Determination of the absolute rotational angle of the rotor of a motor vehicle combustion engine alternator, by use of signals derived from a coarse encoder on the rotor itself and a fine encoder connected to the crankshaft

摘要

Method for determining the absolute rotational angle of the rotor (10) of an alternator linked to a combustion engine. Accordingly: a first periodic rotational impulse signal (S2) is generated by a coarse rotational encoder on the rotor; a second high frequency impulse signal (S1) is generated by a fine rotational encoder (3) coupled to the engine crankshaft; and the rotational angle (W) is determined from the two signals taking into account the gearing ratio of the drive (13).