Engine monitoring system
US4408483A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1981 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Aug 21, 2001 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B3/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for monitoring the performance of an internal combustion engine includes a pressure sensor that has a mounting configuration external to the cylinders such that it is capable of monitoring the pressures within two adjacent cylinders. The signal output of the sensor is filtered to remove undesired engine noise and blank out those signals which are unrelated to compression and firing, thereby reducing errors in the signal output. After filtering the signals to reduce noise, a successive number of samples related to compression and firing are obtained to provide an adequate number of signals which will average out mechanical and electrical noise. From the successive samples, a straight line approximation of the slope of the cylinder pressure curve, relative to crank angle, is obtained. The derived slope values are compared with upper and lower limits to determine whether or not the pressure within the engine cylinder of interest is acceptable. If the upper limit is exceeded or if the value obtained is less than the lower limit a fault in the cylinder operation is assumed to have occurred. This fault measurement and analysis procedure is repeated a prescribed number of times a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.