In collaboration with Payame Noor University and the Iranian Society of Instrumentation and Control Engineers

Document Type : Research Article

Authors

1 Engineering Faculty, Electrical Department, Ferdowsi University of Mashhad, Mashhad, Iran.

2 Department of Electrical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran.

Abstract

In this paper, we present an event-triggered fault-tolerant control framework for nonlinear affine multi-agent systems, together with a state-observer–based fault detection scheme. The proposed approach integrates an event-triggered controller that reduces communication and computation while guaranteeing closed-loop stability, with a robust fault-detection mechanism capable of identifying sensor faults, including current-sensor faults, under bus and load disturbances, and leveraging sensor redundancy to enable rapid recovery. A rigorous stability and robustness assessment based on eigenvalue analysis of the observer matrix is complemented by extensive MATLAB simulations that demonstrate resilience to parameter variations and external disturbances. Open-loop analyses under unconventional inputs reveal high sensitivity to fault types while exhibiting insensitivity to load disturbances, underscoring the detector’s discriminative capability. To mitigate startup and transient effects, a low-pass filter is implemented at the detector output, reducing transients and improving fault-detection accuracy for real-time identification of current sensor faults. The overall results show reliable fault detection, rapid recovery, and maintained performance in the presence of sensor faults and load disturbances, thereby enhancing the robustness of nonlinear affine multi-agent systems.‎

Highlights

    •  Introduces an Event-Triggered Fault-Tolerant Control (ETFC) framework with a state-observer–based fault detector for nonlinear affine multi-agent systems, enabling rapid recovery via sensor redundancy.
    • Affine nonlinear multi-agent dynamics with parameter variations; observer integrated into an event-driven control loop; Direct Torque Control (DTC) to handle nonlinearity; low-pass filter to reduce transients.
    • Detects step, gradual, intermittent, and three-sensor faults; robust under bus/load disturbances; discriminates faults from disturbances.
    • Replace faulty sensors with backups to swiftly restore pre-fault operation and maintain stability.
    • Eigenvalue analysis shows inherent stability; diagnostic accuracy remains under significant parameter changes; open-loop tests indicate insensitivity to loading disturbances.
    • ETFC reduces communication/computation without sacrificing safety or detection; transients are filtered to preserve fault discrimination.
    • MATLAB results confirm robustness to parameter variations and disturbances; faults are reliably identified and classified.

Keywords

Main Subjects

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