| With the rapid development of network communication technology, Networked Control Systems (NCSs) which arises out from combination on the traditional control system and communication network have been applied in Scientific Research and industrial production widely. Increasing attention has been paid on the safe and reliable operation of the NCSs. Fault Detection and Diagnosis (FDD) of NCSs has attracted a lot of interest of many scholars. Recently, many achievements have been made on FDD of NCSs in which the control objects are linear. However, many virtual nonlinear characteristics exist in really objects widely; it has important application value on the research on nonlinear NCSs. In this paper, some analyses and study on the fault detection for few kinds of nonlinear NCSs, which have different characters, are developed based on methods of traditional FDD.(1) For a kind of nonlinear NCSs with short time delay, it is modeled based on T-S fuzzy model, at the same time; the short time delay is transformed into a kind of system uncertainty based on the theory of matrix analysis. Then, residual generator is designed using the state observer. Last, the stable condition of the residual generator and method of fault detection based on Lyapunov stable theory.(2) A kind of nonlinear NCSs with short time delay and data packet dropout simultaneously is modeled based on T-S fuzzy model. The whole system is modeled as a asynchronous dynamic system with two cases. Then the residual generator is designed and the stable condition is proved. (3) A kind of nonlinear NCSs with short time delay, system uncertainty and external disturbances simultaneously is modeled based on T-S fuzzy model. The robust residual generator is designed based on the fuzzy states observer. The system is sensitive to the fault of the system but robust to external disturbances, and the system uncertainty can also be overcome partly. Last, the stable condition of system and method of fault detection are given. |
PDF Full Text Request