Patent Publication Number: US-11027378-B2

Title: System and method for assembly manufacturing

Description:
PRIORITY 
     This application is a divisional of U.S. Ser. No. 15/244,194 filed on Aug. 23, 2016, which is a divisional of U.S. Ser. No. 14/222,878 filed on Mar. 24, 2014. 
    
    
     FIELD 
     The present disclosure is generally related to assembly manufacturing and, more particularly, to a system and method for assembly manufacturing of a large structural workpiece. 
     BACKGROUND 
     A number of manufacturing applications exist in which large structural workpieces are assembled and, in many cases, joined to form a final structure. For example, large monument machine tools and tooling may be used for assembling large workpieces, such as large panels used for assembling wing planks, wing panels or wing assemblies of aircraft. However, traditional systems have been barriers to attaining a more efficient manufacturing process. 
     For example, current manufacturing processes for large, structural workpieces feature large, floor-mounted machine tools and expensive tooling. The size of the assembly machines is a result of requirements for throat depth and the multiple custom axes for reaching all surfaces of the workpiece. These monument machines and tooling utilize excessive floor space and cannot be reconfigured between different types of structural workpieces. Furthermore, moving large workpieces, for example, by crane may be time-consuming and may create a bottleneck in the manufacturing process. Such delays may leave machine tools idled during material handling and set-up. Additionally, the traditional manufacturing is highly dependent on manual processes, such as fastening workpieces during the assembly process. 
     Accordingly, those skilled in the art continue with research and development efforts in the field of assembly manufacturing. 
     SUMMARY 
     In one embodiment, the disclosed method for assembly manufacturing may include the steps of: (1) positioning, by a material-handling system, an unassembled workpiece in a first assembly position within a tacking cell, (2) performing, by a first plurality of fastening machines, a tack fastening operation on the unassembled workpiece to form a partially assembled workpiece, (3) transferring, by the material-handling system, the partially assembled workpiece from the tacking cell to a fastening cell, (4) positioning, by the material-handling system, the partially assembled workpiece in a second assembly position within the fastening cell, and (5) performing, by a second plurality of fastening machines, a final fastening operation on the partially assembled workpiece to form an assembled workpiece. 
     In another embodiment, the disclosed method for assembly manufacturing may include the steps of: (1) positioning a workpiece in an assembly position within an operational cell, (2) positioning a fastening machine relative to the workpiece, wherein the fastening machine may include a robot frame including a throat, an assembly end effector coupled to the frame about the throat, and a plurality of linear actuators coupled to the frame, (3) moving, by the plurality of linear actuators, the fastening machine about at least one of six degrees of freedom to receive at least a portion of the workpiece within the throat and position the assembly end effector relative to the workpiece, and (4) performing, by the fastening machine, a fastening operation on the workpiece. 
     Other embodiments of the disclosed system and method for assembly manufacturing will become apparent from the following detailed description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of one embodiment of the disclosed system for assembly manufacturing; 
         FIG. 2  is a block diagram of another embodiment of the disclosed system; 
         FIG. 3  is a block diagram of another embodiment of the disclosed system; 
         FIG. 4  is a block diagram of another embodiment of the disclosed system; 
         FIG. 5  is a block diagram of another embodiment of the disclosed system; 
         FIG. 6  is a schematic illustration of one embodiment of the material-handling system of the disclosed system; 
         FIG. 7  is a schematic illustration of one embodiment of the robotic assembly of the disclosed system; 
         FIGS. 8A, 8B, 8C and 8D  are schematic illustration depicting the operational positions of the material handling system; 
         FIG. 9  is a schematic illustration of one embodiment of the fastening machine of the disclosed system; 
         FIG. 10  is a schematic illustration of one embodiment of one operation cell of the disclosed system; 
         FIG. 11  is a schematic illustration of another embodiment of the operation cell; 
         FIG. 12  is flow diagram of one embodiment of the disclosed method for assembly manufacturing; 
         FIG. 13  is flow diagram of an aircraft production and service methodology; and 
         FIG. 14  is a block diagram of an aircraft. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description refers to the accompanying drawings, which illustrate specific embodiments of the disclosure. Other embodiments having different structures and operations do not depart from the scope of the present disclosure. Like reference numerals may refer to the same element or component in the different drawings. 
     Referring to  FIG. 1 , one embodiment of the disclosed system, generally designated  10 , for assembly manufacturing may include a plurality of functional operation cells  12 . In one example of an assembly manufacture operation, the plurality of operation cells  12  may assembly a workpiece in an unassembled condition  14  (referred to generally as unassembled workpiece  14 ) into a workpiece in an assembled condition  16  (referred to generally as an assembled workpiece  16 ). 
     In one embodiment, the plurality of operation cells  12  may include at least one staging cell  18 , at least one tacking cell  20 , at least one fastening cell  22  and at least one extraction cell  24 . The plurality of operation cells  12 , in combination, may acquire the unassembled workpiece  14 , perform one or more assembly operations to assemble the unassembled workpiece  14  into the assembled workpiece  16  and yield the assembled workpiece  16 . In one example implementation, the plurality of operation cells  12  may be utilized for assembly manufacture of large-scale structural panels, such as those typical to a commercial aircraft including, but not limited to, wing skin planks, wing skin panels, fuselage body side panels or wing assemblies. 
     In a specific, non-limiting aerospace example, the unassembled workpiece  14  may include a plurality of stringers and at least one skin section and the assembled workpiece  16  may include a wing plank. For example, the plurality of stringers and at least one skin section (e.g., the unassembled workpiece  14 ) may be transported to the staging cell  18 . The plurality of stringers and at least one skin section may be positioned at an appropriate initial fastening position within the tacking cell  20 . For example, the skin section may be positioned in a generally horizontal position and each stringer of the plurality of stringers may be positioned in a fastening position on the skin section. The tacking cell  20  may perform one or more machining and/or assembly operations on the plurality of stringers and the skin section to initially fasten the plurality of stringers to the skin section. A partially assembled plurality of stringers and skin section may be positioned at an appropriate final fastening position within the fastening cell  22 . The fastening cell  22  may perform one or more machining and/or assembly operations on the plurality of stringers and the skin section to finally fasten the plurality of stringers to the skin section. For example, the partially assembled plurality of stringers and skin section may be positioned in a generally horizontal position and each stringer of the plurality of stringers may be finally fastened to the skin section. A fully assembled plurality of stringers and skin section may then be positioned within the extraction cell  24  for removal of the fully assembled plurality of stringers and skin section (e.g., the assembled workpiece  16 ). 
     In another specific, non-limiting aerospace example, the unassembled workpiece  14  may include at least two wing planks and at least one splice stringer and/or at least one side of body and the assembled workpiece  16  may include a wing assembly. For example, the at least two wing planks and at least one splice stringer and/or at least one side of body (e.g., unassembled workpiece  14 ) may be transported to the staging cell  18 . The at least two wing planks may be positioned at an appropriate initial fastening position within the tacking cell  20 . For example, the wing planks may be positioned in a generally horizontal position and at least one splice stringer and/or at least one side of body may be positioned in a fastening position on the wing planks (e.g., between edge interfaces of the wing planks). The tacking cell  20  may perform one or more machining and/or assembly operations on the at least two wing planks and at least one splice stringer and/or at least one side of body to initially fasten the splice stringer and/or side of body to the wing planks. A partially assembled wing planks, splice stringer and/or side of body may be positioned at an appropriate final fastening position within the fastening cell  22 . The fastening cell  22  may perform one or more machining and/or assembly operations on the partially assembled wing planks, splice stringer and/or side of body may to finally fasten the splice stringer and/or side of body to the wing planks. For example, the partially assembled wing planks, splice stringer and/or side of body may be positioned in a generally horizontal position and the splice stringer and/or side of body may be finally fastened to the wing planks. A fully assembled partially assembled wing planks, splice stringer and/or side of body may then be positioned within the extraction cell  24  for removal of the fully assembled partially assembled wing planks, splice stringer and/or side of body (e.g., the assembled workpiece  16 ). 
     Referring to  FIG. 2 , in another embodiment, the plurality of operation cells  12  may be linked together by a common material-handling system  26 . In another example of an assembly manufacture operation, a material-transport system  28  may be loaded with the unassembled workpiece  14  and deliver the unassembled materials to the staging cell  18 . The material-handling system  26  may remove the unassembled workpiece  14  from the material-transport system  28  and position the unassembled workpiece  14  in the tacking cell  20 . The tacking cell  20  may perform at least one assembly operation on the unassembled workpiece  14  to form a partially assembled workpiece  30 . The material-handling system  26  may remove the partially assembled workpiece  30  from the tacking cell  20  and position the partially assembled workpiece  30  in the fastening cell  22 . The fastening cell  22  may perform at least one assembly operation on the partially assembled workpiece  30  to form the assembled workpiece  16 . The material-handling system  26  may remove the assembled workpiece  16  from the fastening cell  22  and move the assembled workpiece  16  to the extraction cell  24  where the assembled workpiece  16  may be positioned on the material-transport system  28  for transport to another location. 
     Referring to  FIG. 3 , in another embodiment, a plurality of operation cells  12 ′ may be linked to the plurality of operation cells  12 . The assembled workpiece  16  may become unassembled workpiece  14 ′, which are delivered (e.g., via the material-transport system  28 ) to the plurality of operation cells  12 ′. The plurality of operation cells  12 ′ may include at least one staging cell  18 ′, at least one tacking cell  20 ′, at least one fastening cell  22 ′ and at least one extraction cell  24 ′. The plurality of operation cells  12 ′ may be linked together by a common material-handling system  26 ′. The plurality of operation cells  12 ′ may perform one or more assembly operations on the unassembled workpiece  14 ′ to assemble an assembled workpiece  16 ′. Those skilled in the art will recognize that additional pluralities of operation cells may be linked as many times as necessary to assembly manufacture a final assembled workpiece. 
     Referring to  FIG. 4 , in another embodiment, the plurality of operation cells  12  may include at least one staging cell  18 , at least one tacking cell  20 , at least one fastening cell  22 , at least one tacking cell  20 ′, at least one fastening cell  22 ′ and at least one extraction cell  24 . The plurality of operation cells  12  may be linked together by a common material-handling system  26 . The plurality of operation cells  12  may perform one or more assembly operations on the unassembled workpiece  14  to assemble an assembled workpiece  16 . Those skilled in the art will recognize that additional tacking cells and/or additional fastening cells may be included in the plurality of operation cells  12  as necessary to assembly manufacture a final assembled workpiece. 
     As will be described in more detail herein, in yet another embodiment (not shown), the staging cell  18  and/or the extraction cell  24  may be eliminated from the plurality of operation cells  12 , depending upon the manner in which the unassembled workpiece  14  are loaded into the tacking cell  20  and/or how the assembled workpiece  16  is unloaded from the fastening cell  22 . 
     Referring to  FIGS. 5 and 6 , in an example embodiment, the plurality of operation cells  12  (e.g., at least one staging cell  18 , at least one tacking cell  20 , at least one fastening cell  22  and/or at least one extraction cell  24 ) may be arranged in a linear configuration (e.g., an assembly line). The material-handling system  26  may include a pair of transfer rails  32  (only a single transfer rail  32  is shown in  FIG. 6 ). The transfer rails  32  may extend substantially the entire length of the plurality of operation cells  12 . For example, the transfer rails  32  may extend longitudinally from the first cell (e.g., the staging cell  18  in  FIG. 6 ) to the last cell (e.g., the extraction cell  24  in  FIG. 6 ) of the plurality of operation cells  12 . The transfer rails  32  may be positioned above (e.g., overhead transfer rails) the plurality of operation cells  12 . For example, the transfer rails  32  may be positioned above a functional operation area  34  (e.g., the area where one or more assembly operations is performed) of each of the plurality of operation cells  12 . 
     In an example construction, the transfer rails  32  may be supported in a substantially horizontal position by a plurality of substantially vertical support stanchions  46 . In another example construction, the transfer rails  32  may be connected to and extend between opposing structures, such as walls or structural support beams of a manufacturing facility. 
     In an example construction, at least one gantry  36  (a plurality of gantries  36  are shown in  FIG. 6 ) may be operably connected between the pair of transfer rails  32 . The transfer rails  32  may be spaced apart laterally, for example, to the outside of the plurality of operation cells  12  ( FIG. 7 ). Each gantry  36  may include at least one robotic assembly  38 . The gantry  36  may be linearly movable along the pair of transfer rails  32 , for example, in the direction of arrow  52 . The gantry  36  may longitudinally traverse the pair of transfer rails  32  to position the robotic assembly  38  over any one of the plurality of operation cells  12  (e.g., within the functional operation area  34  of each of the plurality of operation cells  12 ). For example, the gantry  36  (or the plurality of gantries  36 ) may traverse the pair of transfer rails  32  from proximate a first end  48  to proximate a second end  50 . 
     The gantry  36  may be driven upon the pair of transfer rails  32  by any suitable driving system (not shown) including, but not limited to, a mechanical driving system, an electromechanical driving system, a hydraulic driving system, a pneumatic driving system or the like. In a specific, non-limiting example, the gantry  36  may be driven by and/or the relative position of the gantry  36  with respect to each of the plurality of cells  12  may be controlled by one or more servomechanisms. 
     Referring to  FIG. 7 , the robotic assembly  38  may include a robot carriage  40  operably connected to an underside of the gantry  36  (e.g., above the functional operation area  34 ). A robotic arm  42  may be operably connected to the robot carriage  40 . The robot carriage  40  may be linearly movable along the gantry  36 , for example, in the direction of arrow  54 . The robot carriage  40  may traverse a substantial length of the gantry  36  (e.g., between laterally opposed transfer rails  32 ) to position the robotic arm  42  at any one of a plurality of predetermined positions within the functional operation area  34  of each of the plurality of operation cells  12  (e.g., the staging cell  18 , the tacking cell  20 , the fastening cell  22  and/or the extraction cell  24 ). For example, the robot carriage  40  may traverse the gantry  36  from proximate a first end  55  to proximate a second end  56 . 
     The robot carriage  40  may be driven upon the gantry  36  by any suitable driving system (not shown) including, but not limited to, a mechanical driving system, an electromechanical driving system, a hydraulic driving system, a pneumatic driving system or the like. In a specific, non-limiting example, the robot carriage  40  may be driven by and/or the relative position of the robot carriage  40  with respect to each of the plurality of cells  12  may be controlled by one or more servomechanisms. 
     The robot carriage  40  and the robotic arm  42  may include any robotic assembly suitable for assembly manufacturing operations. In a specific, non-limiting example, the robot carriage  40  and/or the robotic arm  42  may be an industrial robot platform, such as commercially available from KUKA Robotics Corporation of Gersthofen, Germany 
     An end effector  44  may be disposed at an end of the robotic arm  42 . The robotic arm  42  may include one or more independently articulating arm segments to position the end effector  44  at any one of a plurality of predetermined positions within the functional operation area  34  of each of the plurality of operation cells  12 . The robotic arm  42  may be configured to move and/or position the end effector  44  at any location, for example, in the direction of arrow  58  (e.g., along the X-axis), arrow  60  (e.g., along the Y-axis) and/or arrow  62  (e.g., along the Z-axis). The robotic arm  42  may be configured to rotate and/or position the end effector  44  at any location, for example, in the direction of arrow  64  (e.g., about the X-axis), arrow  66  (e.g., about the Y-axis) and/or arrow  68  (e.g., about the Z-axis). In a specific, non-limiting example, the robotic arm  42  and/or the end effector  44  may be driven by and/or the relative position of the robotic arm  42  and/or end effector  44  with respect to each of the plurality of cells  12  may be controlled by one or more servomechanisms. 
     Thus, the robotic arm  42  may provide the end effector  44  with of freedom of movement along six axes (e.g., along the X-, Y- and/or Z-axis and about the X-, Y- and/or Z-axis) and the robot carriage  40  may provide freedom of movement (e.g., linear movement) along a seventh axis (e.g., along the X-axis). 
     The end effector  44  of each robotic arm  42  may be customized to grip, handle, carry and/or manipulate the unassembled workpiece  14 . For example, the end effector  44  may include any suitable mechanism  70  configured to grip or clamp a specific type of unassembled material  14  (e.g., individual pieces of the unassembled workpiece  14 ). In following with the aerospace example above, one or more end effectors  44  of one or more robotic assemblies  38  may be configured to grip a skin section, a stringer, a wing plank, a splice stringer and/or a side of body component. 
     In another example construction, the material-handling system  26  may include a monorail system or similar overhead handling system (not shown). For example, the transfer rails  32  ( FIG. 5 ) may be configured as a cantilever system (not shown), for example, extending from a wall or a support beam. The cantilever system may include a plurality of cantilever beams (not shown) positioned above each operation cell  12  of the plurality of operation cells  12  (e.g., the staging cell  18 , the tacking cell  20 , the fastening cell  22  and/or the extraction cell  24 ). One or more robotic assemblies  38  ( FIG. 5 ) may be operably connected to an underside of each cantilever beam of the cantilever system (e.g., above the functional operation area  34 ). The robotic assembly  38  may be linearly movable along the cantilever beam, for example, by the robot carriage  40 . For example, the robot carriage  40  may traverse a substantial length of the cantilever beam to position the robotic arm  42  of the robotic assembly  38  at any one of a plurality of predetermined positions within the functional operation area  34  of a respective operation cell  12  (e.g., the staging cell  18 , the tacking cell  20 , the fastening cell  22  and/or the extraction cell  24 ). 
     Referring to  FIGS. 8A, 8B, 8C and 8D , in an example assembly manufacturing operation, the material-handling system  26  may engage, transfer and/or position the unassembled workpiece  14 , the partially assembled workpiece  30  ( FIG. 2 ) and/or the assembled workpiece  16  ( FIG. 2 ) from and between the plurality of operation cells  12 . In an example implementation, the material-handling system  26  may utilize repeatable machine positioning and machine accuracy to engage and place the workpiece (e.g., the unassembled workpiece  14 , the partially assembled workpiece  30  and/or the assembled workpiece  16 ) at appropriate positioned between and within the plurality of operation cells  12 . In another example implementation, the material-handling system  26  may utilize one or more metrology systems  124  (e.g., laser tracking, laser radar, Intelligent Global Pooling Systems (iGPS), RFID tracking and the like) to provide for appropriate positioning of the workpiece between and within the plurality of operation cells  12 . 
     For example, the gantries  36  may initially be positioned in a first position (e.g., positioning the robotic assemblies  38  within the functional operational area  34  of the staging cell  18 ), as illustrated in  FIG. 8A . The unassembled workpiece  14  ( FIG. 6 ) may be positioned within the functional operation area  34  of the staging cell  18 , for example, by the material-transport system  28  ( FIG. 6 ). The robotic assemblies  38  may engage (e.g., grip and lift) a first component of the unassembled workpiece  14  while in the first position. The gantry  36  may move to a second position (e.g., positioning the robotic assemblies  38  within the function work area  34  of the tacking cell  20 ), as illustrated in  FIG. 8B . The robotic assemblies  38  may transfer the first component of the unassembled material  14  to an assembly position within the tacking cell  20 . 
     The gantries  36  may return to the first position and the robotic assemblies  38  may engage a second component of the unassembled material  14  while in the first position. The gantries  36  may move to the second position and the robotic assemblies  38  may transfer the second component of the unassembled material  14  to an assembly position with respect to the first material within the tacking cell  20 . This process may be repeated until all of the components of the unassembled workpiece  14  are positioned at an appropriate assembly position within the tacking cell  20 . 
     As another example, the robotic assemblies  38  may be positioned along the cantilever system, as described above, within the functional operation area  34  to engage (e.g., grip, lift and/or transfer) the workpiece between and within the plurality of operation cells  12 . 
     The tacking cell  20  may perform one or more machining and/or assembly operations (e.g., one or more tack fastening operations) on the unassembled workpiece  14  while positioned in the assembly position. The tacking cell  20  may utilize one or more fastening machines  78  to perform initial tack fastening of the unassembled workpiece  14 . Tack fastening may be performed at one or more predetermined locations on the unassembled workpiece  14  while positioned in the assembly position to yield a workpiece in a partially assembled condition  30  (referred to generally as a partially assembled workpiece  30 ) ( FIG. 2 ). For example, the assembly operations performed in the tacking cell  20  (e.g., by the fastening machines  78 ) may include, but are not limited to, preloading (e.g., clamping) the unassembled workpiece  14 , drilling fasteners holes through the unassembled workpiece  14 , coupling fasteners (e.g., tack fasteners) to the unassembled workpiece  14 , setting fasteners and the like. As another example, the material-handling system  26  (e.g., the robotic assemblies  38 ) may preload (e.g., clamp) and hold the unassembled workpiece  14  while the fastening machines  78  drill fasteners holes through the unassembled workpiece  14 , couple fasteners (e.g., tack fasteners) to the unassembled workpiece  14 , set fasteners and the like. 
     Upon completion of the assembly operations performed by the tacking cell  20 , the robotic assemblies  38  may engage the partially assembled workpiece  30 . The gantries  36  may move to a third position (e.g., positioning the robotic assemblies  38  within the functional operation area  34  of the fastening cell  22 ), as illustrated in  FIG. 8C . The robotic assemblies  38  may transfer the partially assembled workpiece  30  to an appropriate assembly position within the fastening cell  22 . 
     The fastening cell  22  may perform one or more assembly operations on the partially assembled workpiece  30  while positioned in the assembly position. The fastening cell  22  may utilize one or more fastening machines  78  to perform final fastening of the partially assembled workpiece  30 . Final fastening may be performed at one or more predetermined locations on the partially assembled workpiece  30  while positioned in the assembly position to yield an assembled workpiece  16  ( FIG. 2 ). For example, the assembly operations performed in the fastening cell  22  (e.g., by the fastening machines  78 ) may include, but are not limited to, preloading (e.g., clamping) the partially assembled workpiece  30 , drilling fastener holes through the partially assembled workpiece  30 , coupling fasteners to the partially assembled workpiece  30 , setting fasteners, panel edge trimming, creating reference features for future operations and the like. As another example, the material-handling system  26  (e.g., the robotic assemblies  38 ) may preload (e.g., clamp) and hold the partially assembled workpiece  30  while the fastening machines  78  drill fasteners holes through the partially assembled workpiece  30 , couple fasteners (e.g., tack fasteners) to the partially assembled workpiece  30 , set fasteners, panel edge trimming, creating reference features for future operations and the like. 
     Upon completion of the assembly operations performed by the fastening cell  22 , the robotic assemblies  38  may engage the assembled workpiece  16 . The gantries  36  may move to a fourth position (e.g., positioning the robotic assemblies  38  within the functional operation area  34  of the extraction cell  24 ), as illustrated in  FIG. 8D . The robotic assemblies  38  may transfer the assembled workpiece  16  to an unloading position within the extraction cell  24 , for example, to be unloaded to the material-transport system  28 . The assembly manufacturing operation illustrated in  FIGS. 8A, 8B, 8C and 8D  may be repeated to assemble additional assembled workpieces. 
     The tacking cell  20  may be configured to perform assembly operations similar to the fastening cell  22  (e.g., final fastening of the partially assembled workpiece  30 ) in situations where the fastening cell  22  is causing a lag in the assembly manufacturing operation. 
     Additionally, one or more of the robotic assemblies  38  of one or more gantries  36  may act as a buffer station and hold the partially assembled workpiece  30  and/or the assembled workpiece  16  while a subsequent assembly operation is being finished. 
     Those skilled in the art will recognize that the disclosed system  10  may include other configurations of the disclosed system  10  in order to optimize throughput of the assembly manufacturing operation. For example, a plurality of staging cells  18  may feed a tacking cell  20 . As another example, a plurality of tacking cells  20  may feed a fastening cell  22 . As another example, a tacking cell  20  may feed a plurality of fastening cells  22 . As yet another example, a plurality of fastening cells  22  may feed an extraction cell  24 . 
     Referring to  FIG. 6 , in an example embodiment, the material-transport system  28  may include a cart  72  to transport the unassembled workpiece  14  to, from and/or between one or more of the plurality of cells  12  (e.g., to the staging cell  20  and/or from the extraction cell  24 ). The cart  72  may be any carrying device suitable to hold and/or maintain the unassembled workpiece  14 . The cart  72  may be customized to hold different types of unassembled workpiece  14 . The cart  72  may be a manually guided cart (e.g., a push cart) or automatically guided cart. 
     In following with the aerospace example above, one configuration of the cart  72  may be configured to hold a plurality of stringers and at least one skin in a generally horizontal orientation such that the robotic assemblies  38  may transfer the unassembled workpiece  14  from the cart  72  upon entering the staging cell  18 . Another configuration of the cart  72  may be configured to hold one or more assembled wing planks transferred to the cart  72  by the robotic assemblies  38  in a generally vertical orientation upon entering the extraction cell  24 . 
     One or more carts  72  may be positioned within the staging cell  18  and/or the extraction cell  24  at any given point in the assembly manufacturing operation. 
     In an example implementation of the assembly manufacturing operation, a vehicle  74  may be utilized to transport the cart  72  to, from and/or between one or more of the plurality of cells  12 . The vehicle  74  may be any mobile transport vehicle suitable to transport the cart  72 . For example, the vehicle  74  may be a manually guided vehicle or an automated guided vehicle. In one example, the cart  72  may include a plurality of wheels and the vehicle  74  may drive (e.g., steer) the cart  72 . In another example, the cart  72  may be carried by the vehicle  74 . As a specific, non-limiting example, the vehicle  74  may be an omniMove mobile platform commercially available from KUKA Robotics Corporation of Gersthofen, Germany. 
     Referring to  FIG. 5 , the staging cell  18  and/or the extraction cell  24  may include one or more positioning systems  76 . The positioning system  76  may define the predetermined position of the cart  72  and/or the vehicle  74  relative to the staging cell  18  such that the unassembled workpiece  14  are properly positioned for transfer from the cart  72  by the robotic assemblies  38 . The positioning system  76  may also define the predetermined position of the cart  72  and/or the vehicle  74  relative to the extraction cell  24  such that the cart  72  is properly positioned for transfer of the assembled workpiece  16  from the extraction cell  24  by the robotic assemblies  38 . 
     The positioning systems  76  may be any system suitable to properly and repeatably position the cart  72  and/or the vehicle  74  relative to one or more of the plurality of cells  12 . The positioning system  76  may be configured to manual positioning of the cart  72  and/or the vehicle  74  or automatic positioning of the cart  72  and/or the vehicle  74 . For example, the positioning systems  76  may include, but is not limited to, cup and cone locators, electronic positioning systems, physical stops and the like. 
     Those skilled in the art will recognize that the manner in which the unassembled workpiece  14  are loaded into the tacking cell  20  and/or the assembled workpiece  16  is unloaded from the fastening cell  22  may determine the need for the staging cell  18  and/or the extraction cell  24 , respectively. For example, the unassembled workpiece  14  may be manually loaded into the tacking cell  20  and/or the assembled workpiece  16  may be manually unloaded from the fastening cell  22 . As another example, the material-handling system  26  may be configured such that the tacking cell  20  transfers the unassembled workpiece  14  directly from the material-transport system  28  and/or the fastening cell  22  may be configured to transfer the assembled workpiece  16  directly to the material-transport system  28 . 
     Referring to  FIG. 5 , the tacking cell  20  and the fastening cell  22  may include at least one fastening machine  78  and at least one tooling fixture  80 . The tooling fixture  80  of the tacking cell  20  may be configured to support the unassembled workpiece  14  in the assembly position as placed by the robotic assemblies  38 . The fastening machine  78  of the tacking cell  20  may be configured to prepare the unassembled workpiece  14  for tack fastening and install tack fasteners to the unassembled workpiece  14 . The tooling fixture  80  of the fastening cell  22  may be configured to support the partially assembled workpiece  30  ( FIG. 2 ) in the assembly position as placed by the robotic assemblies  38 . The fastening machine  78  of the fastening cell  22  may be configured prepare the partially assembled workpiece  30  for final fastening and install final fasteners to the partially assembled workpiece  30 . 
     Referring to  FIG. 9 , in an example embodiment, the fastening machine  78  may include a robot  82 . The robot  82  may include a C-shaped frame  86  having a throat  84 . An end effector  88  may be coupled to the robot  82  about an opening of the throat  84 . The end effector  88  may include one or more machining and assembly devices  114  for performing one or more machining and/or assembly operations on a workpiece  96  ( FIG. 11 ). As used herein, a workpiece  96  may include the unassembled workpiece  14  when used in relation to the tacking cell  20  or the partially assembled workpiece  30  when used in relation to the fastening cell  22  ( FIG. 2 ). For example, the machining and/or assembly operations performed by the end effector  88  may include, but are not limited to, applying a preload, locating fastener locations, drilling fastener holes, aligning fastener holes, installing fasteners, setting fasteners, tightening fasteners, imaging, testing, inspecting and the like. 
     As a general, non-limiting example, the fastening method employed by the end effector  88  may include, but is not limited to, installing rivets, installing collars, installing clamps, installing bulk fasteners (e.g., nut and bolts), welding and the like. As a specific, non-limiting example, the tack fasteners and the final fasteners may be rivets. The machining and assembly device  114  may be configured to drill holes of various sizes to receive a range of different sizes of rivets, install appropriately sized rivets in associated holes and set the rivets (e.g., with up to 50,000 lbs. of force) to tack fasten the unassembled workpiece  14  together (e.g., when used in the tacking cell  20 ) and final fasten the partially assembled workpiece  30  together (e.g., when used in the fastening cell  22 ). In following with the aerospace example above, a plurality of robots  82  of the tacking cell  20  may install rivets to tack fasten the stringers to the skin section at approximately every 52 inches along the length of the plank. A plurality of robots  82  of the fastening cell  22  may install rivets to final fasten the stringers to the skin section at predetermined locations along the length of the wing plank. 
     The robot  82  may be horizontally mounted, for example, to a machine floor or ceiling or vertically mounted, for example, to a wall. In an example construction, the frame  86  may be coupled to a base  90 . A plurality of actuators  92  may be connected between connection locations on the base  90  and connection locations on the frame  86  to position the frame  86  with respect to the base  90 . 
     In an example construction, the base  90  may include at least one rail  100  and/or at least one rail  101 . The base  90  may translate (e.g., linearly) along rail  100  and/or rail  101  to position the robot  82  relative to the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ). The base  90  may be driven upon rail  100  and/or rail  101  by any suitable driving system (not shown) including, but not limited to, a mechanical driving system, an electromechanical driving system, a hydraulic driving system, a pneumatic driving system or the like. In a specific, non-limiting example, the base  90  may be driven by and/or the relative position of the base with respect to the rails  100  may be controlled by one or more servomechanisms. 
     In another example construction, the fastening machine  78  may include one or more wheel assemblies (not shown) to position the robot  82  relative to the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ). For example, the base  90  may include wheel assemblies or the base  90  may be mounted to a wheeled cart or other mobile platform. The fastening machine  78  may be manually moved (e.g., wheeled) into position or may be automatically moved (e.g., driven) into position. 
     The actuators  92  may provide for movement of the frame  86  relative to the base  90  and a range of motion along length of the workpiece  96 . The actuators  92  may be any device suitable to position the frame  86  in any of a plurality of discrete positions. For example, the actuators  92  may be hydraulic or pneumatic linear stroke actuators. In an example construction, two actuators  92  may be connected to opposing sides of the frame  86  proximate a front end, two actuators  92  may be connected to opposing sides of the frame  86  proximate a middle location of the frame  86  and two actuators may be connected proximate to a rear side of the frame  86 . Each actuator  92  may be connected at each end by a freely movable joint  94  such that linear actuation of one or more actuators  92  may position the frame  86  (e.g., the location and angle of the throat  84  and the end effector  88 ) relative to a work surface  98  of the workpiece  96 . 
     The actuators  92  may be configured to move and/or position the frame  86  (e.g., the throat  84  and the end effector  88 ) at any location, for example, in the direction of arrow  102  (e.g., along the X-axis), arrow  104  (e.g., along the Y-axis) and/or arrow  106  (e.g., along the Z-axis). The actuators  92  may be configured to rotate and/or position the frame  86  at any location, for example, in the direction of arrow  108  (e.g., about the X-axis), arrow  110  (e.g., about the Y-axis) and/or arrow  112  (e.g., about the Z-axis). In a specific, non-limiting example, the actuators  92  may be driven by and/or the relative position of the frame  86  with respect to each of the base  90  may be controlled by one or more servomechanisms. 
     Thus, the actuators  92  may provide the frame  86  with of freedom of movement along six axes (e.g., along the X-, Y- and/or Z-axis and about the X-, Y- and/or Z-axis) and the base  90  may provide the robot  82  with freedom of movement (e.g., linear movement) along a seventh axis (e.g., along the Y-axis) and/or an eighth axis (e.g., along the X-axis), for example, upon the rails  100 ,  101  or the wheel assemblies. 
     The end effector  88  may include an upper portion  88   a  and an opposed lower portion  88   b . The upper portion  88   a  and the lower portion  88   b  of the end effector  88  may each be movable about the frame  86  (e.g., linearly) in order to apply a preload to (e.g., clamp) the work surfaces  98  of the workpiece  96  ( FIG. 11 ) prior to performing a machining and/or assembly operation. For example, the upper portion  88   a  and the lower portion  88   b  of the end effector  88  may be configured to apply at least 1,000 lbs. of clamp force on the workpiece  96 . The upper portion  88   a  and the lower portion  88   b  of the end effector  88  may be configured to apply an equal force to each side (e.g., opposed work surfaces  98 ) of the workpiece  96  such that the forces transferred to the base  90  are substantially limited or eliminated. 
     The throat  84  may be suitably sized to at least partially receive the workpiece  96 . The throat  84  may include a throat depth D. The throat depth D may be of a depth sufficient to position the end effector  88  at any location over half the width of the largest applicable workpiece  96 . 
     Referring to  FIGS. 10 and 11 , the tacking cell  20  and the fastening cell  22  may each include a plurality of fastening machines  78  and a plurality of tooling fixtures  80 . For example, a plurality of fastening machines  78  may extend longitudinally along the length of the tacking cell  20  and the fastening cell  22 , as illustrated in  FIG. 10 . The plurality of fastening machines  78  may be positioned on both sides of the tacking cell  20  and the fastening cell  22  (e.g., laterally opposed), as illustrated in  FIG. 11 . The plurality of laterally opposed fastening machine  78  may be offset (e.g., staggered), as illustrated in  FIG. 10 . 
     The plurality of tooling fixtures  80  may include any fixture suitable to support and/or hold the workpiece  96  ( FIG. 11 ) in a substantially horizontal orientation such that the fastening machines  78  may perform one or more machining and/or assembly operation on the workpiece  96 . While the workpiece  96  is illustrated as having substantially planar work surfaces  98 , the fastening machines  78  may perform machining and/or assembly operations on workpieces  96  having non-planar, angled or contoured work surfaces  98 . The actuators  92  may position the frame  86  such that the throat  84  ( FIG. 9 ) may receive the workpiece  96  and the end effector  88  (e.g., the upper portion  88   a  and the lower portion  88   b ) ( FIG. 9 ) may engage the work surfaces  98  at a substantially perpendicular working angle. 
     The plurality of tooling fixtures  80  may extend longitudinally along the length of the tacking cell  20  and the fastening cell  22 , as illustrated in  FIG. 10 . The plurality of tooling fixtures  80  may be positioned between laterally opposed fastening machines  78 , as illustrated in  FIG. 11 . The vertical position of each tooling fixture  80  relative to the workpiece  96  may be adjustable in order for one or more of the tooling fixtures  80  to move out of the way of one or more fastening machines  78 . The horizontal position of each tooling fixture  80  relative to the fastening machines  78  (e.g., an adjacent fastening machine  78 ) may be adjustable in order to move out of the way of one or more fastening machines  78  and/or to minimize unsupported spans along the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ). 
     In an example construction, each tooling fixture  80  may include a vertically extendable and retractable stem  116 . As one example, the tooling fixture retracts to provide access to the workpiece  96  by the fastening machine  78 . As another example, the stem  116  may include two or more sections  118  that may be raised to support the workpiece  96  and/or lowered to allow the fastening machine  78  to access the workpiece  96 . Each tooling fixture  80  may include a vacuum cup  120  at an end thereof to engage the workpiece  96 . For example and as illustrated in  FIG. 11 , as the actuators  92  move and positioned the frame  86  of the robot  82  in position to receive the workpiece  96  within the throat  84  and between the end effector  88 , one or more of the tooling fixtures  80  positioned in front of the fastening machine  78  may lower. 
     In following with the aerospace example above, in an example assembly manufacturing operation, the skin section may be positioned on the plurality of tooling fixtures  80  in the tacking cell  20  by the robotic assemblies  38 . The skin section may be oriented such that the outer mold line (e.g., the exterior surface of the wing assembly) is in contact with the vacuum cups  120  and the inner mold line (e.g., the interior surface of the wing assembly) is in position for placement of the plurality of stringers by the robotic assemblies  38 . 
     Referring to  FIG. 5 , in an example embodiment, the material-transport system  28 , the material-handling system  26  and the plurality of operation cells  12  may be programmed to interact and perform the assembly machining operation automatically. The fastening machines  78  and the plurality of tooling fixtures  80  (e.g., of both the tacking cell  20  and the fastening cell  22 ) may operate synchronously with each other to perform the assembly machining operation automatically. 
     In an example implementation, the disclosed system  10  (e.g., the material-handling system  26 , the tacking cell  20  and fastening cell  22 ) may automatically position of the workpiece at appropriate positions and/or locations between and within a particular operation cell  12  (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ). As an example, the machine accuracy of the material-handling system  26  (e.g., the gantry  36  and the robotic assembly  38 ), the tacking cell  29  (e.g., the fastening machines  78  and the tooling fixtures  80 ) and the fastening cell  22  (e.g., the fastening machines  78  and tooling fixtures  80 ) may be sufficient to repeatably position the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ) such that no separate indexing or position verification may be needed. 
     In another example implementation, the disclosed system  10  (e.g., the material-handling system  26 , the tacking cell  20  and fastening cell  22 ) may index and/or verify the position of the workpiece. As an example, the machine accuracy of the material-handling system  26  (e.g., the gantry  36  and the robotic assembly  38 ), the tacking cell  29  (e.g., the fastening machines  78  and the tooling fixtures  80 ) and the fastening cell  22  (e.g., the fastening machines  78  and tooling fixtures  80 ) may receive information and/or feedback from the metrology system  124 . For example, the metrology system  124  may measure the position of the workpiece (e.g., the unassembled workpiece  14  on the material-transport system  28  in the staging cell  18 , the unassembled workpiece  14  in the tacking cell  20 , or the partially assembled workpiece  30  in the fastening cell  22 ) and/or the fastening machines  78  (e.g., of the tacking cell  20  and the fastening cell  22 ). The information and/or feedback may drive the components of the system  10  (e.g., the gantry  36 , the robotic assembly  38 , the fastening machines  78  and/or the tooling fixtures  80 ) to correct index positions. 
     As another example, the tacking cell  20  and/or fastening cell  22  may include sensors and/or machine vision systems (not shown) that detect critical features (e.g., existing pilot holes or edges) of the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ) that allows the components of the system  10  (e.g., the gantry  36 , the robotic assembly  38 , the fastening machines  78  and/or the tooling fixtures  80 ) to align correctly to the workpiece. As yet another example, the components of the system  10  (e.g., the gantry  36 , the robotic assembly  38 , the fastening machines  78  and/or the tooling fixtures  80 ) may be driven (e.g., automatically) to an accurate location and physically act as the index for the workpiece (e.g., the unassembled workpiece  14  in the tacking cell  20  or the partially assembled workpiece  30  in the fastening cell  22 ). 
     The disclosed system  10  may include at least one controller  122 . The controller  122  may be associated with at least one of the material-handling system  26  (e.g., the gantry  36 , the robot carriage  40 , the robotic arm  42  and/or the end effector  44 ), the tacking cell  20  (e.g., the plurality of fastening machines  78  and/or the plurality of tooling fixtures  80 ), the fastening cell  22  (e.g., the plurality of fastening machines  78  and/or the plurality of tooling fixtures  80 ) and/or the material-transport system  28  (e.g., the vehicle  74 ). 
     The controller  122  may include any repeatable programming system, for example, to drive and position (1) the material-transport system  28  to predetermined positions with respect to the staging cell  18  and/or the extraction cell  24 , (2) the material-handling system  26  (e.g., the gantries  36  and the robotic assemblies  38 ) to predetermined positions to transfer the unassembled workpiece  14  from the material-transport system  28  to the tacking cell  20 , transfer the partially assembled workpiece  30  from the tacking cell  20  to the fastening cell  22 , transfer the assembled workpiece  16  from the fastening cell  22  to the extraction cell  24  and transfer the assembled workpiece  16  from the extraction cell  24  to the material-transport system  28 , (3) the fastening machines  78  to predetermined machining and/or assembly locations relative to the unassembled workpiece  14  (when in the assembly position) in the tacking cell  20 , (4) the fastening machines  78  to predetermined machining and/or assembly locations relative to the partially assembled workpiece  30  (when in the assembly position) in the fastening cell  22  and (5) the plurality of tooling fixtures  80  to predetermined extended and/or retracted positions relative to the location of the fastening machines  78  (e.g., in both the tacking cell  20  and the fastening cell  22 ). 
     The controller  122  may be pre-programmed via a desktop computer, laptop computer, automation controller, industrial network control system, and the like. For example, the material-handling system  26  and the fastening machines  78  may include programmable industrial robots (e.g., the robotic assembly  38  and the robot  82 ) capable of learning (e.g., via programming and iterative instruction) positional data and iterative procedures. Metrology, navigation and/or factory-level control software may be implemented by the controller  122  and used coordinate the multiple automated and autonomous systems working in close proximity with residual manual operations. Additionally, the metrology system  124  may be used for locating, indexing, and quality-control functions. 
     Referring to  FIG. 12 , also disclosed is one embodiment of a method, generally designated  150 , for assembly manufacturing. The method  150  may begin with the step of transporting, by a material-transport system, an unassembled workpiece to a predetermined position within a staging cell, as shown at block  152 . 
     As shown at block  154 , the unassembled workpiece may be transferred, by a material-handling system, from the material-transport system to a tacking cell. 
     As shown at block  156 , the unassembled workpiece may be positioned, by the material-handling system, in an assembly position within the tacking cell. 
     As shown at block  158 , at least one tack fastening operation may be performed, by a first plurality of fastening machines, on the unassembled workpiece to form a partially assembled workpiece. The tack fastening operation may include, but is not limited to, holding the unassembled workpiece, applying a preload to the unassembled workpiece, locating at least one fastening position on the unassembled workpiece and installing at least one tack fastener to the unassembled workpiece. 
     As shown at block  160 , the partially assembled workpiece may be transferred, by the material-handling system, from the tacking cell to a fastening cell. 
     As shown at block  162 , the partially assembled workpiece may be positioned, by the material-handling system, in an assembly position within the fastening cell. 
     As shown at block  164 , at least one final fastening operation may be performed, by a second plurality of fastening machines, on the partially assembled workpiece to form an assembled workpiece. The final fastening operation may include, but is not limited to, holding the partially assembled workpiece, applying a preload to the partially assembled workpiece, locating at least one fastening position on the partially assembled workpiece and installing at least one final fastener to the partially assembled workpiece. 
     As shown at block  166 , the assembled workpiece may be transferred, by the material-handling system, from the fastening cell to an extraction cell. 
     As shown at block  168 , the material-transport system may be positioned at a predetermined location within the extraction cell. 
     As shown at block  170 , the assembled workpiece may be transferred, by the material-handling system, from the extraction cell to the material-transport system. 
     Accordingly, the disclosure system and method includes a high-throughput, workpiece assembly system (e.g., large panel fastening system) with multiple operational cells for automatic (e.g., robotic) drilling, tacking and fastening. The disclosed system and method may include an array of automated technologies to reduce labor and tooling costs, as well as increase throughput and free space on a factory floor. 
     Examples of the disclosure may be described in the context of an aircraft manufacturing and service method  200 , as shown in  FIG. 13 , and an aircraft  202 , as shown in  FIG. 14 . During pre-production, the aircraft manufacturing and service method  200  may include specification and design  204  of the aircraft  202  and material procurement  206 . During production, component/subassembly manufacturing  208  and system integration  210  of the aircraft  202  takes place. Thereafter, the aircraft  202  may go through certification and delivery  212  in order to be placed in service  214 . While in service by a customer, the aircraft  202  is scheduled for routine maintenance and service  216 , which may also include modification, reconfiguration, refurbishment and the like. 
     Each of the processes of method  200  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 venders, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on. 
     As shown in  FIG. 14 , the aircraft  202  produced by example method  200  may include an airframe  218  with a plurality of systems  220  and an interior  222 . Examples of the plurality of systems  220  may include one or more of a propulsion system  224 , an electrical system  226 , a hydraulic system  228 , and an environmental system  230 . Any number of other systems may be included. 
     Apparatus and methods embodied herein may be employed during any one or more of the stages of the production and service method  200 . For example, components or subassemblies corresponding to component/subassembly manufacturing  208 , system integration  210 , and or maintenance and service  216  may be fabricated or manufactured using the disclosed system  10  and method  150 . Also, one or more apparatus examples, method examples, or a combination thereof may be utilized during component/subassembly manufacturing  208  and/or system integration  210 , for example, by substantially expediting assembly of or reducing the cost of an aircraft  202 , such as the airframe  218 . Similarly, one or more of system examples, method examples, or a combination thereof may be utilized while the aircraft  202  is in service, for example and without limitation, to maintenance and service  216 . 
     The disclosed system and method are described in the context of an aircraft; however, one of ordinary skill in the art will readily recognize the disclosed service system and may be utilized for a variety of different components for a variety of different types of vehicles. For example, implementations of the embodiments described herein may be implemented in any type of vehicle including, e.g., helicopters, passenger ships, automobiles and the like. 
     Although various embodiments of the disclosed system and method have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.