Method for determining at least one position of a mobile structure of an aircraft from its speed and aircraft comprising a device for executing it

1 . A method for determining at a given time at least one position of a landing gear of an aircraft, said landing gear being configured to move based on operation of a controller which is configured to execute said method, said landing gear being moved in at least one movement between a first position and a second position and configured to occupy intermediate positions between the first position and the second position, wherein the method comprises:

generating, beforehand, at least one list for the at least one movement associating listed positions and speeds of the landing gear, the listed positions comprising the first position, the second position, and the intermediate positions, each of said listed positions being associated with a listed speed;

determining, in operation, at least one speed of the landing gear at a given time;

comparing the at least one speed with the listed speeds each associated with a listed position;

determining a position of the landing gear at the given time that corresponds to the listed position associated with the listed speed equal to or closest to the at least one speed determined at the given time; and,

updating the listed speeds in the at least one list based on measured speeds used to determine the position of the landing gear.

2 . The method according to claim 1 wherein the determining the at least one speed of the landing gear comprises:

capturing a first image and a second image separated by a given time period in which the landing gear is visible;

determining a change of scale between the first image and the second image, and

calculating the at least one speed of the landing gear from the given time period and the change of scale between the first image and the second image.

3 . The method according to claim 2 , wherein the at least one speed of the landing gear is equal to a mean value of calculated speeds.

4 . The method according to claim 1 , wherein the determining the at least one speed of the landing gear comprises:

determining a frequency shift for a wave emitted and received by a radar after the wave has been reflected by the landing gear, and

calculating the at last one speed of the landing gear from the frequency shift.

5 . The method according to claim 4 , wherein the at least one speed of the landing gear is equal to a mean value of calculated speeds.

6 . The method according to claim 1 , wherein the generating the list comprises:

moving the landing gear in the movement, and,

for each position listed in the list, determining a speed of the landing gear and associating the speed determined with said position in the list.

7 . The method according to claim 1 , wherein the generating the list is carried out only once.

8 . A device for determining at least one position of a landing gear enabling determining at a given time at least one position of a landing gear of an aircraft, wherein the device comprises:

at least one storage unit configured to store a list associating listed positions and speeds of the landing gear;

at least one speed determination system configured to evaluate or to measure a speed of the landing gear, and,

at least one processor unit configured to compare at least one speed measured by the speed determination system and the listed speeds and to determine a position of the landing gear as a function of the comparison,

wherein the device is configured to perform the method of claim 1 .

9 . The device according to claim 8 , wherein the at least one speed determination system comprises at least one video camera.

10 . The device according to claim 8 , wherein the at least one speed determination system comprises at least one radar utilizing Doppler effect.

11 . The device according to claim 8 , further comprising:

a plurality of speed determination systems.

12 . An aircraft comprising:

the device according to claim 9 .

13 . The method according to claim 1 , wherein the determining of the at least one speed of the landing gear is done with at least one speed determination system which is rigidly fixed to the aircraft, such that the at least one speed determination system is disposed entirely outside the aircraft.