Abstract
Identification of operating mode is a key step in the fault diagnosis of the hybrid systems. The novelty of this paper is the definition of a hybrid observer where discrete event is identified and then continuous model of a sub-system is selected for the design of observer using sliding mode technique. The observer output is finally used for mode identification and fault diagnosis. The proposed method is applied on Spark Ignition (SI) engine for misfire fault detection. The first order sliding mode observer is used to accomplish the task. The mode identification scheme is validated on data generated through hybrid model simulations as well as for data obtained from a 1.3L production vehicle.
