| 主权项 |
1. A method of determining the longitudinal air speed VairX and the longitudinal ground speed VsolX of a rotary wing aircraft depending on the exposure to the wind of the aircraft, the aircraft flying along a track Tsol relative to the ground with a speed of advance Va, which speed of advance Va may be determined relative to the ground in order to form a ground speed Vsol and relative to the air in order to form an air speed Vair, a longitudinal direction X extending from the rear of the aircraft towards the front of the aircraft, an elevation direction Z extending upwards perpendicularly to the longitudinal direction X, and a transverse direction Y extending from right to left perpendicularly to the longitudinal and elevation directions X and Z, the aircraft comprising:
an autopilot for generating control signals in compliance with predefined modes of operation and in compliance with flight setpoints, the control signals being capable of causing the aircraft to perform movements in rotation and/or translation relative to the directions (X, Y, Z); at least one control means enabling a pilot of the aircraft to pilot the aircraft by transparency while the autopilot is in operation; and at least one computer and at least one memory; wherein the memory stores characteristic speed curves for the aircraft defining the longitudinal ground speed VsolX and the longitudinal air speed VairX of the aircraft as a function of a longitudinal speed of the relative wind to which the aircraft is being subjected, each characteristic speed curve corresponding to a stage of flight of the aircraft and being made up of operating points of the aircraft, each operating point being characterized by a longitudinal ground speed VsolX and by a longitudinal air speed VairX in a coordinate system having a longitudinal ground speed VsolX of the aircraft up the ordinate axis and the longitudinal air speed VairX of the aircraft along an abscissa axis, a stage of flight corresponding to a flight of the aircraft during which a pilot of the aircraft does not cause any acceleration or deceleration of the aircraft along the longitudinal direction X, the method comprising the following steps: during an initialization step, for a current stage of flight of the aircraft, identifying an initial characteristic speed curve on which the current operating point of the aircraft lies; for the current stage of flight, controlling the longitudinal air and ground speeds VairX and VsolX of the aircraft as a function of the variation of the total speed of the wind on the longitudinal direction X so that the current operating point of the aircraft moves on the initial characteristic speed curve; and following the pilot taking action on the longitudinal direction to cause the aircraft to accelerate or decelerate, identifying a new characteristic speed curve on which the current operating point of the aircraft lies once the longitudinal air and ground speeds VairX and VsolX have stabilized and are substantially constant. |
