Abstract: An internal combustion engine is operative in a spark ignition combustion mode and a controlled auto-ignition combustion mode. Operating the engine includes commanding a transition from a first combustion mode to a second combustion mode. A change in openings and closings of the intake and exhaust valves is commanded to a preferred duration of a negative valve overlap period corresponding to operating in the second combustion mode. Fuel injection parameters and spark ignition events are adjusted to effect operation in the second combustion mode only when a realized duration of the negative valve overlap period exceeds a predetermined threshold.

Abstract: An internal combustion engine operates in an unthrottled condition during HCCI operation while preferred combustion phasing is determined. An EGR mass flow rate is commanded to correspond with the preferred combustion phasing. The EGR valve is controlled to achieve commanded EGR mass flow rate. Position of the throttle valve is controlled to achieve commanded EGR mass flow rate when the commanded EGR mass flow rate exceeds control authority of the EGR valve.

Abstract: A control system and method for operating an engine includes a threshold determination module that determines a plurality of combustion mode thresholds based on the engine speed and engine temperature. The control module also includes a transition module that compares the engine load and the plurality of combustion mode thresholds and changes a combustion mode of the engine in response to comparing the engine load and the plurality of combustion mode thresholds.

Abstract: A method for operating an internal combustion engine including extended operation in a homogeneous charge compression ignition mode at high loads includes operating the engine in the homogeneous charge compression ignition mode including spark-assisted ignition, monitoring an engine load, monitoring an engine speed, determining the engine to be in a high ringing range based upon the engine load and the engine speed, and when the engine load is in the high ringing range, operating the engine in a reduced ringing mode. The reduced ringing mode includes modulating a fuel injection timing according to a calibrated maximum combustion chamber cooling fuel injection timing, determining a preferred combustion phasing value, and modulating a spark timing based upon the modulated fuel injection timing and the preferred combustion phasing value.

Abstract: A method for controlling a homogeneous-charge compression-ignition capable engine, operating with spray-guided spark ignition stratified combustion at low load, includes monitoring a speed of the engine, monitoring a load of the engine, determining a desired fuel pressure based upon the speed of the engine and the load of the engine, and utilizing the desired fuel pressure to control fuel injection into the engine, wherein the desired fuel pressure is calibrated to the speed and the load based upon increased stability of the engine at lower fuel pressures and lower soot emissions from the engine at higher fuel pressures.

Abstract: An engine operating in a spark-assisted homogeneous charge compression ignition mode during warm-up cycle is controlled using settings determined by interpolating between cold engine temperature settings fully warmed-up engine temperature settings.

Abstract: A multi-cylinder spark-ignition direct-injection internal combustion engine is re-fired subsequent to a fuel cutoff event wherein fuel to all cylinders is cutoff. Re-firing the engine includes selectively firing individual cylinders during re-firing engine cycles exclusively at a predetermined fixed fuel mass until all cylinders have been fired at least once, whereafter subsequent firing of individual cylinders is not limited to the predetermined fixed fuel mass.

Abstract: An internal combustion engine includes intake and exhaust camshafts including high-lift lobes and low-lift lobes separated by a lobe separation angle. The engine transitions between operating in a controlled auto-ignition combustion mode with positive valve overlap and a controlled auto-ignition combustion mode with negative valve overlap solely by selecting the corresponding one of the high-lift lobes and the low-lift lobes.

Abstract: An internal combustion engine is operative in a spark ignition combustion mode and a controlled auto-ignition combustion mode. Operating the engine includes commanding a transition from a first combustion mode to a second combustion mode. A change in openings and closings of the intake and exhaust valves is commanded to a preferred duration of a negative valve overlap period corresponding to operating in the second combustion mode. Fuel injection parameters and spark ignition events are adjusted to effect operation in the second combustion mode only when a realized duration of the negative valve overlap period exceeds a predetermined threshold.

Abstract: An engine operating in a spark-assisted homogeneous charge compression ignition mode during warm-up cycle is controlled using settings determined by interpolating between cold engine temperature settings fully warmed-up engine temperature settings.

Abstract: A method for operating an internal combustion engine including extended operation in a homogeneous charge compression ignition mode at high loads includes operating the engine in the homogeneous charge compression ignition mode including spark-assisted ignition, monitoring an engine load, monitoring an engine speed, determining the engine to be in a high ringing range based upon the engine load and the engine speed, and when the engine load is in the high ringing range, operating the engine in a reduced ringing mode. The reduced ringing mode includes modulating a fuel injection timing according to a calibrated maximum combustion chamber cooling fuel injection timing, determining a preferred combustion phasing value, and modulating a spark timing based upon the modulated fuel injection timing and the preferred combustion phasing value.

Abstract: A method for operating a direct-injection internal combustion engine includes unevenly distributing load among a plurality of cylinders by operating a portion of the plurality of cylinders in a spark ignition mode and the remaining portion of the plurality of cylinders in a homogeneous charge compression ignition mode.

Abstract: A method for operating a multi-cylinder spark-ignition direct-injection internal combustion engine responsive to a low load demand includes monitoring an engine state associated with combustion for each cylinder during each combustion cycle during low load operation, determining a combustion stability index for each cylinder based upon the monitored engine state associated with combustion for the respective cylinder, and individually adjusting an initiation of a spark discharge relative to an end of a fuel injection event for each cylinder based upon the combustion stability index determined for the respective cylinder.

Abstract: A method for controlling an internal combustion engine includes monitoring an engine operating state and selectively operating the engine in a multiple-injection, multiple-ignition combustion mode comprising three injection events based upon the engine operating state. The selective operation includes controlling a first injection during a recompression period of the combustion cycle, controlling a second injection event effective to establish a homogeneous fuel charge prior to a main combustion, and controlling a third injection late in the compression phase of the combustion cycle.

Abstract: A method for controlling a homogeneous-charge compression-ignition capable engine, operating with spray-guided spark ignition stratified combustion at low load, includes monitoring a speed of the engine, monitoring a load of the engine, determining a desired fuel pressure based upon the speed of the engine and the load of the engine, and utilizing the desired fuel pressure to control fuel injection into the engine, wherein the desired fuel pressure is calibrated to the speed and the load based upon increased stability of the engine at lower fuel pressures and lower soot emissions from the engine at higher fuel pressures.

Abstract: A control system for an engine comprises an air per cylinder (APC) generating module that generates measured and desired APC values. A combustion transition module selectively transitions the engine from spark ignition (SI) combustion to homogeneous charge compression ignition (HCCI) combustion and from HCCI combustion to SI combustion. A spark control module selectively retards spark during the transitions based on a ratio of the measured APC value and the desired APC value. Alternately, spark retard can be based on measured and desired engine torque representing values (ETRVs).

Abstract: Transitioning between combustion modes includes an intermediate combustion mode. Transitions are controlled in accordance with a preferred fuel mass and permissible fuel mass ranges corresponding to changing intake airflow.

Abstract: A control system and method for operating an engine includes a spark ignited (SI) control module controlling the engine in a spark ignited mode, a pre-homogeneous charge compression (HCCI) module controlling the engine in an HCCI mode after the spark ignited mode, and an HCCI module controlling the engine in an HCCI mode after the pre-HCCI mode. The SI module controls the engine in the SI mode after the HCCI mode.

Abstract: A spark-ignition direct-injection internal combustion engine is controlled at low loads through split fuel injections and spark discharges including one injection and spark during a negative valve overlap period and another injection and spark during a compression phase of the engine cycle.