Low-cost, high-performance multi-head drill and fill machine

Abstract

To provide a low-cost, low-complexity system for rapid throughput of assemblies.SOLUTION: There is provided a manufacturing system employing a bifurcated backbone having an upper plate and lower plate, with a longitudinal slot between the upper and lower plates. Multiple actuator groups are mounted longitudinally adjacently the slot. A carrier supports a panel for longitudinal translation into the slot, and the carrier is configured to pulse longitudinally in the slot relative to the multiple actuator groups during a sequence of fabrication operations by the multiple actuator groups on the panel.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates generally to the field of structural assembly systems, and more specifically to a drill and fill machine having multiple actuator stations aligned for linear pulse transfer flow motion on a structural element. [Background technology]

[0002] The manufacturing of commercial aircraft and other large structures is typically modularized to accommodate assembly operations. Using commercial aircraft as an example, many structural elements need to be riveted assemblies, often using thousands of rivets. The assembly needs to be drilled to accept the rivets, the rivets inserted, and then backed up. For automated manufacturing, many typical operations include highly complex robotic heads with 3D placement capabilities and end effectors for the heads that use multiple tooling systems such as automated vision systems for placement, hole drilling systems, rivet or fastener feeding systems, and rivet fastening or rivet backing systems. Summary of the Invention [Problem to be solved by the invention]

[0003] To accommodate the various fastener size requirements with a common robotic head, an automatic tool changer is typically used. The cost and complexity of such systems are both high. Furthermore, the separate drilling and fastener insertion processes typically result in only 5-7 fasteners per minute being completed with a robotic system due to the time required. A riveted assembly with thousands of rivets may take 10 hours or more to complete. It is therefore desirable to provide a low-cost, low-complexity system to speed up the throughput of assemblies. [Means for solving the problem]

[0004] An exemplary implementation provides a manufacturing system that uses a bipartite backbone having an upper plate and a lower plate with a longitudinal slot between the upper plate and the lower plate, a plurality of actuator groups are mounted longitudinally adjacent the slot, and a carrier supports a panel for longitudinal translational movement into the slot, the carrier configured to pulse longitudinally within the slot relative to the plurality of actuator groups during a sequence of assembly operations by the plurality of actuator groups on the panel.

[0005] An exemplary implementation provides a method for assembling panels by inserting the panels into a multi-head drill-and-fill (MDF) machine having a bipartite backbone with a longitudinal slot for receiving the panels. The panel is moved clockwise to align a plurality of actuator groups with the stringers of the panel. The panel is translated longitudinally to pulse move position 1. Each drill of the actuator group is used to drill a hole in the stringer and skin. The panel is pulsed longitudinally one position to pulse move position 2, a first rivet is inserted with each rivet feed of the actuator group and a second hole is drilled with each drill. The panel is pulsed longitudinally one position to pulse move position 3, a first rivet is engaged and fastened to each of the aligned fasteners and each of the backing bars of the actuator group, a third hole is drilled with each drill, and a second rivet is inserted with each rivet feed. The minute panel is pulsed one position in the longitudinal direction to pulse movement position 4, a fourth hole is drilled using each of the drills, a third rivet is inserted using each of the rivet supplies, and a second rivet is engaged and fastened to each of the fasteners and each of the backing bars. The minute panel is then pulsed one position in the longitudinal direction to pulse movement position 5, a fifth hole is drilled using each of the drills, a fourth rivet is inserted using each of the rivet supplies, and a third rivet is engaged and fastened to each of the fasteners and each of the backing bars. The minute panel is pulsed one position in the longitudinal direction to pulse movement position 6, a sixth hole is drilled using each of the drills, a fifth rivet is inserted using each of the rivet supplies, and a fourth rivet is engaged and fastened to each of the fasteners and each of the backing bars. The panel is pulsed longitudinally one position to pulse move position 7, a sixth rivet is inserted using each of the rivet supplies, and a fifth rivet is engaged and tightened using each of the fasteners and each of the bucking bars. The panel is pulsed longitudinally one position to pulse move position 8, and the fasteners and bucking bars are manipulated to tighten the sixth rivet.

[0006] The described features, functions, and advantages can be realized independently in various implementations or can be combined in yet other implementations, further details of which can be understood with reference to the following description and drawings. [Brief description of the drawings]

[0007] [Figure 1] 1 is an exemplary commercial aircraft fuselage having multiple panels included in an assembly. [Diagram 2] FIG. 2 is a cross-sectional view illustrating an exemplary skin panel disposed on a fuselage. [Diagram 3] 1 is a detailed illustration of an exemplary skin panel. [Figure 4] 1 is an illustration of a support backbone and actuator for use in a drill and fill station incorporating an exemplary implementation. [Diagram 5] FIG. 2 is a detailed enlarged view of an example actuator used in an implementation. [Figure 6] 1 is an illustration of a panel engaged with a drill and fill station. [Figure 7] 1 is a close-up view of the engaged panels. [Figure 8] FIG. 13 is an end view of the engaged panels. [Figure 9] FIG. 13 is a detailed close-up view of the panel positioned for drilling, rivet feeding and backing. [Figure 10] FIG. 13 is an end view of the engaged panels in a clockwise translation position. [Figure 11] 1 is a diagram of a manufacturing cell supporting a drill and fill station. [Figure 12] 1 is an illustration of a carrier for supporting and positioning panels within a drill and fill station and cell. [Figure 13] 1 is an illustration of the carrier in a closed position. [Figure 14] FIG. 2 is an end view of a carrier supporting a panel, including details of a panel roller system. [Figure 15] 1 is a diagram of a carrier that supports a panel for placement in a cell. [Figure 16] 1 is an illustration of a carrier within a cell undergoing a drill-and-fill operation. [Figure 17] FIG. 4 is a block diagram of a control system for the actuator groups and carriers. [Figure 18A] 1 is a flowchart of a method of hybrid additive manufacturing using an exemplary implementation. [Figure 18B] 1 is a flowchart of a method of hybrid additive manufacturing using an exemplary implementation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Implementations described herein provide a multi-head drill and fill (MDF) machine with multiple actuator groups, each actuator group having a drill, a rivet supply, and a fastener with a bucking bar aligned in linearly adjacent positions for sequential operation on a panel. The actuator groups are supported by a bipartite backbone through which a panel is inserted with a carrier. The carrier incorporates a roller system that engages the panel for clockwise movement. The carrier is pulsed to position each actuator of the actuator group and is longitudinally translatable for simultaneous operation of the actuators of each actuator group.

[0009] Referring to the drawings, FIG. 1 shows an aircraft fuselage 10 with multiple skin panels 12 as an example of panels that the present implementations can be used to assemble. FIG. 2 shows a cross-section of a fuselage with one exemplary panel 12 shown exaggerated for clarity. Each panel has a skin 14 supported by multiple frames 16 and longitudinal stringers 18, as shown in FIG. 3. For assembly operations using the implementations described herein, the frames 16 and stringers 18 are adhesively bonded to the skin to maintain their orientation and alignment. Bonding the frames 16 and stringers 18 temporarily fixes the alignment of the elements of the panel 12 and allows for precise drilling and fastening. Additionally, bonding prior to processing prevents debris, such as shavings, dust, burrs, or other processing residues, from being trapped between the skin 14 and the frames 16 and stringers 18.

[0010] An exemplary implementation of an MDF machine 20 is shown in FIG. 4. A bipartite backbone 21 having an upper plate 22 and a lower plate 24 with a slot 25 extending longitudinally (illustrated by arrow 100) between the upper and lower plates provides a strong, stiff and stable structure that supports a number of longitudinally spaced actuator groups 26 attached to the upper and lower plates adjacent the slot 25. In an exemplary implementation, the backbone 21 is a 1 inch thick, 28 foot long, 4 foot high steel plate, supported by 14 inch I-beam stiffeners 23 (attached to the plate on the opposite surface from the actuator groups, as shown only in FIG. 8) to maintain a delta Z of less than 0.005 inches per side during riveting, as will be described later. In alternative implementations, the backbone 21 may be a steel truss, aluminum plate, CFRP plate, or similar rigid material with C-channel or other stiffener configurations. In an exemplary implementation, each actuator group 26 has a drill 28 attached to the lower plate 24, a rivet supply 30 attached to the upper plate 22, and a fastener 32 attached to the lower plate 24 with an aligned bucking bar 34 attached to the upper plate 22, as shown in FIG. 5. The drill 28 is attached to the lower plate 24 to allow for vertical dropping of shavings and other debris. However, in alternative implementations, the arrangement of the various elements of the actuator group may be reversed. In an exemplary implementation, the actuators are hydraulically actuated. The actuators of each actuator group 26, the drill 28, the rivet supply 30, and the fastener / bucking bar (32, 34), function in a pulse movement motion. The panel 12 is inserted into a slot 25 between the upper plate 22 of the backbone 21 and the lower plate 24 of the backbone 21, as shown in FIGS. 6-9.As will be described in more detail below, a carrier 38 (shown in FIG. 12 ) supports the panel 12 and is configured for longitudinal translational movement into the slot 25 and is further configured for pulse movement relative to the slot at incremental predetermined pulse movement widths during a sequence of assembly operations on the panel 12 by the plurality of actuator groups 26. The carrier 38 further moves the panel 12 clockwise, relative to the plurality of actuator groups 26, to a plurality of clockwise movement positions, each clockwise movement position enabling alignment of actuators of the actuator group with structural elements on the skin 14, which in the illustrated example are stringers 18 for the fastener rows.

[0011] As shown in FIG. 5, the elements of each actuator group 26 are spaced apart by pulse travel width 40, and each actuator group is spaced apart by an aperture width 41, which is equal to three pulse travel widths. The pulse travel width 40 is determined by the design spacing of the rivets in the panel 12. In an exemplary implementation, the spacing between the actuator groups and the spacing between the elements of each actuator group is determined by the frame spacing to ensure hole alignment with the frame during clockwise movement. The number of pulse travels between frames is derived by the fastener pitch, frame spacing, and fastener diameter. A typical pitch is usually 1 to 1.5 inches. In operation, the carrier inserts the panel 12 into the slot 25 to a first longitudinal alignment position, as shown in FIG. 8 and FIG. 9, to move the panel 12 clockwise to align a selected stringer 18a with the actuator group and place it in pulse travel position 1. Each drill 28 in the first plurality 27a of actuator groups 26 drills a hole in the stringer 18 and the skin 14. The rivet fastener 32 and bucking bar 34 are not actuated in position 1. The panel 12 is then pulsed longitudinally one position to position 2 where the rivet supply 30 is now aligned with the first drill hole and inserts the first rivet. The drill 28 in the first plurality of actuator groups 26 drills a second hole. The rivet fastener 32 and bucking bar 34 are not actuated in position 2. The panel is then pulsed longitudinally one position to position 3 where the aligned fastener 32 and bucking bar 34 engage and fasten the first rivet. The drill 28 in the first plurality of actuator groups 26 drills a third hole and the rivet supply 30 inserts the second rivet. The panel is then pulsed longitudinally one position to position 4, the drills 28 in the actuator group 26 of the first plurality 27a each drill a fourth hole, the rivet supply inserts a third rivet, and the fastener 32 and bucking bar 34 engage and tighten the second rivet.The panel is then pulsed to position 5 where each of the drills 28 drills a fifth hole while each of the rivet supplies 30 inserts a fourth rivet and each of the fasteners and each of the bucking bars engages and tightens the third rivet. The panel is then pulsed to position 6 where each of the drills 28 drills a sixth hole while each of the rivet supplies 30 inserts a fifth rivet and each of the fasteners and each of the bucking bars engages and tightens the fourth rivet. Note that the first, second and third rivets are in positions 4-6 during pulse movements 4-6 and are therefore within the aperture width 41 and are not engaged during any of the actuator group movements. The sequence is completed by a seventh pulsing movement involving actuation of the rivet supply and fastener / bucking bar to insert the sixth rivet and only set the fifth rivet, and an eighth pulsing movement involving actuation of the fastener 32 and bucking bar 34 to only set the sixth rivet.

[0012] In an exemplary implementation (see, e.g., FIG. 6), additional actuator groups 27b and 27c are shown to illustrate that various panel lengths may be accommodated by additional actuator groups for longer panels and a reduced number of actuator groups (of the initial plurality 27a) for shorter panels 12. The number of actuator groups 26 in the plurality of actuator groups is determined by dividing the length 101 of the panel 12 by six pulse travel widths, which in turn are determined by the design of the rivet spacing in the panel.

[0013] In alternative implementations that accommodate other types of fasteners, the rivet feeder, fastener, and bucking bar may be replaced with actuators appropriate for the type of fastener, such as a bolt feeder and a nut torque system. Additionally, in alternative implementations, the number of actuators in each actuator group may vary depending on the number of operations in the assembly sequence for each fastener, with the number of pulse movement positions being equal to the number of actuators. The aperture width between the actuator groups is similarly equal to the number of pulse movement positions associated with the actuator group. The number of excess pulse movements to complete the assembly of the last inserted fastener is equal to the number of actuators minus one. The individual elements of the actuator group are modular, allowing for rapid replacement of actuator group element types and sizes. The top plate 22 and bottom plate 24 of the backbone 21 may be pre-drilled or have a quick connect fastening system to accommodate replacement of actuator group elements.

[0014] Once the rivet row has been worked, the panel 12 is withdrawn eight pulse widths and moved clockwise to another stringer 18b as shown in Figure 10, where the six pulse sequence is repeated. Once all clockwise positions have been worked, the panel 12 is complete and withdrawn from the MDF machine 20.

[0015] To provide support for the MDF machine 20, the assembly cell 50 shown in FIG. 11 incorporates a concrete slab floor 52 supporting vertical concrete walls 54. A plurality of trusses 56 extend between the walls, and the top plate 22 is supported by the trusses. In the exemplary implementation, the trusses 56 are steel, and the top plate 22 is welded between opposing truss segments 57a and 57b for vertical suspension. The bottom plate 24 is supported by concrete A-pillars 58 attached to the floor 52. A plurality of longitudinally oriented rails 60 extend from the floor 52.

[0016] FIG. 12 shows the carrier 38 resting on rails 60 for longitudinal translational movement. A frame 62 is attached to a base having two side plates 64, 66 separated by a channel 68 sized to receive an A-pillar 58, with the frame 62 providing rigidity to the separated plates. A plurality of internal support fixtures 70 extend from the side plates 64, 66. The internal support fixture 70 has a vertical post 72 that supports two bisected arcuate arms 74 separated by a channel 75 in which the lower plate 24 is received. A plurality of motorized wheel assemblies 76 extend radially outward from the arcuate arms 74. The panel 12 is received on the motorized wheel assemblies 76. The motorized wheel assemblies engage the underside of the skin 14 with wheels 77, actuation of which causes the panel 12 to move in a clockwise direction.

[0017] The arcuate outer support fixtures 78 extend from a frame 80 rotatably mounted to the peripheries 82, 84 of the side plates 64, 66. The frame 80 is rotatable between an open position and a closed position. The pair of outer support fixtures 78 support a number of rollers 86 which, in the closed position, engage the outer surface of the skin 14 of the panel 12 and act as counteracting idler rollers to maintain frictional engagement by the motorized wheel assembly 76. With the outer support fixtures 78 rotated to the open position, as shown in FIG. 12, the panel 12 is inserted onto the wheel assembly of the inner support fixture. The outer support fixtures 78 are then rotated to the closed position, as shown in FIG. 13. When closed, the outer support fixtures 78 maintain a channel 79 in which the top plate 22 is received. Each of the motorized wheel assemblies 76 is retractable on an extension arm 81 so as to avoid interference between each of the motorized wheel assemblies 76 and the stringer 18 when the panel 12 is moved clockwise, as shown in FIG. 14. The arcuate arms 74 are longitudinally spaced apart to be received between the frames 16 of the panels 12.

[0018] Once loaded with the panel 12, the carrier 38 is ready for longitudinal translation into the assembly cell 50 for operation by the MDF machine 20, as shown in FIG. 15. As it translates into the cell and the MDF machine, as shown in FIG. 16, the previously described pulsing operation is performed. Upon completing the riveting sequence operations, the carrier is withdrawn from the cell 50 and the external support fixture 78 is rotated to the open position shown in FIG. 12 and the panel 12 is removed. The longitudinal translation of the carrier 38 on the rails 60 is achieved by wheeled supports on the side plates 64, 66 or by low friction air bearings. In alternative implementations, electrical or hydraulic actuation may be employed for longitudinal translation and longitudinal pulsing of the carrier 38 during the assembly sequence.

[0019] Control of the elements of the exemplary implementation is accomplished using a microprocessor-based controller 90, as shown in FIG. 17. The controller 90 issues control signals to the carrier 38 and the actuator groups 26 to control the pulsing operations. As described in the previous sequence of operations, the actuator groups 26 operate in combination during most pulsing steps, with only individual control of the actuator group elements at the first three pulsing positions and the last two pulsing positions. A command bus 92 to each of the actuator groups provides this functionality. The controller provides command signals 94 to open and close the external support fixtures to insert the panel onto the carrier and to extract the panel from the carrier when the assembly operation is completed. Command signals 96 are issued by the controller 90 to request longitudinal translation of the carrier into and out of the cell, as well as coordinated pulsing of the carrier through the eight pulsing positions.

[0020] A method 1800 for assembling a panel 12 using an MDF machine and assembly cell 50 is shown in Figures 18A and 18B. In step 1802, the panel 12 is placed on a carrier 38 having an inner support fixture 70 with bisecting arcuate arms 74 and a radially extending motorized wheel assembly 76 that engages the inner surface of the skin 14. In step 1804, a rotatably mounted concentric arcuate outer support fixture 78 is closed to engage the outer surface of the panel skin with rollers 86. In step 1806, the carrier translates longitudinally into the assembly cell 50 and the panel 12 is inserted into the MDF machine 20, which has a bisecting backbone 21 with longitudinal slots 25 for receiving the panel. In step 1808, the motorized wheel assembly is actuated to move the panel clockwise to align the multiple actuator groups 26 with the stringers 18 of the panel. At step 1810, the individual wheel assemblies are retracted to avoid interfering with the stringer during clockwise movement. At step 1812, the carrier is translated longitudinally to place the panel in pulse movement position 1. At step 1814, each drill 28 of the actuator group 26 drills a hole in the stringer 18 and skin 14. The riveting unit 32 and bucking bar 34 are not activated at position 1. At step 1816, the panel 12 is then pulsed longitudinally one position to position 2 where the rivet supply 30 inserts a first rivet and the drill 28 of the actuator group drills a second hole. The riveting unit 32 and bucking bar 34 are not activated at position 2. In step 1818, the panel is then pulsed longitudinally at one position to position 3, the aligned fasteners 32 and bucking bar 34 engage and tighten the first rivet, the drills 28 drill a third hole, and the rivet supply 30 inserts a second rivet. In step 1820, the panel is then pulsed longitudinally at one position to position 4, the drills 28 each drill a fourth hole, the rivet supply inserts a third rivet, and the fasteners 32 and bucking bar 34 engage and tighten the second rivet.In step 1822, the panel is then pulsed to position 5, where each of the drills 28 drills a fifth hole while each of the rivet supplies 30 inserts a fourth rivet, and each of the fasteners and each of the bucking bars engages and tightens the third rivet. In step 1824, the panel is then pulsed to position 6, where each of the drills 28 drills a sixth hole while each of the rivet supplies 30 inserts a fifth rivet, and each of the fasteners and each of the bucking bars engages and tightens the fourth rivet. In step 1826, the panel is then pulsed to position 7, where the rivet supplies and fasteners / bucking bars are activated only to insert a sixth rivet and tighten the fifth rivet. In step 1828, the panel is then pulsed to position 8, where the fasteners 32 and bucking bars 34 are activated only to tighten the sixth rivet. In step 1830, the panel 12 is pulled out eight pulse moves and moved clockwise to another stringer 18b. The eight pulse move sequence of steps 1814-1828 is repeated. In step 1832, once all clockwise move positions have been worked, the panel 12 is finished and the panel 12 is pulled out of the MDF machine 20 by reverse longitudinal translation of the carrier 38. In step 1834, the external support fixture is rotated open and in step 1836 the panel 12 is removed.

[0021] The number of pulse movement operations of the MDF machine can be roughly estimated, and each actuator group is z y The panel has a second plurality of n actuators designated as x, where y=1 to n. The panel is driven by a series of pulses moving positions x q (q=1 to 2n+(n-1)). With actuator z1 at pulse movement position x1, an operation is performed on the panel. The panel is moved to the next position x2, and an operation using actuator z2 is performed on the panel while actuator z1 is operating. Next, the panel is moved to pulse movement position x m The pulse moves through all of (m=3~2n), and the action at each pulse movement position is za executed simultaneously for all actuators (a = series (1~n-m, m < n)). Next, the panel pulse moves over the positions x p with a pulse movement over all of them (p = 2n~2n+n-1), and the operation is performed at each pulse movement position using all z b actuators (b = series (n~n(p-2n))).

[0022] By the operation of the MDF machine using the method described, as shown in the exemplary implementation, up to approximately 50 rivets per minute can be inserted and tightened using 10 actuator groups. Since an exemplary panel generally contains 5000 rivets, the panel can be completed in about 100 minutes, which significantly improves throughput compared to current assembly systems.

[0023] Having described various implementations in detail as required by the patent laws, those skilled in the art will recognize modifications and substitutions to the specific implementations disclosed herein. Such variations are within the scope and spirit of the following claims. In the specification and claims, the terms "comprising," "incorporate," "incorporates," or "incorporating," "include," "includes," or "including," "has," "have," or "having," or "contain," "contains," or "containing" are intended to be non-exclusive descriptions, and additional or equivalent elements may be present. As used herein, the terms "upper" and "lower" are used to describe relative placement and, outside of the specific implementation disclosed, may be replaced with appropriate descriptive terms such as "first" and "second," "top" and "bottom," or "right" and "left," depending on the orientation of the actual implementation. [Explanation of symbols]

[0024] 1-8 Pulse travel position, 10 Aircraft fuselage, 12 Panel, 14 Skin, 16 Frame, 18, 18a, 18b Stringer, 20 MDF machine, 21 Backbone, 22 Upper plate, 23 I-beam stiffener, 24 Lower plate, 25 Slot, 26, 27b Actuator group, 28 Drill, 30 Rivet supply, 32 Fastening, 34 Backing bar, 38 Carrier, 40 Pulse travel width, 41 Opening width, 50 Assembly cell, 52 Concrete slab floor, 54 Vertical concrete wall, 56 Truss, 57a, 57b Truss segment, 58 Concrete A-pillar, 60 Rail, 62 Frame, 64, 66 Side plate, 68 Channel, 70 Internal support fixture, 72 Vertical column, 74 Bow arm, 75 Channel, 76 Motorized wheel assembly, 77 Wheel, 78, external support fixture, 79, channel, 80, frame, 81, extension arm, 82, 84, periphery, 86, roller, 90, controller, 92, command bus, 94, 96, command signal, 100, arrow, 101, length

Claims

1. a bifurcated backbone having an upper plate and a lower plate with a longitudinal slot between the upper plate and the lower plate; a plurality of actuator groups mounted longitudinally adjacent the slot, each actuator group of the plurality of actuator groups having a plurality of actuators that are different from one another; a carrier configured to support a panel for longitudinal translational movement into the slot and to pulse longitudinally within the slot relative to the plurality of actuator groups during a sequence of assembly operations by the plurality of actuator groups on the panel; Equipped with A manufacturing system, wherein identical ones of the actuators of the actuator groups are configured to operate simultaneously at a plurality of aligned longitudinal positions on the panel in each pulse.

2. The manufacturing system of claim 1 , wherein each actuator group of the plurality of actuator groups includes a drill, a rivet supply, and a fastener with which a bucking bar is aligned.

3. The manufacturing system of claim 2 , wherein the carrier is configured to rotationally move the panel relative to the plurality of actuator groups to a plurality of circumferential movement positions.

4. The carrier is The foundation, a plurality of internal support fixtures extending from the base; Equipped with Each of the internal support fixtures is a vertical post supporting the bow arm; a plurality of motorized wheel assemblies extending radially outward from the arcuate arms, the panel being received on the motorized wheel assemblies for providing rotational movement to the panel; The manufacturing system of claim 3 .

5. The carrier is a plurality of arcuate external support fixtures extending from a frame rotatably mounted to the base, the frame being rotatable from an open position to a closed position; Further equipped with 5. The manufacturing system of claim 4, wherein the external support fixture supports a plurality of rollers for engaging the panel as idler rollers that react to maintain frictional engagement by the motorized wheel assemblies.

6. the panel comprises a skin adhesively bonded and supported by a plurality of spaced apart frames and a plurality of longitudinal stringers; a wheel in each of the plurality of powered wheel assemblies contacting an inner surface of the skin; the roller contacts an outer surface of the skin; each of the motorized wheel assemblies having an extension arm; 6. The manufacturing system of claim 5, wherein the extension arm is retractable to continuously avoid interference with the stringer during rotational movement of the panel.

7. The manufacturing system of claim 6 , wherein each of the plurality of circumferential movement positions aligns a stringer with the plurality of actuator groups.

8. Further comprising an assembly cell; The assembly cell comprises: a concrete slab floor supporting a vertical concrete wall; a plurality of trusses extending between the walls, the top plate of the backbone being supported by the trusses; a concrete A-pillar attached to the floor supporting the lower plate; a plurality of longitudinally oriented rails extending from the floor; The manufacturing system according to claim 6 or 7, comprising:

9. the carrier is configured for longitudinal translation into the assembly cell; the base comprises two side plates separated by a channel; The manufacturing system of claim 8 , wherein the channel receives the A-pillar as the carrier translates longitudinally into the assembly cell.

10. The manufacturing system of claim 9 , wherein the two side plates are supported on the rails.

11. The manufacturing system according to any one of claims 2 to 10, wherein the drill, the rivet supply portion, and the fastening portion in each of the plurality of actuator groups are separated in the longitudinal direction by a predetermined pulse movement width.

12. 12. The manufacturing system of claim 11, wherein the plurality of actuator groups are separated longitudinally by an aperture width equal to four pulse travel widths.

13. 13. The manufacturing system of claim 12, wherein a number of actuator groups in the plurality of actuator groups is equal to a length of the panel divided by six pulse travel widths.

14. 1. A method for assembling a panel, comprising: inserting the panel into a multi-head drill and fill (MDF) machine having a bipartite backbone, the MDF machine having a longitudinal slot for receiving the panel; rotating the panel to align a number of actuator groups with stringers of the panel, each actuator group having a drill, a rivet supply, and a fastener with a bucking bar aligned therewith; translating the panel longitudinally to pulse move position 1; drilling holes in the stringers and skins using each of the drills in the actuator group; pulsing the panel longitudinally one position to a pulsing position 2 and inserting a first rivet using each of the rivet supplies of the actuator group and drilling a second hole using each of the drills; pulsing the panel longitudinally one position to a pulsing position 3, engaging and tightening the first rivet with each of the fasteners and each of the aligned bucking bars, drilling a third hole with each of the drills, and inserting a second rivet with each of the rivet supplies; pulsing the panel longitudinally one position to a pulsing position 4, inserting a third rivet using each of the rivet supplies, and engaging and fastening the second rivet using each of the fasteners and each of the aligned bucking bars; pulsing the panel longitudinally one position to a pulsing position 5 and engaging and tightening the third rivet with each of the fasteners and each of the aligned bucking bars; A method comprising:

15. the step of pulsing the panel longitudinally to pulsing position 4 further comprises drilling a fourth hole with each of the drills; said step of pulsing said panel longitudinally to a pulsing position 5 further comprises drilling a fifth hole with each of said drills and inserting a fourth rivet with each of said rivet supplies; The method further comprising: pulsing the panel longitudinally one position to a pulsing position six, drilling a sixth hole with each of the drills, inserting a fifth rivet with each of the rivet supplies, and engaging and tightening the fourth rivet with each of the fasteners and each of the aligned bucking bars; pulsing the panel longitudinally one position to a pulsing position 7, inserting a sixth rivet using each of the rivet supplies, and engaging and tightening the fifth rivet using each of the fasteners and each of the aligned bucking bars; pulsing the panel longitudinally one position to a pulsing position 8 and engaging and fastening the sixth rivet with each of the fasteners and each of the aligned bucking bars; The method of claim 14 further comprising:

16. 16. The method of claim 15, further comprising the step of withdrawing the panel a distance of eight pulse widths and moving the panel circumferentially to another stringer.

17. 17. The method of claim 16, further comprising the step of retracting the individual wheel assemblies to avoid interference with the stringers during rotational movement.

18. placing the panel on a carrier having an internal support fixture with bisected arcuate arms and radially extending motorized wheel assemblies engaging an inner surface of the skin; closing a rotatably mounted concentric arcuate outer support fixture to engage an outer surface of the skin of the panel with a roller; Further comprising:

20. The method of claim 17, wherein the step of inserting the panel into the MDF machine includes translating the carrier longitudinally into an assembly cell housing the MDF machine.

19. translating the carrier in a reverse longitudinal direction out of the assembly cell; Rotating the external support fixture to open it; removing the panel; 20. The method of claim 18 further comprising:

20. 1. A method for assembling a panel, comprising: Inserting a panel into an MDF machine having a two-part backbone with a longitudinal slot for receiving said panel; circumferentially moving the panel to align a first plurality of actuator groups with structural elements in the panel on which an assembly operation is to be performed, wherein each actuator group moves in a direction greater than or equal to z ｙ having a second plurality of n actuators designated Y=1 to Y=n; A series of pulses moving position x ｑ translating the panel longitudinally through a range of q=1 to 2n+(n−1); The actuator z １ is the pulse movement position x １ performing an operation on said panel while in said state; The panel is moved to the next position x ２ Then, the actuator z ２ On the panel, an operation using the actuator z １ and performing the operations of Pulse movement position x ｍ (m=3 to 2n, n≧4), and z ａ a step of simultaneously executing an operation at each pulse movement position using all the actuators (a=1 to n-m, m<n); Pulse movement position x ｐ (p=2n to 2n+n−1), and z ｂ performing an operation at each pulse movement position using all the actuators (b=n to n-(p-2n)); A method for assembling a panel, comprising:

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