Closed loop sensor condition detector
US4214308A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1978 |
| Grant date | Jul 22, 1980 |
| Priority date | — |
| Expiry date | Jun 22, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/1432
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating air/fuel ratio that is corrected with a closed loop signal developed by an integral controller. The integral controller bases the closed loop correction signal on a signal from an exhaust gas composition sensor located in the engine exhaust manifold. Various conditions of the system are sensed by a closed loop sensor condition detector to provide information on whether the sensor is up to operating temperature and is operative. If the exhaust gas sensor is functioning and the operating system parameters indicate the system operation should move to closed loop control, the loop is closed by the condition detector. Included in the condition detector circuit is a timer whose cycle is RPM dependent. The timer will time out if the sensor has not indicated an operational capability in one timing cycle or a set number of RPM counts and will generate a signal indicating a sensor failure. After closing the loop, the detector circuit will check for a sensor transition on a periodic basis related to the authority of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.