Method and device for controlling at least two piezo-actuators

The method involves determining a parameter for each of two or more piezoelectric actuators, and adjusting the parameters to a setting value. The parameter is determined based on an electrical value that is used to drive the piezoelectric actuator, e.g. the voltage applied to the actuator. The parameter may be an edge, extreme value, or kink in the curve of the electrical value. The setting value may be the average of the parameters. An Independent claim is included for an apparatus for controlling at least two piezoelectric actuators.