Engine misfire detection with rough road inhibit
US5544521A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/702
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method are provided for detecting cylinder misfires in an internal combustion engine of a motor vehicle and inhibiting misfire detection during the presence of noise related events. Misfire detection is performed to detect the occurrence of one or more misfire events. Crankshaft rotation is sensed and crankshaft velocities are measured for each cylinder and changes in angular velocity are determined for each cylinder firing event. Angular velocity changes are sorted and averaged to provide an average change in velocity value and a deviation value is determined. The deviation is compared to a threshold value and misfire events are determined based on the comparison. A comparison value is determined as a function of change in positive deviations of change of velocity and a time decay rate. The comparison value is compared with a threshold value. Misfire detection is disabled or inhibited when the comparison value exceeds the threshold value. The comparison value is reduced with the time decay rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.