Various embodiments include a method for operating a fuel injector comprising: applying a first current to a solenoid to perform a first injection process and inject a predefined injection quantity; determining a value of a system parameter indicating the relationship between the actual fuel quantity and the predefined quantity; determining, on the basis of the value of the system parameter, whether the actually injected fuel quantity is smaller than the predefined fuel quantity by a predefined amount corresponding to a disparity between a magnetic force exerted on the armature in the direction of the pole piece and an opposite hydraulic force exerted on the armature by fuel; and if it was determined that the quantities differ by enough, applying a second current to the solenoid to perform a second injection; wherein the second current exerts a lower magnetic force on the armature in the direction of the pole piece.

A method is disclosed of controlling operation of a fuel injector in response to measuring a quantity of fuel injected by the fuel injector from a fuel accumulator to an engine cylinder during operation of a fuel pump that delivers fuel to the accumulator, comprising: determining an average pressure of the fuel accumulator during a first time period before a fuel injection event; predicting a mass of fuel delivered to the fuel accumulator during a pumping event (Q.sub.pump); determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating a leakage of fuel; computing the injected fuel quantity by adding the average pressure during the first time period to Q.sub.pump, and subtracting the average pressure during the second time period and the leakage; and using the computed injected fuel quantity to control operation of the fuel injector.

A control device for an internal combustion engine includes a fuel injector configured to inject fuel, a pressure increasing device that is provided upstream of the feel injector and is configured to increase the pressure of fuel supplied to the fuel injector, and an electronic control unit. The electronic control unit is configured to calculate an actual fuel injection amount based on a difference between a fuel pressure in the fuel injector in a case where the pressure increasing device increases the fuel pressure without fuel injection by the fuel injector and a fuel pressure in the fuel injector in a case where the fuel injector performs fuel injection according to the driving of the pressure increasing device.

A fuel injector controller is disclosed. The fuel injector controller may determine respective values of a set of parameters of the engine; process, using a neural network, the respective values to determine a target fuel output of a fuel injector, wherein the neural network is configured to determine the target fuel output based on the set of parameters being an input layer of the neural network; determine, based on an output of the neural network, the target fuel output; and provide the determined target fuel output to the fuel injector to permit the fuel injector to inject fuel according to the target fuel output.

A method and a system for controlling combustion of a natural gas engine. The method includes: determining, based on a current operation parameter of a natural gas engine, an operation state of the natural gas engine, and calculating a total injection quantity of natural gas and pilot diesel required by the natural gas engine in the operation state; adopting a direct injection diffusion-combustion mode in a case that the operation state is an idle state or a low load state; adopting a natural gas homogeneous hybrid active control compression-ignition mode in a case that the operation state is a medium load state; configuring the total injection quantity into three parts including a compression-ignition natural gas injection quantity, a pilot diesel injection quantity, and a diffusion-combustion natural gas injection quantity in a case that the operation state is a high load state, and sequentially injecting them into a combustion chamber.

An engine control device includes an air amount detector, a requested torque acquisitor, a search axis value acquisitor, a storage, and a control target value acquisitor. The air amount detector detects an actual amount of intake air. The requested torque acquisitor acquires a requested torque. In a region of a lean burn region where the actual amount of intake air increases as the requested torque increases, the search axis value acquisitor acquires a value corresponding to the actual amount of intake air. In a region of the of the lean burn region where the actual amount of intake air does not increase as the requested torque increases, the search axis value acquisitor acquires a value corresponding to the requested torque. The control target value acquisitor acquires a control target value of an engine device by searching a device control map using an acquired search axis value.

A fuel injector controller is disclosed. The fuel injector controller may determine respective values of a set of parameters of the engine; process, using a neural network, the respective values to determine a target fuel output of a fuel injector, wherein the neural network is configured to determine the target fuel output based on the set of parameters being an input layer of the neural network; determine, based on an output of the neural network, the target fuel output; and provide the determined target fuel output to the fuel injector to permit the fuel injector to inject fuel according to the target fuel output.

The present disclosure relates to assessing the intake air flow of industrial engines. For an industrial engine that receives vent gas added to intake air for combustion, a gas concentration sensor is used to measure a concentration of a particular gas, e.g. methane, in the intake air. An amount of the methane component in the intake air flowing to the engine that was added by the vent gas can be determined from the measured concentration of methane in the intake air and a flow rate of the intake air. The intake air flow rate may be directly measured, or calculated using instrumentation which may already be in place for engine air-to-fuel ratio control.

Methods and systems are provided for injector balancing without disabling a cam actuated high pressure fuel pump. In one example, one of a plurality of cam lobes of the pump is selectively and sequentially disabled while a group of injectors are concurrently operated to learn a pressure drop across each injector. The selection of the injectors is based on the identity and stroke timing of the disabled cam lobe.

A method of operating a fuel injection system for a motor vehicle includes one or more of the following: operating a fuel injector to perform a fuel injection, the fuel injector being in fluid communication with a fuel rail; sampling a rail pressure in the fuel rail during the fuel injection; regulating the rail pressure at a desired injection pressure, P.sub.inj, to the fuel injector; measuring an overall leakage on variations of the rail pressure across an engine cycle for the motor vehicle and between two engine positions of an internal combustion engine for the motor vehicle; and restarting a new measurement cycle for a new pressure measurement target.