Control system for internal combustion engine

• US 20070021901A1
• Filed: 07/12/2006
• Published: 01/25/2007
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Yamaguchi, Satoshi, Hasegawa, Mamoru, Sakamoto, Hideki, Kitayama, Naoto
• Granted Patent: US 7,258,106 B2
• Time in Patent Office: Days
• US Class Current: 701/105
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02D 41/401 Controlling injection timing F02D41/402 takes precedence
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A control system for an internal combustion engine having fuel injection valves provided in a combustion chamber and an exhaust gas recirculation mechanism. Target maximum cylinder pressure change rates are set according to the operating condition of the engine. The maximum change rate of the detected cylinder pressure and a fuel injection timing correction amount are calculated wherein a difference between the calculated maximum change rate and the target maximum cylinder pressure change rate decreases. The fuel injection timing is corrected with the fuel injection timing correction amount. The recirculation amount of exhaust gases is controlled using the calculated control value. A correction amount of the exhaust gas recirculation amount is calculated when the fuel injection timing correction amount exceeds a predetermined amount. The exhaust gas recirculation amount is controlled using the control value corrected with the correction amount of the exhaust gas recirculating amount.

Claims

1. A control system for an internal combustion engine having fuel injection means provided in a combustion chamber of the engine for injecting fuel into the combustion chamber, and an exhaust gas recirculation mechanism for recirculating exhaust gases of the engine to an intake system of the engine, the control system comprising:

operating condition detecting means for detecting an operating condition of the engine;

fuel injection control means for determining a fuel injection timing according to the detected engine operating condition, and executing a fuel injection through the fuel injection means;

cylinder pressure detecting means for detecting a cylinder pressure of the engine;

target cylinder pressure change rate storing means for storing target maximum cylinder pressure change rates which are target values of the maximum change rate of the cylinder pressure, the target maximum cylinder pressure change rates being set according to the operating condition of the engine;

fuel injection timing correction amount calculating means for calculating a maximum change rate parameter indicative of a maximum change rate of the cylinder pressure detected by the cylinder pressure detecting means or a change rate in the vicinity of the maximum change rate, and calculating a fuel injection timing correction amount so that a difference between the calculated maximum change rate parameter and the target maximum cylinder pressure change rate decreases;

exhaust gas recirculation control means for calculating a control value of a recirculation amount of exhaust gases through the exhaust gas recirculation mechanism according to the detected engine operating condition, and controlling the recirculation amount of exhaust gases using the calculated control value; and

exhaust gas recirculation correction amount calculating means for calculating a correction amount of the exhaust gas recirculation amount when the fuel injection timing correction amount exceeds a predetermined amount,

wherein the fuel injection control means corrects the fuel injection timing with the fuel injection timing correction amount, and executes the fuel injection according to the corrected fuel injection timing, and

the exhaust gas recirculation control means corrects the control value with the correction amount of the exhaust gas recirculating amount, and controls the exhaust gas recirculation amount using the corrected control value.

2. The control system according to claim 1, wherein the exhaust gas recirculation correction amount calculating means includes learning value calculating/storing means for calculating a learning value of the correction amount of the exhaust gas recirculation amount, and storing the calculated value according to the detected engine operating condition, and the exhaust gas recirculation correction amount calculating means retrieves the stored learning value according to the detected engine operating condition and outputs the retrieved learning value as the correction amount.

3. A control method for an internal combustion engine having at least one fuel injection valve provided in a combustion chamber of the engine for injecting fuel into the combustion chamber, and an exhaust gas recirculation mechanism for recirculating exhaust gases of the engine to an intake system of the engine, the control method comprising the steps of:

a) detecting an operating condition of the engine;

b) determining a fuel injection timing according to the detected engine operating condition;

c) detecting a cylinder pressure of the engine;

d) calculating a maximum change rate parameter indicative of a maximum change rate of the cylinder pressure detected by the cylinder pressure detecting means or a change rate in the vicinity of the maximum change rate;

e) retrieving a target cylinder pressure change rate map according to the detected operating condition of the engine to calculate a target cylinder pressure change rate which is a target value of the maximum change rate of the cylinder pressure, the target maximum cylinder pressure change rate map being set according to the operating condition of the engine;

f) calculating a fuel injection timing correction amount so that a difference between the calculated maximum change rate parameter and the target maximum cylinder pressure change rate decreases;

g) calculating a control value of a recirculation amount of exhaust gases through the exhaust gas recirculation mechanism according to the detected engine operating condition;

h) calculating a correction amount of the exhaust gas recirculation amount when the fuel injection timing correction amount exceeds a predetermined amount;

i) correcting the fuel injection timing with the fuel injection timing correction amount;

j) executing the fuel injection according to the corrected fuel injection timing through the at least one fuel injection valve;

k) correcting the control value with the correction amount of the exhaust gas recirculating amount; and

l) controlling the exhaust gas recirculation amount using the corrected control value.

4. The control method according to claim 3, further comprising the steps of calculating a learning value of the correction amount of the exhaust gas recirculation amount, and storing the calculated value according to the detected engine operating condition, wherein the stored learning value is retrieved according to the detected engine operating condition and used as the correction amount of the exhaust gas recirculation amount.