Abstract: An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode. Operating the internal combustion engine includes determining an integrated thermal state parameter from an aggregation of engine environment factors. A feed-forward engine control scheme is executed to determine states for engine control parameters. The states for the engine control parameters correspond to a preferred combustion phasing responsive to an operator torque request and the integrated thermal state parameter. Operation of the internal combustion engine is controlled to achieve the preferred combustion phasing using the states for the engine control parameters.

Abstract: A direct-injection internal combustion engine includes an intake camshaft with a low-lift intake cam and a high-lift intake cam, a variable lift control for selectively operating an intake valve in one of a low-lift intake valve profile with the low-lift intake cam and a high-lift intake valve profile with the high-lift intake cam, a variable cam phase control operative on the intake camshaft for simultaneously controlling the phase of the low-lift intake cam and the high-lift intake cam, an ignition spark control, a fuel injection control, an exhaust gas recirculation control, and an intake throttle control.

Abstract: An engine is transitioned from a first combustion mode to a second combustion mode. Phase and lift of the intake and exhaust valves are sequentially adjusted corresponding to intake air cylinder volume and residual gas cylinder volume corresponding to the first and second combustion modes.

Abstract: A method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between HCCI and SI modes includes providing a low-lift intake valve, un-throttled stoichiometric SI operation intermediate a low-lift exhaust and intake valve HCCI mode and a high-lift exhaust and intake valve, un-throttled SI mode.

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: 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 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 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 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.

Abstract: A method for controlling an amount of fuel reforming in an internal combustion engine configured to selectively operate in a homogeneous charge compression-ignition combustion mode with an exhaust recompression strategy includes monitoring in-cylinder pressures during a current combustion cycle, utilizing the monitored in-cylinder pressures to project reforming required in a next combustion cycle, and controlling the next combustion cycle based on the projected reforming required in the next combustion cycle.

Abstract: A method to operate a multi-cylinder direct-injection engine in one of a controlled auto-ignition and a spark-ignition combustion mode is described. Engine operation and an operator torque request are monitored. Fuel delivery to a portion of the cylinders is selectively deactivated and torque output from non-deactivated cylinders is selectively increased to achieve the operator torque request when the monitored engine operation is above a predetermined threshold. An engine operating point at which an engine load demand exceeds an operating capability of the engine in a stoichiometric HCCI mode is identified. The engine is selectively operated in an unthrottled spark-ignition mode with at least one cylinder unfueled and torque output from the remaining cylinders is selectively increased.

Abstract: The invention comprises a method for controlling operation of a homogeneous charge combustion ignition engine operating in an auto-ignition mode. The method comprises determining a desired combustion phasing; and, controlling a mass flowrate of externally recirculated exhaust gas based upon an actual combustion phasing. A closed-loop control scheme is executed to control the mass flowrate of externally recirculated exhaust gas based upon a difference between the actual and the desired combustion phasing.

Abstract: A method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between HCCI and SI modes includes providing a low-lift intake valve, un-throttled stoichiometric SI operation intermediate a low-lift exhaust and intake valve HCCI mode and a high-lift exhaust and intake valve, un-throttled SI mode.

Abstract: The invention comprises a method for controlling operation of a homogeneous charge combustion ignition engine operating in an auto-ignition mode. The method comprises determining a desired combustion phasing; and, controlling a mass flowrate of externally recirculated exhaust gas based upon an actual combustion phasing. A closed-loop control scheme is executed to control the mass flowrate of externally recirculated exhaust gas based upon a difference between the actual and the desired combustion phasing.

Abstract: A method to operate a multi-cylinder direct-injection engine in one of a controlled auto-ignition and a spark-ignition combustion mode is described. Engine operation and an operator torque request are monitored. Fuel delivery to a portion of the cylinders is selectively deactivated and torque output from non-deactivated cylinders is selectively increased to achieve the operator torque request when the monitored engine operation is above a predetermined threshold. An engine operating point at which an engine load demand exceeds an operating capability of the engine in a stoichiometric HCCI mode is identified. The engine is selectively operated in an unthrottled spark-ignition mode with at least one cylinder unfueled and torque output from the remaining cylinders is selectively increased.