Device and method for controlling an injection valve

A device for ascertaining parameter values for a fuel injector for an internal combustion engine of a motor vehicle, said fuel injector having a coil drive for moving a closing element, the device comprising:

• an application unit for applying a voltage pulse to the coil drive of the fuel injector;
• a detection unit for detecting a time curve of the current intensity of a current flowing through the coil drive or a time curve of the movement of the closing element;
• a memory for storing the detected time curves;
• and
• a processor for:
• determining a plurality of differential curves based on stored time curves of the detected current intensities;
• generating a plurality of differential curves each based on two stored time curves of the detected current intensity for successive measurements;
• and
• determining a peak current for driving the actuator of the fuel injector based at least in part on the plurality of differential curves.

A motor controller for an internal combustion engine of a motor vehicle, the internal combustion engine comprising at least one fuel injector having a coil drive for moving a closing element, the device comprising:

• an application unit for applying a voltage pulse to the coil drive of the fuel injector;
• a detection unit for detecting a time curve of the current intensity of a current flowing through the coil drive or a time curve of the movement of the closing element;
• a memory for storing the detected time curves;
• and
• a processor for:
• determining a plurality of differential curves based on stored time curves of the detected current intensities;
• generating a plurality of differential curves each based on two stored time curves of the detected current intensity for successive measurements;
• and
• determining a peak current for driving the actuator of the fuel injector based at least in part on the plurality of differential curves;
• wherein the application unit operates the coil at the determined peak current.

A computer program for ascertaining parameter values for a fuel injector for an internal combustion engine of a motor vehicle, the fuel injector having a coil drive for moving a closing element, wherein the computer program, when it is executed by a processor, is configured to carry out a method comprising:

• carrying out a plurality of measurements, wherein each measurement comprises:
• determining a measurement-specific maximum current value;
• applying a voltage pulse to the coil drive of the fuel injector;
• detecting a time curve of the current intensity of a current flowing through the coil drive;
• ending the voltage pulse when the detected current intensity reaches the maximum current value;
• and
• storing the time curve of the detected current intensity;
• generating a plurality of differential curves each based on two stored time curves of the detected current intensity for successive measurements;
• determining a peak current for driving the actuator of the fuel injector based at least in part on the plurality of differential curves;
• and
• operating the coil at the determined peak current.