Abstract: As a compression-ignition direct-injection engine combustion controller, a program for detecting ignition timing of a main injection Mn (main ignition timing), a program for correcting a command value of main injection execution timing in a direction to the side where a detection value is converged within a predetermined range, a program for determining whether or not the corrected command value is within a predetermined range, and a program for, when it is determined that the command value is not within the range, correcting a command value related to an injection amount of a pilot injection Pt based on whether or not the command value is on a delay side or an advance side of the range.

Abstract: There is disclosed a fuel property detector for detecting a property of fuel injected by a fuel injector into a cylinder of an internal combustion engine. The fuel property detector includes an injection commander, a change detector, and a fuel property determiner. The injection commander commands the fuel injector to perform a fuel injection for fuel property detection into the cylinder of the engine. The change detector detects a change in the rotational speed of the engine which is caused by the fuel injection for fuel property detection. The fuel property determiner determines the property of the fuel based on the change in the rotational speed of the engine detected by the change detector.

Abstract: An exhaust recirculation apparatus is provided to an engine. A high-pressure EGR passage branches from upstream of a turbine of a turbocharger in an exhaust system for recirculating exhaust gas to downstream of a compressor of the turbocharger in an intake system. A high-pressure EGR regulating unit controls exhaust gas through the high-pressure EGR passage. A low-pressure EGR passage branches from downstream of the turbine in the exhaust system for recirculating exhaust gas to upstream of the compressor in the intake system. A low-pressure EGR regulating unit controls exhaust gas through the low-pressure EGR passage. A control unit feedback-controls the high-pressure EGR regulating unit, and open-controls the low-pressure EGR regulating unit when exhaust gas is recirculated through the high-pressure EGR passage and the low-pressure EGR passage. The control unit feedback-controls the low-pressure EGR regulating unit when exhaust gas is recirculated through only the low-pressure EGR passage.

Abstract: A single fuel injection is performed in either one of cylinders during fuel cut control of a diesel engine to sense torque generated with the single fuel injection based upon an increase amount of rotation speed of a crankshaft at the time. Presence/absence of abnormality in an injection start timing of an injector is determined based on a difference in torque caused when the single fuel injection is performed at multiple command injection start timings. Thus, the presence/absence of the abnormality in the injection start timing can be sensed without using a nozzle lift sensor, whereby inhibiting an increase in the number of components.

Abstract: A fuel injector performs a main injection and a pilot injection prior to the main injection. A fuel injection controller detects an ignition timing of a fuel injected at the main injection, detects a driving condition of the internal combustion engine, and varies a pilot injection quantity of the pilot injection when the driving condition is stable. Furthermore, the controller detects a variation in ignition timing due to a variation in the pilot injection quantity, and learns the pilot injection quantity based on the variation in ignition timing due to the variation in the pilot injection quantity.

Abstract: In a system, an actuator is linked to a valve rotatably installed in a passage through which gas flows. The actuator changes torque to be applied to the valve so as to adjust a rotational position of the valve based on a deviation between a current position and a target position. In the system, a first storing unit stores therein a first threshold. The first threshold is defined in a variation range within which a torque parameter is variable depending on change in the torque to be applied to the valve. The first threshold allows whether there is a possibility that an operation of the actuator is unstable. If the torque parameter substantially shifts either to or through the first threshold in the variation range, a restricting unit restricts variation in the torque parameter with the gas-flow being substantially kept through the passage.

Abstract: A control apparatus for a multi-cylinder internal combustion engine includes pressure sensors used for acquiring combustion chamber pressure data for each engine cylinder, during each of a series of selection intervals respectively corresponding to that cylinder, with each selection interval corresponding to a specific angular displacement of the crankshaft and having a timing determined with respect to a reference piston position in the corresponding cylinder. The timing of the selection intervals is adjusted in accordance with current conditions of the engine, such as a fuel injection mode, to be appropriate for monitoring combustion conditions in the cylinders.

Abstract: A fuel injection controller of an internal combustion engine decreases a target intake quantity stepwise and increases an opening degree command value of an EGR valve stepwise when the controller switches control to rich combustion control. Accordingly, an intake quantity gradually decreases and an EGR quantity gradually increases, so an oxygen quantity flowing into a combustion chamber (cylinder inflow oxygen quantity) gradually decreases. The injection quantity is gradually increased in accordance with the gradual decrease of the oxygen quantity. Thus, the fuel injection controller can perform processing for making an air fuel ratio rich in order to discharge nitrogen oxides from an occlusion agent while appropriately inhibiting torque fluctuation.

Abstract: There is disclosed a fuel property detector for detecting a property of fuel injected by a fuel injector into a cylinder of an internal combustion engine. The fuel property detector includes an injection commander, a change detector, and a fuel property determiner. The injection commander commands the fuel injector to perform a fuel injection for fuel property detection into the cylinder of the engine. The change detector detects a change in the rotational speed of the engine which is caused by the fuel injection for fuel property detection. The fuel property determiner determines the property of the fuel based on the change in the rotational speed of the engine detected by the change detector.

Abstract: An abnormality determination device of a cylinder pressure sensor calculates a gain (sensing sensitivity coefficient) and an offset (bias) indicating an output characteristic of the cylinder pressure sensor. The device determines existence or nonexistence of an abnormality in the gain and the offset respectively. When the device determines that the abnormality exists, the device performs failsafe processing set in modes different from each other between the case of the abnormality in the gain and the case of the abnormality in the offset. As the failsafe processing in the case of the abnormality in the gain, the device performs processing for substantially prohibiting usage of a sensor value of the cylinder pressure sensor in control (fuel injection timing control) by using an alternative value (specified value) instead of the sensor value of the cylinder pressure sensor.

Abstract: A fuel injector performs a main injection and a pilot injection prior to the main injection. A fuel injection controller detects an ignition timing of a fuel injected at the main injection, detects a driving condition of the internal combustion engine, and varies a pilot injection quantity of the pilot injection when the driving condition is stable. Furthermore, the controller detects a variation in ignition timing due to a variation in the pilot injection quantity, and learns the pilot injection quantity based on the variation in ignition timing due to the variation in the pilot injection quantity.

Abstract: An engine torque control apparatus is applied to an engine control system comprising an engine for rotating an output shaft by using torque generated through combustion in cylinders. In the apparatus, exhaust gas passing through an exhaust passage of the engine is partially recirculated into an intake passage of the engine. Also, variable control is conducted in the apparatus, when an air-fuel ratio indicating a proportion between air and fuel supplied into the cylinders of the engine is changed to a leaner air-fuel ratio, so that torque parameters for increasing/decreasing output torque of the engine can be variably controlled. As a result, torque fluctuation associated with a temporarily changing recirculated uncombusted fuel quantity can be cancelled in a manner suitable for the temporarily changing recirculated uncombusted fuel quantity, at least during a predetermined period immediately after timing for changing the air-fuel ratio.

Abstract: The internal combustion engine control apparatus includes a calculation function of calculating an energy generation rate of an energy generated by combustion of fuel injected into a combustion chamber of a compression-ignition internal combustion engine, and an ignition detection function of detecting an ignition timing of the fuel in the combustion chamber on the basis of a timing at which the energy generation rate exceeds a first threshold value. When the energy generation rate due to a main injection, which is an object of ignition timing detection by the ignition detection function, exceeds the first threshold value at a plurality of timings, the ignition detection function determines an earliest one of the plurality of the timings as the ignition timing of the main injection.

Abstract: As a compression-ignition direct-injection engine combustion controller, a program for detecting ignition timing of a main injection Mn (main ignition timing), a program for correcting a command value of main injection execution timing in a direction to the side where a detection value is converged within a predetermined range, a program for determining whether or not the corrected command value is within a predetermined range, and a program for, when it is determined that the command value is not within the range, correcting a command value related to an injection amount of a pilot injection Pt based on whether or not the command value is on a delay side or an advance side of the range.

Abstract: A fuel injection controller of an internal combustion engine decreases a target intake quantity stepwise and increases an opening degree command value of an EGR valve stepwise when the controller switches control to rich combustion control. Accordingly, an intake quantity gradually decreases and an EGR quantity gradually increases, so an oxygen quantity flowing into a combustion chamber (cylinder inflow oxygen quantity) gradually decreases. The injection quantity is gradually increased in accordance with the gradual decrease of the oxygen quantity. Thus, the fuel injection controller can perform processing for making an air fuel ratio rich in order to discharge nitrogen oxides from an occlusion agent while appropriately inhibiting torque fluctuation.

Abstract: A fourth cylinder is mounted with a cylinder pressure sensor. The injection timing of the fourth cylinder is operated so as to feedback control the ignition timing of the fourth cylinder, which is detected by the cylinder pressure sensor, to a target ignition timing. The ignition timings of the first cylinder to the third cylinder are indirectly controlled by operating the injection timings so as to make output torques produced by combustion in the first cylinder to the third cylinder correspond to an output torque produced by combustion in the fourth cylinder.

Abstract: A single fuel injection is performed in either one of cylinders during fuel cut control of a diesel engine to sense torque generated with the single fuel injection based upon an increase amount of rotation speed of a crankshaft at the time. Presence/absence of abnormality in an injection start timing of an injector is determined based on a difference in torque caused when the single fuel injection is performed at multiple command injection start timings. Thus, the presence/absence of the abnormality in the injection start timing can be sensed without using a nozzle lift sensor, whereby inhibiting an increase in the number of components.

Abstract: An engine torque control apparatus is applied to an engine control system comprising an engine for rotating an output shaft by using torque generated through combustion in cylinders. In the apparatus, exhaust gas passing through an exhaust passage of the engine is partially recirculated into an intake passage of the engine. Also, variable control is conducted in the apparatus, when an air-fuel ratio indicating a proportion between air and fuel supplied into the cylinders of the engine is changed to a leaner air-fuel ratio, so that torque parameters for increasing/decreasing output torque of the engine can be variably controlled. As a result, torque fluctuation associated with a temporarily changing recirculated uncombusted fuel quantity can be cancelled in a manner suitable for the temporarily changing recirculated uncombusted fuel quantity, at least during a predetermined period immediately after timing for changing the air-fuel ratio.

Abstract: A control apparatus for a multi-cylinder internal combustion engine includes pressure sensors used for acquiring combustion chamber pressure data for each engine cylinder, during each of a series of selection intervals respectively corresponding to that cylinder, with each selection interval corresponding to a specific angular displacement of the crankshaft and having a timing determined with respect to a reference piston position in the corresponding cylinder. The timing of the selection intervals is adjusted in accordance with current conditions of the engine, such as a fuel injection mode, to be appropriate for monitoring combustion conditions in the cylinders.

Abstract: A compression ignition internal combustion engine includes injectors, each of which injects fuel into a corresponding cylinder. An ECU determines target ignition timing based on engine operational information and adjusts fuel injection start timing and a fuel injection quantity of each injector based on the target ignition timing. The engine further includes an air/fuel ratio sensor, which senses an oxygen concentration of exhaust gas. The ECU corrects the target ignition timing based on the oxygen concentration, which is sensed with the air/fuel ratio sensor, with reference to a predefined relationship between the oxygen concentration and ignition timing for achieving a generally equal constant torque of the engine.