| abstract |
The invention relates to a diagnosis of a drive system (1), in particular a door drive system, which has an electric motor (2), preferably a synchronous motor, with a stator (3) with phase windings (4, 5, 6) and with a rotor (7) excited by a permanent magnet. The drive system also has a sensor (9) for determining a position of the rotor (7). The diagnosis is carried out according to the invention in a simple manner with little complexity by means of the following steps: a) rotating the rotor (7) without supplying the phase windings (4, 5, 6) with current, preferably manually rotating the rotor (7) or rotating the rotor (7) by allowing the rotor to coast to a stop after a previous acceleration, b) measuring voltages induced in the phase windings (4, 5, 6) by the rotation and signals generated by the sensor (9) at the same time as the rotation is being carried out, c) ascertaining a spatial indicator angle (γab) of the voltages induced during the rotation and ascertaining a rotor position angle (γel) from the signals generated by the sensor (9) during the rotation, and d) comparing the spatial indicator angle (γab) ascertained during the rotation with the rotor position angle (γel) ascertained during the rotation and ascertaining a difference in a value, a direction, and/or a rotational speed of the two angles in order to diagnose the drive system (1). |