Method and device for controlling angular speed of an electromechanical chain with low damping

Device for controlling the speed of a load (10) driven in rotation by an electric motor (12) through an electromechanical drive train (13) with little damping, comprising means (26) for measuring the real speed of the motor (12) and means for determining a torque actuation reference quantity Γ* of the motor (12) from a speed signal Ωm issued by said speed measuring means (26) and from a set point signal ΩL* representative of a reference speed of the load (10), characterized in that the means for determining said reference quantity include:

• an observer (18) the inputs of which are the reference quantity Γ* and an innovation error represented by the weighted difference between the measured speed Ωm of the motor (12) and an estimated speed {circumflex over (Ω)}m of the motor, the observer (18) being able to calculate an estimated speed {circumflex over (Ω)}L of the load and the difference between the reference speed ΩL* of the load (10) and the estimated speed ΩL of the load;
• a robust CRONE-type non-integer order controller (20), using as an input the calculated difference between the reference speed ΩL* of the load (10) and the estimated speed {circumflex over (Ω)}L of the load and the physical realization of which is provided by a integer order controller, obtained by approximation in the frequency domain.