Method for determining at least one characteristic of the movement of a moving structure of an aircraft, and aircraft comprising a device for its implementation
The method uses image-based reference frames to accurately track aircraft landing gear movement, reducing sensor requirements and maintenance complexity while enhancing position determination accuracy.
Patent Information
- Application Number
- FR2024000812
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-01-29
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2044-01-29
AI Technical Summary
Existing methods for determining the movement of aircraft landing gear require a large number of proximity sensors and substantial wiring, increasing aircraft mass and maintenance complexity, and fail to accurately determine the position of moving elements outside the ends of their stroke.
A method utilizing image acquisition and comparison with reference frames to determine the movement of aircraft landing gear, employing a reduced number of sensors and cameras to capture and process images, allowing precise determination of movement characteristics at any point along the trajectory.
Enables accurate and efficient determination of landing gear movement characteristics without the need for extensive wiring, reducing aircraft mass and maintenance, and allowing continuous position tracking.
Smart Images
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Abstract
Description
Title of the invention: Method for determining at least one characteristic of the movement of a moving 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 moving structure of an aircraft and to an aircraft comprising a device for its placement.
[0002] According to one embodiment, an aircraft includes several movable landing gears, each between retracted and extended positions, and for each of them a landing gear box configured to house the landing gear in the retracted position.
[0003] Each landing gear comprises various elements articulated with respect to each other as well as actuators allowing the landing gear to be moved between the retracted and extended positions.
[0004] Each landing gear compartment includes at least one movable door 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 landing gear compartment hatch and of certain articulated and / or actuator elements of each landing gear.
[0006] According to one embodiment, each of these sensors is a proximity sensor that determines a unique position of a moving element such as one of the articulated elements, actuators, or hatches. Thus, according to one configuration, for a given moving element, the aircraft includes two proximity sensors positioned at the two ends of the stroke of that moving element.
[0007] This embodiment is not entirely satisfactory because it requires a large number of proximity sensors and substantial wiring, which impacts the mass of the aircraft and its maintenance.
[0008] According to another drawback, this embodiment does not allow the position of a moving element to be determined when the latter is not located at one of the ends of its stroke.
[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 the movement of a moving structure of an aircraft, characterized in that the method comprises: a. an acquisition step at a given instant of at least one image on which appears at least one reference frame attached to the moving 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 coordinate system in said plane reference frame, c. a step of comparing the previously determined pair of coordinates with reference pairs of coordinates, each pair of reference coordinates being associated with at least one characteristic of the motion of the moving structure, d. a step of determining the characteristic of the movement of the moving 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 beginning and end of the movement.
[0012] According to another feature, 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 its coordinates those of one of the pairs of reference coordinates, closest to the point which has as its coordinates those of the pair of coordinates obtained by projection.
[0013] According to another feature, the method consists of determining at the given instant for several reference frames at least one characteristic of the motion for each of them, the characteristic of the motion of the mobile structure corresponding to the average of the characteristics of the motion determined for the different reference frames.
[0014] According to another feature, the method includes, beforehand, a step of determining a reference trajectory in the planar reference frame for each reference frame.
[0015] According to another feature, the step of determining a reference trajectory consists, for each given angular position of the moving structure, of determining for each frame a pair of reference coordinates in the plane reference frame corresponding to a projection of the frame in said plane reference frame and of associating the pair of reference coordinates and the given angular position.
[0016] According to another feature, the movable structure is an aircraft landing gear.
[0017] The invention also relates to an aircraft comprising at least one moving structure and a device for implementing 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 one reference frame attached to the moving structure, a database in which pairs of reference coordinates are each associated with at least one characteristic of the movement of the moving structure, and 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 coordinate system 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 motion of the moving 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 feature, each frame attached to the moving structure follows a three-dimensional trajectory extending between first and second endpoints. 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 endpoints of at least one three-dimensional trajectory.
[0020] According to another feature, 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 endpoints of the three-dimensional trajectory.
[0021] Other features and advantages will become apparent from the following description of the invention, given by way of example only, with reference to the accompanying drawings, among which:
[0022] [Fig. 1] is a perspective view of an aircraft landing gear, occupying two positions and three-dimensional trajectories of reference frames fixed to the landing gear between its two positions, illustrating one embodiment of the invention,
[0023] [Fig.2] is a representation of the projections of the trajectories in a plane reference frame three-dimensional visible on the [Fig.l].
[0024] As illustrated in [Fig.1], an 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, said to be deployed, and a second position 12B, said to be retracted.
[0025] According to an embodiment visible in [Fig.1], 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 and 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 brace 18 includes a first end 18.1 connected to the leg 14 and a second end 18.2 connected to the fixed structure 10 by first and second joints 24.1, 24.2.
[0027] Regardless of 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 connecting rod(s) 20, the actuator(s) 22 and the joint(s) 24.
[0028] In addition, the aircraft includes at least one landing gear bay attached to the fixed structure 10 and configured to house the landing gear 12A, 12B in the retracted position. Each landing gear bay includes at least one door movable relative to the fixed structure 10 between an open position in which the door allows the landing gear 12A, 12B to be in the extended position and a closed position in which the door closes the landing gear bay when the landing gear 12A, 12B is in the retracted position.
[0029] Each landing gear compartment hatch of the aircraft is a movable structure, configured to move relative to the fixed structure 10, comprising at least one movable element.
[0030] Regardless of the embodiment, the aircraft includes 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 landing gear bay door.
[0031] According to one configuration, the mobile structure pivots around 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 frame of reference RI to R5 fixed to the mobile structure, which follows a three-dimensional trajectory TT1 in the real frame of reference 3D, when the latter moves from one extreme position to the other. The reference frame can be a point, a line, a circle, or any other element.
[0033] According to the example shown in [Fig. 1], the mobile structure has five reference frames RI to R5 which respectively follow three-dimensional trajectories TT1 to TT5. For each reference frame RI to R5 attached to the mobile structure, each point of its three-dimensional trajectory 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 mark RI, at the first end 18.1 of the strut 18 for mark R2, substantially equidistant from the first and second ends 18.1, 18.2 of the strut 18 for mark R3, at the first joint 24.1 connecting the strut 18 and the fixed structure 10 for mark R4 and substantially equidistant from the first and second joints 24.1, 24.2 connecting the strut 18 and the fixed structure 10 for mark R5.Of course, the invention is not limited to this configuration for the markers.
[0034] A method for determining at a given instant at least one characteristic of a movement of the moving structure comprises: a. an acquisition step at a given time of at least one image on which appears at least one frame RI at R5 fixed to the moving structure, b. a determination step, from the captured image, of a pair of coordinates X, Y in a 2D plane reference frame corresponding to a projection of the frame RI at R5 in said 2D plane reference frame, c. a step of comparing the previously determined X, Y coordinate pair with reference coordinate pairs X0, Y0 stored in a database 30, each reference coordinate pair X0, Y0 being associated with at least one characteristic of the movement of the moving structure, d. a step of determining the characteristic of the movement of the moving 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 includes a device for determining at least one characteristic of a movement of the moving structure, which comprises at least one acquisition system 28 configured to capture at least one image on which appears at least one reference frame RI to R5 attached to the moving 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 moving structure, and 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 frame RI to R5 in said 2D plane reference frame, b. compare the previously determined X, Y coordinate pair with the reference XO, YO coordinate pairs stored in database 30, and c. determine the characteristic of the motion of the moving 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 camera. Of course, the invention is not limited to this embodiment for the acquisition system 28. Thus, any system that allows any point located in a three-dimensional frame of reference to be projected into a planar frame of reference could be used.
[0037] According to one method, the determined movement characteristic 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 the only ones determined. The method of the invention makes it possible to determine the angular positions of the intermediate landing gear positions between the retracted and extended positions.
[0038] According to one operating method, 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 those 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 applying the method for several frames RI to R5 and determining at the given instant for each of the frames 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 method, the desired characteristic of the movement of the mobile structure corresponds to the average of the movement characteristics determined for each of the different frames RI to R5.
[0040] According to one operating method, the process of determining at least one characteristic of a movement of the mobile structure includes, in advance, a step of determining a reference trajectory TRI to TR5 in the 2D planar reference frame for each frame R1 R5, as illustrated in [Fig.2].
[0041] According to one embodiment, this last step consists, for each given angular position of the mobile structure, of capturing at least one image in which the reference frames RI to R5 are shown, of determining for each reference frame RI to R5 a pair of reference coordinates X0, Y0 in the 2D plane reference frame corresponding to the projection of the reference frame RI to R5 in said 2D plane reference frame and of associating in the database 30 the pair of reference coordinates X0, Y0 and the given angular position.
[0042] Thus, to each three-dimensional trajectory TT1 to TT5 in the real 3D frame corresponds a reference trajectory TRI to TR5 in the 2D planar frame, each reference trajectory TRI to TR5 corresponding to the set of reference coordinate pairs X0, Y0 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 endpoints PI, P2. In parallel, each acquisition system 28 has a sighting axis A28. According to one configuration, the acquisition system 28 is positioned so that its sighting axis A28 forms the smallest possible angle, preferably less than 30°, with a plane equidistant from the first and second endpoints PI, P2 of at least one three-dimensional trajectory TT1 to TT5. This configuration improves the accuracy of the estimation of the desired motion characteristic.
[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 endpoints PI, P2 of the three-dimensional trajectory TT1 to TT5.
Claims
Demands
1. A method for determining at a given instant at least one characteristic of a movement such as a pivot angle or an angular position of a moving structure chosen from an aircraft landing gear and a landing gear bay door of an aircraft landing gear, characterized in that the method comprises: a. a step of acquiring at the given instant at least one image on which appears at least one frame (RI to R5) fixed to the moving structure, b. a step of determining from the captured image a pair of coordinates (X, Y) in a plane (2D) reference frame corresponding to a projection of the frame (RI to R5) in said plane (2D) reference frame, c.a step of comparing the previously determined coordinate pair (X, Y) with reference coordinate pairs (XO, YO), to each reference coordinate pair (XO, YO) being associated with at least one characteristic of the movement of the moving structure, the comparison step consisting of determining the point which has coordinates of one of the reference coordinate pairs (XO, YO), closest to the point which has coordinates of the previously determined coordinate pair (X, Y), d. a step of determining the characteristic of the movement of the moving structure which is associated with the reference coordinate pair (XO, YO) corresponding to the coordinate pair (X, Y) in the planar 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 those of the pair of coordinates (X, Y) obtained by projection.
3. A method according to any one of the preceding claims, characterized in that the method consists of determining at a given time for several reference frames (RI to R5) at least one characteristic of the movement for each of them, the characteristic of the movement of the moving structure corresponding to the average of the characteristics of the movement determined for the different reference frames (RI to R5).
4. A method according to any one of the preceding claims, characterized in that the method includes, beforehand, a step of determining a reference trajectory (TRI to TR5) in the planar reference frame (2D) for each reference frame (R1 R5).
5. Method according to the preceding claim, characterized in that the step of determining a reference trajectory (TRI, TR2) consists, for each given angular position of the mobile structure, of determining for each frame (RI to R5) a pair of reference coordinates (XO, YO) in the plane reference frame (2D) corresponding to a projection of the frame (RI to R5) in said plane reference frame (2D) and of associating the pair of reference coordinates (XO, YO) and the given angular position.
6. A method according to any one of the preceding claims, characterized in that the movable structure is an aircraft landing gear.
7. Aircraft comprising at least one movable structure selected from an aircraft landing gear and a landing gear bay door, 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 is shown at least one reference frame (RI to R5) integral with the movable structure, a database (30) in which pairs of reference coordinates (XO, YO) are each associated with at least one feature of the motion such as a pivot angle or an angular position of the movable structure and 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 frame (RI to R5) in said plane reference frame (2D), b. compare the pair of coordinates (X, Y) determined previously with the reference coordinate pairs (XO, YO) stored in the database (30),. this comparison step consists of determining the point which has coordinates of one of the reference coordinate pairs (X0, Y0), closest to the point which has coordinates of the previously determined coordinate pair (X, Y), and c. determining the characteristic of the movement of the moving structure which is associated with the reference coordinate pair (X0, Y0) corresponding to the coordinate pair (X, Y) in the plane (2D) reference frame.
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 any one of claims 7 to 8, characterized in that each reference frame (RI to R5) attached to the moving structure follows a three-dimensional trajectory (TT1 to TT5) which extends between first and second endpoints (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 endpoints (PI, P2) by 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 endpoints (PI, P2) of the three-dimensional trajectory (TT1 to TT5).