Interval Observer Design for a Class of Nonlinear Time-varying Systems with Application in Fault Detection

Abstract

For systems with unknown inputs or uncertainties, the interval observer requires more relaxed design conditions than the general observer. This paper presents a new design method of interval observer for a class of nonlinear time-varying systems with external disturbances and measurement noise based on the coordinate transformation method. Among them, the disturbance and noise only limit the boundedness. The interval observer design is carried out by time-invariant coordinate transformation when the gain matrix cannot be directly derived. The proposed method is applied to fault detection and the effect of fault detection is improved by optimizing the interval width. The interval observer is validated through simulation examples.