Control system for internal combustion engine
AssigneeDenso Corporation
InventorsKazuo Kobayashi, Hiroshi Haraguchi, Toshio Kondo, Sumiko Kohira
Life of this patent
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Abstract
An O2 amount in the intake air is determined based on a fresh air and an EGR gas. A consumed O2 amount is determined with a command injection amount Qr. Then, the consumed O2 amount is subtracted from the O2 amount in the intake air to obtain an exhaust O2 amount. An exhaust O2 concentration is estimated based on the exhaust O2 amount. According to the invention, the system is not affected by a delay for the exhaust gas to reach an O2 sensor and a delay of the chemical reaction in the O2 sensor. Therefore, the exhaust O2 concentration can be highly precisely estimated compare to the case in which the exhaust O2 concentration is detected by the O2 sensor.
Claims16
A control system for an internal combustion engine having an EGR system to recirculate a portion of exhaust gas to intake, comprising:
- intake measuring means for measuring an amount of intake air to be sucked into an intake passage;
- an intake pressure sensor for detecting an intake pressure in said intake passage;
- command injection amount calculating means for calculating a command injection amount on the basis of at least a operational state of said internal combustion engine;
- exhaust O2 concentration estimating means for estimating an exhaust O2 concentration of each combustion in a cylinder by using an intake airflow signal outputted from said intake measuring means, an intake pressure signal outputted from said intake pressure sensor, and command injection amount information calculated by said command injection amount calculating means;
- and
- means for controlling at least one of an EGR valve of said EGR system and a fuel injection amount in accordance with the estimated exhaust O2 concentration estimated by said exhaust O2 concentration estimating means.
Dependencies are inferred from the claim text.