Control Theory & Systems
Mohammad Zangouei; Naser Pariz; Reihaneh Kardehi Moghaddam
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 ...
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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.
Sayyed Hossein Ejtahed; Naser Pariz; Ali Karimpour
Abstract
Switched linear systems are noted as a major category of control systems. Fault detection of these systems is affected by switching phenomena and therefore their integrated fault detection and robust control (IFDRC) are the central issues of recent studies. Existing studies on IFDRC ...
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Switched linear systems are noted as a major category of control systems. Fault detection of these systems is affected by switching phenomena and therefore their integrated fault detection and robust control (IFDRC) are the central issues of recent studies. Existing studies on IFDRC do not consider the effects of all of the parameter uncertainties, input disturbance, and mode-dependent time-varying state delay in the presence of mode-dependent average dwell time (MDADT) switching together in these systems. To address the issue based on output feedback, in this paper, the IFDRC design problem is formulated as a multi-objective or mixed H∞/H- optimization problem. H∞ performance indicator guarantees the robustness of residual to disturbance, and H- performance represents the sensitivity index of residual to the fault. A piecewise Lyapunov-Krasovskii function is employed together with the MDADT scheme and therefore, sufficient conditions are derived in terms of linear matrix inequalities (LMIs) in order to deal with the problem. Then to clarify the design procedure, we also present an algorithm in the light of the proposed approach. Eventually, to illustrate the efficiency of the suggested approach, the designed IFDRC framework is simulated for a case study of an Electrical Circuit system.
