Method and device for controlling angular speed of an electromechanical drive train with little damping

Device for controlling a speed of a load driven in rotation by an electric motor through an electromechanical drive train with little damping, comprising means for measuring the real speed of the motor and means for determining a torque actuation reference quantity Γ* of the motor from a measured speed ωm issued by said speed measuring means and from a set point signal ΩL* representative of a reference speed of the load, characterized in that the means for determining said reference quantity comprises:

• an observer, the inputs of which are the reference quantity Γ* and an innovation error represented by a weighted difference between the measured speed Ωm of the motor and an estimated speed {circumflex over (Ω)}m of the motor, the observer calculating an estimated speed {circumflex over (Ω)}L of the load and the difference between the reference speed ωL* of the load and the estimated speed {circumflex over (Ω)}L of the load;
• a robust CRONE-type non-integer order controller, which has an input comprising the calculated difference between the reference speed ΩL of the load and the estimated speed {circumflex over (Ω)}L of the load, and the physical realization of which is provided by an integer order controller, obtained by approximation in the frequency domain.