The invention relates to a method for operating an internal combustion engine installed in a vehicle, in particular a diesel engine, in which the instantaneous concentration of a pollutant contained in the exhaust gas, in particular the NO.sub.x concentration in the exhaust gas, is measured or calculated in the flow direction after an exhaust gas aftertreatment. Using the determined pollutant concentration, the predefined distance- and/or power-based compliance with pollutant limiting values in mg/km or mg/kWh are monitored by means of specifically influencing the operating parameters of the internal combustion engine and/or an exhaust gas after treatment system in regulated form.

Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to a sensed exhaust oxygen concentration by changing a fuel injection timing to maintain particulate matter (PM) within a range, and then adjusting an exhaust gas recirculation (EGR) amount based on NOx sensor output and based on the change in fuel injection timing.

An internal combustion engine control apparatus including an electronic control unit having a microprocessor and a memory. The microprocessor is configured to perform switching an injection mode between a first injection mode in which the fuel is injected in a range including an intake stroke and a compression stroke of an internal combustion engine and a second injection mode in which the fuel is injected in the range so that an injection frequency in the compression stroke in the second injection mode is greater than an injection frequency in the compression stroke in the first injection mode; and determining whether the injection mode needs to be switched based on an ignition timing of the ignitor.

An internal combustion engine control apparatus including a microprocessor. The microprocessor is configured to perform determining whether a warm-up of an exhaust catalyst device disposed on an exhaust passage of an internal combustion engine is complete; acquiring an information on a temperature inside a cylinder of the internal combustion engine; switching an injection mode to a first injection mode or a second injection mode in accordance with an information on a temperature inside the cylinder when it is determined that a warm-up of the exhaust catalyst device is complete; and controlling a fuel injector so as to inject the fuel in accordance with an injection mode.

An internal combustion engine control apparatus including a microprocessor. The microprocessor is configured to perform determining whether a start of the internal combustion engine is complete, determining whether a warm-up of an exhaust catalyst device is needed, acquiring an information on a temperature inside a cylinder, switching an injection mode, and controlling the fuel injector to inject the fuel in accordance with the injection mode, the switching including switching the injection mode to the first injection mode when the start of the internal combustion engine is complete and the warm-up of the exhaust catalyst device is needed, and switching the injection mode to the second injection mode or the third injection mode in accordance with the information on the temperature when the start of the internal combustion engine is complete and the warm-up of the exhaust catalyst device is not needed.

An internal combustion engine control apparatus including a microprocessor. The microprocessor is configured to perform controlling a fuel injector so as to inject a fuel of a target injection amount by dividing into a plurality of times at a predetermined time interval in an area from a first crank angle at which an intake stroke is started to a second crank angle at which a compression stroke is ended, and setting the predetermined time interval. The microprocessor is configured to perform the setting including setting the predetermined time interval so that a spray length from a tip of the fuel injector to a tip of a spray of the fuel injected from the fuel injector becomes shorter than the spray length when the fuel of the target injection amount is injected at once in the area by a predetermined rate.

Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to a sensed exhaust oxygen concentration by changing a fuel injection timing to maintain particulate matter (PM) within a range, and then adjusting an exhaust gas recirculation (EGR) amount based on NOx sensor output and based on the change in fuel injection timing.

A port injection valve injects fuel into an intake passage. A base injection amount is an injection amount proportional to an amount of fresh air introduced into a cylinder of an internal combustion engine. A division process involves dividing the base injection amount into a synchronous injection amount and an asynchronous injection amount. In an intake-synchronous injection, the fuel is injected in synchronization with a period in which an intake valve is open. In an intake-asynchronous injection, the fuel is injected at a time advanced with respect to the intake-synchronous injection. In a selective correction process, the asynchronous injection amount is corrected according to a required correction amount for the base injection amount, and the synchronous injection amount is not corrected.

An engine control device includes a processor configured to execute a fuel injection control including: a first fuel injection processing for injecting an amount of fuel according to a first intake air amount based on an intake air flow rate detected by an air flow sensor; and a second fuel injection processing for injecting an amount of fuel according to a second intake air amount based on a throttle opening degree detected by a throttle position sensor. The processor selects the first fuel injection processing when a pulsation rate of the intake air flow rate is equal to or lower than a pulsation rate threshold value, and selects the second fuel injection processing when the pulsation rate is higher than the pulsation rate threshold value. The pulsation rate threshold value is smaller when a temperature correlation value is low than when the temperature correlation value is high.

An engine control device for an electric vehicle having an electrical rotating machine, includes: an engine control unit determining an engine rotational speed and an engine torque such that a particulate number of particulate matter per unit gas quantity that the engine releases into an atmosphere becomes equal to or less than a target value having been set in association with a warm-up state of the engine, the engine rotational speed, and the engine torque, and such that the engine rotational speed when a vehicle speed is less than a threshold value is lower than the engine rotational speed when the vehicle speed is equal to or more than the threshold value, and controlling the engine based on the determined engine rotational speed and the engine torque.