초록 ▼

A method and system for detecting engine misfire in an internal combustion engine. A data signal containing a plurality of groups of data points generated from sampling crankshaft rotational displacement over three pre-determined angular sampling windows; is generated. Each of the plurality of group

A method and system for detecting engine misfire in an internal combustion engine. A data signal containing a plurality of groups of data points generated from sampling crankshaft rotational displacement over three pre-determined angular sampling windows; is generated. Each of the plurality of groups of sampled data points represents a cylinder firing event. The data signal is conditioned, and the plurality of groups of sampled data points are, mapped into single misfire data points. The mapped single misfire detection points are then compared to a misfire detection dynamic threshold, and a misfire detection signal is output if the misfire detection points fall outside the dynamic threshold. The misfire detection system achieves high degree of accuracy through a multi-stage signal conditioning, multi-rate signal processing and statistical decision technology and a mixed size of window sampling strategy, and is capable of being installed on a large scale in motor vehicles through use of existing on board automotive microcontroller technology.

대표청구항 ▼

[ What is claimed is:] [1.] A motor vehicle internal combustion engine misfire detection system, comprising:a crankshaft velocity sensor that senses velocity of a vehicle crankshaft based on medium data rate crankshaft sampling and that generates a corresponding engine speed signal;a manifold pressu

[ What is claimed is:] [1.] A motor vehicle internal combustion engine misfire detection system, comprising:a crankshaft velocity sensor that senses velocity of a vehicle crankshaft based on medium data rate crankshaft sampling and that generates a corresponding engine speed signal;a manifold pressure sensor that senses manifold absolute pressure (MAP) and generates a corresponding manifold absolute pressure signal;a signal processor that extracts average and fluctuation signal components from said engine speed and MAP signals for detecting both engine normal fire and misfire cylinder firing events;a decimator that, for a medium data sampling rate with M points sampled per cylinder firing event, where M is a positive integer greater than one, maps every M points into one mapped data point for misfire detection processing;a dynamic decision sub-system that determines, from said mapped data points, if said signal represents an engine misfire cylinder firing event or an engine normal fire cylinder firing event and that generates an output signal indicative thereof, said dynamic decision subsystem comprising a running mean estimator that generates a mean output of said normal and misfire cylinder firing events, and a running deviation estimator that generates a deviation output of said normal and misfire cylinder firing events; anda dynamic threshold generator that updates the dynamic threshold of said subsystem based on outputs of said running mean and deviation estimators.