Design of Adaptive Finite-Time Fault-Tolerant Controller for Stochastic Nonlinear Systems With Multiple Faults

In this paper, the adaptive fault-tolerant control (FTC) problem is addressed for the stochastic nonlinear systems with multiple faults. The multiple faults, including the actuator and abrupt system faults, are first discussed in the same theoretical framework. The unknown nonlinearities are approximated by multi-dimensional Taylor networks (MTNs). By taking advantage of backstepping technique and finite-time control, the actual control law and virtual control signals are constructed, and then a novel adaptive FTC scheme based on the finite-time control method is proposed. The proposed controller guarantees that the closed-loop system is semi-global finite-time stable in probability (SGFSP) and the tracking error converges to a small neighborhood around the origin in the finite-time. Lastly, three examples are given to illustrate the effectiveness of the proposed scheme. Note to Practitioners-This research is motivated by the fact that actuators faults exist widely in real applications, which often degrade the control accuracy of the system and even result in the system instability. So far, the actuator and abrupt system faults of the stochastic nonlinear system have not yet been considered under the same theoretical framework. Therefore, this study designs a new MTN-based adaptive finite-time FTC scheme, which can ensure that the closed-loop system is SGFSP. The proposed control scheme has excellent practical value.

IEEE Transactions on Automation Science and Engineering