A PCM (100) selects one of a CI mode or an SI mode based on the operating conditions of the engine (1). In the CI mode, the engine (1) is operated by compression ignition combustion. In the SI mode, the engine (1) is operated by spark ignition combustion. if, while the engine (1) is being operated in the CI mode, a determination is made that an estimated value (Tc) of the catalyst temperature is lower than or equal to a warming start temperature (Ts), the PCM (100) further performs first warming control to assign four cylinders (18) as CI and SI cylinders, which perform the compression ignition combustion and the spark ignition combustion, respectively, such that the four cylinders (18) alternately perform the compression ignition combustion and the spark ignition combustion in accordance with the order of combustion of the cylinders.

An engine control apparatus includes a control system including one or more memories and one or more processors communicably coupled to one another, and controlling ignition timing of a spark plug. The one or more memories hold first and second ignition timing maps that provide setting of the ignition timing for each engine operation point. The one or more processors determine the number of injection stages of an injector. When the number of injection stages of the injector is the first number of injection stages, the one or more processors control the ignition timing of the spark plug based on the first ignition timing map. When the number of injection stages of the injector is the second number of injection stages greater than the first number of injection stages, the one or more processors control the ignition timing of the spark plug based on the second ignition timing map.

An ignition control device controls the alternate grounding of magnetos, or other ignition systems, in internal combustion engines utilizing two spark plugs per cylinder. The ignition control device can include two separate ignition systems to control each magneto. The ignition control device can alternate arcing of opposing spark plugs for each combustion cycle of the internal combustion engine.

The present invention relates to a control apparatus and method for an internal combustion engine including two fuel injection valves in the intake port of each cylinder. In the present invention, fuel injection from a first fuel injection valve is activated while fuel injection from a second fuel injection valve is temporarily stopped at the resumption of fuel injection from the deceleration fuel cut-off state in response to a decrease in the engine rotation speed. The amount of minimum fuel injection to each cylinder that ensures the accuracy of fuel measurement can be reduced, and fuel is injected from the first fuel injection valve in an amount equal to or greater than the amount of minimum fuel injection. Thus, fuel injection can be resumed at a lower engine speed than when fuel injection is resumed from the two fuel injection valves.

An electronic control unit performs a cylinder-by-cylinder correction of a fuel injection amount to cause differences among air-fuel ratios of air-fuel mixture burned in multiple cylinders. In a case in which the cylinder-by-cylinder correction of the fuel injection amount results in a cylinder in which combustion is performed at an air-fuel ratio richer than an output air-fuel ratio, the output air-fuel ratio being an air-fuel ratio at which combustion torque is maximized, the electronic control unit performs a cylinder-by-cylinder correction of ignition timing such that the ignition timing of the cylinder in which combustion is performed at the air-fuel ratio richer than the output air-fuel ratio becomes more advanced than the ignition timing of the other cylinders.

Systems and methods for operating an internal combustion engine based on output of an intake manifold pressure sensor and output of an in cylinder pressure sensor are described. The systems and methods provide a way of determining cylinder air charge so that a fuel injector has sufficient time to provide a desired amount of fuel to a cylinder during a cycle of the cylinder.

Systems and methods for operating an internal combustion engine based on output of an intake manifold pressure sensor and output of an in cylinder pressure sensor are described. The systems and methods provide a way of determining cylinder air charge so that a fuel injector has sufficient time to provide a desired amount of fuel to a cylinder during a cycle of the cylinder.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

A multi-cylinder spark-ignition internal combustion engine includes a monitored cylinder and a plurality of non-monitored cylinders, a pressure sensor disposed to monitor in-cylinder pressure in the monitored cylinder and a rotational position sensor. The controller is in communication with the pressure sensor, the rotational position sensor and the spark controller. The controller monitors, via the pressure sensor, in-cylinder pressure for the monitored cylinder during a combustion event, and determines a first spark timing based upon a desired spark timing and the in-cylinder pressure. A spark controller controls spark timing for the monitored cylinder based upon the final spark timing. The controller monitors, via the rotational position sensor, engine rotational speed and crankshaft speed pulsations associated with the monitored cylinder and the non-monitored cylinders, and determines a modal coefficient for the non-monitored cylinders based upon the engine rotational speed and the crankshaft speed pulsations.

A method for extracting characterizing features from an ion current trace retrieved from spark plugs of cylinders of an internal combustion engine, comprises the steps of: i. dividing the ion current signal into crank angle subintervals; 5 ii. calculating a measure of ion current in each crank angle subinterval; and iii. Performing a calculation on the measure of ion currents from different subintervals such that the result of the calculation is dimension free. Further it relates to a method of monitoring combustion processes where a plurality of ion current signals from a number of spark plugs (4A, 4B) are 10 retrieved and used in combination.