Methods for assessing presence of electrical, electronic, and/or mechanical faults in electromechanical linear actuators

A method of assessing presence of electrical, electronic, and/or mechanical fault in an electromechanical linear actuator (1), said electromechanical linear actuator, the electromechanical linear actuator comprising:

• a containment structure;
• independent first and second lead nuts, each having its own thread and its own thread direction;
• two electric motors in the containment structure, operably connected with the first and second lead nuts to rotate them about an axis of rotation;
• a shaft inserted in the first and second lead nuts;
• a rotation-preventing mechanism operable on the shaft to prevent the shaft from rotating about the axis of rotation;
• coupling means configured to mechanically couple the first and second lead nuts with the shaft, so that a rotational movement of the first and/or second lead nuts will cause a translation of the shaft along the axis of rotation;
• first and second electric brakes, operable on the first and second lead nuts respectively, to brake their rotation about the axis of rotation;
• and
• command and control electronics for each electric motor and electric brake, comprising a plurality of sensors in the containment structure operatively connected with the command and control electronics, wherein the plurality of sensors is configured to detect a position of the shaft so as to detect its movements along the axis of rotation;
• the coupling means comprising:
• an intermediate coupling stage inserted in the first and second lead nuts;
• respective first mechanical connection means for coupling the intermediate coupling stage with each lead nut;
• and
• second mechanical connection means;
• wherein the shaft is fitted into the intermediate coupling stage and is connected with the intermediate coupling stage through the second mechanical connection means;
• the method comprising:
• actuating the two electric motors to drive the first and second lead nuts in a same direction of rotation or in opposite directions of rotation;
• during the actuating of the two electric motors, checking via the plurality of sensors whether the shaft translates relative to the containment structure and whether the shaft does not translate relative to the containment structure;
• checking whether there is a mechanical failure of the intermediate coupling stage with either of the first and second lead nuts, to thereby actuate the two electric motors in the same direction of rotation;
• and
• checking whether there is a mechanical failure of the shaft with the intermediate coupling stage, to thereby actuate the two electric motors in the opposite directions of rotation.