Method for determining at least one motion characteristic of movable structure of aircraft
Through the method of image processing and reference coordinate comparison, the weight and maintenance problems caused by the large number of proximity sensors in the prior art are solved, and the precise determination of the position and angle of the movable structure of the aircraft is achieved.
Patent Information
- Application Number
- CN202510093908.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-29
- Filing Date
- 2025-01-21
- Publication Date
- 2025-08-05
AI Technical Summary
The prior art requires a large number of proximity sensors to determine the position of the movable elements of the aircraft, resulting in increased weight and maintenance difficulties, and the inability to determine the position of the element at non-endpoint positions.
The motion characteristics of the aircraft movable structure are determined by acquiring images and determining the coordinate pairs of marks in the plane reference frame, and comparing the camera or lidar-type camera with the reference coordinate pairs in the database.
Reduces component count, reduces weight and maintenance difficulty, while accurately determining the position and angle of the movable structure at any moment.
Smart Images
Figure CN120423048A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a method for determining at least one kinematic characteristic of a movable structure of an aircraft and to an aircraft comprising a device for carrying out the method. Background Art
[0002] According to one embodiment, an aircraft includes a plurality of landing gears, each landing gear being movable between a retracted position and an extended position; and a landing gear well for each of the landing gears, configured to accommodate the landing gear in the retracted position.
[0003] Each landing gear comprises different elements articulated relative to one another and an actuator allowing the landing gear to be moved between a retracted position and an extended position.
[0004] Each landing gear well includes at least one flap movable between an open position, in which the flap allows the landing gear to be in an extended position, and a closed position, in which the flap encloses the landing gear well when the landing gear is in a retracted position.
[0005] The aircraft also includes sensors for determining the position of each flap of each landing gear bay and the position of certain articulation elements and / or actuators of each landing gear.
[0006] According to one embodiment, each of these sensors is a proximity sensor that allows determining a single position in a movable element, such as one of an articulated element, an actuator, or a flap. Thus, according to one configuration, for a given movable element, the aircraft includes two proximity sensors positioned at the ends of the travel of the given movable element.
[0007] This embodiment is not entirely satisfactory since it requires a large number of proximity sensors and the resulting wiring, which affects the weight of the aircraft and its maintenance.
[0008] Another disadvantage is that this embodiment does not allow the position of the movable element to be determined when it is not at one of the two ends of its travel. Summary of the Invention
[0009] The present invention aims to remedy all or part of the shortcomings of the prior art.
[0010] To this end, the present invention relates to a method for determining at a given moment at least one kinematic characteristic (such as a pivot angle or angular position) of a movable structure of an aircraft, the movable structure being selected, for example, from the group consisting of an aircraft landing gear and a flap of an aircraft landing gear bay, characterised in that the method comprises the following steps:
[0011] acquiring at least one image at a given moment in time, wherein at least one marker integral to the movable structure is displayed on the image;
[0012] determining a coordinate pair in a planar reference system based on the acquired image, the coordinate pair corresponding to a projection of the marker in the planar reference system;
[0013] comparing a previously determined coordinate pair to reference coordinate pairs, wherein each reference coordinate pair is associated with at least one motion characteristic of the movable structure, the comparing step comprising determining a point having coordinates of one of the plurality of reference coordinate pairs that is closest to a point having coordinates of the previously determined coordinate pair;
[0014] A kinematic characteristic of the movable structure is determined, the kinematic characteristic being associated with a reference coordinate pair corresponding to a coordinate pair in the planar reference system.
[0015] This solution allows, with a reduced number of elements, the determination of the movement characteristics of the movable structure at every moment of the movement and not only at the beginning and end of the movement.
[0016] According to another feature, the step of comparing the coordinate pair obtained by projection with the reference coordinate pair comprises determining in the plane reference system the point having the coordinates of one of the reference coordinate points of the plurality of reference coordinate pairs that is closest to the point having the coordinates of the coordinate pair obtained by projection.
[0017] According to another feature, the method comprises determining, at a given moment in time, for a plurality of markings, at least one kinematic characteristic for each of the markings, the kinematic characteristic of the movable structure corresponding to an average of the kinematic characteristics determined for the plurality of markings.
[0018] According to another characteristic, the method comprises a preliminary step of determining a reference trajectory of each marker in a planar reference system.
[0019] According to another feature, the step of determining the reference trajectory comprises, for each given angular position of the movable structure, determining for each marker a reference coordinate pair in the planar reference system corresponding to the projection of the marker in said planar reference system and associating the reference coordinate pair with the given angular position.
[0020] According to another feature, the movable structure is a landing gear of an aircraft.
[0021] The invention also relates to an aircraft comprising at least one movable structure chosen from a landing gear of the aircraft and a flap of a landing gear bay of the aircraft, and a device allowing the implementation of the method according to one of the preceding features. According to the invention, the device comprises: at least one acquisition system configured to be able to capture at least one image on which at least one marker integral to the movable structure is displayed; a database in which reference coordinate pairs are each associated with at least one kinematic characteristic of the movable structure, such as a pivot angle or an angular position; and at least one processing system configured to be able to:
[0022] - determining, from the images acquired by the acquisition system, a pair of coordinates in a planar reference system corresponding to a projection of the marking in said planar reference system;
[0023] - comparing a previously determined coordinate pair with reference coordinate pairs stored in a database, the comparison comprising determining the point having the coordinates of one of the reference coordinate pairs (X0, Y0) that is closest to the point having the coordinates of the previously determined coordinate pair (X, Y); and
[0024] - determining a kinematic characteristic of the movable structure associated with a reference coordinate pair corresponding to a coordinate pair in the planar reference system.
[0025] According to another feature, each acquisition system is a camera, more particularly a LiDAR type camera.
[0026] According to another feature, each marker integral with the movable structure follows a three-dimensional trajectory extending between a first end point and a second end point. In addition, each acquisition system has a sighting axis, each acquisition system being positioned such that its sighting axis forms an angle of less than at least 30° with a plane equidistant from the first end point and the second end point of at least one three-dimensional trajectory.
[0027] According to another feature, the device comprises a given number of acquisition systems, 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 at least 30° with a plane equidistant from the first and second end points of the three-dimensional trajectory. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Other features and advantages will appear from the following description of the invention, given by way of example only and with reference to the accompanying drawings, in which:
[0029] - Figure 1 is a perspective view of a landing gear of an aircraft showing an embodiment of the present invention in two positions and the three-dimensional trajectory of a marking integral to the landing gear between its two positions,
[0030] - Figure 2 yes Figure 1Representation of the projection of the three-dimensional trajectory visible in the plane reference system (Figure). DETAILED DESCRIPTION
[0031] like Figure 1 As shown, the aircraft comprises a fixed structure 10 and at least one landing gear 12A, 12B movable relative to the fixed structure 10 between a first position 12A, called the deployed position, and a second position 12B, called the retracted position (collapsed position).
[0032] according to Figure 1 In the embodiment visible in FIG, 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 beam 18 connecting the leg 14 to the fixed structure 10 of the aircraft, at least one link 20, at least one actuator 22 and a hinge 24 connecting the leg 14, the wheel(s) 16, the beam(s) 18, the link(s) 20 and the actuator(s) 22 to each other or to the fixed structure 10.
[0033] The beam 18 comprises a first end 18 . 1 connected to the leg 14 and a second end 18 . 2 connected to the fixed structure 10 via a first hinge 24 . 1 and a second hinge 24 . 2 .
[0034] Regardless of the embodiment, the landing gear 12A, 12B is a movable structure configured to be displaceable relative to the fixed structure 10, including elements of a leg 14, one or more wheels 16, one or more beams 18, one or more links 20, one or more actuators 22, and one or more hinges 24.
[0035] In addition, the aircraft includes at least one landing gear well integral with the fixed structure 10 and configured to accommodate the landing gear 12A, 12B in a retracted position. Each landing gear well includes at least one flap movable relative to the fixed structure 10 between an open position, in which the flap allows the landing gear 12A, 12B to be in an extended position, and a closed position, in which the flap closes the landing gear well when the landing gear 12A, 12B is in a retracted position.
[0036] Each baffle of the landing gear bay of the aircraft is a movable structure, configured to be displaceable relative to the fixed structure 10 , and includes at least one movable element.
[0037] Whatever the embodiment, the aircraft comprises at least one movable structure configured to be displaced in a real 3D reference system according to a given movement between a first and a second extreme position relative to a fixed structure 10 of the aircraft, said movable structure being chosen from the landing gear of the aircraft and the baffle of the landing gear bay.
[0038] According to one configuration, the movable structure pivots relative to the fixed structure 10 about an axis between a first extreme position and a second extreme position corresponding to the extended position and the retracted position, respectively.
[0039] Each movable structure has at least one marker R1 to R5 integral with the movable structure, which follows a three-dimensional trajectory TT1 in the real 3D reference system when the movable structure is displaced from one extreme position to another. The marker can be a point, a line, a circle or any other element.
[0040] according to Figure 1 In the example shown in FIG. 1 , the movable structure has five markers R1 to R5, which are located along three-dimensional trajectories TT1 to TT5, respectively. For each marker R1 to R5 integral with the movable structure, each point of its three-dimensional trajectory TT1 to TT5 is associated with a position of the movable structure. According to one configuration, for the markers R1 to R5, marker R1 is located at the first end 14.1 of the leg 14; marker R2 is located at the first end 18.1 of the beam 18; marker R3 is located substantially equidistant from the first end 18.1 and the second end 18.2 of the beam 18; marker R4 is located at the first hinge 24.1 connecting the beam 18 to the fixed structure 10; and marker R5 is located substantially equidistant from the first hinge 24.1 and the second hinge 24.2 connecting the beam 18 to the fixed structure 10. Of course, the present invention is not limited to this configuration of markers.
[0041] A method for determining at least one motion characteristic of a movable structure at a given time, comprising:
[0042] - a step of acquiring at a given moment at least one image on which at least one marking R1 to R5 integral with the movable structure is shown;
[0043] - a step of determining, from the acquired image, coordinate pairs X, Y in the plane reference system 2D corresponding to the projections of the markers R1 to R5 in said plane reference system 2D;
[0044] a comparison step of comparing the previously determined coordinate pair X, Y with reference coordinate pairs X0, Y0 stored in the database 30, each reference coordinate pair X0, Y0 being associated with at least one kinematic characteristic of the movable structure;
[0045] A step of determining a kinematic characteristic of the movable structure associated with a plurality of reference coordinate pairs X0, Y0 corresponding to coordinate pairs X, Y in a planar reference system 2D.
[0046] To implement the method, the aircraft comprises means 26 for determining at least one kinematic characteristic of the movable structure, comprising: at least one acquisition system 28 configured to capture at least one image on which at least one marking R1 to R5 integral to the movable structure is displayed; a database 30 in which a plurality of reference coordinate pairs X0, Y0 are each associated with at least one kinematic characteristic of the movable structure; and at least one processing system 32 configured to be able to:
[0047] - determining, from the images acquired by the acquisition system 28 , coordinate pairs X, Y in the plane reference system 2D corresponding to the projections of the markers R1 to R5 in said plane reference system 2D;
[0048] - comparing the previously determined coordinate pair X, Y with the reference coordinate pair X0, Y0 stored in the database 30; and
[0049] - determining a kinematic characteristic of the movable structure associated with a reference coordinate pair X0, Y0 corresponding to a coordinate pair X, Y in a planar reference system 2D.
[0050] 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 of the acquisition system 28. Thus, any system that allows any point located in a three-dimensional reference system to be projected into a planar reference system may be used.
[0051] According to one operating mode, the kinematic characteristic determined is the pivot angle or 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 uniquely determined. The method of the present invention allows the angular position of the landing gear to be determined in intermediate positions between the retracted and extended positions.
[0052] According to one operating mode, the step of comparing the coordinate pair X, Y obtained by projection with the reference coordinate pair X0, Y0 stored in the database 30 comprises determining the point closest to the point having the coordinates of the coordinate pair X, Y obtained by projection and having the coordinates of one of the reference coordinate pairs X0, Y0 stored in the database 30.
[0053] According to one embodiment, the method for determining at a given moment at least one kinematic characteristic of a movable structure comprises carrying out the method for a plurality of markers R1 to R5 and determining at a given moment at least one kinematic characteristic for each of the markers R1 to R5 by repeating steps a), b), c) and d). According to one operating mode, the desired (required) kinematic characteristic of the movable structure corresponds to the average of the kinematic characteristics determined for each of the different markers R1 to R5.
[0054] According to one mode of operation, the method of determining at least one kinematic characteristic of a movable structure comprises beforehand a step of determining a reference trajectory TR1 to TR5 of each marker R1 to R5 in a plane reference system 2D, such as Figure 2 shown.
[0055] According to one embodiment, for each given angular position of the movable structure, this last step comprises: acquiring at least one image in which the markers R1 to R5 are illustrated; determining, for each marker R1 to R5, a reference coordinate pair X0, Y0 corresponding to the projection of the marker R1 to R5 in the plane reference system 2D, and associating the reference coordinate pair X0, Y0 with the given angular position in the database 30.
[0056] In this way, each three-dimensional trajectory TT1 to TT5 in the real 3D reference system corresponds to a reference trajectory TR1 to TR5 in the planar reference system 2D, and each reference trajectory TR1 to TR5 corresponds to all reference coordinate pairs X0, Y0 determined for the different angular positions of the movable structure between the first and second extreme positions.
[0057] Each three-dimensional trajectory TT1 to TT5 extends between a first endpoint P1 and a second endpoint P2. In parallel, each acquisition system 28 has a sighting axis A28. According to one configuration, the acquisition system 28 is positioned such that its sighting axis A28 forms an angle as small as possible, preferably less than 30°, with a plane equidistant from the first endpoint P1 and the second endpoint P2 of at least one three-dimensional trajectory TT1 to TT5. This configuration allows for an improved accuracy in estimating the desired (investigated) motion characteristic.
[0058] The device comprises a given number of acquisition systems 28, which number is determined so that for each three-dimensional trajectory TT1 to TT5, at least one aiming axis A28 in the acquisition system 28 forms an angle that is as small as possible, preferably an angle of less than 30°, with a plane equidistant from the first end point P1 and the second end point P2 of the three-dimensional trajectory TT1 to TT5.
Claims
1. A method for determining at a given moment at least one kinematic characteristic of a movable structure of an aircraft, said movable structure being selected from the group consisting of a landing gear of the aircraft and a flap of a landing gear bay of the aircraft, said at least one kinematic characteristic being, for example, a pivot angle or an angular position, characterized in that The method comprises the following steps: - acquiring at a given moment at least one image on which at least one marking (R1 to R5) integral with the movable structure is displayed; - determining, from the acquired images, in a plane reference system (2D) coordinate pairs (X, Y) corresponding to the projections of the markings (R1 to R5) in the plane reference system (2D); - comparing a previously determined coordinate pair (X, Y) with a plurality of reference coordinate pairs (X0, Y0), each reference coordinate pair (X0, Y0) being associated with at least one kinematic characteristic of the movable structure, said comparison step comprising determining the point having coordinates of one of the reference coordinate pairs (X0, Y0) that is closest to the point having coordinates of the previously determined coordinate pair (X, Y); - determining a kinematic characteristic of the movable structure associated with the reference coordinate pair (X0, Y0) corresponding to the coordinate pair (X, Y) in the planar reference system (2D).
2. The method according to claim 1, characterized in that The step of comparing the coordinate pair (X, Y) obtained by projection with the reference coordinate pair (X0, Y0) comprises determining a point in the plane reference system (2D) that is closest to the point having the coordinates of the coordinate pair (X, Y) obtained by projection and having the coordinates of one of the reference coordinate pairs (X0, Y0) among the plurality of reference coordinate pairs.
3. The method according to claim 1 or 2, characterized in that The method comprises: The at least one motion characteristic of each of a plurality of markers (R1 to R5) is determined for the plurality of markers at a given moment, the motion characteristic of the movable structure corresponding to an average of the motion characteristics determined for the different markers (R1 to R5).
4. The method according to any one of the preceding claims, characterized in that The method comprises the following steps which are performed in advance: A reference trajectory (TR1 to TR5) in the planar reference system (2D) is determined for each marker (R1 to R5).
5. The method according to claim 4, characterized in that The step of determining a reference trajectory (TR1, TR2) comprises: for each given angular position of the movable structure, determining for each marker (R1 to R5) a reference coordinate pair (X0, Y0) in a planar reference system (2D) corresponding to the projection of the marker (R1 to R5) in the planar reference system (2D); and associating the reference coordinate pair (X0, Y0) with the given angular position.
6. The method according to any one of the preceding claims, characterized in that The movable structure is the landing gear of the aircraft.
7. An aircraft comprising at least one movable structure selected from the group consisting of a landing gear of the aircraft and a baffle of a landing gear bay of the aircraft, characterized in that: The aircraft comprises means for performing the method according to any one of the preceding claims, the means comprising: at least one acquisition system (28) configured to capture at least one image on which at least one marker (R1 to R5) integral with the movable structure is displayed; a database (30) in which a plurality of reference coordinate pairs (X0, Y0) are each associated with at least one kinematic characteristic of the movable structure, such as a pivot angle or an angular position; and At least one processing system (32) configured to: - determining, from the images acquired by the acquisition system (28), coordinate pairs (X, Y) in a plane reference system (2D) corresponding to the projections of the markings (R1 to R5) in the plane reference system (2D); - comparing a previously determined coordinate pair (X, Y) with the plurality of reference coordinate pairs (X0, Y0) stored in the database (30), the comparison comprising determining a point having coordinates of one of the plurality of reference coordinate pairs (X0, Y0) that is closest to the point having coordinates of the previously determined coordinate pair (X, Y); and - determining a kinematic characteristic of the movable structure associated with the reference coordinate pair (X0, Y0) corresponding to the coordinate pair (X, Y) in the planar reference system (2D).
8. The aircraft according to claim 7, characterized in that Each acquisition system (28) is a camera, more specifically a LiDAR type camera.
9. The aircraft according to claim 7 or 8, characterized in that Each marker (R1 to R5) integral with the movable structure follows a three-dimensional trajectory (TT1 to TT5) extending between a first endpoint (P1) and a second endpoint (P2), and each acquisition system (28) has an aiming axis (A28), each acquisition system (28) being positioned such that an angle of less than 30° is formed between its aiming axis (A28) and a plane equidistant from the first endpoint (P1) and the second endpoint (P2) of at least one three-dimensional trajectory (TT1 to TT5).
10. The aircraft according to claim 9, characterized in that The device comprises a given number of acquisition systems (28), the number being determined so that for each three-dimensional trajectory (TT1 to TT5), at least one acquisition system (28) has an aiming axis (A28) forming an angle of less than 30° with a plane equidistant from a first end point (P1) and a second end point (P2) of the three-dimensional trajectory (TT1 to TT5).