Interval Sliding Mode Observer Based Incipient Sensor Fault Detection With Application to a Traction Device in China Railway High-Speed

This paper proposes an interval sliding mode observer (ISMO) and an incipient sensor faults detection method for a class of nonlinear control systems with observer unmatched uncertainties. The interval bounds for continuous nonlinear functions and new injection functions are constructed to design ISMOs. An incipient fault detection framework with newly designed residual and threshold generators is proposed. The detectability is then studied, and a set of sufficient detectable conditions are presented. Applications to an electrical traction device used in China Railway High-speed (CRH) are presented to verify the effectiveness of the proposed incipient sensor fault detection methodology.