Fault detection for interval type-2 fuzzy systems with sensor nonlinearities

This paper deals with the fault detection problem for interval type-2 (IT2) fuzzy systems subject to sensor nonlinearities. By using a general observer-based fault detection filter as a residual generator, the fault detection problem is described as a filter design problem. The fault detection filter is designed to guarantee the prescribed H∞ performance level. A decomposition approach is employed to handle the characteristic of sensor saturation. Using Lyapunov stability theory, a novel type of IT2 fault detection filter is designed to guarantee that the fault detection system is asymptotically stable with an H∞ performance. In the design procedure, the parameters of the IT2 filter can be solved by the standard software. The IT2 fuzzy model and IT2 fuzzy filter do not require to share the same lower and upper membership functions. A numerical example is given to demonstrate the feasibility and effectiveness of the proposed method.