Method and apparatus for controlling and / or regulation of an actuator

The control and/or regulation of a selling member, in particular for influencing the instant of fuel injection into an internal combustion engine, comprises determining the error (SBD) between a target value (SBS) and an actual value (SBI) of, for example, injection needle movement. A regulator (130) presets a selling value (P) for action on the selling member in dependence on the error. If the error lies outside a range defined by at least two values, a maximum value (PMAX, PMIN) is applied as the selling value. The Regulator (130) may have proportioned-integral behaviour and its operation may be suspended when the error falls outside the range. On restarting, the integral valve is set in dependance on its previous valve and the previous and current error. A model (160) may provide simulated actual valve or error signals between sampling instants.