INTERRUPTING METHOD OF COMBUSTION MISFIRE DETECTION OPERATING ON BASIS OF FLUCTUATION OF ROTATING SPEED IN INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To surely detect a rough road zone on the basis of a rotation irregularity value of a small number, by summing plural measures during one operation cycle, examining whether the value exists in a specified band width or not, and interrupting the detection of misfire when the value does not exist in the specified band width. ;SOLUTION: The rotation irregularity value Lut is determined as a measure to the rotation irregularity of an internal combustion engine by the continuous measuring and processing (S4.1). A sum SLut of plural rotation irregularity values continuously formed during one operation cycle of the internal combustion engine, is determined (S4.2). An absolute value |SLut| of the summed signal SLut of the rotation irregularity value Lut, is formed, and the value FSLut is determined by the low pass filtering (S4.3). The exceeding of the absolute value of FSLut to the specific threshold value (S4.4), is evaluated as a sign of the travelling on the rough road, and the detection of the misfire is interrupted. That is, the function is cut (S4.5). Thereby the rough road zone can be surely detected.;COPYRIGHT: (C)1997,JPO