Diagnosis of individual Cylinder Misfires by Signature Analysis of Crankshaft Speed Fluctuations

This paper describes the development of diagnostic algorithms for the detection of misfiring cylinders in an internal combustion engine. The algorithms are applied to a measurement of engine angular velocity obtained by means of an inexpensive nonconlacting sensor, and are broadly applicable to many classes of internal combustion engines, including spark and compression ignition engines.

The computational efficiency of the algorithms is such that the onboard implementation of these diagnostic procedures is certainly feasible with currently employed microprocessors.

Experimental work conducted on production vehicles has confirmed that it is possible to apply these algorithms with minimal hardware and computational overhead.