A method of calculating a nitrogen oxide (NOx) mass adsorbed in a lean NOx trap (LNT) of an exhaust purification device includes calculating a NOx mass flow stored in the LNT, calculating a NOx mass flow thermally released from the LNT, calculating a NOx mass flow released from the LNT at the rich air/fuel ratio, calculating a NOx mass flow chemically reacting with the reductant at the LNT, and integrating a value obtained by subtracting the NOx mass flow thermally released from the LNT, the NOx mass flow released from the LNT at the rich air/fuel ratio, and the NOx mass flow chemically reacting with the reductant at the LNT from the NOx mass flow stored in the LNT.

An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

The present disclosure relates to internal combustion engines. The teachings thereof may be embodied in methods and devices for controlling the combustion processes taking place in the cylinders of an internal combustion engine. A method for controlling a combustion process in an internal combustion engine may include: measuring an actual camshaft position; measuring the actual rail pressure; calculating a phase correction value based on the measured actual rail pressure and a mass of fuel to be injected; calculating corrected actual camshaft positions based on the measured actual camshaft position and the respective phase correction value; calculating a mass of air depending on the determined corrected actual camshaft position; and calculating a fuel injection mass based on the mass of air determined for each cylinder.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

A method for operating an engine in which fuel is supplied to the engine by a fuel pump and by a high-pressure fuel pump, and in which the speed of the fuel pump and/or the electrical current for feeding the fuel pump is controlled in accordance with a requirement variable, taking into account a determination specification. When the engine has changed to an overrun mode of operation, a calibration is performed and the speed of the fuel pump is detected and is maintained. Once the triggering pressure for a calibration valve has been reached, the pump current is detected, a bypass volumetric flow rate of the high-pressure fuel pump is determined during calibration using operating parameters and the triggering pressure for the calibration valve, the determined speed, the bypass volumetric flow rate and the determined pump current are used to calibrate the determination specification.

An apparatus and method for operating a fuel injector of an internal combustion engine is disclosed. A first energizing electrical current is supplied to an injector solenoid, causing the opening of an injector control volume and a pressure reduction in said injector control volume, for a first energizing time. The first energizing time is predetermined to avoid that the pressure in the injector control volume approximates a value which would cause an injector needle to raise up and a fuel injection to start. After the predetermined time interval, a second energizing electrical current is supplied to the injector solenoid for a predetermined second energizing time, which is a function of a rail pressure (p.sub.rail) and a fuel injection quantity.

An internal combustion engine including a pilot subchamber, a pilot fuel injector having a tip in communication with the pilot subchamber, an ignition element positioned to ignite fuel within the pilot subchamber, and a main fuel injector spaced apart from the pilot fuel injector. The engine includes a common rail in fluid communication with the main fuel injector and with the pilot fuel injector. The internal combustion engine may be a reciprocating engine. A method of combusting fuel in an internal combustion engine is also provided.

When fuel injections into Otto-engines are carried out, pressure pulsations occur in the entire fuel injection system. These prevent detailed information about the fuel injection to be deduced from the pressure signals measurable in the system. When specially designed dampers for these pressure pulsations are employed, pressure difference signals over the pulsation damper can readily be employed for instantaneous volume flow rate measurements. Furthermore, the inserted pressure pulsation dampers also allow the pressure reduction in the Common-Rail, due to the fuel injections, to be employed to measure the instantaneous fuel injection volume flow rates, in running Otto-engines. The authors' development work in this field is described in this paper and results of verification measurements are presented.

An engine control apparatus is equipped with a fuel injection amount computation unit, a determination process unit, and an engine abnormality process unit. The determination process unit determines, based on a deviation between a command injection amount and a monitoring injection amount, whether or not there is an abnormality in fuel injection control. An injection amount threshold, which is used to make a determination on an abnormality in fuel injection control, is set larger based on a vehicle speed-associated parameter when the vehicle speed-associated parameter is a value corresponding to a case where a vehicle speed is high than when the vehicle speed-associated parameter is a value corresponding to a case where the vehicle speed is low.

A method for operating an internal combustion engine with a high pressure accumulator for a fuel injection system, includes the steps of: monitoring, in a time-dependent manner, a high pressure in the fuel injection system; conducting a check, at a high pressure-dependent starting time point, as to whether a continuous injection detection is to be carried out; and checking whether a high-pressure oscillation has occurred within an oscillation time interval prior to a starting time.