Patent ID: 8362630

Claim:
A method for controlling a self- piloted alternator-starter ( 10 ), for the starting or re-starting of a thermal engine ( 11 ) of a motor vehicle, the alternator-starter ( 10 ) comprising: a rotor ( 14 ) equipped with a rotor winding ( 22 ); a stator ( 16 ) equipped with a set of stator windings ( 40 ); and a flexible drive unit ( 48 ) for flexible transmission of the torque of the rotor ( 14 ) of the alternator-starter ( 10 ) to a crankshaft ( 46 ) of the thermal engine ( 11 ); the control method comprising: a first, pre-flux step (E 1 ) during which the rotor winding ( 22 ) is excited by an electrical pre-flux current to induce a magnetic rotor field (CMr), whereas the stator windings ( 40 ) are not excited, such that the rotor ( 14 ) is not rotated; and a second, starter step (E 2 ) triggered at the end of the first, pre-flux step (E 1 ), and during which the stator windings ( 40 ) are excited whilst the rotor winding ( 22 ) is kept excited, such that the rotor ( 14 ) is rotated, the pre-flux step (E 1 ) lasts between 10 and 100 ms, such that the flexible drive unit ( 48 ) is taut before a deterioration tension occurs during triggering of the second, starter step (E 2 ).