Closed loop mass airflow determination via throttle position
US4999781A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1989 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Jul 17, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Mass air flow into an internal combustion engine is measured as a function of throttle opening. The mass air flow rate is expressed as an idle offset constant and the product of gain and effective air intake area which is a function of throttle position. During idle, the idle offset term is updated in response to an exhaust oxygen sensor feedback and during part throttle operation the gain is similarly updated to achieve stoichiometry. For subsonic air flow the mass air flow is further modified as a function of the ratio of manifold pressure to the pressure upstream of the throttle. At the same time the manifold dilution is controlled via an EGR valve to a predetermined schedule.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.