An engine misfire detection method, device and system

Abstract

The invention provides an engine misfire detection method, device and system, and the method comprises: an obtaining step: obtaining first data detected by a crankshaft sensor in an engine and currentdata detected by a knocking sensor in the engine; a passing time calculation step of calculating respective passing time of a plurality of cylinders in the engine according to the first data; a misfire judgment parameter calculation step: calculating the kinetic energy difference between the current cylinder and other air cylinders in the plurality of cylinders according to the passing time, andtaking the maximum kinetic energy difference as a misfire judgment parameter; a filtering parameter calculation step of calculating current filtering data according to the current data and historicalfiltering data; and a misfire judgment step: judging that the current cylinder is misfire when the misfire judgment parameter is greater than or equal to a first threshold value and the current filtering data is less than a second threshold value.

Description

technical field [0001] The invention relates to an engine misfire detection method, device and system. Background technique [0002] On-line misfire diagnosis has a significant impact on the safety of engine operation and exhaust emissions. Inaccurate misfire detection will lead to failure to detect gasoline engine fire in time and increase the emission of harmful gases. Therefore, it is of great significance to realize accurate engine cylinder misfire detection to reduce exhaust emissions and air pollution. [0003] Usually, the judgment of misfire failure can be realized through the engine cylinder pressure sensor or the crankshaft sensor. Although the cylinder pressure sensor has high detection accuracy, due to its high cost and short life, the crankshaft sensor is generally used in mass-produced engines to achieve misfire detection. [0004] In Chinese patent CN200610093868, a misfire detection method based on a crankshaft sensor is disclosed. Based on the combustion...

AI Technical Summary

Problems solved by technology

However, if two or three cylinders of the engine misfire consecutively, the misfire cannot be detected because the time difference between the two misfired cylinders may be less than the threshold

In addition, due to the severe cylinder time difference when passing through bumpy roads, continuous cylinder misfires may also be mistaken for bumpy roads, and misfires cannot be detected.

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