Patent ID: 8739613

Claim:
A method of detecting misfire in an internal combustion engine, the engine having a plurality of cylinders, a corresponding plurality of pistons, and a shaft operatively connected to the plurality of pistons, the shaft having a longitudinal axis about which the shaft rotates, the method comprising: sensing a temporal signature of a lateral displacement of the engine via an acceleration sensor, the acceleration sensor sensing the lateral displacement in at least one direction, the at least one direction being non-parallel relative to the longitudinal axis of the shaft, the acceleration sensor being connected to a control unit, the temporal signature being decomposable into a plurality of frequencies, associated magnitudes, and associated phase angles, each of the plurality of frequencies being associated with a corresponding one of a plurality of orders of the engine; sending a signal corresponding to the temporal signature of the lateral displacement from the acceleration sensor to the control unit; processing the signal with the control unit, the processing comprising: performing a spectral analysis of the temporal signature of the lateral displacement to extract a magnitude of a predetermined frequency, the predetermined frequency being associated with one of the plurality of orders of the engine, the one of the plurality of orders being representative of engine displacement due to in-cylinder pressures; and determining that misfiring in at least one of the plurality of cylinders has occurred based on the magnitude of the predetermined frequency.