Abstract: A control apparatus and method for an internal combustion engine are provided for ensuring a stable combustion state and improving the fuel efficiency when an air-fuel mixture is burnt with self ignition while auxiliarily using a spark ignition. The control apparatus for an internal combustion engine which is operated in a plurality of modes including a torch self ignition combustion mode comprises an ECU. In the torch self ignition combustion mode, the ECU controls an internal EGR amount, calculates an actual exhaust closing angle, calculates a target exhaust closing angle, calculates a closing angle deviation, calculates a fuel injection amount for forming a homogeneous air-fuel mixture, calculates a correction coefficient in accordance with the closing angle deviation, and corrects a basic value by the correction coefficient to calculate a fuel injection amount for forming a stratified air-fuel mixture.

Abstract: An EGR control apparatus and method for an internal combustion engine which burns an air-fuel mixture with self ignition in addition to a flame propagation combustion, are provided for improving the combustion efficiency, engine output, drivability, and exhaust gas characteristics in an internal combustion engine which involves a self ignition combustion of an air-fuel mixture in addition to a flame propagation combustion.

Abstract: An internal EGR control device for an internal combustion engine, which is capable of properly controlling an internal EGR amount, while causing conditions of burned gases to be reflected thereon in controlling the internal EGR by changing valve-closing timing of an exhaust valve. An internal EGR control device sets a target internal EGR amount EGRINCMD as a target of the internal EGR amount according to detected operating conditions of an internal combustion engine, and a target internal EGR amount EGRINC is determined by correcting the target internal EGR amount based on a gas state equation, using obtained temperature and pressure of exhaust gases, and a calculated gas constant R. Then, according to the corrected target internal EGR amount EGRINC, the valve-closing timing of an exhaust valve is calculated, and a variable valve mechanism is controlled based on the calculated valve-closing timing of the exhaust valve.

Abstract: An internal EGR control device for an internal combustion engine, which is capable of properly controlling an internal EGR amount, while causing conditions of burned gases to be reflected thereon in controlling the internal EGR by changing valve-closing timing of an exhaust valve. An internal EGR control device sets a target internal EGR amount EGRINCMD as a target of the internal EGR amount according to detected operating conditions of an internal combustion engine, and a target internal EGR amount EGRINC is determined by correcting the target internal EGR amount based on a gas state equation, using obtained temperature and pressure of exhaust gases, and a calculated gas constant R. Then, according to the corrected target internal EGR amount EGRINC, the valve-closing timing of an exhaust valve is calculated, and a variable valve mechanism is controlled based on the calculated valve-closing timing of the exhaust valve.

Abstract: A fuel injection control apparatus and method for an internal combustion engine are provided for appropriately calculating fuel injection times for an in-cylinder fuel injection valve and a port fuel injection valve, thereby accurately controlling the amounts of fuel supplied to the internal combustion engine from the in-cylinder fuel injection valve and the port fuel injection valve, respectively. The fuel injection control apparatus calculates an in-cylinder fuel injection amount which should be injected by the in-cylinder fuel injection valve, and calculates an in-cylinder fuel injection time which is a valve opening time of the in-cylinder fuel injection valve in accordance with the calculated in-cylinder fuel injection amount and an acquired cylinder internal pressure.

Abstract: An air-fuel ratio of an air-fuel mixture produced by fuel injected from a first injector into an intake port (or into a combustion chamber) is set in a range of 28 to 38. Therefore, when the temperature and pressure rise with a first combustion started by spark-ignition around a spark plug to the fuel injected from a second injector into the combustion chamber, the timing of starting a second compressive hypergolic ignition is optimized to provide a stable combustion state free of knocking and misfire.

Abstract: A control system for an internal combustion engine, which is capable of positively preventing a misfire or knocking during a compression ignition combustion mode by switching from the compression ignition combustion mode to a spark ignition combustion mode in appropriate timing. The engine is operated while switching between the compression ignition and spark ignition combustion modes. The control system (ECU) sets a target operating gas temperature to which the temperature of operating gases in a combustion chamber is to be controlled in the compression ignition combustion mode, sets a target internal EGR amount to which the internal EGR amount is to be controlled, such that the temperature of operating gases in the combustion chamber becomes equal to the target operating gas temperature, and switches the combustion mode to the spark ignition combustion mode depending on the target internal EGR amount.

Abstract: An air-fuel ratio of an air-fuel mixture produced by fuel injected from a first injector into an intake port (or into a combustion chamber) is set in a range of 28 to 38. Therefore, when the temperature and pressure rise with a first combustion started by spark-ignition around a spark plug to the fuel injected from a second injector into the combustion chamber, the timing of starting a second compressive hypergolic ignition is optimized to provide a stable combustion state free of knocking and misfire.

Abstract: A fuel injection control apparatus and method for an internal combustion engine are provided for appropriately controlling the amounts of fuel supplied from an in-cylinder fuel injection valve and a port fuel injection valve to a cylinder in a simple control approach while satisfactorily reflecting a fuel transport behavior as a whole cylinder. An ECU calculates a required in-cylinder injection amount and a required port injection amount, calculates an in-cylinder injected fuel behavior parameter of a fuel from the in-cylinder fuel injection valve and a port injected fuel behavior parameter of the fuel from the port fuel injection valve, a net in-cylinder injection amount in accordance with the in-cylinder and port injected fuel behavior parameters based on the required in-cylinder injection amount, and a net port injection amount in accordance with the in-cylinder and port injected fuel behavior parameters based on the required port injection amount.

Abstract: A control apparatus and method for an internal combustion engine are provided for ensuring a stable combustion state and improving the fuel efficiency when an air-fuel mixture is burnt with self ignition while auxiliarily using a spark ignition. The control apparatus for an internal combustion engine which is operated in a plurality of modes including a torch self ignition combustion mode comprises an ECU. In the torch self ignition combustion mode, the ECU controls an internal EGR amount, calculates an actual exhaust closing angle, calculates a target exhaust closing angle, calculates a closing angle deviation, calculates a fuel injection amount for forming a homogeneous air-fuel mixture, calculates a correction coefficient in accordance with the closing angle deviation, and corrects a basic value by the correction coefficient to calculate a fuel injection amount for forming a stratified air-fuel mixture.

Abstract: A fuel injection control apparatus and method for an internal combustion engine are provided for appropriately calculating fuel injection times for an in-cylinder fuel injection valve and a port fuel injection valve, thereby accurately controlling the amounts of fuel supplied to the internal combustion engine from the in-cylinder fuel injection valve and the port fuel injection valve, respectively. The fuel injection control apparatus calculates an in-cylinder fuel injection amount which should be injected by the in-cylinder fuel injection valve, and calculates an in-cylinder fuel injection time which is a valve opening time of the in-cylinder fuel injection valve in accordance with the calculated in-cylinder fuel injection amount and an acquired cylinder internal pressure.

Abstract: An EGR control apparatus and method for an internal combustion engine which burns an air-fuel mixture with self ignition in addition to a flame propagation combustion, are provided for improving the combustion efficiency, engine output, drivability, and exhaust gas characteristics in an internal combustion engine which involves a self ignition combustion of an air-fuel mixture in addition to a flame propagation combustion.

Abstract: An EGR failure determination system for an internal combustion engine, which is capable of accurately determining failures of both an external EGR device and an internal EGR device, irrespective of whether the EGR amount is large or small, thereby making it possible to enhance marketability of the system. The EGR failure determination system includes an ECU. The ECU calculates an actual fresh air ratio, and sets a target value thereof. Further, it calculates a feedback correction coefficient according to the actual fresh air ratio and the target value, and controls an exhaust recirculation mechanism and three variable mechanism. When the feedback correction coefficient is not within a predetermined range, and if it is larger than 0.5, at least one of the three variable mechanism is determined to be faulty, whereas if it is not larger than 0.5, the exhaust recirculation mechanism is determined to be faulty.

Abstract: A control system for an internal combustion engine, which is capable of positively preventing a misfire or knocking during a compression ignition combustion mode by switching from the compression ignition combustion mode to a spark ignition combustion mode in appropriate timing. The engine is operated while switching between the compression ignition and spark ignition combustion modes. The control system (ECU) sets a target operating gas temperature to which the temperature of operating gases in a combustion chamber is to be controlled in the compression ignition combustion mode, sets a target internal EGR amount to which the internal EGR amount is to be controlled, such that the temperature of operating gases in the combustion chamber becomes equal to the target operating gas temperature, and switches the combustion mode to the spark ignition combustion mode depending on the target internal EGR amount.

Abstract: A control system for an internal combustion engine, which can determine just enough amounts of demanded combustion fuel and auxiliary fuel during execution of auxiliary fuel supply, for improvement of fuel economy and drivability and the emission-reducing capability of a catalyst. The control system carries out auxiliary fuel supply for a cylinder during a predetermined time period within the expansion and exhaust strokes, to control the catalyst to a predetermined state for its emission-reducing capability. The control system calculates a whole demanded fuel amount to make oxygen concentration in exhaust gases equal to a predetermined value for controlling the catalyst to the state during auxiliary fuel supply, determines the amount of demanded combustion fuel to be supplied to obtain engine output, and determines the auxiliary fuel amount based on the difference between the whole demanded fuel amount and the demanded combustion fuel amount.

Abstract: An internal EGR control system for an internal combustion engine, which is capable of controlling the internal EGR amount with accuracy, when controlling the internal EGR by changing both the exhaust cam phase and the exhaust valve lift. An internal EGR control system for an internal combustion engine controls internal EGR in which combustion gases are caused to remain in a cylinder. An ECU sets a target cam phase serving as a target of the exhaust cam phase, and controls a variable exhaust cam phase mechanism such that the exhaust cam phase becomes equal to the target cam phase. ECU 2 sets a target lift of an exhaust valve according to a detected actual cam phase and calculated valve-closing timing, and controls a variable exhaust valve lift mechanism such that the lift of the exhaust valve becomes equal to the target lift.

Abstract: An EGR control system that is capable of controlling the amount of recirculation of high-temperature and low-temperature recirculated gases, with high accuracy, to thereby improve the control accuracy of in-cylinder temperature. An ECU of an ERG control system calculates a fresh intake air ratio, and sets a target value of the fresh intake air ratio. The ECU calculates a feedback correction coefficient for converging the fresh intake air ratio to the target value, with an I-PD control algorithm, and sets an external EGR ratio and an internal EGR ratio. The ECU controls the EGR amount whose ratio is the larger, according to the larger one of the two ratios and the feedback correction coefficient, and controls the EGR amount whose ratio is the smaller, according to the smaller of the ratios and the learned value thereof.

Abstract: In a control system for a compression-ignition engine whose operation is switchable between a compression-ignition operation in which an air-fuel mixture supplied to a combustion chamber auto-ignites to burn owing to compression and a spark-ignition operation in which the air-fuel mixture is ignited to burn by a spark of a spark plug, it is determined whether a predetermined prohibitive condition to prohibit switching from the spark-ignition to the compression-ignition operation is satisfied, and switching from the spark-ignition operation to the compression-ignition operation is prohibited when the predetermined prohibitive condition is satisfied, thereby enabling to avoid premature ignition and misfire and to prevent drivability and fuel consumption performance from being affected therefrom.

Abstract: An EGR failure determination system for an internal combustion engine, which is capable of accurately determining failures of both an external EGR device and an internal EGR device, irrespective of whether the EGR amount is large or small, thereby making it possible to enhance marketability of the system. The EGR failure determination system includes an ECU. The ECU calculates an actual fresh air ratio, and sets a target value thereof. Further, it calculates a feedback correction coefficient according to the actual fresh air ratio and the target value, and controls an exhaust recirculation mechanism and three variable mechanism. When the feedback correction coefficient is not within a predetermined range, and if it is larger than 0.5, at least one of the three variable mechanism is determined to be faulty, whereas if it is not larger than 0.5, the exhaust recirculation mechanism is determined to be faulty.

Abstract: A control system for an internal combustion engine, which can determine just enough amounts of demanded combustion fuel and auxiliary fuel during execution of auxiliary fuel supply, for improvement of fuel economy and drivability and the emission-reducing capability of a catalyst. The control system carries out auxiliary fuel supply for a cylinder during a predetermined time period within the expansion and exhaust strokes, to control the catalyst to a predetermined state for its emission-reducing capability. The control system calculates a whole demanded fuel amount to make oxygen concentration in exhaust gases equal to a predetermined value for controlling the catalyst to the state during auxiliary fuel supply, determines the amount of demanded combustion fuel to be supplied to obtain engine output, and determines the auxiliary fuel amount based on the difference between the whole demanded fuel amount and the demanded combustion fuel amount.