Model based diagnosis of the air path of an automotive diesel engine

摘要

A model based diagnosis system for the air-path of a turbo-charged diesel engine with EGR is constructed. The faults considered are air mass-flow sensor fault, intake-manifold pressure sensor fault, air-leakage, and the EGR-valve stuck in closed position. A non-linear engine model, with four states, is constructed. The diagnosis system is then constructed in the framework of structured hypothesis tests and by using observers estimating unknown fault-parameters. To handle modeling errors a new method for adaptive thresholds is proposed. The diagnosis system is successfully evaluated in a real car driving on the road.