A Novel Integrated Fault-Tolerant Control Approach for Uncertain Linear Discrete-Time Systems Under Input Nonlinearity

Abstract

This paper focuses on the challenge of integrated active fault-tolerant control (IAFTC) for linear discrete-time systems utilizing compatible linear matrix inequality (LMI) techniques. The presence of input nonlinearity, additive faults, external disturbances, and uncertainty in the system matrix makes this problem more applicable to real-world systems while expanding the complexity and functional range. In such a situation, the designer must take an integrated approach instead of synthesizing fault estimation (FE) and fault-tolerant control (FTC) as separate modules; yet, the LMI-based design conditions can be overly conservative. As a result, the reduction of the bi-directional interaction effect between FE and FTC units does not lead to satisfactory improvements in the overall behavior of the control system. To provide an integrated design approach, we propose a dynamic output feedback controller that plays the role of the FTC unit. This scheme incorporates two effective decision parameters and a descriptor observer (As FE), contributing to the IAFTC block's functionality. The design criteria are formulated using tractable LMI constraints in a convex optimization problem, and the (Formula presented.) -stability criterion is proved for the overall closed-loop system. The superiority and effectiveness of the proposed IAFTC are demonstrated through three comparative simulation examples. © 2025 John Wiley & Sons Ltd.