An ECU as a valve body operation estimation device includes a sampling unit that obtains at least one of voltage and current of the electromagnetic coil as sample values at intervals of a predetermined time in a sampling period set based on a predetermined reference timing, a variation calculation unit that calculates a degree of variation of the sample values obtained in the sampling period, a variation waveform which represents a change of the degree of variation caused by shifting the reference timing including a point at which the degree of variation reduces and then rises as the reference timing is delayed, the point referred to as a rising start point, and a timing estimation unit that estimates an operation timing of a valve body based on the reference timing at the rising start point.

A fuel injection control device first causes a first power supply unit to apply a voltage to a fuel injection valve, subsequently causes a second power supply unit to apply a voltage to the fuel injection valve, and after the first power supply unit applies the voltage, executes a lift position determination process to determine that a valve element of the fuel injection valve reaches a predetermined lift position based on a change in a drive current. A first control unit performs a drive control on the fuel injection valve without executing the lift position determination process. A second control unit executes the lift position determination process and performs a drive control on the fuel injection valve. The second control unit controls the drive current to decrease when the valve element reaches the predetermined lift position compared to a case where the first control unit performs drive control.

A control device for a fuel injection valve including a variable lift mechanism of two or more stages is provided. The control device includes an inflection point detection unit for detecting an inflection point from at least one of a drive current when the fuel injection valve is opened or a drive voltage when the fuel injection valve is closed. The control device also includes a drive sensing unit for sensing a drive lift of the fuel injection valve from at least one of an inflection point of a drive current during valve opening operation or a drive voltage during valve closing operation. The control device is configured to limit the command drive lift when the sensed drive lift is different from a command drive lift.

A method for detecting the malfunction of a software solution configured to generate data representing the instant of interruption of fuel injection of an internal combustion engine. The method comprises acquiring data by a data acquisition device which is connected to a measurement device fixed to an injector body and configured to emit data representing closure instants of an injection nozzle, recording the data generated by the software solution and the data emitted by the measurement device, over a predetermined duration, synchronizing the data generated by the software solution and the data emitted by the measurement device, and comparing the data generated by the software solution and the data emitted by the measurement device, the software solution being considered to be malfunctioning when they do not satisfy predefined criteria.

A fuel injection control device includes a valve closing detection unit (54) to detect a valve closing timing by using either of an electromotive force quantity detection mode and a timing detection mode, a selection unit (21) to select either of the electromotive force quantity detection mode and the timing detection mode for detecting the valve closing timing, and a correction unit (21) to calculate a correction coefficient for correcting a requested injection quantity so as to reduce the difference between an estimated injection quantity and the requested injection quantity, and the selection unit selects the electromotive force quantity detection mode regardless of the value of the requested injection quantity when the calculation of the correction coefficient is not completed.

To reduce collision noise caused when an electromagnetic valve of a high-pressure fuel supply pump is opened. Therefore, in a control device for controlling a high-pressure fuel supply pump including: an anchor; a fixed core configured to attract the anchor with an electromagnetic force; a suction valve configured to be opened or closed when the anchor is sucked by the fixed core; and an electromagnetic force generation unit configured to generate the electromagnetic force when applied with a driving voltage, it can be achieved by providing a control unit configured to perform control to lower a driving current from a peak current before a timing at which the anchor is sucked by the fixed core and collides in an operation state where an engine is under no load and an engine rotation speed is equal to or less than a set rotation speed.

A method for operating an internal combustion engine having at least one fuel injector that is activated for opening and closing via a solenoid valve of a respective fuel injector. Commencing with the activation of the fuel injector for opening, structure-borne sound waves emitted by the fuel injector over the time are detected by measurement. A structure-borne sound wave signal detected by measurement over the time is evaluated such that dependent on the amount of at least one maximum of the structure-borne sound wave signal and/or dependent on the number of the maximums of the structure-borne sound wave signal and/or in the presence of multiple maximums dependent on the time sequence and/or on the amount of the maximums, an operating state of the respective fuel injector is deduced.

The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.

A fuel injection control device includes a valve closing detection unit to detect a valve closing timing by using either of an electromotive force quantity detection mode and an timing detection mode and a selection unit to select either of the electromotive force quantity detection mode and the timing detection mode for detecting the valve closing timing, and the selection unit: selects the timing detection mode when a requested injection quantity is larger than a prescribed reference injection quantity in partial lift injection; and selects the electromotive force quantity detection mode when the requested injection quantity is smaller than the reference injection quantity.

A fuel injection control device includes an additional energization unit. Concerning an undershoot state caused by a first energization for fuel injection, a return period is an estimated period required for a movable core to return to an initial position from a first energization. An injection interval ranges from the first energization to a second energization that is for a next fuel injection. An allowable period is obtained by subtracting a rise period estimated for the second energization from the return period. The additional energization unit adds an additional energization between the first energization and the second energization when the injection interval is longer than or equal to the allowable period and is shorter than or equal to the return period.