Method and device for operating an injection valve

A controller for operating an injection valve having a nozzle needle that moves between a closed position that prevents a metering of fluid and other positions that allow the metering of fluid, and a solid-state actuator that acts on the nozzle needle to influence its position, wherein the controller is programmed to:

• acquire values of a characteristic variable for a state of charge of the solid-state actuator with a predefined sampling rate,
• determine a starting reference time and a final reference time that are chronologically correlated with an operating phase in which the solid-state actuator is discharged to a predefined reference state by taking up the energy in a discharge resistor,
• determine a correction reference value as a function of (a) a value of the characteristic variable for the state of charge of the solid-state actuator which is determined in connection with an end of the operating phase, and (b) a predefined reference value,
• determine a correction value profile as a function of the final reference time, the starting reference time and the correction reference value,
• correct the acquired values of the characteristic variable for the state of charge as a function of the correction value profile, and
• actuate the injection valve for at least one injection cycle using corrected values of the characteristic variable.