Method of air/fuel ratio control for internal combustion engine

Patent · Tue Aug 30 04:00:00 EDT 1988

OSTI ID:6526348

Nakajima, T; Okada, Y; Mieno, T; Oono, N

This patent describes a method of air/fuel ratio control for a multi-cylinder internal combustion engine provided with at least one oxygen concentration sensor mounted within an exhaust system of the internal combustion engine for producing an output which varies substantially in proportion to an oxygen concentration in exhaust gas from the engine, the method comprising: setting a basic value for airfuel ratio control, in accordance with a plurality of engine operating parameters relating to engine load; detecting the air/fuel ratio of a mixture supplied to the engine, based upon the output from the oxygen concentration sensor; compensating the basic value by at least an air/fuel ratio feedback compensation value which is derived in accordance with a deviation from a target air/fuel ratio of an air/fuel ratio detected utilizing the output from the oxygen concentration sensor and by a learning control compensation value representing a secular change of an air/fuel ratio control system. The improvement comprises: detecting a predetermined operating condition of the engine in which variations of the detected air/fuel ratio are small and, computing the updating respective individual values of the learning control compensation value for the respective cylinders of the engine.

• Assignee: Honda Giken Kogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4766870
• OSTI ID: 6526348
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL
CONTROL SYSTEMS
DETECTION
ENGINES
ENRICHMENT
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
METERING
OXYGEN ENRICHMENT