This disclosure generally relates to fabrication of large scale composite structures using automated fiber placement techniques, and deals more particularly with a system for automated fiber placement using networked autonomous fiber placement vehicles.
Composite structures such as those used in the automotive, marine and aerospace industries may be fabricated using automated composite material application machines, commonly referred to as automated fiber placement (AFP) machines. AFP machines may be used in the aircraft industry, for example, to fabricate structural shapes and skin assemblies by wrapping relatively narrow strips of slit composite tape or “tows”, collimated into a wider band, on or around a manufacturing tool. The AFP machine aligns and places a plurality of tape strips, typically six or more, in substantially continuous, substantially edge-to-edge contact forming a single wide, conformal band which is placed on and compacted against the tool.
While current AFP machines are highly flexible and efficient, their productivity may be limited in higher production environments. For example, current AFP machines may employ a single head containing six to eight tape control modules that may lay down a bandwidth of six to eight tape courses. In order to increase productivity, additional tape control modules may be added to the head order to increase the bandwidth. Also, it may be possible to use multiple tape application heads, each mounted on a robotic device, such as a NC controlled gantry, however this approach also has limitations. The use of multiple robotic devices results in increased machine complexity and greater mass which may adversely affect machine reliability and/or limit velocity and/or acceleration profiles. Moreover, the use of fixed structural robotic devices such as foundation-based gantry systems may represent a significant capital investment and may limit functional flexibility as well as the ability to expand future production capacity.
Accordingly, there is a need for a system and method for rapid automated assembly of composite laminate parts and structures employing automated tape placement, that increases productivity while providing greater operational flexibility. There is also a need for a reduced cost system and method having reduced complexity and high reliability.
The disclosed embodiments provide improvements in laminate course placement and assembly of composite parts and structures through the use of networked, autonomous fiber placement vehicles. The fiber placement vehicles employ tape application heads that may be tailored in complexity to best match the tape application task for a particular area of the laminate structure. Tape application rate may be increased by adding additional vehicles. The use of multiple, autonomous tape application vehicles increase overall system reliability while reducing down time.
According to one disclosed embodiment, a system is provided for fabricating a composite structure. A plurality of independently operable vehicles perform differing tape application tasks and are arranged in a network. A control system is provided for controlling the independent operation of the vehicles.
According to another disclosed embodiment, a system is provided for fabricating a composite laminate structure. A plurality of tape application vehicles are independently moveable over a tool surface and respectively include differently configured tape application heads for independently applying differently configured courses of composite tape over the tool surface. Control means arte provided for controlling both the independent movement of the vehicles over the tool surface, and the operation of the tape application heads. In one embodiment, the tool surface is divided into a plurality of sectors and the vehicles are respectively associated with and operate within the sectors.
According to a disclosed method embodiment, courses of composite tape are applied over a tool surface. A plurality of autonomous vehicles are coupled in a network. Each of the vehicles is equipped with a composite tape application head for applying courses of composite tape over the tool surface. Operation of the vehicles is coordinated within the network and the vehicles are dispatched to apply courses of composite tape in different areas of the tool surface.
According to another disclosed method embodiment, laying up a composite laminate comprises applying differently configured courses of composite tape over different sectors of a tool surface using a plurality of independently controlled tape application vehicles.
The disclosed embodiments satisfy the need for a system and method for assembling laminate structures that employs multiple autonomous tape application vehicles operating within a network to simultaneously perform differing tape application tasks on different areas of the tool surface.
Referring first to
Each of the tape application heads 26 may be adapted to apply differently configured courses 30a, 30b, and 30c of tape 32 on the tool surface 28. For example, course 30a comprises substantially uniform width tape strips 32 with ply drop-offs 33. Course 30b comprises tape strips 32 which are fewer in number, but wider in width than those forming course 30a. The course 30c applied by tape application head 26c include two strips 32c which are relatively wide and as well as a series of narrow, high resolution strips 32d. The courses 30a-30c shown in
Referring now to
Additional details of the central control station 27 and one of the vehicles 22 is shown in
Each of the vehicles 22 includes a wireless transmitter/receiver 50 which communicates with the wireless transmitter/receiver 36 at the central station 27 via the wireless communication link 35. In addition to transmitting control signals from the central station 27 to the vehicles 22, the wireless communication link 35 may transmit signals in the vehicles 22 to the central station 27 in order to provide information about the location of the vehicle 22 and the functional status of its internal systems.
One technique for guiding the tape application vehicles 22 is disclosed in U.S. patent application Ser. No. 10/986,292 filed Nov. 12, 2004 and published as US 2006/0106507A1 on May 18, 2006, the entire contents of which is incorporated by reference herein. Each of the vehicles 22 includes a laser sensor 62 and an associated interface control module 60, along with a drive servo motor 58 and a steering servo motor 56, each of which is electronically linked to a controller 52. In addition, the vehicle 22 may include at least one end effector servo motor 54, or actuator, which is electronically operated by the controller 22. In one embodiment, the drive servo motor 58 and the steering servo motor 56 are mechanically coupled to a drive system (not shown) which drives and steers the vehicle 22 through the traction wheels 34 (
The end effector servo motor 54 may be mechanically coupled to a robotic end effector such as a tape lamination material dispensing head. One example of such a dispensing head is disclosed in U.S. Pat. No. 7,213,629, which is incorporated by reference herein, and which discloses a vacuum assisted ply placement shoe. The laser beam 48 projected from the laser guide 46 delineates a guide path for the vehicle 22 which is detected by the laser sensor 62. The laser sensor 62 generates an electrical signal representative of the location of the laser beam 48 on the tool surface 28. The signal is sent to the interface control module 60 which conditions the signal and sends it to the controller 52. The controller 52 performs an algorithm to determine the location of the laser beam 48 relative to that of the laser sensor 62.
Referring now to
Each of the vehicles 22 includes a tape application head that may be particularly configured in terms of its tape application capability to apply a specifically configured course 30 in a particular one or more of the sectors 28a-28f of the tool surface 28. The vehicles 22 may be dispatched from a staging area 66 to a particular one of the sectors 28a-28f. Also, the staging area 66 may be used to carry out maintenance on the vehicles 22, including replenishing the vehicles 22 with composite tape. Since a number of vehicles 22 may be in use simultaneously, no one vehicle 22 is required to carry a significant amount of composite tape, thereby reducing the complexity of the vehicle 22. Moreover, in the event of a malfunction or loss of one vehicle 22, other vehicles 22 in the network 24 may be reassigned to perform the tasks that were assigned to the nonfunctional vehicle.
The path of travel of the vehicles 22 may be controlled by the laser guide 46 which, as previously discussed, directs laser beams 48 onto the tool surface 28 which are sensed by the vehicles 22 and used as a guide to steer the vehicles 22 (
A central task processor 76, which may form a part of the previously discussed computer 40 (
The vehicles 22 are dispatched from the staging area 66 to the appropriate sector 28a-28f on the tool surface 28 based on the commands issued by the central control station 27. Additional support functions 70 for the vehicles 22 may include a vehicle motivative support base 78, and a material transfer base 80. The vehicles motivative support base 78 may include a variety of service and maintenance functions, including parts that may be required to support servicing operations of the vehicles 22. Similarly, the material transfer base 80 may comprise a supply system of raw materials used by the vehicles 22, including rolls or cassettes (not shown) of composite fiber tape.
Attention is now directed to
The tape application head 26 may typically include an onboard supply of tape 90, fiber tension control 92, a fiber alignment module 94, a vacuum assist placement device 96, and an add drive system module 88. The onboard tape supply 90 may comprise a set of composite tape reels or cassettes each of which supplies a strip of tape that is aligned, fed and cut by the fiber alignment module 94. In one embodiment, for example and without limitation, a maximum of six tape reels may be provided which produce an output laminate bandwidth 30 of six, substantially contiguous tape strips. The fiber tension control module 92 may comprise a simple mechanical feedback system (not shown) coupled with a brake (not shown) that provides tension on the supplied tape strips, based on the speed of the vehicle 22.
The fiber alignment module 94 may comprise, for example and without limitation, a module similar to that disclosed in U.S. patent application Ser. No. 12/038,155 filed Feb. 27, 2008. The fiber alignment module 94 disclosed in the above mentioned application may include a wedge and a substantially equally space channel slots that are sized to match the width of the input tape such that a weave pattern is formed and a single bandwidth 30 is output from the tape application head 26. The fiber alignment module 94 includes mechanisms for feeding, cutting and restarting the tape for the module 94.
In some applications, the cutting operation may be performed using a single cutter while in other embodiments, multiple cutters may be used to independently cut each tape strip. The autonomous vehicle 22 reacts against a compaction force applied to the output laminate bandwidth 30 by the tape application head 26 using a technique described in U.S. Pat. No. 7,213,629, which is incorporated by reference herein, in which a vacuum assist tape placement module 96 is employed. The vacuum assist tape placement module 96 produces at least a partial vacuum between the tape and substrate as the tape is being applied which effectively forces and compacts the tape against the substrate. Alternatively, the required tape compaction force may be generated by using a system of manifold directors (not shown) which apply a downward force directly on the vehicle 22, which in turn compacts the tape against the substrate.
Simultaneous with the placement of tape in sector 28a, autonomous vehicles 28c and 28d operating within sector 28b may apply courses 30 of one quarter inch tape representing a normal resolution. Autonomous vehicle 22c may include multiple, independent tape cutting mechanisms (not shown) forming part of the module 94 shown in
Finally, autonomous vehicles 22e and 22f operating in sector 28c may apply courses 30 of one half inch wide tape thereby providing rapid placement of tape over large areas. Vehicles 22e, 22f may have either multiple, independent tape cutting mechanisms or a single, group cutting mechanism.
Attention is now directed to
Next, at 104, a tool surface 28 is provided which may be divided into a plurality of sectors, as shown at 106. At 108, the operation of the vehicles 22 is controlled and coordinated. Step 108 may include retrieving part definitions at 110, which describe the plies, and courses making up each ply required to assemble a particular composite laminate. At 112, the tape application process is optimized based on the retrieved part/ply definitions performed at 110. This optimization process, as previously described, involves optimization of the use of the vehicles 22, including dispatching the vehicles to the various sectors 28a-28f and operating them to simultaneously apply courses of tape in the most time efficient manner. Thus, after the tape application process has been optimized, the vehicles 22 may be dispatched to the various sectors 28a-28f, as shown at step 114.
At 116, as the vehicles 22 exhaust their tape, they may return to the staging area 66 where they are re-supplied with tape. Following completion of the tasks assigned to a vehicle 22, the vehicle 22 returns to the staging area 66, as shown at step 118. When all the vehicles 22 have completed their assigned tasks, the process ends at 120.
Embodiments of the disclosure may find use in a variety of potential applications, particularly in the transportation industry, including for example, aerospace, marine and automotive applications. Thus, referring next to
Each of the processes of method 122 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
As shown in
The apparatus embodied herein may be employed during any one or more of the stages of the production and service method 122. For example, components or subassemblies corresponding to production process 130 may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft 124 is in service. Also, one or more apparatus embodiments may be utilized during the production stages 130 and 132, for example, by substantially expediting assembly of or reducing the cost of an aircraft 124. Similarly, one or more apparatus embodiments may be utilized while the aircraft 124 is in service, for example and without limitation, to maintenance and service 138.
Although the embodiments of this disclosure have been described with respect to certain exemplary embodiments, it is to be understood that the specific embodiments are for purposes of illustration and not limitation, as other variations will occur to those of skill in the art.
This application is related to co-pending U.S. patent application Ser. Nos. 11/116,222, filed Apr. 28, 2005 and published Nov. 23, 2006 as US Publication No. 20060260751 A1; 11/750,154 filed May 17, 2007 and published Nov. 20, 2008 as US Publication No. 20080282863 A1; 11/196,455 filed Aug. 4, 2005 and published Feb. 8, 2007 as US Publication No. 20070029030 A1; and 12/038,155 filed Feb. 27, 2008, all of which applications are incorporated by reference herein in their entirety.