Systems and methods for estimating a temperature of an after treatment device in an exhaust system of an engine are described. In one example, the temperature is estimated during condition when an engine exits a fuel cut-out mode and excess fuel is delivered to the after treatment device for the purpose of increasing after treatment device efficiency.

Emission targets, such as NOx levels, for gaseous fuelled internal combustion engines that burn a gaseous fuel in a diffusion combustion mode are increasingly more challenging to achieve. A method of fuel injection for an internal combustion engine fuelled with a gaseous fuel comprises introducing a first amount of pilot fuel in a first stage of fuel injection; introducing a first amount of main fuel (the gaseous fuel) in a second stage of fuel injection; and introducing a second amount of main fuel in a third stage of fuel injection. The first and second amounts of main fuel contribute to load and speed demand of the internal combustion engine. Engine maps calibrated for different engine performance can be employed in different regions of the load and speed range of the engine. The engine maps are blended when the engine transitions between two regions; and momentary excursions into different regions do not change the engine calibration.

A method and a device for controlling an internal combustion engine, in particular of a motor vehicle, the internal combustion engine including components which are each operated in an operating mode established by an operating mode coordinator, and it being in particular provided that the operating mode coordinator carries out the aforementioned establishment of at least one operating mode based on further operating aspects of the components.

Methods and systems are described for conserving energy used by an energy consuming device. In certain embodiments, an energy conservation system can be configured to deliver energy to the energy consuming device for a period, followed by a period where energy delivery is dampened and/or cut. By cycling the delivery of energy in this fashion, the energy conservation can achieve a pulsed efficiency.

An object of the invention is to reduce the amount of smoke generated and to improve the stability of diesel combustion in cases where an EGR apparatus is used in an internal combustion engine that performs diesel combustion using fuel having a relatively high self-ignition temperature. A control apparatus performs first injection at a first injection time during the compression stroke, causes spray guide combustion to occur, and starts to perform second injection at such a second injection time that causes combustion of injected fuel to be started by flame generated by the spray guide combustion, thereby causing self-ignition and diffusion combustion of fuel to occur. The apparatus changes the ratio of the first injected fuel quantity to the total fuel injection quantity and the ratio of the second injected fuel quantity to the total fuel injection quantity for the same total fuel injection quantity in one combustion cycle, based on the EGR rate in the intake air.

A method for controlling fuel injection of a combustion engine and a corresponding system includes providing at least a first predetermined air-fuel mixture map and determining a first air-fuel ratio based on at least one engine operating parameter and the at least first predetermined air-fuel mixture map; determining a second air-fuel ratio that is offset with a first constant value from the first air-fuel ratio, determining if a first operating mode or a second operating mode is selected; controlling engine fuel injection according to the first air-fuel ratio when a currently requested fueling rate results in a smaller air-fuel ratio than the first air-fuel ratio and the first operating mode is selected; or alternatively controlling engine fuel injection according to the second air-fuel ratio when a currently requested fueling rate results in a smaller air-fuel ratio than the second air-fuel ratio and the second operating mode is selected.

When an internal combustion engine operates in a stoichiometric mode, a control apparatus operates a cooling system so that the temperature of intake air becomes 45° C. When the internal combustion engine operates in a lean mode, the control apparatus operates the cooling system so that the temperature of intake air becomes 35° C. Also, the control apparatus calculates a crank angle period from an ignition timing until a crank angle at which a mass fraction burned becomes 10% and adjusts a fuel injection amount so that the SA-CA10 coincides with a target SA-CA10. Then, the control apparatus sets the target SA-CA10 short immediately after switching from the stoichiometric mode to the lean mode and extends the target SA-CA10 in accordance with a decrease in the temperature of intake air.

An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

In control device of an internal combustion engine, for each first period, a calculation unit calculates number of fuel injections within one combustion cycle and fuel injection rate. For first period, a first storage unit stores number of fuel injections and fuel injection rate of calculation unit. For each second period, a reference unit refers to the number of fuel injections and fuel injection rate stored by the first storage unit. A second storage unit stores for an interval, from the start time of the first fuel injection until start of the last fuel injection of at least one combustion cycle, the number of fuel injections and fuel injection rate referred to by reference unit. A control unit controls a fuel injection valve so that fuel is injected in accordance with the number of fuel injections fuel injection rate stored by second storage unit.

An engine control system controls a work machine including an engine, a fuel injection device that injects fuel into the engine, and a hydraulic pump that is driven by the engine. The rotation state amount specification unit specifies a rotation state amount related to rotation of the engine. The injection amount determination unit determines a fuel injection amount by the fuel injection device based on the rotation state amount.