A controller for an internal combustion engine is configured to control the fuel injection valve so that the fuel injection valve selectively performs partial lift injection, which does not open a valve member at a fully open position, and full lift injection, which opens the valve member at the fully open position. The internal combustion engine includes the fuel injection valve and a fuel supply system. The controller includes an energizing time setting unit, a fuel pressure calculation unit, and a smoothening process unit. The energizing time setting unit is configured to set an energizing time for the full lift injection based on graded fuel pressure calculated by the smoothening process unit and set an energizing time for the partial lift injection based on fuel pressure calculated by the fuel pressure calculation unit.

A controller for an internal combustion engine is configured to control the fuel injection valve so that the fuel injection valve selectively performs partial lift injection, which does not open a valve member at a fully open position, and full lift injection, which opens the valve member at the fully open position. The internal combustion engine includes the fuel injection valve and a fuel supply system. The controller includes an energizing time setting unit, a fuel pressure calculation unit, and a smoothening process unit. The energizing time setting unit is configured to set an energizing time for the full lift injection based on graded fuel pressure calculated by the smoothening process unit and set an energizing time for the partial lift injection based on fuel pressure calculated by the fuel pressure calculation unit.

An internal-combustion engine includes an EGR device that recirculates a portion of exhaust gas, as EGR gas, from an exhaust passage to an intake passage through an EGR valve. A control device for the control device is configured to perform: EGR ratio estimation processing that calculates, by using an estimation model, an estimated EGR ratio; and estimation model update processing that updates the estimation model. The estimation model is configured to calculate the estimated EGR ratio based on a pressure parameter being a ratio of or a difference between gas pressures upstream and downstream of the EGR valve. The pressure parameter is represented by a pressure parameter model that is updatable. The estimation model update processing includes: calculating an actual EGR ratio; and updating the pressure parameter model such that the estimated EGR ratio becomes closer to the actual EGR ratio.

A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

The purpose of the present invention is to provide a control device for an internal combustion engine with which it is possible to favorably control an engine even if there could occur a difference in temperatures of fuel injected into respective cylinders. The present invention is a control device for an internal combustion engine, for controlling an internal combustion engine provided with fuel injection valves for directly injecting fuel respectively to a plurality of cylinders, wherein: the control device is provided with a fuel temperature acquiring means for acquiring respective temperatures of fuel injected to each of the cylinders; and at least one of a fuel injection valve control amount, ignition control amount, and intake and exhaust valve control amount of each of the cylinders is set in accordance with the respective temperatures of fuel acquired by the fuel temperature acquiring means. Alternatively, the present invention is a control device for an internal combustion engine, for controlling an internal combustion engine provided with fuel injection valves for directly injecting fuel respectively to a plurality of cylinders, wherein the control device is provided with a valve-closing time detecting means for detecting a valve-closing time of a valve body of each of the fuel injection valves, and a fuel temperature estimating means for estimating the temperature of fuel on the basis of the valve-closing duration of the valves detected by the valve-closing time detecting means.

A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

An injection control device controls a fuel injection valve driven by an electric power. The injection control device includes a current detection unit to detect a driving current supplied to a solenoid of the fuel injection valve, an identification unit to identify a theoretical model of the driving current in a state where a movable core moved by an electromagnetic force generated by the solenoid is at rest, and a state detection unit to detect a state of the movable core. The state detection unit detects the state of the movable core, based on a deviation between the driving current detected by the current detection unit and the theoretical model.

An injection control device controls a fuel injection valve driven by an electric power. The injection control device includes a current detection unit to detect a driving current supplied to a solenoid of the fuel injection valve, an identification unit to identify a theoretical model of the driving current in a state where a movable core moved by an electromagnetic force generated by the solenoid is at rest, and a state detection unit to detect a state of the movable core. The state detection unit detects the state of the movable core, based on a deviation between the driving current detected by the current detection unit and the theoretical model.

A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel configured to supplement a primary fuel used by an engine. The electronic valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of the engine. The controller is configured to control the electronic valve such that the electronic valve is (i) closed to prevent the supplemental fuel from being provided to the air supply system in response to the temperature being less than a temperature threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the temperature being greater than the temperature threshold.