Air-fuel ratio feedback control method for internal combustion engines

Patent · Tue May 20 04:00:00 EDT 1986

OSTI ID:5635471

Wazaki, Y; Koike, A; Koike, Y

A method is described of effecting feedback control of the air-fuel ratio of an air-fuel mixture being supplied to an internal combustion engine having an exhaust pipe and an exhaust gas ingredient concentration detecting means arranged in the exhaust pipe, by correcting a basic fuel supply quantity by the use of a coefficient variable in value in response to the output of the exhaust gas ingredient concentration detecting means, while the engine is operating in a predetermined air-fuel ratio feedback control effecting region. The method consists of the steps of: (1) previously dividing the predetermined air-fuel ratio feedback control effecting region into at least first and second subdivided regions; (2) determining whether or not the engine is operating in one of the first and second subdivided regions; (3) calculating and storing a first mean value of values of the coefficient which have been applied in the feedback control effected when the engine is operating in the first subdivided region, while calculating and storing a second mean value of values of the coefficient which have been applied in the feedback control effected when the engine is operating in the second subdivided region; (4) initiating the air-fuel ratio feedback control by using the first mean value as an initial value of the coefficient, when it is detected that the operation of the engine has entered the first subdivided region; and (5) initiating the air-fuel ratio feedback control by using the second mean value as an initial value of the coefficient, when it is detected that the operation of the engine has entered the second subdivided region.

• Assignee: Honda Giken Kogyo K.K., Tokyo
• Patent Number(s): US 4589390
• OSTI ID: 5635471
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
COMPUTER CALCULATIONS
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
DISPERSIONS
ENGINES
EXHAUST GASES
EXHAUST SYSTEMS
FEEDBACK
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEMORY DEVICES
MIXTURES
OPERATION
WASTES