Abstract: Internal combustion engine with variable actuation of the valves providing electronic control means which, when the engine is subject to an operating variation request from a first operating condition to a second operating condition, are adapted to select a cylinder to which to assign said second operating condition based on a determined programming delay only as a function of the engine speed.

Abstract: An engine control system includes an fuel injector for each cylinder of the engine, an air-fuel ratio sensor disposed in an exhaust manifold and an electronic control unit to which signals from various sensors are fed. Operation of the engine is controlled by the electronic control unit. An air-fuel ratio deviation among cylinders is calculated based on output signals of the air-fuel ratio sensor, and injection amount errors of each injector are calculated from the deviation of air-fuel ratio among cylinders. An injection characteristic of each injector is learned from the injection amount errors, and a right amount of fuel is supplied to each cylinder based on the learned injection characteristic. In this manner, the injection amount errors are effectively adjusted, and the air-fuel ratio deviation among cylinders due to external disturbances is surely adjusted.

Abstract: A method for controlling an engine having an intake manifold and an outlet control device coupled to the manifold for controlling flow exiting the manifold and entering at least one cylinder of the engine, the engine further having an inlet control device for controlling flow entering the manifold, the method comprising determining a driver torque command; calculating a desired cylinder charge based on said driver torque command; adjusting the outlet control device to provide said desired cylinder charge; and adjusting the inlet control device based on intake manifold pressure.

Abstract: The air-fuel-ratio control apparatus for an internal combustion engine obtains a composite air-fuel ratio abyfs from a downstream-side correction value Vafsfb(k) based upon an output value Voxs from a downstream air-fuel-ratio sensor 67 and an output value Vabyfs from an upstream air-fuel-ratio sensor 66, and obtains an upstream-side feedback correction value DFi on the basis of the composite air-fuel ratio abyfs. A fuel injection quantity Fi is determined to a value obtained by adding the upstream-side correction value DFi to a control-use base fuel injection quantity Fbasec (=base fuel injection quantity Fbase·coefficient Ksub).

Abstract: The present invention provides an intake air amount control apparatus for an engine and a control method of an intake air amount of an engine, in which, when the atmospheric pressure exceeds a threshold value, a target lift amount of an intake valve is determined based on a target intake air amount and an electronically controlled throttle is controlled to generate a target boost pressure. On the other hand, when the atmospheric pressure does not exceed the threshold value because of a vehicle traveling at a high altitude, the target lift amount of the intake valve is fixed to a maximum lift amount and the opening angle of the electronically controlled throttle is determined in response to the target intake air amount. Consequently, an actual intake air amount is controlled to be brought to the target intake air amount thereby generating negative pressure necessary for exhaust gas recirculation.

Abstract: In a lower partial load range of, a setpoint value of the mass flow of air into the combustion chambers is determined as a function of a predefined torque request such that it is greater than necessary for implementing the predefined torque request and large enough that individual exhaust packets can be differentiated from one another with the exhaust gas probe. Depending on the air/fuel ratio setpoint value, an actuator is actuated whose position affects the actual air mass flow. To implement the torque request, engine efficiency is simultaneously reduced by actuating another actuator. A measurement signal of the exhaust gas probe is detected. The air/fuel ratios of the exhaust packets are determined as a function of the measurement signal detected. At least one operating parameter affecting the air/fuel ratio in at least one of the cylinders is adapted as a function of the air/fuel ratios determined.

Abstract: A control apparatus for an internal combustion engine can learn an alcohol concentration of fuel in a fuel tank according to air fuel ratio feedback control, and accurately calculate, even upon interruption of learning, an alcohol concentration in an injector by estimating an alcohol concentration change delay from the fuel tank to the injector. The alcohol concentration in the fuel tank is estimated based on an air fuel ratio correction amount calculated from an air fuel ratio detected. A delay behavior of an alcohol concentration change until the fuel in the fuel tank reaches the injector is estimated. The alcohol concentration of fuel supplied to the engine is calculated from the estimated alcohol concentration in the fuel tank and the estimated delay behavior. An alcohol concentration correction coefficient is calculated based on the alcohol concentration, and an amount of fuel supplied to the engine is corrected by the correction coefficient.

Abstract: A fuel injection system designed to execute a learning operation to spray fuel through fuel injectors at each of given pressures of the fuel to determine the quantity of fuel sprayed actually from each of the fuel injectors (i.e., an actual injection quantity) into an internal combustion engine. The system calculates a deviation of each of the actual injection quantities from a target quantity to determine an injection correction value required to eliminate such a deviation. The system determines whether each of the injection correction values has an error or not and analyzes the mode in which the errors appear at the injection correction values to specify types of malfunction occurring in the system. The system relearns ones of the injection correction values as determined to have the errors.

Abstract: A fuel injection system for an internal combustion engine which is designed to determine an instantaneous engine speed in a cycle of, for example, 30° CA of the engine to learn an actual injection quantity that is the quantity of fuel actually sprayed from a fuel injector. The system filters the instantaneous engine speed using a band-pass filter to extract a cyclic component which varies in synchronism with an engine operating cycle to produce an engine speed change which has arisen from the spraying of fuel into the engine from which unwanted noise components are removed and uses it to determine the actual injection quantity.

Abstract: An air-fuel ratio feedback control range is enlarged to improve exhaust purification performance and output stability. In one aspect, an air-fuel ratio control apparatus of an internal combustion engine comprises an air-fuel ratio sensor capable of detecting an air-fuel ratio across both lean and rich ranges with a theoretical air-fuel ratio interposed therebetween. Feedback control is performed so as to bring an actual air-fuel into a target air-fuel ratio at least in a predetermined operational range on the basis of a detected value of the air-fuel ratio sensor. Even in a range where the air-fuel ratio is made richer than the theoretical air-fuel ratio, the target air-fuel ratio is set to be richer, and the air-fuel ratio feedback control may still be executed.

Abstract: The present disclosure provides an engine operating method and high power density internal combustion engine, including an engine housing with a plurality of cylinders. Fuel injectors are provided and disposed at least partially within each cylinder, and configured to inject fuel such as diesel, JP8 or another fuel therein for compression ignition. The engine is configured to burn a quantity of injected fuel to yield at least about 150 horsepower per liter of engine displacement at a smoke output of less than about 0.4 grams, and in some cases less than about 0.75 grams, smoke per horsepower-hour, at a fuel consumption of less than about 250 grams fuel per kilowatt-hour output of the engine.

Abstract: An engine controller performs low opening degree control during a first intake stroke period since an engine start is commenced until first intake strokes of respective cylinders end. Thus, an opening degree of an intake throttle valve is controlled to a fully closed position or proximity of the fully closed position such that intake pressure downstream of the intake throttle valve becomes equal to or lower than critical pressure with respect to intake pressure upstream of the intake throttle valve during an intake stroke of each cylinder. The controller calculates a leak air quantity at the time when the intake throttle valve is fully closed based on an intake air quantity sensed during the low opening degree control. The controller corrects a feedback gain of idle speed control in accordance with the leak air quantity of the intake throttle valve.

Abstract: A change in a torque request for an internal combustion engine during a prediction period is predicted as a change in a target torque. Further, a change in an outputtable upper-limit torque during the prediction period is calculated as an upper-limit torque change. When the target torque is greater than the upper-limit torque by more than a judgment value during the prediction period, control is exercised to increase an intake air amount. Moreover, the torque difference between the target torque and upper-limit torque at a second time, which is later than a first time, is calculated to correct the torque difference with higher responsiveness than exhibited for intake air amount control.

Abstract: Described herein are various embodiments of an apparatus, system and method for operating a dual fueled spark ignition engine. For example, according to one illustrative embodiment, a method for operating a dual fueled spark ignition engine includes fueling the engine solely with a combustion promoter within a first engine load range between zero and an engine load associated with a target combustion condition selected from the group consisting of rough limit, knock limit, and any of various conditions between the rough limit and knock limit. Within the first engine load range, the amount of combustion promoter fueling the engine increases as the load increases. The method further includes fueling the engine on a mixture of ammonia and the combustion promoter within a second engine load range between the engine load associated with the selected target combustion condition and the engine load associated with a maximum operating pressure of the engine.

Abstract: A base engine torque generated with an estimated intake air amount is estimated. An engine torque is corrected by correcting an ignition timing based on a difference between a required engine torque and the base engine torque. A torque correction amount is calculated based on a correction amount of the ignition timing. An actual engine torque is estimated based on the calculated torque correction amount and the base engine torque. A permitted component driving torque is a difference between the actual engine torque and the required vehicle driving torque. A component is controlled based on the permitted component driving torque.

Abstract: The present invention reduces exhaust emissions at startup, provides improved fuel pressure control performance in a low-load region, and detects high-pressure fuel system abnormalities. Disclosed is a high-pressure fuel system control device which includes a high-pressure pump for pressurizing fuel and discharging the pressurized fuel to a fuel rail, an injector for injecting the fuel stored in the fuel rail, and a fuel pressure sensor for measuring the pressure of the fuel stored in the fuel rail, and controls the high-pressure pump and the injector in accordance with an output generated from the fuel pressure sensor.

Abstract: In a method for limiting the power output of an internal combustion engine, an air mass flow deviation of an actual air mass flow (mL(IST)) from a reference air mass flow (ML(REF)) is determined and, depending on the air mass flow deviation, a power output reduction is determined by which the maximum power output limit of the internal combustion engine is to be reduced in order to prevent overheating of the internal combustion engine.

Abstract: A method for recognizing the fuel type in a diesel engine; the method envisages determining a stoichiometric air/fuel ratio of the last type of fuel used; determining a quantity of fresh air fed to a number of cylinders of the engine; determining a quantity of fuel injected in the cylinders; determining a theoretical air/fuel ratio of combustion according to the quantity of fresh air fed to cylinders, according to the quantity of fuel injected into cylinders, and according to the stoichiometric air/fuel ratio of the last type of fuel used; determining an actual air/fuel ratio of combustion; comparing the theoretical air/fuel ratio with the actual air/fuel ratio; and recognizing the fuel type actually used according to the comparison between the theoretical air/fuel ratio and the actual air/fuel ratio.

Abstract: There is provided an air amount computing unit, and a fuel control unit, of an internal combustion engine that calculates a cylinder flow-in air amount during a transient state without response delay and so as not to have any inflection point in changes of flow rate and that allows a desirable air-fuel ratio to be kept.

Abstract: An engine controller for engine control apparatus is configured to retard an ignition timing, from an engine starting mode timing to a catalyst warm-up mode timing at an idle attainment moment at which an engine idling condition is reached, and to regulate an intake air quantity at a prior moment prior to the idle attainment moment. Moreover, the controller increases a fuel injection quantity by an increase quantity during a period from the prior moment until an intake settlement moment at which an intake air condition settles down. The controller sets the increase quantity of the fuel injection quantity in accordance with a parameter representing a condition of the intake air or fuel supplied to the engine.

Abstract: A method of switching a combustion mode of a diesel engine may include determining a carbon dioxide concentration in an intake manifold of a diesel engine, operating the diesel engine in a first combustion mode, and operating the diesel engine in a second combustion mode when the determined carbon dioxide concentration is greater than a predetermined carbon dioxide concentration value.

Abstract: An engine system for a power unit is disclosed. The engine system includes an exhaust system having at least one exhaust treatment device and an air induction system having at least one heater. The heater is configured to raise the temperature of an intake flow in the air induction system in response to a physical property of the exhaust treatment device.

Abstract: A carburetor includes a body, a fuel metering system carried by the body to regulate fuel flow to the body, and a fuel-and-air mixing passage in fluid communication with the fuel metering system. The mixing passage extends through the body and is partitioned into a rich mixture passage, and a lean mixture passage positioned between the rich mixture passage and the fuel metering system.

Abstract: Method of controlling the combustion of an internal-combustion engine, in particular a direct-injection supercharged engine, notably of gasoline type, wherein the engine comprises at least one cylinder (12) with a combustion chamber (14) within which a compression stage takes place, followed by a stage of combustion of a fuel mixture by a spark-ignition means (34), characterized in that it consists in measuring a quantity related to at least one parameter representative of the state of the fuel mixture during said stages; in determining a value that depends on the amplitude of the measured quantity; in comparing the determined value with at least one threshold value representative of the quantity related to said parameter representative of the conventional state of the fuel mixture during said stages; in detecting the start of an abnormal combustion when the determined value exceeds said threshold value and when the ignition means is not actuated; in controlling the course of the abnormal combustion detected

Abstract: In an internal combustion engine the fuel is injected into an intake manifold. A quantity characterizing the injection quantity is a function of a predicted quantity which characterizes a predicted air charge. A setpoint quantity is used for determining the predicted quantity which characterizes a setpoint air charge.

Abstract: A learning time counter is started and updated if an operation state is stabilized after shifting to a certain operation range. Then, convergence of a FCCB correction value of a variation in an injection characteristic is determined. If the FCCB correction value is determined to have converged, a permit flag is turned on and the FCCB correction value is decided as a learning value. Even if the FCCB correction value does not converge, the learning value is compulsorily decided when the learning time counter reaches a threshold. If the FCCB correction value is decided early, a surplus time is added to a threshold of the next operation range. Thus, the variation of the injection characteristics among cylinders can be learned highly accurately while averting unnecessary lengthening of a learning time.

Abstract: Provided is a control device for an internal combustion engine, which is provided to allow a throttle opening degree to be controlled in accordance with a target engine intake air flow quantity even during transitional operation. The actual cylinder intake air flow quantity calculating unit (21) calculates a response delay model for an intake system from a volumetric efficiency equivalent value (Kv) calculated from a rotational speed (Ne) of an engine (1) and an intake manifold pressure (Pim), an intake pipe volume (Vs), and a displacement (Vc) of each of cylinders (2), and calculates an actual cylinder intake air amount (Qcr) from an actual engine intake air amount (Qar) obtained from an air flow sensor (4) and the response delay model. The intake air flow quantity controlling unit (24) controls the throttle opening degree (TP) in accordance with the target engine intake air amount (Qat).

Abstract: A method and system for controlling fuel flow in a fuel metering system that includes a metering valve and a proportional bypass valve that produces a differential pressure error across the metering valve includes supplying a first fraction of fuel through the metering valve. A second fraction of the fuel is directed through the proportional bypass valve. The differential pressure error produced by the bypass valve is determined, and fuel flow through the supply line is controlled by adjusting the metering valve based at least in part on the determined differential pressure error, and by adjusting the proportional bypass valve to maintain a substantially constant metering valve differential pressure across the metering valve.

Abstract: A control system for controlling a valve in a fuel system of engine including an engine airflow sensor that senses a mass engine airflow (Mengair), a barometric pressure sensor that senses a barometric pressure (Pbaro), and an ambient temperature sensor that senses an ambient temperature (Tamb). An actuator determination module determines an effective area (Aeff) of the valve based on at least one of the Mengair, the Pbaro, and the Tamb. A duty cycle (DC) calculation module that determines a first duty cycle (DC) of the valve based on the Aeff.

Abstract: An internal combustion engine system has an internal combustion engine with an intake for air and an exhaust for products of combustion. The engine has a turbocharger for pressurizing intake air in response to passage of the products of combustion. An exhaust aftertreatment device receives the exhaust from the engine to filter diesel particulates. A device for regenerating the exhaust aftertreatment device has a feed line and nozzle for injecting duel upstream of the exhaust aftertreatment device on a periodic basis. A system and method for purging the fuel line and the nozzle utilizes pressurized air from the engine turbocharger via an air tank when the regenerating device is not injecting fuel.

Abstract: Disclosed is a fuel filter for removing sulfur containing compounds from an internal combustion fuel stream. In one embodiment, the fuel filter comprises at least one column comprising an adsorbent. In one exemplary embodiment the adsorbent is capable of removing sulfur containing compounds, especially sulfur containing aromatic compounds, from fuels used in internal combustion engines, especially diesel fuels. Also disclosed is an apparatus for extending the life cycle of a post combustion emission control device. In one exemplary embodiment, the apparatus comprises a fuel filter for removing sulfur containing compounds from an internal combustion fuel stream and an emission control device. Finally, a method for removing sulfur containing compounds from an internal combustion fuel stream is disclosed.

Abstract: A method of monitoring air flow restriction in an air intake of an internal combustion engine includes monitoring a plurality of manifold absolute pressure (MAP) samples and determining respective MAP thresholds corresponding to each of the MAP samples. Each of the MAP samples is compared to its respective MAP threshold. A percentage of failed MAP samples is determined based on the comparing and an over-restricted air intake condition is selectively indicated based on the percentage of failed MAP samples.

Abstract: A fuel injection control system makes it possible to obtain an output of a lean combustion type engine through an easy operation, even in a throttle opening region of greater than a lean limit. A throttle valve is configured to be turnable up to an over-fully opened position, which is greater than a fully opened position that corresponds to a maximum air flow rate, where the air flow rate is not substantially varied from the maximum air flow rate. In a region where the throttle valve is operated to or above the fully opened position when under a high load, the fuel-air mixture is enriched and a high output is obtained by controlling the throttle opening through operating only a power lever.

Abstract: A method is provided for controlling an engine having an intake manifold and an outlet control device coupled to the manifold for controlling flow exiting the manifold and entering at least one cylinder of the engine. The engine further includes an inlet control device for controlling flow entering the manifold. The method includes providing an engine command; calculating a desired cylinder charge based on said command; and adjusting the outlet control device to provide said desired cylinder charge. The engine command may be, for example, a driver command, such as a driver torque command. Further, the outlet control device may be implement in with a variety of mechanisms. For example, in one embodiment the outlet control device is a valve of the engine having a variable lift. In one embodiment the outlet device is a valve having variable timing. Likewise, the inlet device may be adjusted in response to a variety of parameters.

Abstract: An apparatus for an aspiration plate for a rotary internal combustion engine. The engine has three rotating members that orbit about the center of a three-armed rotor as the rotor rotates within a housing with three lobes. The tips of the rotating members engage the lobes and a circular cutout in the rotor as the rotor rotates. A back, or aspiration, plate includes inlet and exhaust ports that are sequentially opened and closed by the rotating members and rotor as they move within the housing. A front plate rotates with the rotor and separates the combustion chambers from a planetary gear assembly that ensures the alignment of the rotating members as they orbit the rotor shaft. Fuel is injected after the compression cycle is initiated.

Abstract: An engine system for a motor vehicle including a source of pressurized fuel and an intake system having one or more of a converter unit, a mixer unit, a pressure balance line, and a primer system. The pressure balance line may be configured with offset access to an air stream within the charge tube during operation, leading to improved overall responsiveness of the engine system. A snowmobile and personal watercraft are two motor vehicles finding particular utility for the engine system.

Abstract: A dual injection type internal combustion engine including an injector for in-cylinder injection and an injector for intake manifold injection includes a learning device for learning a background noise level based on an output signal of a knock sensor, and a knocking suppression control device for performing, while learning the background noise level, knocking suppression control by controlling fuel injection of the injector for in-cylinder injection or the injector for intake manifold injection. Alternatively, the engine includes a fixing device for fixing, while learning the background noise level, a start timing or end timing of fuel injection by the injector for in-cylinder injection at a basic timing determined by an operating state of the engine.

Abstract: A cylinder air filling amount is divided into a first amount of air and a second amount of air, the first amount of air and the second amount of air are calculated, and the first amount of air and the second amount of air are totaled to calculate a cylinder air filling amount. The first amount of air is the excess of the cylinder air filling amount with respect to the throttle valve air passage amount occurring due to an intake stroke being performed. The drop in intake pressure occurring due to an intake stroke being performed is detected for each cylinder and the total value of the intake pressure drop in a 720° crank angle range is calculated. The first amount of air is calculated based on an intake pressure drop and the intake pressure drop total value. Due to this, it is possible to simply and accurately calculate a cylinder air filling amount.

Abstract: A method for controlling an engine having at least one cylinder, the engine coupled to a vehicle, the engine also having an intake manifold and an outlet control device for controlling flow from the intake manifold into the cylinder, the engine further having an inlet control device for controlling flow into the intake manifold, the outlet control device including an electronic throttle, the engine also having an exhaust gas oxygen sensor, the method comprising of generating a signal representing a request from a driver, determining a desired torque based on said request in response to said signal and to improve drive feel, adjusting the outlet control device based on said desired torque, adjusting throttle position based on an operating parameter and injecting fuel into the engine based on a signal from the sensor to maintain average air/fuel at stoichiometry.

Abstract: A method and associated arrangement for achieving an adjusted engine setting utilizing engine output and/or fuel consumption. An engine that consumes fuel is run. Fuel consumption and/or engine operation output is determined. A value is determined utilizing the determined fuel consumption and/or the determined engine operation output. The engine setting is adjusted to cause the determined value to change toward a desired value.

Abstract: A base engine torque generated with an estimated intake air amount is estimated. An engine torque is corrected by correcting an ignition timing based on a difference between a required engine torque and the base engine torque. A torque correction amount is calculated based on a correction amount of the ignition timing. An actual engine torque is estimated based on the calculated torque correction amount and the base engine torque. A permitted component driving torque is a difference between the actual engine torque and the required vehicle driving torque. A component is controlled based on the permitted component driving torque.

Abstract: Method for controlling and improving the transient emissions of an electronically controlled heavy duty diesel engine having an ECM with memory, a turbocharger and an EGR system.

Abstract: In an engine having a premixed combustion mode, an EGR flow rate estimating precision is deteriorated at a transient time, and a torque fluctuation and an exhaust gas deterioration are caused. In an engine control apparatus having a premixed combustion mode and a diffusion combustion mode, a sensor detecting an EGR flow rate is arranged in an EGR flow path of the engine, and a cylinder state of the engine is estimated by using an output value of the sensor detecting the EGR flow rate at a time when the engine is in the premixed combustion mode. Since it is possible to accurately detect the EGR flow rate at the transient time and feed back the EGR flow rate at a high response, it is possible to prevent a torque fluctuation and an exhaust gas deterioration.

Abstract: An intake air heating system for an internal combustion engine is disclosed and includes an electric heater that heats the intake air and a control module that switches a voltage to the electric heater based on a control signal. The control module includes a gate drive module that includes a bootstrap charge pump module and generates a gate drive signal based on the control signal and that is referenced to the voltage. The control module also includes a power module that switches the power to the electric heater based on the gate drive signal.

Abstract: An intake air heating system for an internal combustion engine includes an electric heater that heats the intake air, a control circuit that switches a voltage to the electric heater based on a control signal and an over-temperature signal, a temperature sensor that generates a temperature signal based on a temperature of the control circuit, and a temperature sensing circuit that generates the over-temperature signal based on the temperature signal and a predetermined temperature.

Abstract: A control system for an internal combustion engine having fuel injection valves provided in a combustion chamber and an exhaust gas recirculation mechanism. Target maximum cylinder pressure change rates are set according to the operating condition of the engine. The maximum change rate of the detected cylinder pressure and a fuel injection timing correction amount are calculated wherein a difference between the calculated maximum change rate and the target maximum cylinder pressure change rate decreases. The fuel injection timing is corrected with the fuel injection timing correction amount. The recirculation amount of exhaust gases is controlled using the calculated control value. A correction amount of the exhaust gas recirculation amount is calculated when the fuel injection timing correction amount exceeds a predetermined amount. The exhaust gas recirculation amount is controlled using the control value corrected with the correction amount of the exhaust gas recirculating amount.

Abstract: A fuel injection system during operation of an internal combustion engine with at least two separately stored fuel types is supplied with at least one first fuel type. With the supply of a second fuel type or with the change from the supply of the first fuel type to the second fuel type, the fuel volume conveyed by the injection system is determined and dependent thereon the presence of a given fuel mixture ratio is verified.

Abstract: A motor-driven supercharger of the invention is provided with a cooling fluid flow rate adjusting device (a flow rate adjuster (37) and a controller (40)) capable of adjusting a flow rate of a cooling fluid. On the basis of the flow rate adjuster (37) and the controller (40), a flow rate of a cooling fluid (41) is set to a first flow rate (a large flow rate) for cooling an electric motor (20) in a state where a temperature difference obtained by subtracting a temperature of the cooling fluid (41) from a temperature of the electric motor (20) is equal to or more than a predetermined temperature equal to or more than zero, and the flow rate of the cooling fluid (41) is set to a second flow rate (a small flow rate) which is smaller than the first flow rate and is for suppressing a heating effect to the electric motor (20) in a state where the temperature difference is lower than a predetermined temperature equal to or more than zero.

Abstract: A method and apparatus for controlling engine operation to compensate for effects of combustion chamber deposits (CCDs) on combustion in a controlled auto-ignition engine is presented. Control methodologies comprise operation of variable valve actuation, fuel injection, spark timing, and intake air and coolant temperature to dynamically compensate for the effect of CCDs. A sensitivity to core gas temperature and chamber wall thermal conditions is shown, which is correlatable to in-cylinder CCD formation. Intake charge or coolant temperature control can be used to compensate for CCD effects. An engine control scheme relies upon a parametric input that quantifies instantaneous CCD formation in the combustion chamber. The result is further applicable to control pre-ignition in a conventional spark-ignition engine.

Abstract: A method for rapidly transitioning from a lean combustion mode to a rich combustion mode, such as often required for the regeneration of aftertreatment devices, is provided by abrupt intake air reduction and a concurrent abrupt increase in fuel injection quantity with accompanying retardation of fuel injection timing. The abrupt increase in fuel quantity is to a maximum value sufficient to immediately provide a defined initial rich air/fuel ratio for a coexistent oxygen concentration in the cylinder. The fuel quantity is then proportionally reduced from the maximum value to a target fuel quantity to maintain a target air/fuel ratio during the transition. Simultaneously, injection timing is abruptly retarded to a value sufficient to avoid torque increase as a result of the increased injected fuel. The injection timing is subsequently proportionally advanced from the abruptly retarded timing value when the target fuel quantity and air/fuel ratio values are achieved.