Application of extension theory in misfire fault diagnosis of gasoline engines

A misfire fault diagnosis method in gasoline engines is proposed by extension theory. The extension diagnosis method is based on the matter-element model and extended correlation function for the misfire fault diagnosis of gasoline engines. First, the matter-element models of the engine fault are built according to diagnostics derived from specialists’ knowledge of practical experience and then, the fault types of misfire in engines can be directly identified by relation indices. The validity and reasonability of the proposed method is verified by the experimentation of EQ6102 engine. Diagnosis results show that the proposed method cannot only diagnose the main fault types of engines and can also detect useful information for future trends by the relation indices. This fault diagnosis method is easier and more practical than other traditional AI methods. Therefore, it will be favorable to diagnose the engine fault.