Dynamic collar swaging consistency check based on swage tool parameters

Abstract

The present disclosure relates to dynamic collar swage conformance checking based on swage tool parameters. Systems and methods for checking fastener installation are provided. One embodiment is a method for checking installation of a fastener. The method includes the steps of determining an initial distance between a nose of a swage tool and an inner mold line (IML) of a part; operating the swage tool to collar swage a fastener protruding through the IML of the part; determining an end point distance between the nose and the IML during swaging before a shank break of the fastener; and drawing a conclusion indicating a fastener installation status based on the end point distance.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of assembly and, in particular, to the application of fasteners in the form of lockbolts having collars for swaging. BACKGROUND

[0002] The number of fasteners (e.g., bolts) used to assemble an aircraft can be astronomical. For example, a medium-sized commercial jet airliner can have millions of fasteners installed to join different parts together.

[0003] Furthermore, technicians must inspect the fasteners installed by automated tools in order to ensure that the work was performed correctly. The inspection of the aforementioned millions of fasteners is a labor-intensive process involving manual inspection of the fasteners, e.g., involving manual inspection of every fastener on the aircraft.

[0004] Therefore, it would be desirable to have a method and apparatus that addresses at least some, if not all, of the problems discussed above, as well as possibly other problems. For example, it would be desirable to have a method and apparatus that overcomes the technical problem of automating the installation of fasteners. SUMMARY

[0005] The embodiments described herein provide systems and methods that are able to determine whether the installation of a fastener has been successfully completed based on position information indicative of the position of the nose of an automated installation tool. The systems and methods described herein can also take into account pressure measurements of a hydraulic system that drives the automated installation tool. This provides a technical benefit in that the installation tool is allowed to report that a fastener should be reinstalled if the readings indicate that the installation has not been completed in the desired manner. Thus, the automated installation tools described herein can obviate the need for manual fastener inspection required by existing systems.

[0006] One embodiment is a method for inspecting the installation of a fastener. The method includes the steps of determining an initial distance between a nose of a swaging tool and an internal mold line (IML) of a part; operating the swaging tool to swage a collar on a fastener protruding through the IML of the part; determining an end point distance between the nose and the IML during swaging before a shank of the fastener breaks; and drawing a conclusion based on the end point distance that is indicative of the state of fastener installation.

[0007] Other embodiments are a non-transitory computer readable medium embodying programming instructions that, when executed by a processor, are operable to perform a method for inspecting installation of a fastener. The method includes the steps of determining an initial distance between a nose of a swage tool and an internal mold line (IML) of a part; operating the swage tool to swage a collar onto a fastener protruding through the IML of the part; determining an end point distance between the nose and the IML during swaging before a shank of the fastener breaks; and drawing a conclusion indicating a state of fastener installation based on the end point distance.

[0008] Other embodiments are an apparatus for inspecting installation of a fastener, the apparatus including a swage tool. The swage tool includes a nose to swage a collar onto a fastener, a hydraulic cylinder to drive the nose, a finger to hold the collar in place at the fastener before swaging, and a sensor to measure an end point distance between the nose and an internal mold line (IML) of a part receiving the fastener.

[0009] Apparatuses, media, and methods of the present invention are also mentioned in clauses that should not be confused with the claims.

[0010] Clause 1. A method for inspecting installation of a fastener, the method including the steps of:

[0011] determining an initial distance between a nose of a swage tool and an internal mold line (IML) of a part (202);

[0012] operating the swage tool to swage a collar onto a fastener protruding through the IML of the part (204);

[0013] determining an end point distance between the nose and the IML during swaging before a shank of the fastener breaks (206); and

[0014] drawing a conclusion indicating a state of fastener installation based on the end point distance (208).

[0015] Clause 2. The method of clause 1, wherein:

[0016] determining the initial distance includes the steps of:

[0017] placing a tip of a presser foot of the swage tool in contact with the IML;

[0018] determining a separation between the tip of the presser foot and a tip of the nose; and

[0019] determining the initial distance based on the separation between the tip of the presser foot and the tip of the nose.

[0020] Clause 3. The method of clause 1 or 2, wherein:

[0021] determining the end-point distance comprises the steps of:

[0022] analyzing hydraulic readings to identify a time point at which the shank of the fastener fractured; and

[0023] determining a distance between the nose and the IML at the time point.

[0024] Clause 4. The method of any of clauses 1-3, wherein:

[0025] determining the end-point distance comprises the steps of:

[0026] analyzing hydraulic readings to identify a first time point at which the shank of the fastener fractured;

[0027] identifying a second time point at which hydraulic pressure reached a threshold value prior to the first time point; and

[0028] determining a distance between the nose and the IML at the second time point.

[0029] Clause 5. The method of any of clauses 1-4, further comprising the steps of:

[0030] determining the end-point distance and drawing the conclusion are performed in real-time prior to installation of a next fastener.

[0031] Clause 6. The method of any of clauses 1-5, wherein:

[0032] drawing a conclusion indicative of the status of the fastener installation comprises the steps of:

[0033] if the end-point distance is less than a threshold amount, drawing a conclusion that fastener installation has been successfully completed; and

[0034] if the end-point distance is not less than the threshold amount, drawing a conclusion that fastener installation has not been successfully completed.

[0035] Clause 7. The method of any of clauses 1-6, wherein:

[0036] reporting the status of the fastener installation comprises the steps of:

[0037] including the status of the fastener installation in a report detailing the status of fastener installations for a plurality of fasteners within a region of the part; and

[0038] providing the report for viewing by a technician via a display.

[0039] Clause 8. The method of any of clauses 1-7, further comprising the steps of:

[0040] reporting the fastener installation status for review.

[0041] Clause 9. A portion of an aircraft assembled according to the method of any of the preceding clauses 1-8.

[0042] Clause 10. A non-transitory computer readable medium embodying programming instructions that are operable when executed by a processor to perform a method for inspecting installation of a fastener, the method comprising the steps of:

[0043] determining (202) an initial distance between a nose of a swage tool and an inner mold line, IML, of a part;

[0044] operating (204) the swage tool to swage a collar onto a fastener protruding through the IML of the part;

[0045] determining (206) an end point distance between the nose and the IML during swaging prior to a shank break of the fastener; and

[0046] drawing (208) a conclusion indicative of a fastener installation status based on the end point distance.

[0047] Clause 11. The medium of clause 10, wherein:

[0048] determining the initial distance comprises the steps of:

[0049] placing a tip of a presser foot of the swage tool in contact with the IML;

[0050] determining a separation between the tip of the presser foot and a tip of the nose; and

[0051] determining the initial distance based on the separation between the tip of the presser foot and the tip of the nose.

[0052] Clause 12. The medium of clause 10 or 11, wherein:

[0053] determining the end point distance comprises the steps of:

[0054] analyzing a hydraulic reading to identify a point in time of the shank break of the fastener; and

[0055] determining a distance between the nose and the IML at the point in time.

[0056] Clause 13. The medium of any of clauses 10-12, wherein:

[0057] determining the end point distance includes:

[0058] analyzing hydraulic readings to identify a first point in time of the pin tail breakage of the fastener;

[0059] identifying a second point in time when the hydraulic pressure reaches a threshold value prior to the first point in time; and

[0060] determining a distance between the nose and the IML at the second point in time.

[0061] Clause 14. The medium of any of Clauses 10-13, wherein the method further includes the steps of:

[0062] determining the end point distance and drawing the conclusion are performed in real time prior to installation of a next fastener.

[0063] Clause 15. The medium of any of Clauses 10-14, wherein:

[0064] drawing a conclusion indicative of the fastener installation status includes the steps of:

[0065] if the end point distance is less than a threshold amount, drawing a conclusion that fastener installation has been successfully completed; and

[0066] if the end point distance is not less than a threshold amount, drawing a conclusion that fastener installation has not been successfully completed.

[0067] Clause 16. The medium of any of Clauses 10-15, wherein:

[0068] reporting the fastener installation status includes the steps of:

[0069] including the fastener installation status in a report detailing fastener installation status for a plurality of fasteners within a region of the part; and

[0070] providing the report for viewing by a technician via a display.

[0071] Clause 17. The medium of any of Clauses 10-16, wherein the method further includes the steps of:

[0072] reporting the fastener installation status for viewing.

[0073] Clause 18. A portion of an aircraft assembled according to a method defined by instructions stored on a computer readable medium of any of the preceding Clauses 10-17.

[0074] Clause 19. An apparatus for inspecting installation of a fastener, the apparatus comprising:

[0075] a swage tool (140) comprising:

[0076] a nose (142) to swage a collar (150) onto a fastener;

[0077] a hydraulic cylinder (126) to drive the nose;

[0078] a finger (144) to hold the collar in place at the fastener before swaging; and

[0079] a sensor (146) to measure an end-of-travel distance between the nose and an inner mold line, IML, of a part (160) that receives the fastener.

[0080] Clause 20. The apparatus of clause 19, further comprising:

[0081] a controller (110) to draw a conclusion indicative of a fastener installation state based on the end-of-travel distance, and to report the fastener installation state for review.

[0082] Clause 21. The apparatus of clause 20, wherein:

[0083] the controller draws the conclusion indicative of the fastener installation state by drawing a conclusion that fastener installation has been successfully completed if the end-of-travel distance is less than a threshold amount, and drawing a conclusion that fastener installation has not been successfully completed if the end-of-travel distance is not less than the threshold amount.

[0084] Clause 22. The medium of any one of clauses 19-21, wherein:

[0085] the sensor comprises a load cell to detect contact between the swage tool and the IML.

[0086] Clause 23. The apparatus of clause 22, wherein:

[0087] the swage tool further comprises a presser foot (180), and the sensor is coupled with the presser foot to detect contact between the presser foot and the IML.

[0088] Clause 24. Manufacturing a portion of an aircraft using the apparatus of any one of clauses 19-23.

[0089] Other example implementations (e.g., methods and computer-readable media related to the foregoing implementations) can be described below. The features, functions, and advantages that have been discussed can be implemented independently in various implementations or can be implemented in combination with other implementations, and additional details can be found in the following description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0090] Some implementations of the present disclosure will now be described, by way of example only, with reference to the attached drawings. On all drawings, like reference numbers will be used to refer to like elements or parts throughout.

[0091] Figure 1 is a block diagram of a fastener installation system in accordance with example implementations.

[0092] Figure 2 is a flowchart illustrating a method of monitoring installation of fasteners in accordance with example implementations.

[0093] Figures 3 to 12 is an end-of-line machine of a fastener installation system that tracks nose position to evaluate fastener installation in accordance with example implementations.

[0094] Figure 13 is an end-of-line machine of a fastener installation system that includes a range-finding sensor in accordance with example implementations.

[0095] Figure 14 is a chart illustrating a relationship between pressure, position, and time during fastener installation in accordance with example implementations.

[0096] Figure 15 is a flowchart of a method of aircraft manufacturing and service in an example implementation.

[0097] Figure 16 is a block diagram of an aircraft in an example implementation. DETAILED DESCRIPTION

[0098] The accompanying drawings and following description provide a specific example implementation of the present disclosure. Thus, it will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within its scope. Furthermore, any examples described herein are intended to help illustrate the principles of the present disclosure and are thus to be construed as not limiting to the specifically recited examples and conditions. As a result, the present disclosure is not limited to the specific implementations described below, but includes all alternatives, modifications, and equivalents falling within the scope of the claims and equivalents thereof.

[0099] Figure 1is a block diagram of a fastener installation system 100 in an illustrative embodiment. The fastener installation system 100 can include a platform that carries a bias collar installer for a locking bolt, or can include any other suitable components and devices for performing swaging to install a fastener (e.g., a locking bolt) in place. The fastener installation system 100 has been enhanced to track the position of a nose 142 of a swaging tool 140. By tracking the position of the nose 142 during a swaging operation, the installation of each fastener can be viewed in a manner that ensures the fastener is installed in a desired manner.

[0100] In this embodiment, the fastener installation system 100 includes a controller 110 that directs the operation of the hydraulic motor 122 and other electronically manageable components of the fastener installation system 100. The controller 110 can be implemented as, for example, custom circuitry, as a hardware processor that executes programmed instructions, or some combination thereof.

[0101] The controller 110 also controls the placement of the foot 180. The foot 180 is used to clean and / or inspect one or more holes 164 drilled in the part 160, prior to insertion of a locking bolt into the holes 164. The foot 180 also applies a vacuum to facilitate clamping for single piece assembly. The foot 180 can include a hollow channel that is placed over the drilled portion of the part 160, and can apply a vacuum that draws loose material from the drilled portion prior to insertion of the locking bolt 170 in place. When the foot 180 contacts the surface 162 of the part 160, a load sensor or other contact sensor coupled with the foot 180 is triggered. Based on the known distance between the foot 180 and the nose 142 of the swaging tool 140, the distance from the nose 142 to the surface 162 can be determined. After the hole 164 is inspected and / or cleaned by the foot 180, the locking bolt 170 is driven through the hole. A collar 150 is set to the finger 144 via the feed arm 148. The collar 150 is placed on the locking bolt 170 by the finger 144, and awaits swaging on the locking bolt 170 via action of the swaging tool 140.

[0102] To perform swaging, controller 110 directs hydraulic motor 122 to actuate swaging tool 140. Pressure generated by hydraulic motor 122 is applied to hydraulic cylinder 126 via hydraulic line 124, and this pressure in hydraulic line 124 is monitored by pressure sensor 130. Changes in pressure cause hydraulic cylinder 126 to move, which in turn drives swaging tool 140. For example, an increase in pressure can cause hydraulic cylinder 126 to move nose 142 of swaging tool 140 into contact with collar 150, which is held in place by fingers 144. Collar 150 is held in place at surface 162 (e.g., the inner mold line (IML)) of part 160, over locking bolt 170, which has been driven through hole 164 in part 160. As part of this process, centerline 152 of collar 150 is brought into alignment with centerline 172 of locking bolt 170. During the swaging operation, nose 142 acts as an anvil to swage collar 150 onto locking bolt 170. Swaging collar 150 onto locking bolt 170 secures parts 160 together and disengages pintail 174 (i.e., the frangible portion of locking bolt 170) from locking bolt 170. When pintail 174 breaks off, nose 142 rebounds slightly in direction R.

[0103] During the swaging process, position sensor 146 acquires measurements indicating the distance D between nose 142 and surface 162, and pressure sensor 130 measures the pressure at hydraulic cylinder 126. Based on these measurements acquired during swaging, controller 110 characterizes each fastener installation. For example, controller 110 can evaluate one or more position measurements over time to determine whether a fastener has been installed as desired. In this embodiment, controller 110 controls the operation of marker 182 (e.g., an applicator of ink, sticker, or other visually distinguishable marking). Marker 182 is used to indicate the location of fasteners that have not been installed as desired, such as fasteners that have been installed out of tolerance. Controller 110 can also track the identifiers or locations of such fasteners for subsequent reporting.

[0104] Will target Figure 2 Discussing illustrative details of the operation of fastener installation system 100. For this embodiment, assume that the fastener installation system has placed collar 150 on surface 162 of part 160 and is waiting for pressure to be applied that will cause nose 142 to swage collar 150 onto locking bolt 170.

[0105] Figure 2 is a flow chart illustrating a method 200 for monitoring fastener installation in an exemplary embodiment. Figure 1The fastener installation system 100 of FIG. 1 describes the steps in the method 200, but those skilled in the art will appreciate that the method 200 can be performed in other systems. The steps in the flowcharts described herein are not comprehensive and can include other steps not shown. The steps described herein can also be performed in alternative orders.

[0106] In step 202, the controller 110 determines an initial distance between the nose 142 of the swage tool 140 and the IML (e.g., the surface 162) of the part 160. The initial distance is determined prior to initiating the swaging operation. For example, the initial distance can be determined when the foot 180 contacts the surface 162 based on a known separation between the tip of the foot 180 and the tip of the nose 142. In another example, the initial distance can be measured via a range-finding sensor, such as a laser or ultrasonic range-finding sensor. In one implementation, the distance measurement of the nose 142 is determined based on (clamped position - panel data indicating the position of the surface 162 + known position of the swage tool based on the clamped position + a constant).

[0107] In step 204, the controller operates the swage tool 140 to swage the collar 150 onto the fastener (e.g., the captive bolt 170) protruding through the IML. During this operation, the change in position of the nose 142 is continually sampled at a known rate (e.g., every 5 milliseconds, every 20 milliseconds, etc.) based on input from the hydraulic cylinder 126 or a range-finding sensor at the swage tool 140 (e.g., an implementation of the position sensor 146). The measurements of the position of the nose 142 can indicate the distance to the surface 162 of the part 160, can indicate the distance traveled by the nose 142 during swaging, or other parameters that can be used to infer the amount of distance the nose 142 has advanced on the collar 150 during swaging. The controller 110 stores these position measurements in internal memory. As the hydraulic motor 122 runs, the pressure in the hydraulic system 120 increases, which causes the hydraulic cylinder 126 to extend further outward. The controller 110 also acquires measurements from the pressure sensor 130 as desired (e.g., at a sampling rate corresponding to the position measurement rate).

[0108] In step 206, the controller 110 determines the end-point distance between the nose 142 and the IML during swaging before the shank tail 174 of the fastener breaks off from the fastener. The end-point distance is the shortest distance between the nose 142 and the IML during the swaging operation. The end-point distance can be determined a posteriori (i.e., after the shank tail has broken off) based on a regression analysis of the pressure and the position measurements acquired during swaging. The controller 110 can analyze the hydraulic readings to identify the point in time at which the shank tail of the fastener breaks off and determine the distance D between the nose and the IML at that point in time.

[0109] When the pin tail breaks off, the pressure measurement forms a detectable peak-valley pattern. According to this pattern, since the nose 142 is at the time of pin tail breaking off, Figure 1 The nose 142 rebounds in the direction R of the swaging direction, causing the pulling pressure (i.e., the pressure applied to the hydraulic line 124 during swaging as the nose 142 advances toward the surface 162) (which was already increasing) to rapidly decrease and then rapidly increase to a peak value. For example, the controller 110 may detect a point in time when the pressure decreases at a rate exceeding 100 PSI per second over a 50 millisecond period, interpreting this point in time as an indication of pin tail breakage. The controller 110 may then identify the peak value before the pressure decreases and determine the endpoint distance based on the nose position at the first point in time at which the peak value is reached. In other examples, the controller 110 may proceed backward from the first point in time until reaching a second point in time at which a pressure threshold is reached. The pressure threshold may be a predetermined value indicating a minimum pressure at which the pin tail may break, or may be 5 to 10 percent less than the minimum pressure, or 5 to 10 percent less than the detected peak pressure. The controller 110 may then determine the distance between the nose 142 and the IML at the second point in time. Therefore, during operation, the controller 110 utilizes the pressure readings to determine the point in time at which the endpoint distance is measured.

[0110] In step 208, the controller 110 concludes a fastener installation status of the fastener being installed based on the endpoint distance measured at the time indicated by the pressure measurement. For example, if the endpoint distance is less than a threshold amount, the controller 110 concludes that the fastener installation has been successfully completed. If the endpoint distance is not less than the threshold amount, the controller 110 concludes that the fastener installation has not been successfully completed. The threshold distance amount can be, for example, 0 mm, less than 2 mm, or any other suitable predetermined distance indicating that the nose 142 has fully swaged the collar 150 into position within tolerance.

[0111] In step 210, the controller 110 reports the fastener installation status for review. This can include the controller 110 providing the fastener installation status in a digital report for review by a technician via a display (e.g., screen), generating and sending or printing a document indicating the fastener installation status, etc. In one implementation, a large number of fasteners are installed within each of a plurality of segments of an aircraft being assembled, and the controller 110 provides a report for each segment indicating the fastener installation status for each fastener in that segment. In other implementations, the controller 110 reports the fastener installation status by activating a marker 182 at the nose 142 that applies a marking fluid (e.g., bright ink) directly onto the collar 150 and / or fastener to indicate the presence of an unsuccessful fastener installation. This facilitates the fastener being locatable for manual review and distinguished from other fasteners installed in the same area. In other implementations, the controller immediately alerts a technician when an out-of-tolerance condition is detected via a visual image and / or audio indication on a screen. Steps 206-208 and / or 210 can be performed in real-time for each fastener before the next fastener is installed.

[0112] The method 200 provides technical benefits over the prior art because it enables detection of conditions that previously had to be manually inspected using manually placed gauges (e.g., “go-no-go gauges”), and because the method 200 performs this detection without requiring specialized or expensive vision-sensing equipment (e.g., cameras).

[0113] Figures 3 to 12 A picture of an inner mold line machine of a fastener installation system that tracks nose position via a pressure sensor is illustrated in accordance with an illustrative implementation. Specifically, Figure 3 A swage tool 300 is illustrated being held above a part 350 (e.g., a lap joint between skin panels 354) in which a fastener is to be installed. For enhanced clarity, fingers of the swage tool 300 are not shown, but the fingers hold the collar 330 in place at the nose 310. As Figure 3 shown, the feed arm 340 has supplied the collar 330 to the nose 310 of the swage tool. The press foot 320 is disposed proximate the nose 310 and can be actuated to be placed on the IML 352 of the part 350. The nose 310 has a top end 312 and the press foot 320 has a top end 322.

[0114] In Figure 4 , the feed arm 340 has been retracted, which prepares the nose 310 to perform swaging by removing components that would otherwise cause physical interference. In Figure 5 , the press foot 320 is driven downward until the top end 322 is placed in contact with the part 350. The swaging Figure 5the distance (Dl) between the nose 310 and the part 350 is determined. The foot 320 is applying a vacuum that holds it in place on the IML 352. The contact between the foot 320 and the IML 352 triggers the load cell 610 at the swage tool 300. After the load cell 610 is triggered, the position of the foot 320 is determined based on the current extension of the foot 320 from the retracted position as depicted in Figure 4 , for example, as indicated by the actuator for the foot 320. Based on the position of the tip 322 of the foot 320 and the known separation between the tip 322 and the tip 312, the initial distance (Dl) between the tip 312 of the nose 310 and the IML 352 is determined in Figure 5 . In Figure 6 , while the vacuum is applied, an outer mold line (OML) machine (not shown) drills a hole 600 at the part 350. The resulting debris from the drilling is removed via the vacuum applied by the foot 320. In Figure 7 , the foot 320 is retracted, and in Figure 8 , the swage tool 300 is repositioned laterally to align the nose 310 with the hole 600. In Figure 9 , the nose 310 is driven down until the collar 330 is placed in contact with the IML 352 while the collar 330 is still axially aligned with the hole 600 such that the centers of both are on the axis 900.

[0115] In Figure 10 , the fastener 1000 is driven through the hole 600 and the collar 330 such that the shank tail 1010 of the fastener enters the nose 310. Then, the hydraulic motor is activated, and the nose 310 advances over the collar 330 to swage the collar 330 in place on the fastener 1000 as shown in Figure 11 . This results in the lip 1120 at the collar 330, and also causes the shank tail 1010 to break off from the fastener 1000. The controller of the swage tool 300 determines the moment at which or before the shank tail 1010 is broken off the position of the nose 310 (e.g., as indicated by the actuator for the nose 310). Based on this position, the end point distance (D2) of the nose 310 from the IML 352 is determined. If the end point distance is less than a threshold, then the fastener has been installed as desired. In Figure 12 , the swage tool 300 is retracted, leaving the fastener 1000 in place.

[0116] With the above-provided discussion regarding the exemplary technique for fastener installation, Figure 13 other possible implementations of a swage tool are illustrated that include an active distance measuring sensor, such as a laser or LIDAR sensor, and Figure 14Pressure and position measurements that can be used to determine whether fastener installation has been successfully performed are illustrated.

[0117] Figure 13 An in-mold liner machine including a distance measuring sensor 1310 according to an illustrative embodiment of a fastener installation system is illustrated. In this embodiment, the swage tool 1300 includes a distance measuring sensor 1310 in the form of an infrared, ultrasonic, or laser distance measuring sensor that measures the distance (D) to the lap panel 1320. By comparing the distance initially measured by the distance measuring sensor 1310 before the swaging begins and just before the pin tail of the fastener has been broken, the controller of the swage tool 1300 can determine whether swaging has been successfully completed for the fastener. The difference between the initial distance (e.g., D1 discussed in the previous figures) and the end distance (e.g., D2 discussed in the previous figures) can be compared, and if the difference is less than the desired amount indicated in the design parameters, the swaging operation can be flagged as out of tolerance. In other embodiments, the swage tool 1300 is coupled with a sensor in the form of a force measuring sensor that detects the distance by reporting when the nose of the swage tool 1300 contacts the IML of the part (i.e., by reporting a distance of 0 between the nose and the IML).

[0118] Figure 14 A graph illustrating the relationship between pressure, position, and time during fastener installation according to an illustrative embodiment is illustrated. Figure 14 Position 1410, pull pressure 1420, and return pressure 1430 measured for a swage tool over time are illustrated. The controller of the swage tool can retrospectively determine whether the swaging was performed in the desired manner by looking at the pull pressure 1420 at the first point in time (P1) at which the pressure (due to the physical springback after the pin tail breaks) sharply drops and then rises again. The controller can then determine the position of the nose of the swage tool at the first point in time or at a second point in time (P2) before the first point at which the pressure is less than a predefined threshold (e.g., five to ten percent less than the minimum break pressure of the known pin tail).

[0119] In one embodiment, the swage nose position is calculated by the following equation:

[0120] (1) Swage Nose Position = Clamping Axis Position - Panel Datum + Swage Tool Position + System Bias Constant

[0121] According to this equation, the "Panel Datum" is measured as the initial distance discussed above, the clamping axis is Figure 5The "system bias constant" is calculated by comparing the controller measurements to a set of direct inspection measurements of the holes, in the direction indicated by the arrows in FIG. 6, and is selected to minimize the difference between the T-distance value and the measured T value of the swage collar (T is based on the position of the nose of the swage at or before the pressure threshold pin tail pops out). Thus, the "system bias constant" is a calibration factor. In one embodiment, the nose position data is filtered out during and / or after the pin tail breaks. Note that the equation assumes all axes are oriented in the same direction for simplicity.

[0122] Example

[0123] In the following examples, additional processes, systems, and methods are described in the context of a fastener installation system.

[0124] With more particular reference to the drawings, embodiments of the disclosure can be described in the context of an aircraft manufacturing and service method 1500 as shown in FIG. 15 and an aircraft 1502 as shown in FIG. 16. During pre-production, the method 1500 can include specification and design 1504 of the aircraft 1502 and material procurement 1506. During production, component and subassembly manufacturing 1508 and system integration 1510 of the aircraft 1502 takes place. Thereafter, the aircraft 1502 can go through certification and delivery 1512 in order to be placed in service 1514. While in service 1514 by a customer, the aircraft 1502 is scheduled for routine maintenance and service 1516, which can also include modification, reconfiguration, refurbishment, and / or the like. Figure 15 Figure 16 During pre-production, the method 1500 can include specification and design 1504 of the aircraft 1502 and material procurement 1506. During production, component and subassembly manufacturing 1508 and system integration 1510 of the aircraft 1502 takes place. Thereafter, the aircraft 1502 can go through certification and delivery 1512 in order to be placed in service 1514. While in service 1514 by a customer, the aircraft 1502 is scheduled for routine maintenance and service 1516, which can also include modification, reconfiguration, refurbishment, and / or the like.

[0125] Various processes of the method 1500 can be performed or executed by system integrators, third parties, and / or operators (e.g., customers). For the purposes of this description, a system integrator can include, without limitation, any number of aircraft manufacturers and major system subcontractors; a third party can include, without limitation, any number of suppliers, subcontractors, and vendors; and an operator can be an airline, lease company, military entity, service organization, and / or the like.

[0126] As Figure 16 ​As shown in FIG. 15, an aircraft 1502 produced using the method 1500 can include a fuselage 1518 having a plurality of advanced systems 1520 and an interior 1522. Examples of systems 1520 include one or more of a propulsion system 1524, an electrical system 1526, a hydraulic system 1528, and an environmental system 1530. Any number of other systems can be included. Although an aerospace example is shown, the principles of the present application can be applied to other industries such as the automotive industry.

[0127] As already mentioned above, the apparatus and methods embodied herein can be employed during any one or more of the stages of production and maintenance described in the method 1500. For example, components or subassemblies corresponding to component and subassembly manufacturing 1508 can be fabricated or manufactured with similar equipment as that used in the production of the aircraft 1502 while the aircraft 1502 is in service. Further, the apparatus embodiments, method embodiments, or a combination thereof can be employed during the subassembly manufacturing 1508 and system integration 1510 stages to, for example, expedite assembly of the aircraft 1502 or to reduce the cost of the aircraft 1302. Similarly, one or more of the apparatus embodiments, method embodiments, or a combination thereof can be utilized during the in-service 1514 stage, for example, without limitation, maintenance and service 1516. For example, technologies and systems described herein can be used for material procurement 1506, component and subassembly manufacturing 1508, system integration 1510, in-service 1514, and / or maintenance and service 1516, and / or can be used for the fuselage 1518 and / or interior 1522. These technologies and systems can even be used for systems 1520, including, for example, propulsion system 1524, electrical system 1526, hydraulic system 1528, and / or environmental system 1530.

[0128] In one embodiment, a part includes a portion of the fuselage 1518 and is manufactured during the component and subassembly manufacturing 1508. The part can then be assembled onto an aircraft during the system integration 1510 and then utilized during the in-service 1514 until wear renders the part unusable. The part can then be discarded and replaced with a newly manufactured part during the maintenance and service 1516. To install fasteners during the manufacturing of the new part, the components and methods of the present application can be utilized throughout the component and subassembly manufacturing 1508.

[0129] Any of the various control elements (e.g., electrical or electronic components) shown in the figures or described herein can be implemented as hardware, software implemented processor, software implemented processor, or some combination thereof. For example, an element can be implemented as dedicated hardware. Dedicated hardware elements can be referred to as "processors", "controllers" or some similar terminology. When provided by a processor, these functions can be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which can be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and can implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), or other circuitry, field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), nonvolatile memory, logic or some other physical hardware component or module.

[0130] Additionally, a control element can be implemented as instructions executable by a processor or computer to perform the function of the element. Some examples of instructions are software, program code, and firmware. The instructions, when executed by the processor, are operable to direct the processor to perform the function of the element. The instructions can be stored on a storage device readable by the processor. Some examples of storage devices are digital or solid state memory, magnetic storage media such as diskettes and tape, hard drives, or optical storage media.

[0131] Although specific embodiments were described herein, the scope of the disclosure is not limited to those specific embodiments. The scope of the disclosure is defined by the following claims and any equivalents thereof.

Claims

1. A method for inspecting installation of a fastener, the method comprising the steps of: determining an initial distance between a nose of a swage tool and an inner mold line, IML, of a part (202); operating the swage tool to swage a collar onto a fastener protruding through the IML of the part (204); determining an end point distance between the nose and the IML during swaging before a shank break of the fastener (206); and deriving a conclusion indicative of a fastener installation status based on the end point distance (208), wherein: determining the end point distance comprises the steps of: analyzing hydraulic readings to identify a time point of the shank break of the fastener; and determining a distance between the nose and the IML at the time point.

2. The method of claim 1, wherein: determining the initial distance comprises the steps of: placing a tip of a presser foot of the swage tool in contact with the IML; determining a separation between the tip of the presser foot and a tip of the nose; and determining the initial distance based on the separation between the tip of the presser foot and the tip of the nose.

3. The method of claim 1 or 2, wherein, determining the end point distance comprises the steps of: analyzing hydraulic readings to identify a first time point of the shank break of the fastener; identifying a second time point at which hydraulic pressure reaches a threshold value before the first time point; and determining a distance between the nose and the IML at the second time point.

4. The method of claim 1 or 2, further comprising the steps of: performing the steps of determining the end point distance and deriving the conclusion in real time before installation of a next fastener.

5. The method of claim 1 or 2, wherein: deriving a conclusion indicative of the fastener installation status comprises the steps of: deriving a conclusion that fastener installation has been successfully completed if the end point distance is less than a threshold amount; and deriving a conclusion that fastener installation has not been successfully completed if the end point distance is not less than a threshold amount.

6. The method of claim 1 or 2, wherein: reporting the fastener installation status comprises the steps of: including the fastener installation status in a report detailing fastener installation status for a plurality of fasteners within a region of the part; and providing the report for viewing by a technician via a display.

7. The method of claim 1 or 2, further comprising the step of: reporting the fastener installation status for viewing.

8. A portion of an aircraft assembled according to the method of any of the preceding claims 1-7.

9. An apparatus for inspecting installation of a fastener, the apparatus comprising: a swage tool (140) comprising: a nose (142) to swage a collar (150) onto a fastener; a hydraulic cylinder (126) to drive the nose; a finger (144) to hold a collar in place at the fastener before swaging; and a display (128) to report a fastener installation status. a sensor (146) that measures an end-point distance between the nose and an inner mold line, IML, of a part (160) that receives the fastener, the apparatus further comprising: a controller (110) that derives a conclusion indicative of a fastener installation state based on the end-point distance, and reports the fastener installation state for review, wherein the controller is capable of analyzing the hydraulic readings to identify a time point of a pin tail breakage of the fastener, and determine a distance between the nose and the IML at the time point.

10. The apparatus of claim 9, wherein: the controller derives the conclusion indicative of the fastener installation state by deriving a conclusion that fastener installation has been successfully completed if the end-point distance is less than a threshold amount, and deriving a conclusion that fastener installation has not been successfully completed if the end-point distance is not less than the threshold amount.

11. The apparatus of claim 9, wherein: the sensor includes a load cell that detects contact between the swage tool and the IML.

12. The apparatus of claim 11, wherein: the swage tool further includes a foot (180), and the sensor is coupled with the foot to detect contact between the foot and the IML.

13. Manufacturing a portion of an aircraft using the apparatus of claim 9.

Images