Fuel injector with a solenoid drive

1. A method for actuating a fuel injector with a solenoid drive to obtain a predefined injection quantity, the method comprising:

setting a starting value of an electrical actuation time, the electrical actuation time representing a duration for which an electrical voltage is applied to the solenoid drive, based at least in part on the predefined injection quantity;

actuating the fuel injector with an electrical actuation pulse for the duration represented by the starting value;

detecting an elapsed time for a closing process, the elapsed time equal to an amount of time required for the fuel injector to physically close after an end of the electrical actuation pulse;

determining an injection quantity from the starting value and the detected elapsed time;

determining a difference between the injection quantity and the predefined injection quantity; and

determining a corrected value of the electrical actuation time based at least in part on the determined difference using a relationship between the electrical actuation time, the time duration of the closing process, and the injection quantity; and

using the corrected value to control a second actuation of the fuel injector.

2. The method as claimed in claim 1 , further comprising:

during the second actuation of the fuel injector with the corrected value, detecting a second time duration (TS) of the closing process;

acquiring a second injection quantity on the basis of the corrected value and the second time duration;

determining a second difference between the acquired second injection quantity and the predefined injection quantity; and

determining a second corrected value of the electrical actuation time on the basis of the determined second difference.

3. The method as claimed in claim 2 , further comprising:

determining whether the second difference is greater than a predetermined threshold value; and

determining the corrected value only if the second difference is greater than the predetermined threshold value.

4. The method as claimed in claim 1 , wherein:

the relationship is represented by a characteristic diagram comprising a multiplicity of curves, each with a constant injection quantity;

the electrical actuation time is specified along a first axis; and

the duration of the closing process is specified along a second axis.

5. The method as claimed in claim 1 , wherein the actuation process of the fuel injector is carried out in a ballistic operating mode.

6. The method as claimed in claim 1 , wherein the actuation process of the fuel injector is carried out in a linear operating mode; and

the method further comprises acquiring a value of a needle stroke for the fuel injector, and selecting the characteristic diagram from a multiplicity of characteristic diagrams on the basis of the acquired value of the needle movement.

7. The method as claimed in claim 1 , further comprising:

acquiring the value of an idle stroke for the fuel injector; and

selecting the characteristic diagram from a multiplicity of characteristic diagrams on the basis of the acquired value of the idle stroke.

8. A method for actuating a fuel injector having a solenoid drive, the method comprising:

obtaining a predefined injection quantity,

setting a starting value of an electrical actuation time, the electrical actuation time representing a duration for which an electrical voltage is applied to the solenoid drive, based at least in part on the predefined injection quantity;

actuating the fuel injector with an electrical actuation pulse for the duration represented by the starting value;

detecting an elapsed timed of a closing process, the elapsed time equal to an amount of time required for the fuel injector to physically close after an end of the electrical actuation pulse;

determining an injection quantity based on the starting value and the detected elapsed time;

determining a difference between the determined injection quantity and the predefined injection quantity; and

determining a corrected value of the electrical actuation time based at least in part on the determined difference using a relationship between the electrical actuation time, the time duration of the closing process, and the injection quantity; and

actuating the fuel injector with the corrected value of the electrical actuation time.

9. An engine controller for a vehicle, the engine controller comprising:

a processor in communication with a memory;

the memory storing a set of instructions, the instructions, when executed by the processor, causing the processor to:

set a starting value of an electrical actuation time, the electrical actuation time representing a duration for which an electrical voltage is applied to the solenoid drive, based at least in part on a predefined injection quantity;

actuate the fuel injector with an electrical actuation pulse for the duration represented by the starting value;

detecting an elapsed timed of a closing process, the elapsed time equal to an amount of time required for the fuel injector to physically close after an end of the electrical actuation pulse;

determine an injection quantity using the starting value and the detected elapsed time;

determine a difference between the injection quantity and the predefined injection quantity; and

determine a corrected value of the electrical actuation time based at least in part on the determined difference using a relationship between the electrical actuation time, the elapsed time, and the injection quantity; and

use the corrected value to control a second actuation of the fuel injector.