Force application device for an active mini-stick and mechanical backup control method

A force application device for an aircraft pilot stick, the device comprising:

• a mechanical joint configured to receive a lever of an aircraft pilot stick, the mechanical joint being rotatably movable about a roll axis and about a pitch axis,
• a force motor comprising a motor shaft extending along a third axis, the rotation of the motor shaft about the third axis being linked to the rotation of the mechanical joint about an axis taken among the roll axis or the pitch axis, the force motor being configured to exert a resistive torque on the motor shaft,
• a rheological brake comprising two facing parts facing each other,
• the brake comprising a volume delimited by said two facing parts, the volume being adapted to contain a rheological material, one of said two parts being arranged on the motor shaft and being rotatably movable about the third axis relative to the other of said two facing parts, and
• a control device controlled to apply an electromagnetic field within said volume so as to vary shear strength of the rheological material.