METHOD OF INSTALLING A FIXTURE AND ASSOCIATED APPARATUS

Abstract

A method of installing a fixture or bracket in a fuselage structure of an aircraft or spacecraft. The method includes arranging an apparatus in, on or adjacent the structure, pre-treating a surface region of the structure by heat ablation using the apparatus and forming the fixture in situ on the structure at the pre-treated surface region using the apparatus based on a digital model of the fixture. The fixture is installed by connecting the fixture to the structure at the pre-treated surface region as the fixture is formed.

Claims

1. A method of installing a fixture in or on a structure of an aircraft or spacecraft, the method comprising: arranging an apparatus in, on or adjacent the structure; pre-treating a surface region of the structure by ablation using the apparatus; and forming the fixture in situ on the structure at the pre-treated surface region using the apparatus based on a digital model of the fixture, wherein the fixture is installed by connecting the fixture to the structure at the pre-treated surface region as the fixture is formed.

2. The method of claim 1, wherein pre-treating the surface region of the structure by ablation comprises laser ablating the surface region via a laser ablation device.

3. The method of claim 2, wherein laser ablating the surface region comprises one or more of: generating a laser beam; positioning a head of the laser ablation device at a predetermined spacing from the structure; focusing the laser beam onto the surface region of the structure; and moving the laser beam over the surface region at a predetermined spacing from the structure.

4. The method of claim 1, wherein pre-treating the surface region of the structure by ablation comprises plasma ablating the surface region via a plasma ablation device.

5. The method of claim 4, wherein plasma ablating the surface region comprises one or more of: generating a plasma stream; positioning a head of a plasma ablation device at a predetermined spacing from the structure; focusing the plasma stream onto the surface region of the structure; and moving the plasma stream over the surface region at a predetermined spacing from the structure.

6. The method of claim 1, wherein the digital model of the fixture includes data on an intended position of the fixture within structure, wherein pre-treating the surface region of the structure includes positioning a head of the ablation device adjacent the structure based on the digital model of the fixture, whereby the structure can include one or more reference markers for spatial correlation to reference points in the digital model of the fixture.

7. The method of claim 1, wherein forming the fixture in situ comprises building the fixture sequentially, preferably by generating and building up layers of the fixture in the surface region with an additive manufacturing device, wherein the layers of the fixture are sequentially deposited on the structure.

8. The method of claim 1, wherein connecting the fixture to the structure includes at least one of: bonding or fusing one or more of the layers of the fixture to the structure as they are generated; and forming the fixture in situ in a mechanical fit or a mechanical engagement with part of the structure.

9. The method of claim 8, wherein bonding the fixture to the structure includes depositing one or more layer or region of adhesive on the pre-treated surface region.

10. An apparatus for installing a fixture in or on a structure of an aircraft or spacecraft, the apparatus comprising: an ablation device for generating and directing an ablating beam onto a surface region of the structure to pre-treat the surface region; an additive manufacturing device for forming the fixture in situ on the pre-treated surface region; and a controller for controlling or operating the ablation device and/or the additive manufacturing device at the surface region of the structure.

11. The apparatus of claim 10, wherein the ablation device comprises a laser ablation device for laser ablating the surface region, wherein the laser ablation device includes a head having one or more of: laser focussing device to adjust a focal length of the laser beam, and at least one sensor for detecting a spacing or displacement of the head with respect to the surface region.

12. The apparatus of claim 10, wherein the ablation device comprises a plasma ablation device for plasma ablating the surface region, wherein the plasma ablation device includes a head having one or more of: laser focusing device to direct or focus a plasma stream, and at least one sensor for detecting a spacing or displacement of the head with respect to the surface region.

13. The apparatus of claim 10, wherein the additive manufacturing device comprises a head for building the fixture sequentially, especially by generating and building up layers of the fixture on the structure, wherein the layers of the fixture are sequentially deposited on the structure by the head.

14. The apparatus of claim 10, wherein the additive manufacturing device and the ablation device are mounted on a robot assembly for adjusting a position thereof with respect to the structure.

15. The apparatus of claim 10, wherein the controller operates or controls based on a digital model of the fixture or structure.

16. The method of claim 9, wherein depositing one or more layer or region of adhesive on the pre-treated surface region is performed before generating and building up layers of the fixture on the structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] For a more complete understanding of the present disclosure and the advantages thereof, exemplary embodiments of the disclosure herein are explained in more detail in the following description with reference to the accompanying drawings, in which like reference characters designate like parts and in which:

[0040] FIG. 1 is a schematic side view of a section of a fuselage or hull structure of an aircraft, upon which a fixture or bracket is being installed according to an embodiment of the disclosure herein;

[0041] FIG. 2 shows four schematic side views (a) to (d) of the fuselage or hull structure in FIG. 1, upon which the fixture or bracket is being installed according to an embodiment of the disclosure herein;

[0042] FIG. 3 is a schematic side view of a section of a fuselage or hull structure of an aircraft, and an apparatus according to an embodiment of the disclosure herein with which a fixture or bracket is installed in situ;

[0043] FIG. 4 is a schematic side view of the apparatus according to the embodiment of FIG. 3 showing the parts of the apparatus for performing a pre-treatment of a surface region of the structure in more detail;

[0044] FIG. 5 is a schematic side view of a section of a fuselage or hull structure of an aircraft, and an apparatus according to another embodiment of the disclosure herein for installing a fixture or bracket in situ;

[0045] FIG. 6 is a schematic side view of the apparatus according to the embodiment of FIG. 5 showing the parts of the apparatus for performing a pre-treatment of a surface region of the structure in more detail;

[0046] FIG. 7 schematically shows three stages (i) to (iii) of a method or technique of installing the fixture or bracket according to a particular embodiment;

[0047] FIG. 8 is a flow diagram which schematically illustrates a method according to a preferred embodiment;

[0048] FIG. 9 is a schematic illustration of an aircraft in which one or more brackets according to an embodiment of the disclosure herein are installed; and

[0049] FIG. 10 is a schematic view of a space station upon which a fixture or element is being installed according to an embodiment of the disclosure herein.

DETAILED DESCRIPTION

[0050] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate particular embodiments of the disclosure herein and together with the description serve to explain the principles of the disclosure herein. Other embodiments of the disclosure herein and many of the attendant advantages of the disclosure herein will be readily appreciated as they become better understood with reference to the following detailed description.

[0051] It will be appreciated that common and well understood elements that may be useful or necessary in a commercially feasible embodiment are not necessarily depicted in order to facilitate a more abstracted view of the embodiments. The elements of the drawings are not necessarily illustrated to scale relative to each other. It will further be appreciated that certain actions and/or steps in an embodiment of a method may be described or depicted in a particular order of occurrences while those skilled in the art will understand that such specificity with respect to sequence is not necessarily required. It will also be understood that the terms and expressions used in the present specification have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study, except where specific meanings have otherwise been set forth herein.

[0052] With reference firstly to FIG. 1 of the drawings, a system or apparatus 100 for installing a fixture 1, here in the form of a bracket, on an airframe or fuselage structure F of an air-craft according to a method of the disclosure herein is illustrated schematically. The airframe or fuselage structure F of the aircraft in this embodiment comprises a curved shell section of the fuselage, comprised of a carbon-fiber reinforced polymer composite, which is supported in this case by brace elements B extending horizontally from a vertically extending supporting framework S. Also shown in FIG. 1 is a robot assembly 2, which includes a robotic arm 3 having a plurality of articulated joints 4, each of which is drivable in at least one and preferably in a number of degrees-of-freedom. The robot assembly 2 is itself mounted for translational movement along a rail member 5 in a direction perpendicular to a plane of drawing FIG. 1. Mounted on a distal end region of the robot arm 3 is a head 6 of an additive manufacturing device 7, which is generally understood or may be referred to as a 3D printer device. This additive manufacturing device 7 may operate on any one of the known 3D printing techniques, such as fused deposition modelling (FDM), laser sintering (LS), or stereo-lithography (SLA). Particularly preferred in this embodiment is a fused deposition modelling (FDM) device 7. The movement of the robotic assembly 2, and more particularly of the robot arm 3 via the articulated joints 4 and its position along the rail member 5, are computer-controlled via a computer processor P (illustrated schematically here, and shown later in FIG. 7), which also controls operation of the additive manufacturing device 7. During installation of a new fixture or bracket 1 according to the inventive method, the head 6 of the device 7 is moved by the robot arm 3 in the direction of the arrow in FIG. 1 to a predetermined position or surface region Z on the fuselage shell F.

[0053] Referring now also to FIGS. 2(a) to 2(d) of the drawings, the steps of forming or building the fixture or bracket 1 in the surface region Z of the fuselage structure F is illustrated schematically in the series of four images (a) to (d). In the image of FIG. 2(a), the head 6 of the FDM device 7 arranged at the distal end region of the robotic arm 3 has been moved into proximity with the surface of the fuselage structure F of the aircraft at position Z. A three-dimensional digital model M of the fixture or bracket 1 is provided or generated in the computer processor P and, based upon the data in this digital model M of the bracket 1, the computer processor P then controls the head 6 of the FDM device 7 to deposit layers of polymer material onto the CFRP fuselage structure as the head 6 of the device 7 is moved along the surface of shell structure F in the direction of the arrow in FIG. 2(a). Then, in FIG. 2(b), one or more layers L1 of the bracket 1 has/have been deposited upon the fuselage structure F at the predetermined position Z, which layer(s) is/are bonded or fused to CFRP structure F.

[0054] The head 6 of the FDM device 7 is then moved slightly away from the fuselage structure F in the direction of the arrow shown in FIG. 2(b). As shown in FIG. 2(c), the head 6 may then commence deposition of one or more new layers L2 of the polymer material, which builds upon the previous layers L1 and thus builds-up the three-dimensional shape or form of the fixture or bracket 1. This procedure continues with reference to FIG. 2(d) of the drawings until the final 3D shape of the bracket 1 has been completed.

[0055] Before the controller or processor P commences operating the ALM or additive manufacturing device 7 mounted on the robotic assembly 2, however, the apparatus 100 is used or employed to pre-treat the surface region Z at which the bracket 1 is to be installed on the structure F by heat ablation. To this end, as illustrated in FIGS. 3 and 4 of the drawings, the apparatus 100 further includes an ablation device 9, a head 8 of which is mounted on a distal end region of a robot arm 3 in the robotic assembly 2. As noted above, movement of the robotic assembly 2, and specifically of the robot arm 3 via the articulated joints 4, is controlled via the processor P.

[0056] Referring to FIG. 3, in this embodiment the ablation device 9 is a laser ablation device configured to generate and direct a laser beam LB onto the fuselage structure F for laser ablating the targeted surface region Z. The ablation device 9 includes a laser generator 10 in the form of a CL20 backpack which is supported on a carriage robot 11 and connected with the laser ablation head 8 via an optical cable 12, e.g., of optical fibers, for transmitting the laser beam LB. The laser generator 10 is rated at 20 W, generates a laser beam LB with a wavelength of 1000 nm, and is powered by a portable battery pack 13, which is movably supported on a carriage robot 14 within the apparatus 100.

[0057] As represented only very schematically in drawing FIG. 4, the laser ablation head 8 includes a focusing lens 15, a focusing control unit 16 and a battery unit 17, which together operate to adjust a focal length of the laser beam LB emitted from the head 8. In this way, the focusing lens 15 and focusing control unit 16 cooperate to adjust an intensity of the laser ablation. Further, the head 8 of the laser ablation device 9 includes a position sensor unit 18 for detecting a spacing or gap δ (and, thus, also a displacement or change in position) of the head 8 with respect to the surface region Z being pre-treated by laser ablation. This spacing or gap δ, which will generally correspond to the focal length adjusted via lens 15 and control unit 16, is typically within the range of about 50 mm to about 100 mm. Furthermore, with laser ablating, the spacing or gap δ is typically controlled and maintained very precisely.

[0058] With reference now to FIGS. 5 and 6 of the drawings, it will be noted that, in another embodiment of the apparatus 100, the ablation device 9 is a plasma ablation device configured to generate and direct a plasma stream PS onto the fuselage structure F for plasma ablating the desired surface region Z. The plasma ablation device 9 comprises a generator control unit 19 which is supported on a movable carriage robot 20 and connected via a power cable 21 both with a battery pack 22 (also on a carriage robot 20) and with the plasma head 8. The plasma ablation device 9 in this case operates at 600 W on AC having 10 kV and 60 mA.

[0059] The plasma stream PS itself is generated at the head 8, which is an air flow coupled plasma head 8. As is represented only very schematically in drawing FIG. 6, the ablation head 8 in this case includes a position sensor unit 23, a gap control unit 24, and a ball screw and motor 25, which co-operate to monitor and adjust the spacing or gap δ (and, thus, also a displacement or change in position) of the ablation head 8 with respect to the surface region Z being pre-treated. This spacing or gap δ is typically within the range of about 10 mm to about 30 mm, but high precision is generally not required.

[0060] Fourier transform infrared spectroscopy (FTIR) NDI equipment may be employed to check the degree of residue removal and/or heat damage by the heat ablation pre-treatment. If a long time has elapsed since heat ablation pre-treating a surface region, a re-treatment of the surface may be conducted to ensure or maintain the good surface condition by the pre-treatment process. Such a re-treatment process will generally be the same as described above, but the power or intensity may be lower in view of the low amount of material to remove.

[0061] With reference also now to FIG. 7 of the drawings, the method according to this preferred embodiment of the disclosure herein is illustrated in the three stages (i) to (iii). For example, in FIG. 7(i) an operator O is shown at a work-station W of the computer processor P engaged in the task of providing and/or generating the three-dimensional (3D) digital model M of the fixture or bracket 1 to be installed according to the method of this embodiment. The computer processor P at which the operator O is working is also responsible for the computer-controlled operation of the robot assembly 2, as well as both the additive manufacturing device 7 and the ablation device 9 described above with respect to FIGS. 1 to 6.

[0062] FIG. 7(ii) schematically illustrates the step of positioning the robot assembly 2 with respect to the fuselage structure F upon which the bracket 1 is to be formed and installed. In this regard, the robot assembly 2 is movable on one or more rails 5 within the tubular fuselage structure F, preferably on one of a plurality of separate rails 5, e.g., at separate heights or separate floors in the fuselage F. In this regard, the fuselage structure F may be a tubular shell as seen in FIG. 7(ii), rather than just a shell section shown in FIG. 1. Also, the robot assembly 2 may include a plurality of robotic arms 3 for simultaneously operating at various different positions Z within the fuselage structure F, i.e., in order to simultaneously pre-treat the respective surface regions and to build and install a plurality of fixtures or brackets 1 at different positions Z.

[0063] With regard to the positioning of the robotic assembly 2, the digital model M of the fixture or bracket 1 may include data concerning a specific desired or predetermined surface region or position Z on the fuselage structure F for a particular bracket 1. This data can then be used together with reference markers R provided on the fuselage structure F, which are preferably detectable and identifiable by sensors (not shown) provided on the robot assembly 2 to give spatial correlation for moving the robotic arm 3 relative to the body or fuselage structure F, and especially the head 9 of an ablation device 8 and the head 6 of an additive manufacturing device 7, to the correct position or surface region Z for pre-treating the surface and then forming and installing a specific bracket 1 based upon the data in the digital model M. The data in the digital model may also include detailed data on the structure F in or on which the bracket or fixture 1 is to be installed.

[0064] In other words, FIG. 7(ii) represents controlling operation of both the ablation device 9 and the additive manufacturing device 7 in the apparatus 100 for performing both the steps of: pre-treating the surface region Z of the structure F by heat ablation using the ablation device 9 provided on the robotic assembly 2, and then forming the bracket or fixture 1 in situ on the structure at the pre-treated surface region Z using the ALM device 7 on the robotic assembly 2.

[0065] FIG. 7(iii) essentially corresponds to FIG. 2 of the drawings and schematically illustrates the sequential deposition or layer build-up and installation of a particular bracket 1 at the desired or predetermined position Z within the fuselage structure F, with the bracket 1 being simultaneously bonded or fused to the material of the fuselage structure F.

[0066] Referring now to FIG. 8 of the drawings, a flow diagram is shown that again schematically illustrates the steps in the method of the preferred embodiment. In this regard, the first box I of FIG. 8 represents the step of arranging an apparatus 100 in, on or adjacent to the structure F, as generally shown in FIGS. 1, 3 and 5 of the drawings. The second box II then represents the step of pre-treating a surface region Z of the structure F by heat ablation using the laser/plasma ablation device 9 on the apparatus 100 to remove contaminant residues from the surface region Z and thereby to prepare the surface region Z for connection of the bracket or fixture 1. In this regard, this step involves controlling movement of the head 8 of the ablation device 9 with respect to the predetermined position Z in the fuselage structure F based on position data in the digital model M of the bracket or fixture 1 via the processor or control unit P. The third box III represents the step of depositing one or more layer or region of adhesive on the pre-treated surface region Z for subsequently bonding the bracket or fixture 1 to the CFRP fuselage structure F. The final box IV in drawing FIG. 8 represents the step of forming the bracket 1 in situ on the fuselage structure F with the head 6 of the FDM device 7. This involves moving the head 6 of the FDM device 7 to the pre-treated surface region Z in the fuselage structure F based on position data in the three-dimensional digital model M and then sequentially building up the bracket 1 in layers L1, L2 based upon the digital model M in the computer processor P, which operates and controls the robot assembly 2 carrying the FDM device 7. The bracket 1 is connected by bonding to the CFRP fuselage structure F as the bracket 1 is formed.

[0067] Following the above description of the method and apparatus of the disclosure herein, FIG. 9 of the drawings now schematically illustrates an aircraft A that incorporates a fuselage structure F, in which at least one fixture or bracket 1, and preferably a plurality thereof, has or have been installed according to a method of the present disclosure.

[0068] With reference to FIG. 10 of the drawings, on the other hand, an alternative embodiment is now illustrated schematically. In this embodiment, the inventive method is being carried out on a space station T which is currently in orbit. The space station T includes solar collector modules C, modules H for human occupation, and an antenna module I, all of which are interconnected by a structural framework X. In this example, the method is employed to conduct a repair to a part on the antenna module I. Again, a robot assembly 2, which includes a robotic arm 3 having remotely controlled articulated joints 4 is employed, which avoids the need for an astronaut to under-take a space-walk. The structural framework X may include one or more rails 5 for guiding movement of the robot 2 to the antenna module I. Also, a head 6 of an additive manufacturing device 7 or 3D printer device is mounted at an end region of the robotic arm 3. In this way, the method described above with reference to FIGS. 1-8 can be performed with the robot assembly 2 on the space station T to generate and install a new element or fixture 1 to repair the antenna module I. In the event that no rails 5 are available for the robot 2 on the structural framework X, it will be noted that the head 6 of the additive manufacturing device 7 may also be used to generate and install rail members 5 on the framework X of the space station T according to the method of the disclosure herein for guiding the robotic assembly 2 to that part of the antenna module I to be repaired.

[0069] Although specific embodiments of the disclosure herein have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations exist. It should be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0070] In this document, the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e., non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and “an” used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, “third”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects.

[0071] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.