A control device is configured to perform, when it is estimated that a combustion fluctuation increases, estimation related to an ignition delay for initial flame generated from a discharge spark and an air-fuel mixture containing fuel spray injected by intake stroke injection. When it is estimated that the ignition delay for the initial flame is increased from that before the increase in the combustion fluctuation, an injection amount in expansion stroke injection is reduced in a next time cycle. When it is estimated that the ignition delay for the initial flame is reduced from that before the increase in the combustion fluctuation, the injection amount in expansion stroke injection is increased in a next time cycle.

A control device is configured to perform, when it is estimated that a combustion fluctuation increases, estimation related to an ignition delay for initial flame generated from a discharge spark and an air-fuel mixture containing fuel spray injected by intake stroke injection. When it is estimated that the ignition delay for the initial flame is increased from that before the increase in the combustion fluctuation, an injection amount in expansion stroke injection is reduced in a next time cycle. When it is estimated that the ignition delay for the initial flame is reduced from that before the increase in the combustion fluctuation, the injection amount in expansion stroke injection is increased in a next time cycle.

The control apparatus for a compression ignition type engine includes a plurality of cylinder inner pressure sensors that detect pressure in each cylinder, and a combustion control unit. The combustion control unit corrects a target fuel injection amount of each cylinder by an injector based on a deviation between a predicted combustion period that is a period from an ignition timing by an ignition plug to a predetermined mass combustion timing and that is obtained based on a preset combustion model, and an actual combustion period that is a period from the ignition timing by the ignition plug to an actual combustion timing and that is obtained based on cylinder inner pressure, such that the period from the ignition timing by the ignition plug to the predetermined mass combustion timing, which is the timing when fuel having a predetermined mass ratio combusts, is equalized in each cylinder.

The control apparatus for a compression ignition type engine includes a plurality of cylinder inner pressure sensors that detect pressure in each cylinder, and a combustion control unit. The combustion control unit corrects a target fuel injection amount of each cylinder by an injector based on a deviation between a predicted combustion period that is a period from an ignition timing by an ignition plug to a predetermined mass combustion timing and that is obtained based on a preset combustion model, and an actual combustion period that is a period from the ignition timing by the ignition plug to an actual combustion timing and that is obtained based on cylinder inner pressure, such that the period from the ignition timing by the ignition plug to the predetermined mass combustion timing, which is the timing when fuel having a predetermined mass ratio combusts, is equalized in each cylinder.

A misfire detection device for an internal combustion engine includes a storage device and processing circuitry, the storage device stores first mapping data corresponding to a case where a warm-up process of a catalyst provided in an exhaust passage of an internal combustion engine is being executed, and second mapping data corresponding to a case where the warm-up process is not being executed, and each of the first mapping data and the second mapping data uses a rotation waveform variable as an input and defines a mapping that outputs a misfire variable that is a variable related to a probability misfire has occurred. The rotation waveform variable is a variable indicating a difference between a plurality of values of an instantaneous speed variable respectively corresponding to a plurality of different minute angular intervals.

A misfire detection device for an internal combustion engine includes a storage device and processing circuitry, the storage device stores first mapping data corresponding to a case where a warm-up process of a catalyst provided in an exhaust passage of an internal combustion engine is being executed, and second mapping data corresponding to a case where the warm-up process is not being executed, and each of the first mapping data and the second mapping data uses a rotation waveform variable as an input and defines a mapping that outputs a misfire variable that is a variable related to a probability misfire has occurred. The rotation waveform variable is a variable indicating a difference between a plurality of values of an instantaneous speed variable respectively corresponding to a plurality of different minute angular intervals.

The control apparatus for a compression ignition type engine includes a plurality of cylinder inner pressure sensors that detect pressure in each cylinder, and a combustion control unit. The combustion control unit corrects a target fuel injection amount of each cylinder by an injector based on a deviation between a predicted combustion period that is a period from an ignition timing by an ignition plug to a predetermined mass combustion timing and that is obtained based on a preset combustion model, and an actual combustion period that is a period from the ignition timing by the ignition plug to an actual combustion timing and that is obtained based on cylinder inner pressure, such that the period from the ignition timing by the ignition plug to the predetermined mass combustion timing, which is the timing when fuel having a predetermined mass ratio combusts, is equalized in each cylinder.

The control apparatus for a compression ignition type engine includes a plurality of cylinder inner pressure sensors that detect pressure in each cylinder, and a combustion control unit. The combustion control unit corrects a target fuel injection amount of each cylinder by an injector based on a deviation between a predicted combustion period that is a period from an ignition timing by an ignition plug to a predetermined mass combustion timing and that is obtained based on a preset combustion model, and an actual combustion period that is a period from the ignition timing by the ignition plug to an actual combustion timing and that is obtained based on cylinder inner pressure, such that the period from the ignition timing by the ignition plug to the predetermined mass combustion timing, which is the timing when fuel having a predetermined mass ratio combusts, is equalized in each cylinder.

A misfire detection device for an internal combustion engine includes a storage device and processing circuitry, the storage device stores first mapping data corresponding to a case where a warm-up process of a catalyst provided in an exhaust passage of an internal combustion engine is being executed, and second mapping data corresponding to a case where the warm-up process is not being executed, and each of the first mapping data and the second mapping data uses a rotation waveform variable as an input and defines a mapping that outputs a misfire variable that is a variable related to a probability misfire has occurred. The rotation waveform variable is a variable indicating a difference between a plurality of values of an instantaneous speed variable respectively corresponding to a plurality of different minute angular intervals.

A misfire detection device for an internal combustion engine includes a storage device and processing circuitry, the storage device stores first mapping data corresponding to a case where a warm-up process of a catalyst provided in an exhaust passage of an internal combustion engine is being executed, and second mapping data corresponding to a case where the warm-up process is not being executed, and each of the first mapping data and the second mapping data uses a rotation waveform variable as an input and defines a mapping that outputs a misfire variable that is a variable related to a probability misfire has occurred. The rotation waveform variable is a variable indicating a difference between a plurality of values of an instantaneous speed variable respectively corresponding to a plurality of different minute angular intervals.