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U.S. Department of Energy
Office of Scientific and Technical Information

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

Patent ·
OSTI ID:6023837
This patent describes a method for controlling the air-fuel ratio in an internal combustion engine and consists of the following steps: calculating a combustion variation by detecting a difference between values of an engine output parameter at two predetermined crank angle positions for every firing stroke of a predetermined cylinder of the engine; calculating a first standard deviation of the calculated combustion variations extending over one of a predetermined time period and a crank angle; calculating a reference standard deviation of combustion variations in accordance with predetermined parameters of the engine; and controlling the air-fuel ratio of the engine so that the first calculated standard deviation approaches the calculated reference standard deviation.
Assignee:
Nippon Soken, Inc., Nishio
Patent Number(s):
US 4562818
OSTI ID:
6023837
Country of Publication:
United States
Language:
English