Method for filling surface defects in an aircraft wing

Abstract

The invention relates to a method for filling surface defects in an aircraft wing. A filling method for filling surface defects (206) on the surface of a wing (104), and the method comprises: a scanning step, in which a control unit (212) controls a scanner (208) to move across the surface of the wing (104) so ​​as to scan the surface and transmit the collected data to the control unit (212), a calculation step, in which the control unit (212) calculates a digitized surface based on the data, a determination step, in which the control unit (212) determines each surface defect (206) by comparing a reference surface with the digitized surface, and a generation step, in which the control unit (212) generates a digital model of a patch (207) intended to fill the surface defect (206), and a printing step, in which the control unit (212) controls a 3D printer (210) to move across each surface defect (206) and commands the activation of the 3D printer (210) so as to print the patch (207).

Description

Technical Field

[0001] The invention relates to a filling method intended for filling surface defects in a wing of an aircraft, to an aircraft wing in which a depression has been filled by this method, and to an aircraft comprising at least one such wing. Background Art

[0002] During its manufacture, or in the course of its life, the surface of the wing of an aircraft may accidentally present surface defects. The presence of these surface defects may disturb the flow over the surface, and this flow may then become turbulent.

[0003] The occurrence of turbulent flow may result in additional fuel consumption.

[0004] Currently, there is no easy way to fill these surface defects and therefore it is necessary to find a method that allows filling these surface defects. Summary of the invention

[0005] One object of the invention is to propose a filling method intended for filling surface defects in the wings of an aircraft.

[0006] To this end, the invention proposes a filling method for filling surface defects on the surface of a wing of an aircraft, the filling method comprising:

[0007] a scanning step during which a control unit controls the first movement system so as to move a scanner over the surface of the wing to be filled and commands the activation of the scanner, which scans the surface and transmits the acquired data to the control unit,

[0008] - a calculation step during which the control unit calculates a digitized surface from the data thus transmitted,

[0009] - a determination step during which the control unit determines each surface defect by comparing a reference surface with the digitized surface,

[0010] - a generation step during which the control unit generates, for each surface defect, a digital model of a patch intended to fill said surface defect, and

[0011] - a printing step during which the control unit controls the second movement system so as to move the 3D printer past each surface defect to be filled and commands the activation of the 3D printer so as to cause it to print the patch into the surface defect according to the digital model thus generated.

[0012] This method thus makes it possible to fill surface defects in the wings of an aircraft simply and quickly.

[0013] In order to promote patch adhesion, the filling method comprises a preparation step before the printing step, during which a primer is applied to the surface of the wing to be filled.

[0014] Advantageously, the printing step is followed by a smoothing step during which a topcoat coating having surface properties compatible with laminar air flow is sprayed on each patch.

[0015] According to one particular embodiment, the printing step, or, if present, the smoothing step, is followed by a covering step during which a heat shrink film is applied to the surface of the wing to which the patch has been applied.

[0016] According to a particular embodiment, the printing step, or, if present, the smoothing step, is followed by a covering step during which a low-viscosity coating is applied to the surface of the wing to which the patch has been applied.

[0017] According to a particular embodiment, the filling method comprises a forming step before the scanning step, during which the wing is subjected to a vertical load factor of 1g, and a releasing step between the scanning step and the printing step, during which the wing returns to a load factor of 0g.

[0018] According to a particular embodiment, the filling method comprises a shaping step before the scanning step, during which the wing is subjected to a vertical load factor of 1 g, and a releasing step after the printing step, during which the wing returns to a load factor of 0 g.

[0019] The invention also proposes a wing of an aircraft comprising at least one surface defect filled by a patch determined by a filling method according to one of the preceding variants.

[0020] The invention also proposes an aircraft comprising at least one wing according to the preceding variant. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features of the present invention will become more apparent upon reading the following description of an exemplary embodiment given with reference to the accompanying drawings, in which:

[0022] Figure 1 is a partial elevation view of an aircraft including a wing treated using the filling method according to the invention,

[0023] Figure 2 An aircraft wing is shown which has been treated by implementing the method according to the invention,

[0024] Figure 3 depicts the architecture of a control unit intended for implementing the filling method according to the invention, and

[0025] Figure 4 A block diagram depicting a filling method according to the present invention. DETAILED DESCRIPTION

[0026] Figure 1 An aircraft 100 is shown including a fuselage 102 with wings 104 attached on each side of the fuselage.

[0027] Figure 2 The wing 104 is shown fixed by its root 200 to a chassis 202, which chassis itself is fixed to the ground. In order to ensure better stability of the wing 104, struts 250 resting on the ground are placed under the wing 104 so that the wing 104 rests on these struts 250.

[0028] The surface of the wing 104 has at least one surface defect 206 (eg, a dent or a depression), which is filled by a patch 207 , the geometry of which is determined by a filling method described below.

[0029] Typically, the filling of the surface defects 206 consists in scanning the surface of the wing 104 in order to obtain a digitized surface, in comparing the surface thus digitized with a reference surface in order to infer differences therefrom (i.e. surface defects present on the digitized surface), and in subsequently applying, using a 3D printer, a patch 207 directly to the surface of the wing 104 in order to fill the surface defects thus inferred. The reference surface corresponds to a physical or digital model of the object under consideration (in this case the wing 104). The reference surface is recorded in a database. Typically, the digital model is a mass of points, each of which is associated with its spatial position within a given reference system. Initially, the reference surface is the surface of the wing 104 calculated by the structural modeling software under a load factor of 0 g.

[0030] To perform this filling of surface defects 206, a scanner 208 and a 3D printer 210 are used. A 3D printer 210 is a machine that allows the manufacture of parts by addition or accumulation of material.

[0031] The scanner 208 is mounted on a first movement system which moves said scanner 208 in a direction allowing it to fly over the surface of the wing 104 to be scanned, in this case the upper surface of the wing. The first movement system thus causes at least a first movement in the longitudinal direction Y of the wing 104 and a second movement in the transverse direction X of the wing 104, wherein these two directions X and Y are different and coplanar and preferably perpendicular. The first movement system thus takes the form of a mobile crane having two directions of movement as a whole.

[0032] Of course, if necessary, provision can be made for the first movement system to provide a third movement in a height direction Z corresponding to the distance of the scanner 308 from the wing 104. The first movement system then takes the form of a mobile crane with three directions of movement.

[0033] According to a second embodiment, the scanner 208 may be fixedly mounted above the wing, with the first movement system allowing the acquisition angle of the scanner to be oriented to cover the entire wing.

[0034] Similarly, the 3D printer 210 is mounted on a second mobile system that provides movement of the 3D printer 210 in directions that allow it to fly over the surface to be filled. The second mobile system thus provides a first movement along the longitudinal direction Y of the wing 104, a second movement in the transverse direction X of the wing 104 (wherein these two directions X and Y are different and coplanar and preferably perpendicular) and a third movement in the height direction Z, which corresponds to the distance of the 3D printer 210 from the wing 104. The second mobile system thus takes the form of a mobile crane with three directions of movement as a whole. In a variant, the second mobile system can take the form of a six-axis multi-articulated robot with a print head.

[0035] The first moving system and the second moving system are not depicted, but they have a structure known to those skilled in the art, including, for example, rails, motors, and the like.

[0036] The first and second mobile systems, as well as the scanner 208 and the 3D printer 210, are controlled by a control unit 212, which takes the form of a computer, for example. During the control of the first and second systems, the control unit 212 knows the precise position of the scanner 208 and the 3D printer 210 relative to a reference system associated with the wing 104 fixed to the chassis 202. Thus, the data acquired by the scanner 208 allow the surface of the wing 104 to be filled to be mapped relative to this reference system, and the position of the patch 207 to be determined relative to this reference system.

[0037] The control unit 212 is designed to: control the movement of the scanner 208 by controlling the first movement system so as to receive data from the scanner 208, to generate a digitized surface based on these data, to retrieve a reference surface corresponding to a wing without surface defects, to compare the digitized surface with the reference surface, to infer the surface defect 206 therefrom, to control the movement of the 3D printer 210 by controlling the second movement system, and to control the production of a patch 207 by the 3D printer 210, which is directly applied to the surface of the wing 104 to fill the surface defect 206.

[0038] Figure 3 A control unit 212 is shown, which includes: a processor 301 or CPU ("Central Processing Unit"); a RAM ("Random Access Memory") 302; a ROM ("Read Only Memory") 303; a storage unit (such as a hard disk); and at least one communication interface 305 (for example, allowing the control unit 212 to communicate with a scanner 208, a 3D printer 210, and motors of the first and second mobile systems) connected via a communication bus 306.

[0039] The reference surface is stored in the storage unit 304, for example.

[0040] The processor can execute instructions loaded into the RAM from the ROM, from an external memory (not depicted), from a storage medium (such as an SD card), or from a communication network. When the device is powered on, the processor can read the instructions from the RAM and execute them. These instructions form a computer program so that the processor implements the Figure 4 All or some of the algorithms and steps described in conjunction.

[0041] All or some of the algorithms and steps described below may be implemented in the form of software by causing a programmable machine (such as a DSP (digital signal processor) or a microcontroller) to execute a series of instructions, or may be implemented in the form of hardware by a dedicated machine or component (such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit)).

[0042] Figure 4 A block diagram 400 of a filling method according to the present invention is shown, and the method comprises:

[0043] a scanning step 404 during which the control unit 212 controls the first movement system so as to move the scanner 208 over the surface of the wing 104 to be filled and commands the activation of the scanner 208 which scans said surface and transmits the acquired data to the control unit 212,

[0044] - a calculation step 406 during which the control unit 212 calculates the digitized surface from said data thus transmitted,

[0045] a determination step 408 during which the control unit 212 determines each surface defect 206 by comparing the reference surface with the digitized surface,

[0046] a generation step 410 during which the control unit 212 generates, for each surface defect 206 , a digital model of the patch 207 intended to fill said surface defect 206 , and

[0047] - A printing step 412 during which the control unit 212 controls the second movement system so as to move the 3D printer 210 past each surface defect 206 to be filled and commands the activation of the 3D printer 210 so as to print a patch 207 into said surface defect 206 according to the digital model thus generated.

[0048] This filling method thus allows surface defects 206 in wing 104 to be quickly and easily filled.

[0049] The control unit 212 is therefore arranged to: control the first movement system so as to move the scanner 208 over the surface of the wing 104 to be filled, to activate the scanner 208 and to acquire data about the scanned surface and transmitted by the scanner 208, to calculate the digitized surface based on the data thus transmitted, to determine each surface defect 206 by comparing a reference surface with the digitized surface, to generate for each surface defect 206 a digital model of a patch 207 intended to fill the surface defect 206, to control the second movement system so as to move the 3D printer 210 over each surface defect 206 to be filled, and to activate the 3D printer 210 so that it prints the patch 207 into the surface defect 206 based on the digital model thus generated.

[0050] To facilitate the adhesion of the patch 207 to the surface defect 206 and the painting on the rest of the surface, the method includes a preparation step before the printing step 412, during which a primer is applied to the surface of the wing 104 to be filled. The primer is applied by any suitable means, for example by a spraying robot. The primer has a thickness of the order of 100 μm, for example. The primer is, for example, a two-part epoxy polyamide substance.

[0051] The patch 207 can be made of a variety of different materials, such as, for example, ABS (Acrylonitrile Butadiene Styrene) or PLA (Polylactic Acid) or other materials.

[0052] Each surface defect 206 is determined by comparing the digitized surface to a reference surface using methods known to those skilled in the art. The digital model of the patch 207 corresponds to the volume of the surface defect 206 as determined based on the comparison. For example, when the digitized surface is not identical to the reference surface, their difference produces a volume indicating the presence of the surface defect. On the other hand, when they are identical, the digitized surface and the reference surface can be superimposed and coincident.

[0053] To reduce the roughness caused by 3D printing, the printing step 412 is followed by a smoothing step 413 during which a topcoat is sprayed on each patch 207. The topcoat is a material having surface properties compatible with laminar air flow after drying, such as epoxy resin or acrylic paint. The material of the topcoat is, for example, ABS (acrylonitrile butadiene styrene) or PLA (polylactic acid).

[0054] To further improve the surface finish of wing 104, heat shrink film may be applied to the surface of wing 104. Printing step 412 or smoothing step 413 (if present) is followed by covering step 415 during which heat shrink film is applied to the surface of wing 104 to which patch 207 has been applied.

[0055] The heat shrink film may be replaced by a low viscosity coating having a thickness on the order of 100 microns.

[0056] Assuming that in flight the wing 104 is subjected to an upward vertical load factor of 1 g, it is desirable to subject the wing 104 to such a load factor before scanning it and fill the surface defects 206 in such a way that the surface of the wing 104 is as close as possible to the actual state in use.

[0057] The filling method then comprises, prior to a scanning step 404 , a shaping step 403 , during which the wing 104 is subjected to a vertical load factor of 1 g.

[0058] Imposing a load factor of 1 g is achieved by adjusting struts 250 so that they lift the free end of wing 104 and cause wing 104 to adopt a shape corresponding to the shape it would adopt in flight.

[0059] The reference surface then corresponds to the surface of the wing at a load factor of 1 g, calculated by the structural modelling software.

[0060] The struts 250 are adjusted, for example, in a servo-controlled manner by a control unit 212 which controls a jack of each strut 250, wherein the curvature of the wing 104 is monitored by suitable means (such as, for example, a laser) in order to achieve a curvature corresponding to the curvature of a reference surface.

[0061] The control unit 212 is therefore arranged for controlling the jacks of each strut 250 .

[0062] According to a first embodiment of the invention, the filling method comprises, between the scanning step 404 and the printing step 412, a release step during which the wing 104 returns to a load factor of 0 g and printing is then performed with the wing 104 in the 0 g position.

[0063] According to a second embodiment of the invention, the filling method comprises a release step after the printing step 412 during which the wing 104 returns to a load factor of 0 g and printing is then performed with the wing 104 in the 1 g position.

Claims

1. A filling method (400) for filling a surface defect (206) on a surface of a wing (104) of an aircraft (100), the filling method comprising: a scanning step (404), during which the control unit (212) controls the first movement system so as to move a scanner (208) over the surface of the wing (104) to be filled and commands the activation of the scanner (208), which scans the surface and transmits the acquired data to the control unit (212), - a calculation step (406) during which the control unit (212) calculates a digitized surface from the data thus transmitted, - a determination step (408), during which the control unit (212) determines each surface defect (206) by comparing a reference surface with the digitized surface, a generation step (410), during which the control unit (212) generates, for each surface defect (206), a digital model of a patch (207) intended to fill said surface defect (206), and a printing step (412), during which the control unit (212) controls the second movement system so as to move the 3D printer (210) past each surface defect (206) to be filled and commands the activation of the 3D printer (210) so as to cause the 3D printer (210) to print the patch (207) into the surface defect (206) according to the digital model thus generated, The filling method also includes a forming step (403) before the scanning step (404), during which the wing (104) is subjected to a vertical load factor of 1g, and the method also includes a releasing step between the scanning step (404) and the printing step (412) or after the printing step (412), during which the wing (104) returns to a load factor of 0g.

2. The filling method (400) according to claim 1, characterized in that: The method comprises, prior to the printing step (412), a preparation step during which a primer is applied to the surface of the wing (104) to be filled.

3. The filling method (400) according to claim 1, characterized in that: The printing step (412) is followed by a smoothing step (413) during which a topcoat coating having surface properties compatible with laminar air flow is sprayed on each patch (207).

4. The filling method (400) according to claim 3, characterized in that: The smoothing step (413) is followed by a covering step (415) during which a heat shrink film is applied to the surface of the wing (104) to which the patch (207) has been applied.

5. The filling method (400) according to claim 3, characterized in that: The smoothing step (413) is followed by a covering step (415) during which a coating is applied to the surface of the wing (104) to which the patch (207) has been applied.

6. The filling method (400) according to claim 1 or 2, characterized in that: The printing step is followed by a covering step during which a heat shrink film is applied to the surface of the wing to which the patch has been applied.

7. The filling method (400) according to claim 1 or 2, characterized in that: The printing step is followed by a covering step during which a coating is applied to the surface of the wing to which the patch has been applied.

8. A wing (104) of an aircraft (100), comprising at least one surface defect (206) filled by a patch (207) determined by a filling method according to any one of claims 1 to 7.

9. An aircraft (100) comprising at least one wing (104) according to claim 8.

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