Patent ID: 7503208
Filing Date: 2009-03-17
Classification: B60K,B60W,F02D,F02P,G01M,Y02T

Abstract:
1. An engine misfire detection apparatus that detects a misfire in a plural-cylinder internal combustion engine having a variable ignition timing, said engine misfire detection apparatus comprising: a rotational position detection unit that detects a rotational position of a crankshaft of the internal combustion engine; a rotational fluctuation computation module that sequentially calculates rotational fluctuations at crank angles corresponding to respective ignition timings of the plural cylinders in the internal combustion engine, based on the detected rotational positions of the crankshaft of the internal combustion engine; a rotational fluctuation difference computation module that computes a first rotational fluctuation difference and a second rotational fluctuation difference, where the first rotational fluctuation difference represents a difference between each of the rotational fluctuations sequentially calculated at the corresponding crank angles and a rotational fluctuation calculated at a crank angle prior to each of the corresponding crank angles by a preset first angle, and the second rotational fluctuation difference represents a difference between each of the rotational fluctuations sequentially calculated at the corresponding crank angles and a rotational fluctuation calculated at a crank angle prior to each of the corresponding crank angles by a preset second angle that is different from the preset first angle; and an engine misfire detection module that detects a misfire of the internal combustion engine based on the first rotational fluctuation difference and the second rotational fluctuation difference computed by said rotational fluctuation difference computation module, during a time period from a start of the internal combustion engine to satisfaction of a predetermined condition.