Distributed memoryless detection and accommodation of unknown time-delayed interaction faults in a class of interconnected nonlinear systems

This paper addresses a memoryless design problem for the distributed fault detection and accommodation (FDA) of a class of large-scale nonlinear systems in the presence of nonlinear interaction faults with unknown time delays. Existing works designed distributed FDA schemes without considering interaction delays. However, we consider these delays, design distributed memoryless detection estimators and time-varying thresholds for detecting unknown time-delayed interaction faults, and analyze the distributed fault detectability. Then, an approximation-based distributed fault accommodation scheme which is independent of time delays is constructed via Lyapunov stability theorem. Thus, it is shown that all signals of the total controlled closed-loop system are uniformly ultimately bounded and tracking errors of subsystems converge to an adjustable neighborhood of the origin. Finally, a simulation example is presented to show the effectiveness of the proposed methodology.