Abnormal combustion process detection method of multi-cylinder diesel internal combustion engine

摘要

PURPOSE: The structure-borne noise sensors picks up combustion noises in the individual cylinders to recognize irregularities in combustion processes in a multiple cylinder diesel internal combustion engine. CONSTITUTION: Structural noise sensors separately pick up the noise signals for the individual cylinders in measurement windows which can predetermine the combustion noise. Individual structural noise signals are compared with threshold values specific to each cylinder, then check whether or not the noise signals exceed threshold values within or outside established measurement windows. If the threshold values are exceeded outside measurement windows, it regards as injection errors. Otherwise, if the threshold values don't be exceeded within measurement windows in that case of the maximum amplification, it regards as failures.