Method for determining at least one characteristic of a movement of a mobile structure of an aircraft and aircraft comprising a device for its implementation

Abstract

Method for determining at least one characteristic of a movement of a mobile structure of an aircraft and aircraft comprising a device for its implementation The invention relates to a method for determining at a given instant at least one characteristic of a movement of a mobile structure of an aircraft, characterized in that the method comprises: a step of determining a pair of coordinates in a plane reference frame corresponding to a projection of a reference frame (R1 to R5) integral with the mobile structure in said plane reference frame, a step of determining the characteristic of the movement of the mobile structure by comparing the previously determined pair of coordinates with pairs of reference coordinates, with each pair of reference coordinates being associated at least one characteristic of the movement of the mobile structure. The invention also relates to an aircraft comprising a device for implementing said method. Figure 1

Description

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

[0001] The present application relates to a method for determining at least one characteristic of a movement of a mobile structure of an aircraft as well as to an aircraft comprising a device for its installation.

[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 to determine the position of each hatch of each landing gear compartment and 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 characteristic of a movement of a mobile structure of an aircraft, characterized in that the method comprises: a. a step of acquiring at a given time at least one image on which there appears at least one marker integral with the mobile structure, b. a step of determining, from the captured image, a pair of coordinates in a plane reference frame corresponding to a projection of the reference frame in said plane reference frame, c. a step of comparing the previously determined pair of coordinates with pairs of reference coordinates, each pair of reference coordinates being associated with at least one characteristic of the movement of the mobile structure, d. a step of determining the characteristic of the movement of the mobile structure which is associated with the pair of reference coordinates corresponding to the pair of coordinates in the plane reference frame.

[0011] This solution makes it possible, from a reduced number of elements, to determine a characteristic of a movement of the mobile structure at each instant of the movement and not only at the start and end of the movement.

[0012] According to another characteristic, the step of comparing the pair of coordinates obtained by projection with the pairs of reference coordinates consists of determining, in the plane reference frame, the point which has as coordinates those of one of the pairs of reference coordinates, closest to the point which has as coordinates that of the pair of coordinates obtained by projection.

[0013] According to another characteristic, the method consists in determining at the given instant for several reference points at least one characteristic of the movement for each of them, the characteristic of the movement of the mobile structure corresponding to the average of the characteristics of the movement determined for the different reference points.

[0014] According to another characteristic, the method comprises, beforehand, a step of determining a reference trajectory in the plane reference frame for each reference frame.

[0015] According to another characteristic, the step of determining a reference trajectory consists, for each given angular position of the mobile structure, in determining for each reference frame a pair of reference coordinates in the plane reference frame corresponding to a projection of the reference frame in said plane reference frame and in associating the pair of reference coordinates and the given angular position.

[0016] According to another characteristic, the mobile structure is a landing gear of the aircraft.

[0017] The invention also relates to an aircraft comprising at least one mobile structure as well as a device making it possible to implement a method according to one of the preceding characteristics. According to the invention, the device comprises at least one acquisition system configured to capture at least one image on which appears at least at least one reference point integral with the mobile structure, a database in which pairs of reference coordinates are each associated with at least one characteristic of the movement of the mobile structure as well as at least one processing system configured to: a. determine, from an image captured by the acquisition system, a pair of coordinates in a plane reference frame corresponding to a projection of the reference frame in said plane reference frame, b. compare the previously determined coordinate pair with the reference coordinate pairs stored in the database, and c. determine the characteristic of the movement of the mobile structure which is associated with the pair of reference coordinates corresponding to the pair of coordinates in the plane reference frame.

[0018] According to another characteristic, each acquisition system is a camera, more particularly a Lidar type camera.

[0019] According to another characteristic, each reference mark secured to the mobile structure follows a three-dimensional trajectory which extends between first and second end points. In addition, each acquisition system has a sighting axis, each acquisition system being positioned so that its sighting axis forms an angle of less than 30° with a plane equidistant from the first and second end points of at least one three-dimensional trajectory.

[0020] According to another characteristic, the device comprises a given number of acquisition system(s), this number being determined so that for each three-dimensional trajectory, at least one acquisition system has a sighting axis forming an angle of less than 30° with a plane equidistant from the first and second end points of the three-dimensional trajectory.

[0021] 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 the appended drawings, among which:

[0022] [Fig. 1] is a perspective view of an aircraft landing gear, occupying two positions and three-dimensional trajectories of reference points attached to the landing gear between its two positions, illustrating an embodiment of the invention,

[0023] [Fig.2] is a representation of the projections in a plane reference frame of the trajectories three-dimensional visible in [Fig.l].

[0024] As illustrated in [Fig.l], an aircraft comprises a fixed structure 10 as well as at least one landing gear 12A, 12B movable relative to the fixed structure 10 between a first position 12A, called deployed, and a second position 12B, called retracted.

[0025] According to an embodiment visible in [Fig.l], the landing gear 12A, 12B 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 connecting rod 20, at least one actuator 22 as well as joints 24 connecting the leg 14, the wheel(s) 16, the strut(s) 18, the connecting rod(s) 20 and the actuator(s) 22 to each other and / or to the fixed structure 10.

[0026] The strut 18 comprises a first end 18.1 connected to the leg 14 as well as a second end 18.2 connected to the fixed structure 10 by first and second articulations 24.1, 24.2.

[0027] Whatever the embodiment, the landing gear 12A, 12B is a mobile structure, configured to move relative to the fixed structure 10, comprising mobile elements among the leg 14, the wheel(s) 16, the strut(s) 18, the link(s) 20, the actuator(s) 22 and the articulation(s) 24.

[0028] In addition, the aircraft comprises at least one landing gear compartment secured to the fixed structure 10 and configured to house the landing gear 12A, 12B 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 12A, 12B to be in the extended position and a closed position in which the hatch closes the landing gear compartment when the landing gear 12A, 12B is in the retracted position.

[0029] Each hatch of a landing gear compartment of the aircraft is a mobile structure, configured to move relative to the fixed structure 10, comprising at least one mobile element.

[0030] Whatever the embodiment, the aircraft comprises at least one mobile structure configured to move in a real 3D reference frame according to a given movement relative to a fixed structure 10 of the aircraft between first and second extreme positions, said mobile structure being chosen from an aircraft landing gear and a hatch of a landing gear compartment.

[0031] According to one configuration, the mobile structure pivots about an axis relative to the fixed structure 10 between first and second extreme positions which correspond respectively to the extended and retracted positions.

[0032] Each mobile structure has at least one reference frame RI to R5 secured to the mobile structure, which follows a three-dimensional trajectory TT1 in the 3D real reference frame, when the latter moves from one extreme position to the other. The reference frame can be a point, a straight line, a circle or any other element.

[0033] According to the example visible in [Fig.l], the mobile structure has five reference points RI to R5 which respectively follow three-dimensional trajectories TT1 to TT5. For each reference point RI to R5 integral with the mobile structure, each point of its trajectory three-dimensional TT1 to TT5 is associated with a position of the mobile structure. According to one configuration, the marks RI to R5 are located at the first end 14.1 of the leg 14 for the mark RI, at the first end 18.1 of the strut 18 for the mark R2, substantially equidistant from the first and second ends 18.1, 18.2 of the strut 18 for the mark R3, at the first articulation 24.1 connecting the strut 18 and the fixed structure 10 for the mark R4 as well as substantially equidistant from the first and second articulations 24.1, 24.2 connecting the strut 18 and the fixed structure 10 for the mark R5. Of course, the invention is not limited to this configuration for the marks.

[0034] A method for determining at a given instant at least one characteristic of a movement of the mobile structure comprises: a. a step of acquiring at the given instant at least one image on which there appears at least one reference point RI to R5 secured to the mobile structure, b. a step of determining, from the captured image, a pair of X, Y coordinates in a 2D plane reference frame corresponding to a projection of the RI to R5 reference frame in said 2D plane reference frame, c. a step of comparing the pair of coordinates X, Y determined previously with pairs of reference coordinates X0, Y0 stored in a database 30, with each pair of reference coordinates X0, Y0 being associated with at least one characteristic of the movement of the mobile structure, d. a step of determining the characteristic of the movement of the mobile structure which is associated with the pair of reference coordinates X0, Y0 corresponding to the pair of coordinates X, Y in the 2D plane reference frame.

[0035] To implement this method, the aircraft comprises a device 26 for determining at least one characteristic of a movement of the mobile structure which comprises at least one acquisition system 28 configured to capture at least one image on which there appears at least one reference point RI to R5 secured to the mobile structure, a database 30 in which pairs of reference coordinates X0, Y0 are each associated with at least one characteristic of the movement of the mobile structure as well as at least one processing system 32 configured to: a. determine, from an image captured by the acquisition system 28, a pair of coordinates X, Y in a 2D plane reference frame corresponding to a projection of the reference frame RI to R5 in said 2D plane reference frame, b. compare the previously determined pair of coordinates X, Y with the reference pairs of coordinates X0, Y0 stored in the database 30, and c. determine the characteristic of the movement of the mobile structure which is associated with the pair of reference coordinates XO, YO corresponding to the pair of coordinates X, Y in the 2D plane reference frame.

[0036] According to one embodiment, the acquisition system 28 is a camera, more particularly a Lidar type camera. Of course, the invention is not limited to this embodiment for the acquisition system 28. Thus, any system making it possible to project any point located in a three-dimensional reference frame into a plane reference frame could be used.

[0037] According to one method of operation, the characteristic of the movement determined is the pivot angle or the angular position of the landing gear 12A, 12B. Unlike the prior art, the two extreme angular positions of the landing gear corresponding to the retracted and extended positions are not the only ones determined. The method of the invention makes it possible to determine the angular positions of the intermediate positions of the landing gear between the retracted and extended positions.

[0038] According to one operating mode, the step of comparing the pair of coordinates X, Y, obtained by projection with the pairs of reference coordinates X0, Y0 stored in the database 30, consists of determining the point which has as coordinates those of one of the pairs of reference coordinates X0, Y0 stored in the database 30, closest to the point which has as coordinates that of the pair of coordinates X, Y obtained by projection.

[0039] According to one embodiment, the method for determining at a given instant at least one characteristic of a movement of the mobile structure consists of implementing the method for several reference points RI to R5 and determining at the given instant for each of the reference points RI to R5 at least one characteristic of the movement for each of them by reproducing steps a), b), c) and d). According to one operating mode, the desired characteristic of the movement of the mobile structure corresponds to the average of the characteristics of the movement determined for each of the different reference points RI to R5.

[0040] According to one operating mode, the method for determining at least one characteristic of a movement of the mobile structure comprises, beforehand, a step of determining a reference trajectory TRI to TR5 in the 2D plane reference frame for each reference frame R1 to R5, as illustrated in [Fig.2].

[0041] According to one embodiment, this last step consists, for each given angular position of the mobile structure, in capturing at least one image in which the reference points RI to R5 appear, in determining for each reference point RI to R5 a pair of reference coordinates X0, Y0 in the 2D plane reference frame corresponding to the projection of the reference point RI to R5 in said 2D plane reference frame and in associating in the database 30 the pair of reference coordinates X0, Y0 and the given angular position.

[0042] Thus, for each three-dimensional trajectory TT1 to TT5 in the real 3D reference frame corresponds to a reference trajectory TRI to TR5 in the 2D plane reference frame, each reference trajectory TRI to TR5 corresponding to the set of pairs of reference coordinates XO, YO determined for the different angular positions occupied by the mobile structure between the first and second extreme positions.

[0043] Each three-dimensional trajectory TT1 to TT5 extends between first and second end points PI, P2. In parallel, each acquisition system 28 has a line of sight A28. According to one configuration, the acquisition system 28 is positioned so that its line of sight A28 forms the smallest possible angle, preferably less than 30°, with a plane equidistant from the first and second end points PI, P2 of at least one three-dimensional trajectory TT1 to TT5. This configuration makes it possible to improve the accuracy of the estimation of the characteristic of the movement sought.

[0044] The device comprises a given number of acquisition system(s) 28, this number being determined so that for each three-dimensional trajectory TT1 to TT5, at least one of the acquisition systems 28 has a sighting axis A28 forming the smallest possible angle, preferably less than 30°, with a plane equidistant from the first and second end points PI, P2 of the three-dimensional trajectory TT1 to TT5.

Claims

Claims

1. Method for determining at a given instant at least one characteristic of a movement of a mobile structure of an aircraft, characterized in that the method comprises: a. a step of acquiring at the given instant at least one image on which there is at least one reference frame (RI to R5) integral with the mobile structure, b. a step of determining from the captured image a pair of coordinates (X, Y) in a plane reference frame (2D) corresponding to a projection of the reference frame (RI to R5) in said plane reference frame (2D), c. a step of comparing the previously determined pair of coordinates (X, Y) with pairs of reference coordinates (XO, YO), with each pair of reference coordinates (XO, YO) being associated with at least one characteristic of the movement of the mobile structure, d.a step of determining the characteristic of the movement of the mobile structure which is associated with the pair of reference coordinates (XO, YO) corresponding to the pair of coordinates (X, Y) in the plane reference frame (2D).

2. Method according to claim 1, characterized in that the step of comparing the pair of coordinates (X, Y) obtained by projection with the pairs of reference coordinates (XO, YO) consists of determining, in the plane reference frame (2D), the point which has as coordinates those of one of the pairs of reference coordinates (XO, YO), closest to the point which has as coordinates that of the pair of coordinates (X, Y) obtained by projection.

3. Method according to one of the preceding claims, characterized in that the method consists in determining at the given instant for several reference points (RI to R5) at least one characteristic of the movement for each of them, the characteristic of the movement of the mobile structure corresponding to the average of the characteristics of the movement determined for the different reference points (RI to R5).

4. Method according to one of the preceding claims, characterized in that the method comprises, beforehand, a step of determining of a reference trajectory (TRI to TR5) in the plane reference frame (2D) for each reference point (Rà R5).

5. Method according to the preceding claim, characterized in that the step of determining a reference trajectory (TR1, TR2) consists, for each given angular position of the mobile structure, in determining for each reference frame (R11 R5) a pair of reference coordinates (XO, YO) in the plane reference frame (2D) corresponding to a projection of the reference frame (R11 R5) in said plane reference frame (2D) and in associating the pair of reference coordinates (XO, YO) and the given angular position.

6. Method according to one of the preceding claims, characterized in that the mobile structure is a landing gear of the aircraft.

7. Aircraft comprising at least one mobile structure characterized in that the aircraft comprises a device for implementing a method according to one of the preceding claims, said device comprising at least one acquisition system (28) configured to capture at least one image on which appears at least one reference mark (RI to R5) integral with the mobile structure, a database (30) in which pairs of reference coordinates (XO, YO) are each associated with at least one characteristic of the movement of the mobile structure as well as at least one processing system (32) configured to: a. Determine, from an image captured by the acquisition system (28), a pair of coordinates (X, Y) in a plane reference frame (2D) corresponding to a projection of the reference mark (RI to R5) in said plane reference frame (2D), b.comparing the previously determined pair of coordinates (X, Y) with the reference pairs of coordinates (XO, YO) stored in the database (30), and c. determining the characteristic of the movement of the mobile structure which is associated with the reference pair of coordinates (XO, YO) corresponding to the pair of coordinates (X, Y) in the plane reference frame (2D).

8. Aircraft according to the preceding claim, characterized in that each acquisition system (28) is a camera, more particularly a Lidar type camera.

9. Aircraft according to one of claims 7 to 8, characterized in that each reference mark (RI to R5) integral with the mobile structure follows a three-dimensional trajectory (TT1 to TT5) which extends between first and second end points (PI, P2) and in that each acquisition system (28) has a sighting axis (A28), each acquisition system (28) being positioned so that its sighting axis (A28) forms an angle of less than 30° with a plane equidistant from the first and second end points (PI, P2) of at least one three-dimensional trajectory (TT1 to TT5).

10. Aircraft according to the preceding claim, characterized in that the device comprises a given number of acquisition system(s) (28), this number being determined so that for each three-dimensional trajectory (TT1 to TT5), at least one acquisition system (28) has a sighting axis (A28) forming an angle of less than 30° with a plane equidistant from the first and second end points (PI, P2) of the three-dimensional trajectory (TT1 to TT5).

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