SYSTEM AND METHOD FOR DETERMINING CUMULATIVE TOW GAP WIDTH
A system for determining cumulative tow gap width includes an in-process vision system having at least one camera adapted to record images of a composite material and a data analysis computer communicating with and adapted to receive image data from the in-process vision system. The data analysis computer may be adapted to calculate a cumulative gap width of tow gaps in the composite material. A user interface may communicate with and be adapted to receive data analysis results from the data analysis computer. A method for determining cumulative tow width gap of tow gaps in a composite structure is also disclosed.
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The disclosure relates to fabrication of composite structures. More particularly, the disclosure relates to a system and method for determining cumulative tow gap width in fabricated composite structures.
BACKGROUNDMethods of fabricating composite structures include the fiber placement or automated collation process. In such a process, one or more ribbons of composite material or tows may be laid down on a substrate which may be a tool, mandrel or one or more underlying and compacted layers of composite material. Conventional fiber placement processes may utilize a heat source to assist in compaction of the plies of composite material at a localized nip point. The ribbon or tow of composite material and the underlying substrate may be heated at the nip point to increase the tack of the resin of the plies while being subjected to compressive forces to ensure adhesion to the substrate. To complete the part, additional strips of composite material may be applied in a side-by-side manner to form layers and may be subjected to localized heat and pressure during the consolidation process.
A complex and detailed inspection guideline may be necessary for the inspection of composite structures that are fabricated using the fiber and tape placement processes. The guideline may establish acceptance criteria for discrete inconsistencies such as tow gaps, tow overlaps, twists, dropped tows and foreign objects. In-process vision technology may be capable of detecting and making accept/reject decisions on these inconsistencies during the manufacturing process. The guideline may also establish a requirement for maximum allowable cumulative, or total, tow gap width within any 12-inch area perpendicular to the direction of material placement or lay-down.
The existing solution to meeting the requirements of the inspection guidelines may include manual visual inspection by the human eye. An operator may select at random a number of regions of the correct size according to the inspection guideline. The operator may then apply a manual template that will define the area in which the inspection is to be made. The operator may utilize a means of determining and documenting the location of the region with respect to the entire surface area of the ply. Within each area, the operator may be required to visually identify tow gaps and measure each one manually using a tool such as a six-inch scale or a dial caliper. The widths of all identified gaps may be documented, the sum of the gap widths may be calculated and the sum for the specific area may be determined. The approach may be carried out on each ply of each part which is manufactured.
The existing solution to meeting the requirements of the inspection guidelines may require extensive cycle time and touch labor and may carry a high risk of inaccurate measurement. This approach may be viable for small parts but unmanageable for large surface areas. The approach may also be labor-intensive and prone to a high probability of error in measurement. Reduction of fatigue and risk of error may require multiple inspectors which may increase the touch labor required to complete the inspection.
The disclosure is generally directed to a system for determining cumulative tow gap width. An illustrative embodiment of the system includes an in-process vision system having at least one camera adapted to record images of a composite material and a data analysis computer communicating with and adapted to receive image data from the in-process vision system. The data analysis computer may be adapted to calculate a cumulative gap width of tow gaps in the composite material. A user interface may communicate with and be adapted to receive data analysis results from the data analysis computer.
The disclosure is further generally directed to a method for determining cumulative tow gap width of tow gaps in a composite structure. An illustrative embodiment of the method includes providing a composite material, recording periodic images of the composite material, analyzing the images of the composite material for presence of rejectable indications in the composite material and formulating a pass/fail status of the composite material based on the rejectable indications.
The disclosure is generally directed to a system and method for determining tow gap width within any designated area of any ply or tow on the surface of a part or structure produced by automated material placement. The system and method may utilize archived in-process vision data for any automatically placed tow, query selected surface area regions on the tow and sum the detected tow gap widths within each surface area region of the tow. Accordingly, the system and method may extensively reduce inspection cycle times and enhance accuracy of tow gap width measurements in fabrication of composite materials.
Referring to the drawings, an illustrative embodiment of the system for determining cumulative tow gap width, hereinafter system, is generally indicated by reference numeral 22 in the schematic block diagram of FIG. 3. The system 22 may include an in-process vision apparatus 1 which is shown in
As shown in
A screenshot of a suitable exemplary user interface 26 for the data analysis computer 24 is shown in
The pass/fail indicator 40 of the user interface 26 may include a pass button 40a and a fail button 40b. The data analysis computer 24 may be adapted to illuminate the pass button 40a in the event that the calculated cumulative tow gap width meets the maximum allowable cumulative tow gap width criteria and may be adapted to illuminate the fail button 40b in the event that the calculated cumulative tow gap width does not meet the maximum allowable cumulative tow gap width criteria. The pass button 40a may be a highly-visible color such as red and the fail button 40b may be a different color such as green, for example and without limitation.
An exemplary structure for the in-process vision apparatus 1 is shown in
A laser mount bracket 10 may extend from the frame plates 3 of the frame 2. At least one laser 14 having laser wiring 14a may be provided on the laser mount bracket 10. The laser 14 may be adapted to emit a laser beam 15 generally toward the compaction roller 6. At least one digital camera 18 having camera wiring 18a may also be provided on the laser mount bracket 10. At least one area light 16 may be provided on the laser mount bracket 10, or on one or both of the frame plates 3 of the frame 2, generally between the camera 18 and the compaction roller 6. As shown in
As further shown in
The automated collation process may include guiding the tows 32 from material creels (not shown) to the automated collation or fiber placement machine (not shown) with which the in-process vision apparatus 1 works in conjunction. In particular, the tows 32 may be sequentially and automatically guided onto the work surface 34 beneath the in-process vision apparatus 1 and fed under the compaction roller 6. Focused heat energy may then be applied to the incoming tow 32 and the underlying previously-compacted tows 32 that were previously laid on the work surface 34. With the combination of heat and pressure applied by the compaction roller 6, the tow 32 is consolidated into the previous layer of compacted tows 32, thus forming an additional layer of the composite structure 30. As shown in
During compaction of the tows 32 into the composite structure 30, inconsistencies such as the tow gaps 33 shown in
The images which are sighted by the camera 18 of the in-process vision apparatus 1 may be transmitted to and stored in the memory of the data analysis computer 24 (
The data analysis computer 24 may display each image frame which is sighted by the camera 18 in real time in the inspection window 41 (
The image frames 36 on the multiple courses of tows 32 shown in
The cumulative gap density query interface 48 shown in
When the size of the query window 49 has been selected, clicking “OK” on the cumulative gap density query interface 48 may generate an image such as the one shown in
Referring next to
Referring next to
Each of the processes of method 78 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
As shown in
The apparatus embodied herein may be employed during any one or more of the stages of the production and service method 78. For example, components or subassemblies corresponding to production process 84 may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft 94 is in service. Also, one or more apparatus embodiments may be utilized during the production stages 84 and 86, for example, by substantially expediting assembly of or reducing the cost of an aircraft 94. Similarly, one or more apparatus embodiments may be utilized while the aircraft 94 is in service, for example and without limitation, to maintenance and service 92.
Although the embodiments of this disclosure have been described with respect to certain exemplary embodiments, it is to be understood that the specific embodiments are for purposes of illustration and not limitation, as other variations will occur to those of skill in the art.
Claims
1. A system for determining cumulative tow gap width, comprising:
- an in-process vision system having at least one camera adapted to record images of a composite material;
- a data analysis computer communicating with and adapted to receive image data from said in-process vision system;
- said data analysis computer is adapted to calculate a cumulative gap width of tow gaps in the composite material; and
- a user interface communicating with and adapted to receive data analysis results from said data analysis computer.
2. The system of claim 1 wherein said in-process vision system comprises a frame and at least one laser carried by said frame.
3. The system of claim 2 further comprising at least one area light carried by said frame.
4. The system of claim 1 wherein said data analysis computer is adapted to compare said cumulative gap width of tow gaps in the composite material to maximum allowable cumulative tow gap width criteria.
5. The system of claim 4 wherein said data analysis computer is adapted to indicate a pass status of the composite material when said cumulative gap width of tow gaps in the composite material meets said maximum allowable cumulative tow gap width criteria.
6. The system of claim 5 wherein said data analysis computer is adapted to indicate a fail status of the composite material when said cumulative gap width of tow gaps in the composite material does not meet said maximum allowable cumulative tow gap width criteria.
7. The system of claim 6 wherein said user interface comprises a pass/fail indicator having a pass button and a fail button and said data analysis computer is adapted to illuminate said pass button when said data analysis computer indicates said pass status and said data analysis computer is adapted to illuminate said fail button when said data analysis computer indicates said fail status.
8. The system of claim 1 wherein said data analysis computer is adapted to display said image data.
9. A system for determining cumulative tow gap width, comprising:
- an in-process vision system and at least one camera carried by said frame plates and adapted to record images of a composite material;
- a data analysis computer communicating with and adapted to receive and store image data from said in-process vision system;
- said data analysis computer is adapted to query selected regions on the composite material and calculate a cumulative gap width of tow gaps in the selected regions; and
- a user interface communicating with and adapted to receive data analysis results from said data analysis computer.
10. The system of claim 9 wherein said in-process vision system comprises a frame and at least one laser carried by said frame.
11. The system of claim 10 further comprising at least one area light carried by said frame.
12. The system of claim 9 wherein said data analysis computer is adapted to compare said cumulative gap width of tow gaps in the composite material to maximum allowable cumulative tow gap width criteria.
13. The system of claim 12 wherein said data analysis computer is adapted to indicate a pass status of the composite material when said cumulative gap width of tow gaps in the composite material meets said maximum allowable cumulative tow gap width criteria.
14. The system of claim 13 wherein said data analysis computer is adapted to indicate a fail status of the composite material when said cumulative gap width of tow gaps in the composite material does not meet said maximum allowable cumulative tow gap width criteria.
15. The system of claim 14 wherein said user interface comprises a pass/fail indicator having a pass button and a fail button and said data analysis computer is adapted to illuminate said pass button when said data analysis computer indicates said pass status and said data analysis computer is adapted to illuminate said fail button when said data analysis computer indicates said fail status.
16. The system of claim 9 wherein said data analysis computer is adapted to display said image data.
17. A method for determining cumulative tow width gap of tow gaps in a composite structure, comprising:
- providing a composite material;
- recording periodic images of said composite material;
- analyzing said images of said composite material for presence of rejectable indications in said composite material; and
- formulating a pass/fail status of said composite material based on said rejectable indications.
18. The method of claim 17 wherein said analyzing said images of said composite material for presence of rejectable indications in said composite material comprises analyzing said images of said composite material for cumulative width of tow gaps in said composite material.
19. The method of claim 18 wherein said formulating a pass/fail status of said composite material based on said rejectable indications comprises establishing a maximum allowable cumulative tow gap width criteria, comparing said cumulative width of tow gaps in said composite material with said maximum allowable cumulative tow gap width criteria, passing said composite material when said cumulative width of tow gaps in said composite material meets said maximum allowable cumulative tow gap width criteria and failing said composite material when said cumulative width of tow gaps in said composite material does not meet said maximum allowable cumulative tow gap with criteria.
20. The method of claim 17 further comprising displaying said periodic images of said composite material.
Type: Application
Filed: Jan 2, 2008
Publication Date: Dec 27, 2012
Patent Grant number: 8934702
Applicant:
Inventors: Roger W. Engelbart (St. Louis, MO), Reed Hannebaum (Belleville, IL), Eric Rector (St. Charles, MO), Jeffrey Haywood (Belleville, IL)
Application Number: 11/968,395
International Classification: G06K 9/00 (20060101);