Method and apparatus for controlling air-fuel ratio in internal combustion engine

Patent · Tue Apr 18 04:00:00 EDT 1989

OSTI ID:5955644

Nagai, T

A method is described for controlling an air-fuel ratio in an internal combustion engine, comprising the steps of: receiving the output of the air-fuel ratio sensor and calculating an air fuel ratio correction amount in accordance with the detected air-fuel ratio, so that the air-fuel of the engine is brought close to a predetermined air-fuel ratio; detecting a running state parameter of the engine; setting an upper limit value of the air-fuel ratio correction amount at a definite value; calculating a lower limit value of the air-fuel ratio correction amount in accordance with the running state parameter; defining a range between a maximum value and a minimum value of the lower limit value; limiting the lower limit to within the range; limiting the air-fuel ratio correction amount to within a second range defined between the upper limit value and the lower limit value; and adjusting an air-fuel ratio of the engine in accordance with the air-fuel ratio correction amount.

• Assignee: Toyota Jidosha Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4823270
• OSTI ID: 5955644
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
CORRECTIONS
ENGINES
EXHAUST SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
METERING
SIGNAL CONDITIONING