The present invention relates to a method for determining a corrected rotational speed
signal and to an
electric motor arrangement. In one step of the method, a periodic rotational angle
signal havinga rotational-angle-dependent, periodic rotational angle error is determined. The rotational angle
signal is converted into a digital raw rotational speed signal (16) which, on account of the rotational angle error, has an interference
ripple, the
period duration of which corresponds to the
period duration of the rotational angle error. The digital raw rotational speed signal (16) comprises a plurality of sampled values (07) which are spaced apart in terms of time by a sampling
period duration. Half the period duration of the interference
ripple of the raw rotational speed signal (16) is determined. An average is calculated for at least one pair of sampled values (07) of the raw rotational speed signal (16), the temporal spacing of said values being the determined half period duration of the interference
ripple of the raw rotational speed signal (16), apart from a
temporal discretization error. An average value is obtained from the average calculation. A correction value which is dependent on the sampling period duration and on the frequency of the interference ripple is formed in order to take the
discretization error into account. The corrected rotational speed signal is formed from a difference between the average value and the correction value. The correction signal varies in a sawtooth-shaped manner on the basis of the deviation of the sampling period duration from the period duration of the interference ripple, and the
maximum amplitude of the correction signal also increases with the frequency of the interference ripple.