Sliding Mode Observer for Internal Combustion Engine Misfire Detection.

A nonlinear model representing the chamber internal pressure dynamics gathered by means of the ideal gas behavior is used for misfire detection. This model shows that the misfire phenomena is an actuator fault. The use of the pressure variable is the key to achieve a reliable misfire detection. The pressure dynamics are in terms of the crankshaft angle, which is regarded as the independent variable. A sliding mode observer is used as a residual generator for the detection scheme, and it is shown that misfire detection can be accomplished by such method.