Fault detection for nonlinear systems with uncertain parameters based on the interval fuzzy model

In the paper an application of the interval fuzzy model (INFUMO) in fault detection for nonlinear systems with uncertain interval-type parameters is presented. A confidence band for the input–output data, obtained in the normal operating conditions of a system, is approximated using a fuzzy model with interval parameters. The approximation is based on linear programming using l∞l∞-norm as a measure of the modelling error. Applying low-pass filtering when obtaining the confidence band makes it possible to use arbitrary sets of identification input signals. An application of the INFUMO in a fault-detection system for a two-tank system is presented to demonstrate the benefits of the proposed method.