Engine misfire, knock or roughness detection method and apparatus
US5313826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1993 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Jun 10, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S73/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for comparing torsional stress/strain states of a power transmitting member of an internal combustion engine to detect an abnormal combustion condition, including misfire, knock or roughness. Statistical processing steps may be used to detect an abnormal combustion event including: calculating a mean and standard deviation for a set of signals related to the torsional stress induced in the power transmitting member, calculating a difference between a later signal and the mean, calculating a ratio of the difference to the standard deviation, and comparing the ratio to a threshold. The ratio so obtained from a given cylinder may further be compared with one or more other such ratios from other cylinders. In other words, the autocorrelation and/or cross-correlation techniques may be used. A magnetostrictive sensor may preferably be used to obtain the signals relating to the torsional stress in the power transmitting member, such as the engine crankshaft. In addition, the magnetostrictive sensor may include windings to cancel induced electromagnetic interference signals. The magnetostrictive sensor may also generate signals relating to the position of the power t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.