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

Abstract

Method for determining at least one position of a mobile structure of an aircraft from its speed and aircraft comprising a device for its implementation The invention relates to a method for determining at least one position of a mobile structure (M) at a given instant, which comprises a step of determining at least one speed of the mobile structure (M) at the given instant, a step of comparing the determined speed with listed speeds each associated with a listed position, and a step of determining the position of the mobile structure (M) at the given instant, which corresponds to the listed position associated with the listed speed equal to or closest to the speed determined at the given instant. This solution makes it possible, from a limited number of elements, to determine the position of the mobile structure (M) at each instant, and not only at the start and end of the movement.The invention also relates to a device for implementing said method as well as an aircraft comprising at least one such device. Figure 1.

Description

Title of the invention: Method for determining at least one position of a mobile structure of an aircraft from its speed and aircraft comprising a device for its implementation

[0001] The present application relates to a method for determining at least one position of a mobile structure of an aircraft from its speed as well as to an aircraft comprising a device for its implementation.

[0002] According to one embodiment, an aircraft comprises several landing gears each movable between retracted and extended positions as well as for each of them a landing gear compartment configured to house the landing gear in the retracted position.

[0003] Each landing gear comprises different elements articulated relative to each other as well as actuators for moving the landing gear between the retracted and extended positions.

[0004] Each landing gear compartment includes at least one door movable between an open position in which the door allows the landing gear to be in the extended position and a closed position in which the door closes the landing gear compartment when the landing gear is in the retracted position.

[0005] The aircraft also includes sensors for determining the position of each hatch of each landing gear compartment and of certain articulated elements and / or actuators of each landing gear.

[0006] According to one embodiment, each of these sensors is a proximity sensor making it possible to determine a single position of a mobile element such as one of the articulated elements, actuators or hatches. Thus, according to one configuration, for a given mobile element, the aircraft comprises two proximity sensors positioned at the two ends of the travel of the given mobile element.

[0007] This embodiment is not fully satisfactory because it requires a large number of proximity sensors and significant wiring, which impacts the mass of the aircraft and its maintenance.

[0008] According to another drawback, this embodiment does not make it possible to determine the position of a mobile element when the latter is not located at one of the ends of its travel.

[0009] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0010] To this end, the invention relates to a method for determining at a given instant at least one position of a mobile structure of an aircraft, said mobile structure being animated by at least one movement between first and second positions and configured to occupy intermediate positions between the first and second positions.

[0011] According to the invention, the method comprises, beforehand, a step of developing at least one directory for the movement associating listed positions and speeds of the mobile structure, the listed positions being chosen from the first and second positions as well as the intermediate positions, each of said listed positions being associated with a listed speed and, in operation, a step of determining at least one speed of the mobile structure at the given instant, a step of comparing the determined speed with the listed speeds and each associated with a listed position as well as a step of determining the position of the mobile structure at the given instant which corresponds to the listed position associated with the listed speed equal to or closest to the speed determined at the given instant.

[0012] Unlike the prior art, the method for determining at least one position of the mobile structure makes it possible, from a limited number of speed determination systems, to determine the position of the mobile structure at each instant and not only at the start and end of the movement.

[0013] According to a variant, the step of determining a speed of the mobile structure consists of capturing first and second images, separated by a given duration, in which the mobile structure is visible, determining a change in scale between the first and second images captured and calculating the speed of the mobile structure from the given duration and the change in scale between the first and second images captured.

[0014] According to another variant, the step of determining a speed of the mobile structure consists of determining a frequency shift for a wave emitted and received by a radar after having been reflected by the mobile structure and calculating the speed of the mobile structure from the frequency shift determined previously.

[0015] According to another characteristic, the speed of the mobile structure is equal to an average of measured speeds.

[0016] According to another characteristic, the step of developing the directory consists of moving the mobile structure by following the movement as well as, for each position listed in the directory, a step of determining the speed of the mobile structure and associating the determined speed with said position in the directory.

[0017] According to another characteristic, the step of developing the directory is carried out only once.

[0018] According to another characteristic, the method comprises a step of updating the speeds listed in the directory from the speed measurements used to determine the position of the moving structure.

[0019] The invention also relates to a device for determining at least one position of a mobile structure which comprises: a. at least one storage unit configured to store a directory associating listed positions and speeds of the mobile structure, b. at least one speed determination system configured to evaluate or measure a speed of the mobile structure, c. at least one processing unit configured to compare at least one speed measured by the speed determination system and the listed speeds and to determine the position of the mobile structure based on this comparison.

[0020] According to another characteristic, the speed determination system comprises at least one camera such as a Lidar type or time-of-flight type camera or at least one radar using the Doppler effect.

[0021] According to another characteristic, the device comprises several speed determination systems.

[0022] The invention also relates to an aircraft comprising at least one device for determining at least one position of a mobile structure according to one of the preceding characteristics.

[0023] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to [Fig. 1] which is a perspective view of an aircraft landing gear occupying two positions and illustrates an embodiment of the invention.

[0024] As illustrated in [Fig.l], an aircraft comprises a fixed structure 10 as well as at least one landing gear 12, movable relative to the fixed structure 10, driven by a first movement T1 going from a first position PI, called deployed, to a second position P2, called retracted, as well as a second movement T2 going from the second position P2 to the first position PL

[0025] According to an embodiment visible in [Fig.l], the landing gear 12 comprises a leg 14, at least one wheel 16 connected to a first end 14.1 of the leg 14, at least one strut 18 connecting the leg 14 and the fixed structure 10 of the aircraft, at least one link 20, at least one actuator 22 as well as articulations 24 connecting the leg 14, the wheel(s) 16, the strut(s) 18, the link(s) 20 and the actuator(s) 22 to each other and / or to the fixed structure 10.

[0026] Whatever the embodiment, the landing gear 12 is a mobile structure M, configured to move relative to the fixed structure 10 between first and second positions PI, P2, comprising mobile elements among the leg 14, the wheel(s) 16, the strut(s) 18, the connecting rod(s) 20, the actuator(s) 22 and the articulation(s) 24.

[0027] In addition, the aircraft comprises at least one landing gear compartment secured to the fixed structure 10 and configured to house the landing gear 12 in the retracted position. Each landing gear compartment comprises at least one hatch movable relative to the fixed structure 10 between an open position in which the hatch allows the landing gear 12 to be in the extended position and a closed position in which the hatch closes the landing gear compartment when the landing gear 12 is in the retracted position.

[0028] Each hatch of a landing gear compartment of the aircraft is a mobile structure M, configured to move relative to a fixed structure 10, comprising at least one mobile element and following first and second movements T1, T2 back and forth between closed and open positions.

[0029] Whatever the embodiment, the aircraft comprises at least one mobile structure M configured to move relative to a fixed structure 10 by following at least one movement T1, T2 going from a first extreme position PI to a second extreme position P2, said mobile structure M being chosen from a landing gear 12 and a hatch of an aircraft landing gear compartment.

[0030] According to one configuration, the mobile structure M pivots about a pivot axis relative to the fixed structure 10 between first and second extreme positions P1, P2 which correspond respectively to the extended and retracted positions. Of course, the invention is not limited to this kinematics.

[0031] During a given movement T1, T2 between first and second extreme positions PI, P2, the mobile structure M is configured to occupy intermediate positions Pi between the first and second extreme positions PI, P2, distributed between the latter.

[0032] During each movement T1, T2, the mobile structure M has a speed which varies between the first and second extreme positions PI, P2. According to one configuration, during each movement, the speed of the mobile structure M is zero at the start of the movement, increases then decreases until it becomes zero again at the end of the movement.

[0033] A method for determining at least one position of the mobile structure M comprises a step of developing at least one directory for at least one movement T1, T2 of the mobile structure M, said directory associating positions of the movement T1, T2 and speeds of the mobile structure M, with each of said positions listed in the directory being associated with a listed speed. According to one operating mode, the step of developing the directory consists of moving the structure mobile structure M following the movement T1, T2 as well as, for each position listed in the directory, a step of determining the speed of the mobile structure M when it occupies said position and associating the determined speed with said position in the directory. The listed positions are chosen from the first and second extreme positions PI, P2 as well as the intermediate positions Pi.

[0034] The step of developing the directory is carried out only once, in particular before the operation of the aircraft.

[0035] According to one embodiment, to carry out the measuring step, a device for determining at least one position of the mobile structure M comprises at least one system for determining a speed configured to evaluate or measure a speed of the mobile structure M when it occupies a given position. In addition, the device for determining at least one position of the mobile structure M comprises at least one storage unit 26 configured to store the directory associating speeds and positions of the mobile structure M among the first and second extreme positions P1, P2 as well as the intermediate positions P1, each position listed in the directory being associated with a listed speed.

[0036] The method for determining at least one position of the mobile structure M comprises a step of determining at least one speed of the mobile structure M, a step of comparing the speed previously measured with the speeds listed and each associated with a listed position as well as a step of determining the actual position of the mobile structure M which corresponds to the listed position associated with the listed speed equal to or closest to the measured speed.

[0037] For this purpose, the device for determining at least one position of the mobile structure M comprises at least one speed determination system 28, integral with the fixed structure 10, configured to evaluate or measure a speed of the mobile structure M as well as at least one processing unit 30 configured to compare speeds measured by the speed determination system 28 and the listed speeds and determine the actual position of the mobile structure M as a function of this comparison.

[0038] This processing unit 30 may be a computer of the aircraft dedicated exclusively or not to these comparison and determination functions. In the same way, the storage unit 26 may be a storage unit of the aircraft dedicated exclusively to the storage of the directory(ies).

[0039] According to one embodiment, the same speed determination system 28 can be used to develop the directory and determine the actual position of the mobile structure M.

[0040] According to one embodiment, the speed determination system 28 comprises at least one camera such as a Lidar type camera or a time-of-flight type camera (or TOF for Time Of Flight in English). According to this embodiment, the step of determining a speed of the mobile structure M consists of capturing two successive images, separated by a given duration, in which the mobile structure M is visible, determining a change in scale between the two captured images and calculating the speed of the mobile structure from the given duration and the change in scale between the two captured images. The change in scale corresponds to a ratio between a first distance separating two points of the mobile structure M in the first image and a second distance separating the same points of the mobile structure M in the second image.

[0041] According to another embodiment, the speed determination system 28 comprises at least one radar using the Doppler effect and configured to measure the speed of the mobile structure M from a frequency difference of a wave between its transmission and its reception. According to this embodiment, the step of determining a speed of the mobile structure M consists of determining a frequency shift for a wave transmitted and received by the radar after having been reflected by the mobile structure M and calculating the speed of the mobile structure M from the frequency shift determined previously.

[0042] According to one configuration, each speed determination system 28 comprises a sighting axis A28 and is connected to the fixed structure 10 so that its sighting axis A28 is correctly positioned relative to the movement T1, T2 of the mobile structure M in order to optimize the determination of the change of scale or the frequency shift. If necessary, the device for determining at least one position of the mobile structure M may comprise several speed determination systems 28 positioned appropriately to optimize the measurement of the speed of the mobile structure M regardless of its position, the speed of the mobile structure M being equal to an average of the speeds measured by the different speed determination systems 28.

[0043] During operation of the aircraft, the kinematics of the mobile structure M may change due, for example, to the wear of certain elements of the mobile structure M. A difference may then appear between the actual position and the position determined by the method of the invention. According to one embodiment, to correct this possible drift, the method for determining at least one position of the mobile structure M comprises a step of updating the speeds listed in the directory from the speed measurements used to determine the position of the mobile structure M and measured by the speed determination system 28 during operation of the aircraft.

[0044] An aircraft may comprise one or more devices for determining at least one position of a mobile structure M, the latter being chosen from a landing gear 12 and a hatch of an aircraft landing gear compartment.

[0045] Whatever the embodiment, the method for determining at least one position of the mobile structure M makes it possible, from at least one measurement of the speed of the mobile structure M at a given instant, to determine the actual position of the mobile structure M at this given instant by comparing the measured speed with listed speeds each associated with a given position. Unlike the prior art, the method for determining at least one position of the mobile structure M makes it possible, from a limited number of speed determination systems 28, to determine the position of the mobile structure M at each instant and not only at the start and end of the movement.Knowing the actual position of the landing gear at all times, it is possible to better coordinate the movements of the landing gear and the landing gear compartment doors and thus optimize the closing of the landing gear compartment, which results in a reduction in the aircraft's fuel consumption.

[0046] Furthermore, these measurements of the speed of the mobile structure M can make it possible to evaluate a change in its kinematics and to optimize its maintenance.

Claims

Claims

1. Method for determining at a given instant at least one position of a mobile structure (M) of an aircraft, said mobile structure (M) being animated by at least one movement (T1, T2) between first and second positions (PI, P2) and configured to occupy intermediate positions (Pi) between the first and second positions (PI, P2);characterized in that the method comprises, beforehand, a step of developing at least one directory for the movement (T1, T2) associating listed positions and speeds of the mobile structure (M), the listed positions being chosen from the first and second positions (PI, P2) as well as the intermediate positions (Pi), each of said listed positions being associated with a listed speed and, in operation, a step of determining at least one speed of the mobile structure (M) at the given instant, a step of comparing the determined speed with the listed speeds and each associated with a listed position as well as a step of determining the position of the mobile structure (M) at the given instant which corresponds to the listed position associated with the listed speed equal to or closest to the speed determined at the given instant.;

2. Method according to claim 1, characterized in that the step of determining a speed of the mobile structure (M) consists of capturing first and second images, separated by a given duration, in which the mobile structure (M) is visible, determining a change in scale between the first and second captured images and calculating the speed of the mobile structure (M) from the given duration and the change in scale between the first and second captured images.

3. Method according to claim 1, characterized in that the step of determining a speed of the mobile structure (M) consists of determining a frequency shift for a wave emitted and received by a radar after having been reflected by the mobile structure (M) as well as calculating the speed of the mobile structure (M) from the frequency shift determined previously.

4. Method according to one of claims 2 to 3, characterized in that the speed of the mobile structure (M) is equal to an average of measured speeds.

5. Method according to one of the preceding claims, characterized in that

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12. that the step of developing the directory consists of moving the mobile structure (M) following the movement (T1, T2) as well as, for each position listed in the directory, a step of determining the speed of the mobile structure (M) and associating the determined speed with said position in the directory. Method according to one of the preceding claims, characterized in that the step of developing the directory is carried out only once. Method according to one of the preceding claims, characterized in that the method comprises a step of updating the speeds listed in the directory from the speed measurements used to determine the position of the mobile structure (M). Device for determining at least one position of a mobile structure (M) making it possible to implement a method according to one of the preceding claims, characterized in that the device comprises: a. at least one storage unit (26) configured to store a directory associating listed positions and speeds of the mobile structure (M), b. at least one speed determination system (28) configured to evaluate or measure a speed of the mobile structure (M), c. at least one processing unit (30) configured to compare at least one speed measured by the speed determination system (28) and the listed speeds as well as to determine the position of the mobile structure (M) based on this comparison. Device according to the preceding claim, characterized in that the speed determination system (28) comprises at least one camera such as a Lidar type camera or a time-of-flight type camera. Device according to claim 8, characterized in that the speed determination system (28) comprises at least one radar using the Doppler effect. Device according to one of claims 8 to 10, characterized in that the device comprises several speed determination systems (28). Aircraft comprising at least one device for determining at least one position of a mobile structure (M) according to one of claims 8 at 11.

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