A control process of a display element, the process comprising the steps: measuring a position of a control lever, projecting in a base plane the position of the lever to determine a first set of coordinates, determining a homothetic figure on a mechanical stop of the lever, determining a circumscribed square on the homothetic figure, projecting onto the circumscribed square at least one coordinate of the first set of coordinates, calculating a second set of coordinates in a Cartesian reference frame, on the basis of the projection of said at least one coordinate of the first set of coordinates on the circumscribed square.