Robust adaptive fault detection and diagnosis observer design for a class of nonlinear systems with uncertainty and unknown time-varying internal delay

• Published in: ISA transactions Vol. 131; pp. 31 - 42
• Main Authors: Azmi, Hadi, Yazdizadeh, Alireza
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.12.2022
• Subjects: Adaptive weights; Algorithms; Computer Simulation; Fault Detection and Diagnosis (FDD); Linear Matrix Inequality (LMI); Neural Networks, Computer; Nonlinear Dynamics; Nonlinear Lipschitz systems; Robust adaptive observer; Time-varying delays; Uncertainty; Time-varying delays; Adaptive weights; Linear Matrix Inequality (LMI); Fault Detection and Diagnosis (FDD); Nonlinear Lipschitz systems; Robust adaptive observer
• ISSN: 0019-0578; 1879-2022; 1879-2022
• DOI: 10.1016/j.isatra.2022.05.029

This paper introduces a novel robust adaptive fault detection and diagnosis (FDD) observer design approach for a class of nonlinear systems with parametric uncertainty, unknown system fault and time-varying internal delays. The conditions for the existence of the proposed FDD are obtained based on the well-known Linear Matrix Inequalities (LMI) technique. Using Lyapunov stability theory, the adaptation laws for updating the observer weights and unknown faults estimation are derived based on which the convergence of the state estimation error to zero and asymptotic stability of the error dynamics are proven. Toward this, a new structural algorithm for FDD observer design is also derived based on LMIs. The performance of the proposed method is also investigated while applying to some industrial systems. Simulation results illustrate superior performance of the proposed method for the systems subject to time-varying unknown delays on states, uncertainty in nonlinear system modeling and unknown system faults.