System og fremgangsmåde til detektering af rotationsretning

A system (2) for detecting the rotational direction (β) of an electric motor (8) is disclosed. The system (2) comprises: - a detection unit (24) configured to detect signals (x(t)) in a first dimension along a first axis (X) and signals (y(t)) in a second dimension along a second axis (Y) extending perpendicular to the first axis (X), wherein sad signals (x(t), y(t)) are generated by the motor (8), wherein said signals (x(t), y(t)) are indicative of the rotational direction (β) of the motor (8). The system (2) is configured to process the signals (x(t), y(t)) and hereby generate a complex vector defined as: (1) x(t) + j∙y(t). The system (2) is configured to: - carry out a Fourier transformation of the complex vector x(t) + j∙y(t) and hereby split the signals (x(t), y(t)) into a forward part and a backward part and - on the basis of the forward part and the backward part decide if: a) the rotation direction is clockwise, b) the rotation direction is counterclockwise or c) there is no rotation.