Engine dynamic load leveling

A system for controlling a multiple cylinder internal combustion engine, comprising:

• a first portion of cylinders to operate in a homogeneous charge compression ignition (HCCI) mode;
• a second portion of cylinders to operate in a non-HCCI mode;
• and
• an engine controller operably coupled to the first and second portions of cylinders, said controller to adjust valve timing of the second portion of cylinders to a greater extent than the first portion of cylinders to dynamically load level the engine in response to a transient torque demand, where after the transient torque demand, the controller adjusts the non-HCCI cylinders to balance a load over all non-HCCI and HCCI cylinders.

A method for controlling an internal combustion engine having a plurality of cylinders, comprising:

• operating a first portion of the cylinders in a homogeneous charge compression ignition (HCCI) mode;
• operating a second portion of the cylinders in a non-HCCI mode;
• and
• adjusting a torque provided by the second portion of cylinders to respond to a high frequency torque demand and adjusting a torque provided by the first portion of cylinders to respond to a low frequency torque demand, where adjusting the torque provided by the second portion of cylinders includes adjusting a valve timing of the second portion of cylinders to dynamically load level the engine, where the torque adjustment in both cylinder portions includes a greater adjustment, and a faster adjustment, provided by the non-HCCI cylinders as compared to the HCCI cylinders, and where the dynamic load leveling includes balancing a load over all non-HCCI and HCCI cylinders, where after adjusting valve timing in response to the high frequency torque demand, the valve timing of the second portion of cylinders is adjusted to keep the non-HCCI cylinders in a selected range and valve timing of the first portion of cylinders is adjusted until the load reaches a desired balance over HCCI and non-HCCI cylinders.