Abstract: An electronic valve actuation system and control method is described. The valve timing is changed between early and late intake valve closing depending on engine operating conditions. Further, valve timing is adjusted to control engine airflow or engine torque. Finally, air-fuel ratio is adjusted based on feedback from an exhaust gas oxygen sensor as well as an estimate of air, fuel, and residual exhausted from cylinders operating with late valve closing (after bottom dead center) timing.

Abstract: A control method of an EGR system of an engine capable of effectively performing an EGR control at a time of rapid acceleration. For this purpose, an intake air flow rate of the engine is obtained, and from a target EGR valve opening degree and a difference in pressure in front of and behind the EGR valve, a virtual EGR gas flow rate is arithmetically operated. A virtual EGR rate is obtained from the intake air flow rate, the fuel flow rate and the virtual EGR gas flow rate, and a difference from or a ratio to a target EGR rate obtained from the engine speed and the fuel flow rate is obtained. A command EGR valve opening degree is obtained from an EGR valve opening degree correction coefficient obtained from the difference or the ratio, and the target EGR valve opening degree, whereby the EGR vale is driven.

Abstract: An ignition timing control apparatus for an internal combustion engine having a plurality of cylinders, wherein operation of the engine is switchable between a partial-cylinder operation, which operates some of the cylinders, and an all-cylinder operation, which operates all of the cylinders. Basic ignition timing is calculated according to an operating condition of the engine. Knocking is determined based on an output of the knock sensor. A correction amount of the ignition timing is calculated according to a result of the knocking determination to suppress knocking, and the basic ignition timing is corrected with the calculated correction amount. Learning values of the correction amount are calculated corresponding, respectively, to partial-cylinder operation and all-cylinder operation, and one of the calculated learning values is used according to the operating condition of the engine.

Abstract: A control system for an internal combustion engine is disclosed. The engine has an exhaust gas recirculation passage for recirculating a portion of exhaust gases from the engine to an intake system and an exhaust gas recirculation control valve for controlling an amount of exhaust gases recirculated through the exhaust gas recirculation passage. A valve opening amount of the exhaust gas recirculation control valve is detected. A fuel amount to be supplied to the engine is calculated according to the valve opening amount of the exhaust gas recirculation control valve. An average valve opening value, a change rate of which is smaller than that of the detected valve opening amount is used to calculate a correction value for correcting the fuel supply amount. The fuel supply amount is corrected according to the calculated correction value from a time at which an opening of the exhaust gas recirculation control valve is detected.

Abstract: It is an object of the present invention to provide a compression ignition internal combustion engine capable of making compatible an increase in compression self-ignition operating area with an optimum output torque control in the operating area and also smoothly switching between a self-ignition combustion and a spark ignition combustion. The compression ignition internal combustion engine operates by switching between the spark ignition combustion using an ignition device and the compression ignition combustion which self-ignites a mixture by piston compression. Variable valve mechanisms vary at least one of the valve timings and valve lifts of an intake valve and an exhaust valve. Intake air is regulated to vary the amount of air intake into a combustion chamber on the upstream side of a combustion chamber inlet of the compression ignition internal combustion engine.

Abstract: This feature of the present invention comprises an ignition diagnostics and feedback control system based upon detected ionization current in an individual cylinder. The system is divided into two subsystems: an ignition diagnostics subsystem and an ignition feedback control system subsystem. The ignition diagnostics subsystem comprises an ignition system diagnostics, a misfire detector, a knock detector, and a robust multi-criteria minimum timing for best torque MBT timing estimator. The ionization feedback control subsystem comprises five main subsystems: a closed loop cold start retard spark control using ionization feedback, a closed loop MBT timing control using ionization feedback, a closed-loop individual cylinder air to fuel ratio balancing control system, an optimal wide open throttle air/fuel ratio control, and an exhaust gas control using a spark plug ionization signal.

Abstract: An ignition timing control system for an internal combustion engine includes an electronic control unit. In a transition state where an in-cylinder EGR rate varies, the unit calculates an ignition timing corresponding to the in-cylinder EGR rate by means of linear interpolation based on ignition timings for EGR and non-EGR operations determined from maps, sets a retard amount based on the ratio of the in-cylinder EGR rate to a target EGR rate, and performs ignition timing control based on a corrected ignition timing obtained by subtracting the retard amount from the calculated ignition timing, thus preventing occurrences of knocking due to excessively advanced ignition timing, and deteriorated fuel consumption and drivability.

Abstract: An ignition timing control system for an internal combustion engine includes an electronic control unit. In a transition state where an in-cylinder EGR rate varies, the unit calculates an ignition timing corresponding to the in-cylinder EGR rate by means of linear interpolation based on ignition timings for EGR and non-EGR operations determined from maps, sets a retard amount based on the ratio of the in-cylinder EGR rate to a target EGR rate, and performs ignition timing control based on a corrected ignition timing obtained by subtracting the retard amount from the calculated ignition timing, thus preventing occurrences of knocking due to excessively advanced ignition timing, and deteriorated fuel consumption and drivability.

Abstract: An apparatus for controlling an engine responds to the switching of combustion mode from stoichiometric combustion to lean-fuel combustion to vary the target throttle opening in step-wise fashion, causing the quantity of intake air to increase in a fashion of first-order delay. The base fuel injection quantity and base ignition timing are computed based on the response of intake air quantity. Consequently, the torque shock can be reduced and the quick combustion mode switching can be performed. Based on the quick passage of the air-fuel ratio zone in which a large amount of NOx arises, the amount of NOx emission can be reduced.

Abstract: A control system for an internal combustion engine is disclosed. The engine has an exhaust gas recirculation passage for recirculating a portion of exhaust gases from the engine to an intake system and an exhaust gas recirculation control valve for controlling an amount of exhaust gases recirculated through the exhaust gas recirculation passage. A valve opening amount of the exhaust gas recirculation control valve is detected. A fuel amount to be supplied to the engine is calculated according to the valve opening amount of the exhaust gas recirculation control valve. An average valve opening value, a change rate of which is smaller than that of the detected valve opening amount is used to calculate a correction value for correcting the fuel supply amount. The fuel supply amount is corrected according to the calculated correction value from a time at which an opening of the exhaust gas recirculation control valve is detected.

Abstract: A device for controlling an internal combustion engine capable of estimating the amount of NOx emission within short periods of time maintaining high precision and realizing improved control performance without increasing the cost as a result of not using map data in the ROM. The device includes NOx operation circuit for estimating the amount of NOx in the exhaust gas from a theoretical formula and an empirical formula based upon the intake air amount Qa, intake air temperature To, pressure Pb, air-fuel ratio &lgr; and EGR rate &bgr;, and control circuit for controlling at least either the NOx purifying catalyst or the combustion state in the internal combustion engine in order to lower the amount of NOx emission.

Abstract: Method for correction of the spark advance for an internal combustion engine with a continuous phase transformer at the intake and/or exhaust; for each cylinder, the method consists of calculating a theoretical value of the optimum spark advance according to the drive point, calculating a first correction value, which depends on the mass of burnt gas trapped in the cylinder at the end of the intake phase, calculating a second correction value, which depends on the torque value generated, and calculating the actual value of the spark advance, by adding the two correction values to the theoretical value of the spark advance.

Abstract: In order to improve estimation accuracy of estimating the value of the NOx exhaust concentration, the air fuel ratio control apparatus is adapted to estimate the NOx exhaust concentration from at least either one of a value depending on the air fuel ratio or a value depending on the exhaust gas recirculation quantity and a value depending to the ignition timing by means of the ECU 230.

Abstract: An engine control method for an internal combustion engine having a powertrain control module (PCM). The powertrain control module includes a microprocessor and associated memory. A mathematical model of the engine cycle of the engine system is stored in the PCM memory. The PCM continuously monitors a variety of engine operating parameters. From these inputs, the PCM generates optimized control setpoints for the intake airflow, fueling right, spark timing and EGR flow for the engine using the mathematical model. The setpoints are generated in real-time for every engine cycle, and the engine is then operated in accordance with the generated control setpoints. In another aspect of the invention, the engine model includes submodels for fuel delivery, the in-cylinder processes, the engine heat capacitance and cooling system, engine friction, airflow, engine inertia, and the front-end auxiliary drive.