Error correction in measures of speed, acceleration, misfire detection and roughness
US5699252A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1995 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Apr 7, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M15/11
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods are presented to remove from misfire/roughness measures both acceleration effects and those errors which are of a cyclical nature over the engine firing cycle. Included in the latter category are errors which repeat every revolution, e.g. tooth spacing errors resulting from manufacturing tolerances on a multitoothed wheel used to measure speed. Also included are errors arising from the cylinder by cylinder variations occurring in one firing cycle which would be essentially the same in neighboring firing cycles, e.g. mechanical and electrical tolerance effects that are cylinder based. These methods permit the correction in each cylinder measure of such cyclic errors on a cycle basis, i.e., after the completion of one or more of the cycles causing the error, or on a cylinder by cylinder basis, i.e., after the completion of the interval associated with an individual cylinder. The methods permit the correction of speed on a tooth by tooth basis in the same manner that the misfire/roughness measures are corrected on a cylinder by cylinder basis. In this way, the corrected speed forms the basis for determining corrected acceleration measures on a tooth by tooth basis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.