System and method for enhanced combustion control in an internal combustion engine

A method for enhanced combustion control in an internal combustion engine having at least one cylinder, a reciprocating piston within the cylinder to define a combustion chamber therein, comprising:

• performing a split injection wherein a first fuel injection in each engine cycle precedes a second fuel injection that occurs during compression stroke in the same engine cycle;
• producing a spark to ignite a first air/fuel mixture portion created due to the second fuel injection to initiate a first stage combustion, thereby to cause elevation of temperature and pressure high enough to cause auto-ignition of a second air/fuel mixture portion surrounding the first air-fuel mixture portion to initiate an auto-ignited second stage combustion;
• determining beginning time of the auto-ignited second stage combustion in response to at least one of the engine speed and engine load;
• and
• performing control over at most an injection timing of the first fuel injection, an injection timing of the second fuel injection, a spark timing, a proportion of fuel quantity of the second fuel injection to the total quantity injected in each engine cycle, and an exhaust gas recirculation (EGR) rate to cause the auto-ignited second stage combustion to begin at the determined beginning time.

A system for enhanced combustion control in an internal combustion engine having at least one cylinder, a reciprocating piston within the cylinder to define a combustion chamber therein, comprising:

• means for performing a split injection wherein a first fuel injection in each engine cycle precedes a second fuel injection that occurs during compression stroke in the same engine cycle;
• means for producing a spark to ignite a first air/fuel mixture portion created due to the second fuel injection to initiate a first stage combustion, thereby to cause elevation of temperature and pressure high enough to cause auto-ignition of a second air/fuel mixture portion surrounding the first air-fuel mixture portion to initiate an auto-ignited second stage combustion;
• means for determining beginning time of the auto-ignited second stage combustion in response to at least one of the engine speed and engine load;
• and
• means for performing control over at most an injection timing of the first fuel injection, an injection timing of the second fuel injection, a spark timing, a proportion of fuel quantity of the second fuel injection to the total quantity injected in each engine cycle, and an exhaust gas recirculation (EGR) rate to cause the auto-ignited second stage combustion to begin at the determined beginning time.

A system for enhanced combustion control in an internal combustion engine having at least one cylinder, a reciprocating piston within the cylinder to define a combustion chamber therein, comprising:

• a fuel supply system having a fuel injector positioned to directly inject fuel into the combustion chamber, the fuel supply system being capable of performing a split injection wherein a first fuel injection in each engine cycle precedes a second fuel injection that occurs during compression stroke in the same engine cycle;
• spark plug positioned to produce a spark to ignite a first air/fuel mixture portion created due to the second fuel injection to initiate a first stage combustion, thereby to cause elevation of temperature and pressure high enough to cause auto-ignition of a second air/fuel mixture portion surrounding the first air-fuel mixture portion to initiate an auto-ignited second stage combustion;
• an engine controller;
• and
• computer readable storage media having data stored therein representing instructions executable by the engine controller to perform control over beginning time of the auto-ignited second stage combustion in response to at least one of the engine speed and engine load.