System and Method for Control of a Transition Between SI and HCCI Combustion Modes

An engine system comprising:

• a first cylinder;
• a first inlet valve configured to control the flow of gases into the first cylinder;
• a first outlet valve configured to control the flow of gases out of the first cylinder;
• a first throttle configured to control the flow of fuel into the first cylinder;
• a memory including program instructions stored therein;
• and
• a processor operably connected to the first inlet valve, the first outlet valve, the first throttle, and the memory, and configured to execute the program instructions to
• control the first inlet valve and the first outlet valve in accordance with a spark ignition (SI) valve lift profile,
• activate a first spark in the first cylinder while controlling the first inlet valve and the first outlet valve in accordance with the SI valve lift profile,
• control the first inlet valve and the first outlet valve in accordance with a homogeneous charge compression ignition (HCCI) valve lift profile,
• activate a second spark in the first cylinder while controlling the first inlet valve and the first outlet valve in accordance with the HCCI valve lift profile, and
• control the start-of-injection (SOI) timing of the first throttle in an HCCI SOI mode while controlling the first inlet valve and the first outlet valve in the HCCI valve lift profile after activating the second spark.