Abstract: A fuel estimation apparatus includes a combustion characteristic acquisition portion and a mixing ratio estimation portion. The combustion characteristic acquisition portion acquiring a combustion characteristic value indicating a physical amount relating to a combustion of an internal combustion engine acquires the combustion characteristic values of the combustions executed in different combustion conditions. The mixing ratio estimation portion estimates the mixing ratios of various components included in a fuel, based on the combustion characteristic values acquired by the combustion characteristic acquisition portion.

Abstract: A combustion system controller controls an operation of a combustion system including an internal combustion engine. The combustion system controller includes a mixing ratio acquisition portion and a control portion. The mixing ratio acquisition portion acquires the mixing ratios of various components included in a fuel. The control portion controls the operation of the combustion system based on the mixing ratios acquired by the mixing ratio acquisition portion.

Abstract: A fuel estimation apparatus includes a combustion characteristic acquisition portion and a mixing ratio estimation portion. The combustion characteristic acquisition portion acquiring a combustion characteristic value indicating a physical amount relating to a combustion of an internal combustion engine acquires the combustion characteristic values of the combustions executed in different combustion conditions. The mixing ratio estimation portion estimates the mixing ratios of various components included in a fuel, based on the combustion characteristic values acquired by the combustion characteristic acquisition portion.

Abstract: A combustion system controller controls an operation of a combustion system including an internal combustion engine. The combustion system controller includes a mixing ratio acquisition portion and a control portion. The mixing ratio acquisition portion acquires the mixing ratios of various components included in a fuel. The control portion controls the operation of the combustion system based on the mixing ratios acquired by the mixing ratio acquisition portion.

Abstract: An engine control apparatus works to determine target values of a plurality of combustion parameters which represent combustion states of fuel in a combustion engine and are needed to achieve required performances of the combustion engine, calculate a combustion parameter deviation that is a deviation of an actual value of each of the combustion parameters from the target value thereof, select at least one of controlled parameters correlating with the combustion parameters as a function of a degree of a selected one of the combustion parameter deviations for minimizing the selected one of the combustion parameter deviations. The controlled parameters are parameters for controlling operations of actuators working to control the combustion states of the combustion engine. The engine control apparatus controls the one of the controlled parameters, as selected by the controlled parameter selector, to minimize the selected one of the combustion parameter deviations.

Abstract: A fuel injection control system for an internal combustion engine is provided which is designed to perform pilot injection of fuel into the engine through a fuel injector prior to main injection. The system monitors a combustion state parameter representing a combustion state of the fuel within a combustion chamber of the engine which has been sprayed in the event of the pilot injection. When the combustion state parameter is determined as lying out of a stable combustion range where the fuel is to burn stably, the system changes the number of pilot injections to be executed prior to the main injection and/or the quantity of the fuel to be sprayed in each pilot injection, thereby enhancing the ignitability of the fuel in the pilot injection.

Abstract: The instantaneous interruption detection apparatus includes a noise removing section to remove a noise component from an in-cylinder pressure signal inputted thereto, and output a noise-removed in-cylinder pressure signal, a derivative signal calculating section to calculate a detection signal which is a function of a derivative value of the noise-removed in-pressure signal with respect to the crank angle of an internal combustion engine, an instantaneous interruption determining section configured to make determination that instantaneous interruption of the in-cylinder pressure signal has occurred when the detection signal has exceeded a detection threshold, and a threshold setting section configured to set the detection threshold to such a value that the instantaneous interruption determining section can make the determination in accordance with the noise-removed in-pressure signal which is dull compared to the in-cylinder pressure signal inputted to the noise removing section depending on a gain-frequency

Abstract: A fuel injection control system for an internal combustion engine is provided which is designed to perform pilot injection of fuel into the engine through a fuel injector prior to main injection. The system monitors a combustion state parameter representing a combustion state of the fuel within a combustion chamber of the engine which has been sprayed in the event of the pilot injection. When the combustion state parameter is determined as lying out of a stable combustion range where the fuel is to burn stably, the system changes the number of pilot injections to be executed prior to the main injection and/or the quantity of the fuel to be sprayed in each pilot injection, thereby enhancing the ignitability of the fuel in the pilot injection.

Abstract: An engine control apparatus works to determine target values of a plurality of combustion parameters which represent combustion states of fuel in a combustion engine and are needed to achieve required performances of the combustion engine, calculate a combustion parameter deviation that is a deviation of an actual value of each of the combustion parameters from the target value thereof, select at least one of controlled parameters correlating with the combustion parameters as a function of a degree of a selected one of the combustion parameter deviations for minimizing the selected one of the combustion parameter deviations. The controlled parameters are parameters for controlling operations of actuators working to control the combustion states of the combustion engine. The engine control apparatus controls the one of the controlled parameters, as selected by the controlled parameter selector, to minimize the selected one of the combustion parameter deviations.

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: The rotational position detecting apparatus for an internal combustion engine includes a rotational angle sensor outputting a rotation angle signal indicative of a rotational angle of the internal combustion engine, an in-cylinder pressure sensor outputting an in-cylinder pressure signal indicative of an in-cylinder pressure of a cylinder of the internal combustion engine, and a reference rotational position detecting section which detects a specific rotational angle of the internal combustion engine at which the in-cylinder pressure becomes a predetermined reference pressure under a predetermined running condition of the internal combustion engine, and determines the detected specific rotational angle as a reference rotational position of the internal combustion engine.

Abstract: The instantaneous interruption detection apparatus includes a noise removing section to remove a noise component from an in-cylinder pressure signal inputted thereto, and output a noise-removed in-cylinder pressure signal, a derivative signal calculating section to calculate a detection signal which is a function of a derivative value of the noise-removed in-pressure signal with respect to the crank angle of an internal combustion engine, an instantaneous interruption determining section configured to make determination that instantaneous interruption of the in-cylinder pressure signal has occurred when the detection signal has exceeded a detection threshold, and a threshold setting section configured to set the detection threshold to such a value that the instantaneous interruption determining section can make the determination in accordance with the noise-removed in-pressure signal which is dull compared to the in-cylinder pressure signal inputted to the noise removing section depending on a gain-frequency

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: The rotational position detecting apparatus for an internal combustion engine includes a rotational angle sensor outputting a rotation angle signal indicative of a rotational angle of the internal combustion engine, an in-cylinder pressure sensor outputting an in-cylinder pressure signal indicative of an in-cylinder pressure of a cylinder of the internal combustion engine, and a reference rotational position detecting section which detects a specific rotational angle of the internal combustion engine at which the in-cylinder pressure becomes a predetermined reference pressure under a predetermined running condition of the internal combustion engine, and determines the detected specific rotational angle as a reference rotational position of the internal combustion engine.

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 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 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: 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.