Abstract: A method to dynamically determine a parametric value for combustion chamber deposits (CCD), e.g. in a controlled auto-ignition engine, including in-situ evaluation of thickness of CCD, based on a sensor which monitors combustion in a homogeneous charge compression ignition engine. It includes a temperature sensor operative to monitor the combustion chamber, and a CCD parameter that is based upon a peak combustion temperature measured at a crank angle. A CCD parameter can also be determined utilizing an in-cylinder pressure monitor, wherein a combustion chamber deposit parameter is based upon crank angle location of a peak in-cylinder pressure parameter.

Abstract: A method for controlling combustion within an internal combustion engine includes operating the engine in one of an HCCI and SI combustion modes and injecting water into a combustion chamber of the engine during at least periods of relatively high engine load conditions, the injecting water absorbing heat to reduce the occurrence of unintentional combustion ignition.

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: A method for extending the low-load operation of a homogeneous charge compression ignition engine includes employing a valve actuation device creating a negative valve overlap, thereby trapping and recompressing combusted gases within a combustion chamber, the device effecting increasingly longer negative valve overlap as engine load decreases, injecting during the negative valve overlap a fraction of fuel into the recompressed combusted gases, and igniting the fuel with a heat source during the negative valve overlap.

Abstract: A method is disclosed for controlling operation of an HCCI internal combustion engine effective for robust engine warm-up operation. The method includes selectively implementing ones of a plurality of operating modes in response to predetermined catalyst and engine temperature conditions.

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 homogeneous charge compression ignition engine is fueled within a warm-up region of engine temperatures using a minimally defined fuel mass schedule and injection timings and simple interpolative techniques.

Abstract: A direct injection spark ignition multi-cylinder internal combustion engine operative in a controlled auto-ignition combustion mode includes a direct fuel injection system, a spark ignition system and a controllable engine valve system. The air/fuel ratio in the exhaust gas feedstream and an intake mass air flow are measured and an actual air/fuel ratio is calculated based upon the intake mass air flow and engine fueling. Magnitude of a negative valve overlap period between an exhaust valve closing and an intake valve opening is adjusted based upon the measured mass air flow. Timing of pre-injection fueling is adjusted during the negative valve overlap period based upon the measured air/fuel ratio.

Abstract: A multi-cylinder internal combustion engine is operative in a controlled auto-ignition combustion mode. The operation includes monitoring engine operation, and globally adapting fueling for all the cylinders based upon an engine intake mass air flow and an air/fuel ratio. The fueling for each cylinder is individually adapted based upon states of a combustion parameter for all the cylinders.

Abstract: A powertrain and a control method therefore are provided wherein ignition of a combustible charge in a combustion chamber of a controlled auto-ignition internal combustion engine equipped with in-cylinder fuel-injection and a spark ignition device is controlled. A spark-discharge plasma channel is generated between the electrodes of the spark ignition device, and the combustible charge is ignited. The spark-discharge plasma channel is moved toward and entrained by the combustible charge, effective to advance phasing of controlled auto-ignition combustion.

Abstract: An HCCI engine is operated by controlling a plurality of engine operating parameters in accordance with a calibration data set representing equilibrium set-points of engine operation characterized by combustion phasing that is relatively least sensitive to cylinder charge temperature deviations.

Abstract: A powertrain, and a control method therefor, are provided, wherein ignition of a combustible charge in a combustion chamber of a controlled auto-ignition internal combustion engine equipped with in-cylinder fuel-injection and a spark ignition device is controlled. The method comprises generating a spark-discharge plasma channel between the electrodes of the spark ignition device, and igniting the combustible charge. The spark-discharge plasma channel is moved toward and entrained by the combustible charge, effective to advance phasing of controlled auto-ignition combustion.

Abstract: A model-based estimation of mass airflow is provided which provides an accurate estimation of mass airflow without introducing undesirable time delays characteristic of filtered mass airflow signals.

Abstract: A method to dynamically determine a parametric value for combustion chamber deposits (CCD), e.g. in a controlled auto-ignition engine, including in-situ evaluation of thickness of CCD, based on a sensor which monitors combustion in a homogeneous charge compression ignition engine. It includes a temperature sensor operative to monitor the combustion chamber, and a CCD parameter that is based upon a peak combustion temperature measured at a crank angle. A CCD parameter can also be determined utilizing an in-cylinder pressure monitor, wherein a combustion chamber deposit parameter is based upon crank angle location of a peak in-cylinder pressure parameter.

Abstract: Cold start and warm-up operations of an HCCI engine are improved through coordinated control of engine valves, fuel injection and spark timing.

Abstract: A method for controlling combustion within an internal combustion engine includes operating the engine in one of an HCCI and SI combustion modes and injecting water into a combustion chamber of the engine during at least periods of relatively high engine load conditions, the injecting water absorbing heat to reduce the occurrence of unintentional combustion ignition.

Abstract: A method is provided for control of transition between combustion modes of a direct-injection engine operable in a homogeneous charge compression ignition (HCCI) mode at lower loads and a spark ignition flame propagation (SI) mode at higher loads. The engine includes a variable valve actuation system including two-step high and low lift valve actuation and separate cam phasing for both intake and exhaust valves. The method includes operating the engine at steady state, with fuel-air-exhaust gas mixtures at predetermined conditions, for each speed and load, and controlling the engine during mode changes between the HCCI mode and the SI mode by switching the exhaust and intake valves between low lift for HCCI operation and high lift for SI operation.

Abstract: A direct injection controlled auto-ignition engine is operated at steady state, within a homogeneous charge compression-ignition (HCCI) load range and with fuel-air-diluent mixtures at predetermined conditions, for each speed and load, of engine control inputs, including at least fueling mass flow rate, injection timing (FI), spark timing (SI) and exhaust recompression obtained by negative valve overlap (NVO). During load change rates below a predetermined threshold, SI, FI and NVO change rates are synchronized to current changes in the fueling mass flow rate. For fast load increases above the threshold, the cylinder charge is temporarily enriched by increasing the percentage of residual gas or reducing the percentage of fresh air mass in the charge sufficiently to maintain auto-ignition temperature during the load change. This may be done by delaying NVO action for a predetermined speed-dependent number of engine cycles.

Abstract: A control system and method to dynamically determine a parametric value for combustion chamber deposits (CCD), e.g. in a controlled auto-ignition engine, including in-situ evaluation of thickness of CCD, based on a sensor which monitors combustion. It includes a temperature sensor operative to monitor the combustion chamber, and a CCD parameter that is based upon a peak combustion temperature measured at a crank angle. A CCD parameter can also be determined utilizing an in-cylinder pressure monitor, wherein a combustion chamber deposit parameter is based upon crank angle location of a peak in-cylinder pressure parameter.