A method for adapting the injection characteristic of a fuel injection valve of an internal combustion engine to production-related tolerances is described. In the method, an injection quantity correction value is determined from the deviation of the idle travel and the deviation of the injection quantity of the injection valve before the operating phase of the injector. This injection quantity correction value is used to determine the injection-specific deviation of the injection quantity during the operating phase at the start of the operating phase of the injector in conjunction with the current deviation of the idle travel which is determined in the system. The injector-specific deviation of the injection quantity which is determined is used to correct the injection characteristic. As a result, changes in the injection quantity of an injector can be detected and corrected particularly precisely on the basis of production tolerances.

There is provided: a NOx occlusion reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state; an exhaust injector that is provided in the exhaust passage and is positioned further upstream than the NOx occlusion reduction-type catalyst; a NOx-purging control unit that performs NOx purging of reducing and purifying the NOx occluded in the NOx occlusion reduction-type catalyst by lowering the exhaust to a prescribed target lambda by fuel injection by the exhaust injector; and a NOx-purging-prohibition processing unit that inhibits performance of the NOx purging in a case where the exhaust cannot be lowered to the target lambda even if the fuel injection is performed at a maximum limit injection amount of the exhaust injector.

A microcomputer determines a presence of an abnormality of a fuel injection quantity control device based on a comparison between a required injection quantity as a command value for the amount of a fuel injected from an injector in one engine cycle and a total monitor injection quantity as a total value of monitor injection quantities obtained from an energization time monitor value of the injector for each fuel injection in the one engine cycle. The microcomputer removes a micro-injection correction amount from the monitor injection quantity when the monitor injection quantity is below a determination value and executes a removal processing in which the removal of the micro-injection correction amount from the monitor injection quantity is not performed when the monitor injection quantity is at least the determination value. The total value of the monitor injection quantities after the removal processing is regarded as the total monitor injection quantity.

An injection control device for a fuel injection valve includes: a current detection unit, a current area correction control unit, a storage unit, and a reference current value correction unit. The current area correction control unit corrects, based on an energization current profile, an area correction amount of an energization time to equalize the integrated current value of the energization current profile and an integrated current value of the detected current, and obtains the integrated current value of the current based on an attainment time from a start of energization of the fuel injection valve to an attainment of each of plural reference current values. The storage unit stores a reference attainment time. The reference current value correction unit corrects each reference current value based on a difference between the reference attainment time and a detected attainment time at a time of actual drive.

The present invention provides a method for analyzing and optimizing the injection of fluid into an internal combustion engine via a common rail system. Once various injection parameters are determined for a given injection system, these data may be used to model the effect of sequential injection events for the system. A processer can then be used to run the model and to adjust sequential fuel injection events to optimize engine performance and fuel usage.

A reduction method for a catalytic converter in an exhaust system of an internal combustion engine for reducing the oxygen content in the catalytic converter, in particular after an overrun fuel cutoff mode of the internal combustion engine, the method including first injection of fuel into a first cylinder, the first injection taking place after an ignition point in time of a compression stroke of a first working cycle of the cylinder and including an introduction of the injected fuel from the cylinder into the catalytic converter during an exhaust stroke of the first cylinder.

A method of controlling the fuel air mixture of an internal combustion engine following a cold restart includes determining a control parameter based on the value of current coolant temperature at time of current engine start, the value of coolant temperature at time of the previous engine start, a calibratable reference temperature, the total accumulated fuel mass injected during previous engine run time, the time the engine was off before the restart, and the time the engine was run after previous start. The method also includes controlling the fuel air mixture based on said control parameter.

The present invention refers to a method for operating an internal combustion engine in a transition operating mode, comprising the steps of determining an initial fuel oxidizer ratio threshold and a demanded fuel oxidizer ratio for a fuel mixture to be supplied to a combustion chamber of the engine. If the demanded fuel oxidizer ratio exceeds the initial fuel oxidizer ratio threshold, the engine is temporally operated in a raised response mode, in which a fuel oxidizer ratio threshold is increased from the initial fuel oxidizer ratio threshold to a raised fuel oxidizer ratio threshold, and a fuel mixture having the demanded fuel oxidizer ratio is supplied into the combustion chamber of the engine.

A fuel level measurement system and method for liquified natural gas (LNG) powered machines is disclosed. An engine control module (ECM) receives fuel line pressure levels at a first time (e.g., a key-off event) and, again, at a second time (e.g., a key-on event). The ECM predicts an expected change in pressure from the key-off event to the key-on event based on various factors. If the change in pressure detected is greater than a threshold level different from the predicted change in pressure, the ECM determines a fill event and resets a current fuel level. The ECM tracks mass flow commands used to provide fuel to the engine to determine the consumption of fuel from the fuel tank and to determine a new current fuel level based on the amount of fuel consumed. The current fuel level is displayed on a fuel gauge.

An injection control device includes: an arithmetic unit that obtains a valve-closing time for stopping injection of fuel from a fuel injection valve based on a degree of variation in a time change of a voltage generated when the fuel injection valve is driven based on a required injection amount; an injection amount change unit that increases or decreases the required injection amount; and a learning unit that repeats injection control of the fuel to learn the valve-closing time obtained by the arithmetic unit.