US Patent 7334562 Homogenous charge compression ignition engine control

A method is shown for operating an internal combustion engine having a combustion chamber with a piston, the internal combustion engine capable of injecting fuel into the combustion chamber multiple times during a cycle, the method comprising: performing a first fuel injection after approximately −25 crank angle degrees after top dead center and before approximately 15 crank angle degrees after top dead center; and performing a second fuel injection at least 5 degrees after the start of the first fuel injection and less than approximately 25 crank angle degrees after the start of the first fuel injection.