Patent ID: 6062071
Filing Date: 2000-05-16
Classification: F02D,G01P

Abstract:
A method for detecting combustion misfires in a multi-cylinder internal combustion engine by evaluating a rotational speed of a crankshaft, which comprises the following steps:measuring segment times required by a crankshaft to pass through prescribed angular ranges during working cycles of individual cylinders;correcting the segment times by a correction factor including mechanical tolerances of a rotational speed pickup;calculating unsmooth-running values from the corrected segment times;comparing the unsmooth-running values with a threshold value and registering a combustion misfire if the threshold value is exceeded;impressing an interference variable in dependence on an operating state of the internal combustion engine and taking a rotational speed influence caused by torsion vibrations of the crankshaft into account; andcarrying out the impression of the interference variable with an additional correction of the segment times by cylinder-specific correction factors for the segment times.