CONTROL METHOD OF A DIRECT CURRENT ELECTRIC MOTOR

The present invention concerns a method of controlling a rotational speed of a rotor (3) of a direct current electric motor (1) comprising an inductor circuit (A, B) for rotating the rotor, which is configured to rotate continuously and is equipped with permanent magnets. The method comprises: measuring the rotational speed of the rotor ; determining a time drift in the rotor rotation compared to a reference signal; defining N speed thresholds with at least one being a variable speed threshold depending on the determined time drift, the N speed thresholds defining N+1 rotational speed ranges for the rotor ; determining in which one of the N+1 rotational speed ranges the determined rotational speed of the rotor is ; and finally selecting an action relative to the control of the inductor circuit, based on the determined rotational speed range, for controlling the rotational speed of the rotor.