore, due to the generation of the nested linear sliding mode, it decouples the matched integral sliding function time derivative of integral sliding motion dynamics from the mismatched disturbance. This decoupling facilitates the design of "ν(t)$$ \nu (t) $$" through ℋ∞$$ {\mathscr{H}}_{\infty } $$ control theory, then, the closed‐loop systems are ensured to be asymptotically stable with ℋ∞$$ {\mathscr{H}}_{\infty } $$ performance. Lastly, with two classes of barrier functions exploited for the design of sliding mode controllers, both sliding modes cannot be lost for system responses even in the presence of unforeseen actuator failures and disturbances. In simulation, an IEEE 6 bus power system is offered to demonstrate the superiorities of the theoretical results. [ABSTRACT FROM AUTHOR]

This work investigates the problem of robust sliding mode fault-tolerant control for Takagi-Sugeno (T-S) fuzzy systems with disturbances. By virtue of a nonlinear sliding variable with an exponential decaying term, a reduced-order fuzzy sliding motion is established for the system throughout the entire responses. Since the existence of unforeseen actuator faults and disturbances affects the transient performance of sliding variable, which leads to poor performance of sliding motion system. To mitigate the influences of faults and disturbances on the sliding motion system, a class of positive semi-definite barrier functions is introduced to design controller, which ensures the sliding variable within a prescribed upper bound independent to actuator faults and disturbances. Finally, through the Lyapunov direct method, some sufficient conditions are derived such that the closed-loop system is uniformly bounded with time-vary performance boundary. In simulation part, several examples are given to demonstrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]