Method for feedback controlling air and fuel ratio of the mixture supplied to internal combustion engine
US4934328A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1989 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Feb 14, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1456
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method for feedback controlling air-fuel ratio of the mixture supplied to an internal combustion engine having a plurality of cylinders comprises the steps of, detecting respective air-fuel ratios of the exhaust gas from the respective cylinders with an air-fuel ratio sensor having a substantially linear output characteristic; calculating an average air-fuel ratio by using the latest detected air-fuel ratios of the respective cylinders; determining a fundamental feedback correction coefficient .beta..sub.0 for a cylinder of which air fuel ratio is feedback controlled next; retrieving a learning correction coefficient .beta..sub.1 for the cylinder of which air-fuel ratio is feedback controlled next from a learning map prepared by learning for the corresponding cylinder; and determining new learning correction coefficients .beta..sub.1 for the respective cylinders using respective deviations of the respective detected current air-fuel ratios from the latest average air-fuel ratio calculated in the previous step, whereby air-fuel ratio control at any desired air-fuel ratio is carried out with a high accuracy and with a uniform air-fuel ratio throughout the whole cylinders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.