Fourier-based misfire detection strategy
US7530261B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 2007 |
| Grant date | May 12, 2009 |
| Priority date | — |
| Expiry date | Jun 9, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M15/11
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A computer implemented system for engine misfire detection employs a crankshaft-originated speed signal that includes normal variability due to target wheel tooth error and the like. A Discrete Fourier Transform (DFT) is performed on the speed signal to convert it into a frequency-domain raw misfire detection metric. The system is configured to normalize the raw misfire detection metric using a non-misfire metric that is obtained by and corresponds to non-misfire operation of an internal combustion engine. A resulting normalized misfire detection metric has such normal variations removed leaving variations attributable to misfire. The system detects a misfire when the normalized misfire detection metric exceeds a predetermined threshold and is bounded by a predetermined phase angle region. The system detects both continuous misfire as well as intermittent misfire. The system also detects single cylinder misfire and multiple cylinder misfire.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.