Low noise control of a high-pressure fuel pump is performed by reducing noise generated by an anchor colliding with a fixing core. A control device 800 for a high-pressure fuel pump controls a suction valve that opens and closes an inflow port through which fuel flows to a pressurizing chamber by performing energization to a solenoid 205 in synchronization with a reciprocating motion of a plunger. A current energized to the solenoid 205 includes a peak current for giving a force to start closing a valve to the suction valve in a stationary state and a holding current for performing switching in a range smaller a maximum value of the peak current in order to hold the suction valve in a valve closing state. When the control device 800 reduces a peak current application amount of the peak current from a value sufficient to close the high-pressure fuel pump, a valve closing speed of the suction valve becomes small up to a certain application amount, and when the peak current application amount becomes smaller than the application amount, there is a saturation range of a current application amount of the peak current in which the valve closing speed of the suction valve is saturated. The control device 800 controls the current application amount of the peak current to fall in the saturation range.

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 control method of an engine system is a method of controlling the engine system including an engine with a combustion chamber; a fuel injection valve configured to supply fuel to the engine; and an air-fuel ratio sensor provided in a flow path of exhaust gas from the engine. In the control method, feedback control is performed so that an air-fuel ratio in the combustion chamber becomes a target value by controlling the fuel injection valve, using an air-fuel ratio measured value obtained by the air-fuel ratio sensor. In the feedback control, a transfer function is used, the transfer function being obtained by system identification of a plant having the air-fuel ratio in the combustion chamber serve as an input and the air-fuel ratio measured value obtained by the air-fuel ratio sensor serve as an output. In the control method, a filtering process is performed to an air-fuel ratio measured value used in the feedback control, the filtering process cutting a component having a response speed faster than a delay indicated by the transfer function.

To provide a controller for internal combustion engine which suppresses that estimation of the combustion state is performed based on the angle information on which the component due to the torsional vibration is superimposed, when the torsional vibration occurs in the crankshaft. A controller for internal combustion engine determines whether a torsional vibration occurs in a crankshaft based on an angle period; calculates a gas pressure torque in burning based on a crank angle acceleration which is calculated based on the angle period; estimates a combustion state of an internal combustion engine based on the gas pressure torque in burning; and stops estimation of the combustion state, when it is determined that the torsional vibration occurred.

Provided is an internal combustion engine control device that is capable of accurately estimating a stable combustion state at low cost. An internal combustion engine control device according to one aspect of the present invention includes: a rotational speed calculation unit 122a that calculates a time-series value of a crank rotational speed of an internal combustion engine; a rotational, speed phase calculation unit 122b that calculates a phase of the crank rotational speed from the time-series value of the crank rotational speed calculated by the rotational speed calculation unit; and a cycle variation calculation unit 122c that calculates the magnitude of variation between cycles of the phase of the crank rotational speed calculated by the rotational speed phase calculation unit.

Provided is an internal combustion engine control device that is capable of accurately estimating a stable combustion state at low cost. An internal combustion engine control device according to one aspect of the present invention includes: a rotational speed calculation unit 122a that calculates a time-series value of a crank rotational speed of an internal combustion engine; a rotational, speed phase calculation unit 122b that calculates a phase of the crank rotational speed from the time-series value of the crank rotational speed calculated by the rotational speed calculation unit; and a cycle variation calculation unit 122c that calculates the magnitude of variation between cycles of the phase of the crank rotational speed calculated by the rotational speed phase calculation unit.

A control method of a butterfly valve of an internal combustion engine, when said internal combustion engine is running, wherein said butterfly valve is controlled by means of a control signal, indicative of an angular position of said valve, the method comprising a step of applying a first limiting filter of a gradient of said control signal, when a ratio between a target pressure downstream of the butterfly valve and a measured pressure upstream of the butterfly valve is greater than a first predetermined threshold.

A knocking determination device detects a vibration generated in an internal combustion engine during a predetermined period in each combustion cycle of the internal combustion engine. The knocking determination device performs a knocking determination of a presence or absence of a knock based on a vibration waveform in a predetermined frequency band component of the vibration detected.

The invention concerns a test kit comprising a testing program programmed to control an internal combustion engine for testing the internal combustion engine with the engine kept at a fixed load condition, provided with a test module programmed execute a sequence of individual cylinder tests, wherein the test module comprises first computer code for measuring, in each cylinder test, a first engine performance value and further comprises second computer code for providing an amount of fuel to one cylinder under test to differ from an amount of fuel provided to the rest of the plurality of cylinders; and a further test module programmed to measure, in an idle period between subsequent individual cylinder tests of said sequence of individual cylinder tests, a second engine performance value; and said further test module comprising third computer code to discard at least some of the individual cylinder tests if the second engine performance measured by the further test module value passes a threshold.

A system for detecting and controlling misfire and/or AFR imbalance conditions in cylinders of an internal combustion engine having a plurality of cylinders is disclosed.