| 摘要 |
A system and method compensates for systematic irregularities in measured engine velocities caused by torsional flexing in the crankshaft during rotation to improve the accuracy of misfire detection. The present invention compensates for irregularities in "Profile-Ignition-Pick-Up interval" (PIP interval) timing. These irregularities are systematic with respect to different engine cylinders. The present invention is configured to function with a processor unit. Correction factors for each of the n PIP intervals of an engine cycle are generated for each of a multitude of engine operating conditions, where n is the number of cylinders in the engine. Each set of n generated correction factor is stored in a table (a "look-up table" located in a memory unit) having a corresponding unique address location. This table is typically determined empirically in the calibration of the engine type by a test engine. The correction factors are generated while the test engine is rotated at a fixed steady state operating point with combustion, where the operating point is typically a particular speed and load.
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