Nonfragile H∞ fault detection for fuzzy discrete systems under stochastic communication protocol

In this article, considering one type of fuzzy discrete-time networked control systems (NCSs) under stochastic communication protocol (SCP), a fuzzy-based nonfragileH(infinity)filter is developed to detect the subsistent fault signal. The Takagi-Sugeno (T-S) mathematical model is employed to approximate the nonlinearities in the concerned fuzzy NCSs. The SCP is adopted to decide which sensor gets the access to the communication network at certain time instant, and the scheduling model of which is constructed as a Markov chain. Taking into account that the filter gain parameters in real practice may suffer fluctuations during the implementation, a modified nonfragile fuzzy filter is designed to detect the fault occurred in the signal transmission. By using the strong centralized stochastic analysis technique and the matrix calculation method, a Lyapunov function is adopted to derive sufficient conditions under which the filtering error dynamics is stochastically stable and the H-infinity performance is satisfied. Then, the desired nonfragile fuzzy fault detection filter is realized by solving a certain linear matrix inequality. Finally, the effectiveness of the develop fault detection scheme is verified in the simulation example.

Automated summary

This article develops a fuzzy-based nonfragile H-infinity filter for detecting fault signals in a fuzzy discrete-time networked control system (NCS) under stochastic communication protocols. The Takagi-Sugeno mathematical model is used for approximating nonlinearities in the system. By utilizing a centralized stochastic analysis technique and matrix calculation method, a Lyapunov function is employed to derive conditions for stochastically stable filtering error dynamics and H-infinity performance satisfaction. Ultimately, a nonfragile fuzzy fault detection filter is implemented by solving a linear matrix inequality.