Double air-fuel ratio sensor system carrying out learning control operation

Patent · Tue Feb 09 04:00:00 EST 1988

OSTI ID:5401372

Nagai, T; Masui, T; Sato, Y; Katsuno, T

A method for controlling an air-fuel ratio in an internal combustion engine having a catalyst converter for removing pollutants in the exhaust gas thereof, and upstream-side and downstream-side air-fuel ratio sensors disposed upstream and downstream, respectively, of the catalyst converter, for detecting a concentration of a specific component in the exhaust gas is described comprising the steps of: calculating a first air-fuel ratio correction amount in accordance with the output of the upstream-side air-fuel ratio sensor; calculating a second air-fuel ratio correction amount in accordance with the output of the downstream-side air-fuel ratio sensor; determining whether or not a change of density of air taken into the engine is larger than a predetermined value; calculating a learning correction amount so that a mean value of the first air-fuel ratio correction amount is brought close to a reference value, when the change of the intake air density is larger than the predetermined value; adjusting an actual air-fuel ratio in accordance with the first and second air-fuel ratio correction amounts, and the learning correction amount.

• Assignee: Toyota Jidosha Kabushiki Kaisha, Aichi
• Patent Number(s): US 4723408
• OSTI ID: 5401372
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
330700 -- Advanced Propulsion Systems-- Emission Control
99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
AIR POLLUTION CONTROL
CATALYTIC CONVERTERS
COMPUTERIZED CONTROL SYSTEMS
CONTROL
CONTROL SYSTEMS
CORRECTIONS
DESIGN
EQUIPMENT
EXHAUST GASES
FLUIDS
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
MEASURING INSTRUMENTS
METERING
METERS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
WASTES