Drive controller for an electric drive, which comprises an electric machine supplied with electrical energy via a converter , wherein in normal operation the drive controller is continuously embodied - to receive respective raw signals (x, y, α') from a position transmitter detecting a rotational position of a rotor shaft of the electric machine , - based on the respective raw signals (x, y, α') in conjunction with correction variables (rej, imj) to determine a respective actual position (α) of the rotor shaft and - as a function of a respective target position (α*) and the respective actual position (α) or of a respective target rotational speed (n*) and an actual rotational speed (n) of the rotor shaft determined using the respective actual position (α) to determine respective control signals (U*) for the converter and to output them to the converter , wherein in special operation the drive controller is embodied - first to determine control signals (U*) for the converter , based on which the rotor shaft is provided to rotate at an initial rotational speed (n1), and to output these control signals (U*) to the converter , - to then operate the electric machine in a non-powered manner, so that the rotor shaft coasts down, - during the coasting down of the rotor shaft to continuously receive respective raw signals (x, y, α') from the position transmitter and based on the respective raw signals (x, y, α') to determine a respective raw position (α') of the rotor shaft and to buffer it, - based on a plurality of raw positions (α') determined in special operation to determine the correction variables (rej, imj) and - to save the correction variables (rej, imj) in a correction variable memory of the drive controller, so that in normal operation they are available for the determination of the respective actual position (α) and wherein the drive controller is embodied to model the coasting down of the rotor shaft in accordance with a model , wherein the model has a number of model parameters (ki) and wherein the drive controller is embodied to also determine the model parameters (ki) based on the raw positions (α') determined in special operation. - to receive respective raw signals (x, y, α') from a position transmitter detecting a rotational position of a rotor shaft of the electric machine , - based on the respective raw signals (x, y, α') in conjunction with correction variables (rej, imj) to determine a respective actual position (α) of the rotor shaft and - as a function of a respective target position (α*) and the respective actual position (α) or of a respective target rotational speed (n*) and an actual rotational speed (n) of the rotor shaft determined using the respective actual position (α) to determine respective control signals (U*) for the converter and to output them to the converter , - first to determine control signals (U*) for the converter , based on which the rotor shaft is provided to rotate at an initial rotational speed (n1), and to output these control signals (U*) to the converter , - to then operate the electric machine in a non-powered manner, so that the rotor shaft coasts down, - during the coasting down of the rotor shaft to continuously receive respective raw signals (x, y, α') from the position transmitter and based on the respective raw signals (x, y, α') to determine a respective raw position (α') of the rotor shaft and to buffer it, - based on a plurality of raw positions (α') determined in special operation to determine the correction variables (rej, imj) and - to save the correction variables (rej, imj) in a correction variable memory of the drive controller, so that in normal operation they are available for the determination of the respective actual position (α) and <EOS>