Robotic device for ceramic matrix composites

Abstract

An apparatus for controlling a layer of a composite material includes a robotic arm (18) and an end effector (100) mounted on the robotic arm.The end effector (100) comprises a base (112) attached to the robotic arm (18), the base (112) comprising a base track (116) extending along a first translational dimension, a platform (114) supported by the base (112) and movable along the base track (116), the platform (114) comprising a platform track (124) extending along a second translational dimension, a disk (134) supported by the platform (114) and movable along the platform track (124), the disk (134) being rotatable about a first rotational dimension, an arcuate track (136) supported by the disk (134), the arcuate track (136) extending along a second rotational dimension, and a layer manipulator (102) extending from the arcuate track (136) and movable along the arcuate track (136).

Description

Title of the invention: Robotic apparatus for ceramic matrix composites Technical field

[0001] The present invention relates generally to robotics and the manipulation of parts with a robot. STATE OF PRIOR ART

[0002] Modern manufacturing and repair processes often require very precise and accurate inspection and manipulation of objects. When manufacturing items with ceramic matrix composite (CMC) materials, robotic systems use high-precision manipulators to move and rotate layers of the CMC material to form a layup. The layup is then processed to form the item. The high-precision manipulators are controlled with computer systems that have high computing power and use coordination techniques with multiple robotic components to lay down the layers. Brief description of the drawings

[0003] A complete and useful description of the present invention, including the best mode thereof, intended for a person skilled in the art, is set forth in the specification, which refers to the appended figures, in which:

[0004] [Fig.l] is a top-down schematic view of an exemplary system for superimposing layers of a CMC material in a layup.

[0005] [Fig.2] is a schematic view of robotic arms manipulating one of the layers of the CMC material.

[0006] [Fig.3] is a schematic perspective view of an end effector of one of the robotic arms.

[0007] [Fig.4] is an exploded view of the end effector of [Fig.3].

[0008] [Fig.5A] is a schematic view of the end effector moving in translational dimensions.

[0009] [Fig.5B] is a schematic view of the end effector moving in translational dimensions.

[0010] [Fig.5C] is a schematic view of the end effector moving in translational dimensions.

[0011] [Fig.6A] is a schematic view of the end effector moving in rotational dimensions.

[0012] [Fig.6B] is a schematic view of the end effector moving in rotational dimensions.

[0013] [Fig.6C] is a schematic view of the end effector moving in rotational dimensions.

[0014] [Fig.7] is a functional diagram of an exemplary system to control the end effector.

[0015] [Fig.8] is a functional diagram of an exemplary method for superimposing layers of the CMC material. DETAILED DESCRIPTION

[0016] Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and alphabetical designations to refer to features of the drawings. Similar or identical designations in the drawings and description have been used to refer to similar or identical portions of the disclosure.

[0017] The term "exemplary" is used herein to mean "serving as an example, case, or illustration." Any implementation described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other implementations. Furthermore, unless specifically indicated otherwise, all embodiments described herein should be considered exemplary.

[0018] The singular forms “a,” “an,” “the,” and “the” include plural references unless the context clearly indicates otherwise.

[0019] As used herein, the terms "first," "second," "third," and other ordinals are used to distinguish one component from another and are not intended to signify the location or importance of individual components.

[0020] As used herein, a "dimension" is a measurable extent of a degree of freedom of an object. For example, in a Cartesian coordinate system, three axes define six dimensions: a translation dimension along each of the three axes, and a rotation dimension about each of the three axes. An object is movable in a dimension when a position of the object is free to change along or about the axis defining the dimension.

[0021] As used herein, "ceramic matrix composite" or "CMC" refers to a class of materials comprising a reinforcing material (e.g., reinforcing fibers) surrounded by a ceramic matrix phase. Generally, the reinforcing fibers provide structural integrity to the ceramic matrix. Some examples of matrix materials of CMCs may comprise, but are not limited to, limit, non-oxidized silicon-based materials (e.g., silicon carbide, silicon nitride, or mixtures thereof), oxidized ceramics (e.g., silicon oxycarbides, silicon oxynitrides, aluminum oxide (A12O3), silicon dioxide (SiO2), aluminosilicates, or mixtures thereof), or mixtures thereof. Optionally, ceramic particles (e.g., oxides of Si, Al, Zr, Y, and combinations thereof) and inorganic fillers (e.g., pyrophyllite, wollastonite, mica, talc, kyanite, and montmorillonite) may also be included within the CMC matrix. Some examples of CMC matrix materials may include, but are not limited to, non-oxidized silicon-based materials (e.g., silicon carbide, silicon nitride, or mixtures thereof), oxidized ceramics (e.g.,, silicon oxycarbides, silicon oxynitrides, aluminum oxide (A12O3), silicon dioxide (SiO2), aluminosilicates, or mixtures thereof), or mixtures thereof. Optionally, ceramic particles (e.g., oxides of Si, Al, Zr, Y, and combinations thereof) and inorganic fillers (e.g., pyrophyllite, wollastonite, mica, talc, kyanite, and montmorillonite) may also be included within the CMC matrix.

[0022] Some examples of CMC reinforcing fibers may include, but are not limited to, non-oxidized silicon-based materials (e.g., silicon carbide, silicon nitride, or mixtures thereof), non-oxidized carbon-based materials (e.g., carbon), oxidized ceramics (e.g., silicon oxycarbides, silicon oxynitrides, aluminum oxide (A12O3), silicon dioxide (SiO2), aluminosilicates such as mullite, or mixtures thereof), or mixtures thereof.

[0023] Generally, particular CMCs may be referred to by their fiber type / matrix type combination. For example, C / SiC for carbon fiber reinforced silicon carbide; SiC / SiC for carbide fiber reinforced silicon carbide, SiC / SiN for carbide fiber reinforced silicon nitride; SiC / SiC-SiN for silicon carbide fiber reinforced silicon carbide / silicon nitride matrix mixture, etc. In other examples, CMCs may consist of a matrix and reinforcing fibers comprising oxide-based materials such as aluminum oxide (Al2O3), silicon dioxide (SiO2), aluminosilicates, and mixtures thereof. Aluminosilicates may include crystalline materials such as mullite (3Al2O3-2SiO2), as well as glassy aluminosilicates.

[0024] In some embodiments, the reinforcing fibers may be bundled or coated prior to inclusion within the matrix. For example, bundles of the fibers may be formed as a reinforced ribbon, such as a unidirectional reinforced tape. A plurality of the tapes may be layered together to form a preform component. The fiber bundles may be impregnated with a slurry composition before preform formation or after preform formation. The preform may then undergo a thermal treatment, such as curing or burning to achieve a substantial carbon residue in the preform, and a subsequent chemical treatment, such as melt filtration with silicon, to arrive at a component formed from a CMC material having a desired chemical composition.

[0025] Such materials, as well as certain monolithic ceramics (i.e., ceramic materials without reinforcing material), are particularly suitable for higher temperature applications. In addition, these ceramic materials are lightweight compared to superalloys, but can still provide strength and durability to the component prepared therefrom. Therefore, such materials are currently being considered for many gas turbine components used in higher temperature sections of gas turbine engines, such as airfoils (e.g., turbines, and blades), combustors, shrouds, and other similar components, which would benefit from the lighter weight and higher temperature capability that these materials can offer.The present invention generally relates to manipulating layers of a composite material, such as a CMC material, to form a composite article. Placing the layers in a high curvature mold uses operating software that considers six degrees of freedom (DOF). The six DOF corresponds to movement along three translational dimensions and three rotational dimensions. Manipulating the layers along six DOF uses tight time synchronization and high-precision techniques for robotic arms that manipulate the layers. Tolerance stackups can cause stresses in the layers that reduce the accuracy of layer placement in the layup or disrupt the layers to create irregularities in the final article.

[0026] An end effector that includes a translator to control three additional translational dimensions and a rotator to control three additional rotational dimensions improves the accuracy of layer manipulation by circumventing tolerance stacking of robotic arms. More specifically, the end effector moves the layer in a specific orientation in a coordinate system that is local to the end effector, reducing tolerance stacking effects. The orientation is specified to reduce stresses in the layer, improving the accuracy of layer manipulation. and reducing stress-induced disturbance. Thanks to the improved accuracy, layers are superimposed with less divergence and improved strength.

[0027] Referring now to the figures, in which like numerals indicate like elements throughout the figures, [Fig. 1] is a block diagram of an exemplary system 10 for laying layers of a composite material in a layup. The system 10 includes a first robot 12, a second robot 14, and a layup region 16. The first robot 12 and the second robot 14 are configured to engage opposite ends of a layer of composite material ([Fig. 2]) and lay the layer on the layup region 16. More specifically, the first robot 12 includes a first robotic arm 18, and the second robot 14 includes a second robotic arm 20. The layers are laid on the layup region 16 in a layup for further processing.The overlay region 16 may be a suitable location for laying the layer, such as a table, a turntable, a stack of layers, or a composite body. The composite material may be a ceramic matrix composite (CMC) material, as described above. It will be appreciated that the composite material may be a different material, such as a polymer matrix composite (PMC) material. The PMC material may comprise a fiber preform comprising glass, carbon, silicon carbide, alumina, oxide fibers, or combinations thereof. Further, the fibers may be combined with polymeric materials including, but not limited to, thermoplastics, polyimides, polyethylenes, epoxies, phenolic systems, or combinations thereof.

[0028] Referring now to [Fig. 2], a schematic view of robots 12, 14 engaging a layer 30 of a composite material, such as a CMC material, is provided. More specifically, the first robotic arm 18 engages a first end 32 of the layer 30 at a first attachment location 34, and the second robotic arm 20 engages a second end 36 of the layer 30 at a second attachment location 38. It will be appreciated that the attachment locations 34, 38 may be one point, two or more points, a line, two or more lines, an area, or combinations thereof.

[0029] The first robotic arm 18 includes an end effector 100, a layer manipulator 102, and an optional force sensor 104. The end effector 100 is mounted to the first robotic arm 18, such as with fasteners, interference fits, threads, or combinations thereof. As described in more detail below, the end effector 100 is movable in six degrees of freedom (DOF) to control a movement of the first end 32 of the layer 30.

[0030] The layer manipulator 102 extends from the end effector 100 and engages the first end 32 of the layer 30 at the first attachment location 34. The layer manipulator 102 includes one or more devices that secure the layer 30 at the first attachment location 34. For example, the layer manipulator 102 may be a gripping device or a grasping device having two movable fingers. The two movable fingers are arranged on a top face 40 and a bottom face (not shown) of the layer 30 and engage the layer 30 at the first attachment location 34. As another example, the layer manipulator 102 may be a claw that supports the layer 30 from the bottom side. As yet another example, the layer manipulator 102 may be a pair of rollers that secure the top face 40 and the bottom face of the layer 30.

[0031] The force sensor 104 detects a force between the end effector 100 and the first end of the layer. More specifically, the force sensor 104 collects data indicative of stresses of the first end 32 of the layer 30 caused by the layer manipulator 102 engaging the layer 30. As an example, the force sensor 104 may be a piezoelectric sensor that generates an electrical current upon application of a force, and the electrical current may be measured by a controller or processor (FIG. 6) to generate data indicative of the specific amount of force experienced by the layer 30. The force sensor 104 is disposed on the end effector 100, such as on the layer manipulator 102.

[0032] The second robotic arm 20 includes a second layer manipulator 106 that engages the second end 36 of the layer 30 at the second attachment location 38. As with the layer manipulator 102, the second layer manipulator 106 may be a gripper or a grasper with two movable fingers that grasp the layer 30 at the second attachment location 38.

[0033] Referring now to [Fig. 3] through 4, an end effector 100 is illustrated. [Fig. 3] illustrates a perspective view of the end effector 100. [Fig. 4] illustrates an exploded view of the end effector 100.

[0034] The end effector 100 includes a translator 108, a rotator 110, and the layer manipulator 102. The translator 108 is a linear portion of the end effector 100 that is movable in three translational dimensions, and the rotator 110 is a rotatable portion of the end effector 100 that is movable in three rotational dimensions. Thus, the layer manipulator 102 is movable by the translator 108 and the rotator 110 along the three translational dimensions and the three rotational dimensions. The translational and rotational motion of the end effector 100 allows the layer manipulator 102 to adjust the layer in six degrees of freedom to reduce stresses in the layer. In the context of FIGS. 3-4, the three dimensions of translation are represented in a three-dimensional coordinate system along the first, second, and third axes represented in the three-dimensional coordinate system by X, Y, Z, and the three dimensions of rotation are represented in the three-dimensional coordinate system by 0f ¢), y / , representing 6 DGF. The X, Y, Z axes are orthogonal to each other, such that the X axis is orthogonal to the Y axis, the Y axis is orthogonal to the Z axis, and the X axis is orthogonal to the Z axis. The end effector 100 defines an origin O of the three-dimensional coordinate system to define coordinates that locate the layer manipulator 102.

[0035] The translator 108 includes a base 112 attached to the first robotic arm 18 ([Fig. 2]) and a platform 114 supported by the base 112. The base 112 moves other portions of the end effector 100 with the first robotic arm 18 ([Fig. 2]). The base 112 includes a base track 116 extending along a first translation dimension. In the exemplary end effector 100 of [Fig. 3], the base track 116 extends along the Z-axis. The platform 114 moves along the base track 116 to move the layer manipulator 102 forward and backward along the Z-axis.

[0036] The end effector 100 may include one or more devices 118 for moving the platform 114 along the base track 116, such as a linear actuator or a spring. More specifically, the device 118 may be a spring having a first end attached to the base 112 at a base location 120 and a second end attached to the platform 114 at a platform location 122. Forces from the layer 30 may compress or release the spring, moving the platform 114 along the Z-axis in the base track 116 in a passive manner.

[0037] Alternatively, the device 118 may be a linear actuator having a first end attached to the base 112 at the base location 120 and a second end attached to the platform 114 at the platform location 122. The linear actuator is actuated to move the platform 114 in the base track 116 along the Z-axis in an active manner. The linear actuator may be of any suitable type, such as a hydraulic actuator, a pneumatic actuator, an electric actuator, or combinations thereof.

[0038] The platform 114 includes a platform track 124 extending along a second translational dimension and a second platform track 126 extending along a third translational dimension. The platform track 124 extends along the X-axis, and the second platform track 126 extends along the Y-axis. More specifically, the platform 114 has an outer portion 128 and an inner portion 130. The platform track 124 is defined in the outer portion 128, and the inner portion 130 moves in the platform track 124 along the X-axis. The second platform track 126 is defined in the inner portion 130, extending along the Y-axis. The platform 114 may have one or more devices (not shown) for moving the inner portion 130 along the platform track 124, such as a linear actuator as described above.

[0039] The rotator 110 is supported by the inner portion 130 of the platform 114 to move the rotator 110 along the platform track 124. More specifically, the rotator 110 includes a rod 132 slidable along the second platform track 126. The rod 132 extends from the inner portion 130 and holds other portions of the rotator 110 to the inner portion 130 as the inner portion 130 (and the layer manipulator 102) moves along the X-axis. The rod 132 is movable along the second platform track 126, thereby moving the rotator 110 (and the layer manipulator 102) along the Y-axis. The inner portion 130 of the platform 114 may include one or more devices (not shown) or other features for moving or causing movement of the rod 132 along the second platform track 126, such as a spring or a linear actuator as described above.As an example, the end effector 100 may include a spring having a first end attached to the internal portion 130 of the platform 114 and a second end attached to the rotator 110.

[0040] The rotator 110 includes a disk 134 rotatably supported by the rod 132 and rotatable in the first rotational dimension, indicated by the direction that is rotational about the Z-axis. The rotator 110 includes an actuator, such as a motor, a gear, or a combination thereof, that is configured to rotate the disk 134 about the rod 132 in an active manner. The disk 134 rotates the layer manipulator 102 in the V-direction. In the exemplary embodiment of [Fig. 3]-4, the disk 134 may be a two-piece construction including a housing 134A and an insert 134B. Alternatively, the disk 134 may be a one-piece monolithic construction.

[0041] The rotator 110 includes an arcuate track 136 supported by the disk 134. The arcuate track 136 extends along a second rotational dimension, indicated in FIG. 3 by the direction (p) which is rotational about the Y axis. The layer manipulator 102 moves along the arcuate track 136 to move in the direction (p). The rotator 110 includes an actuator configured to move the layer manipulator 102 along the arcuate track 136, such as an actuator, a curved gantry, or combinations thereof.

[0042] The rotator 110 may include a second arcuate track 138 supported by the disc 134, the arcuate track 136, or both. The second arcuate track 138 extends along a third rotational dimension, shown in FIG. 3 by the 0 direction about the X axis. The layer manipulator 102 moves along the second arcuate track 138 to move in the 0 direction. It will be kept in mind that, when the disk 134 is rotating in the V7 direction, the arcuate tracks 136, 138 are rotating in the direction such that movement along the arcuate tracks 136, 138 can result in rotation in both the 0f (p) directions while the arcuate tracks 136, 138 maintain rotational dimensions that are orthogonal to each other.In other words, the three rotational dimensions remain orthogonal to each other even when the arcuate tracks 136, 138 are rotated away from the X and Y axes shown in [Fig. 3] through 4. The rotator 110 may include a second actuator configured to move the layer manipulator 102 along the second arcuate track 138, such as a curved actuator, a curved gantry, or combinations thereof.

[0043] In the exemplary end effector, the first arcuate track 136 and the second arcuate track 138 are configured such that their centers of curvature are concentric with each other and with a specified point, often referred to as the tool center point, on the layer manipulator 102 such that rotation about p or 0 can be achieved without translation of that point.

[0044] Referring to [Fig. 5A] through 5C, exemplary views of the end effector 100 are provided. [Fig. 5A] illustrates the end effector 100 in a default position. [Fig. 5B] illustrates the end effector 100 after the inner portion 130 has been moved in the platform track 124 along the X-axis. [Fig. 5C] illustrates the end effector 100 after the rod 132 has been moved in the second platform track 126 along the X-axis.

[0045] As illustrated in [Fig.5A], the end effector 100 may define a default position for the layer manipulator 102. In the default position, the robotic arm has moved the end effector 100 to engage the layer with the layer manipulator 102, and the end effector 100 has not performed any corrective action based on data from the force sensor 104. The default position is a set of coordinates from which the end effector 100 moves the layer manipulator 102 to reduce stresses in the layer.

[0046] As illustrated in [Fig.5B], the inner portion 130 of the platform 114 moves in the platform track 124 along the X-axis. More specifically, a spring or linear actuator moves the inner portion 130 to move the layer manipulator 102 along the X-axis. When the layer is positioned too far in a negative direction along the X-axis of the tolerance stack, the stresses in the layer increase. To reduce the stresses in the layer, the layer manipulator 102 moves in a positive direction along the X-axis, returning the layer to its intended location and reducing the stresses in the layer. The end effector 100 therefore moves the layer manipulator 102 along one degree of freedom of the three translational dimensions.

[0047] As illustrated in [Fig.5C], the inner portion 130 of the platform 114 moves in the platform track 124 along the X axis and the rod 132 moves in the second platform track 126 along the Y axis. More specifically, the inner portion 130 and the rod 132 move independently to move the layer manipulator 102 along the X and Y axes. The end effector 100 therefore moves the layer manipulator 102 along two degrees of freedom of the three translational dimensions. Although not illustrated in [Fig.5A] to 5C, the outer portion 128 of the platform 114 can move along the Z axis such that the end effector 100 moves the layer manipulator 102 along the X, Y, and Z axes, i.e., the three degrees of freedom of the three translational dimensions.

[0048] Referring now to FIGS. 6A-6C, further exemplary views of the end effector 100 are provided. FIG. 6A illustrates the end effector 100 rotating the layer manipulator 102 in the direction and in the 0 direction. FIG. 6B illustrates the end effector 100 rotating the layer manipulator 102 in the directions < / 6 0 et le long des axes X, Y. La FIG. 6C illustre l’effecteur d’extrémité 100 mettant en rotation le manipulateur de couche 102 dans les directions y / , Q et le long des axes X, Y.

[0049] As illustrated in [Fig.6A], the layer manipulator 102 moves along the arcuate track 136 and around the disk 134 to rotate in two rotational dimensions. More specifically, the layer manipulator 102 slides along the arcuate track 136 to rotate the layer manipulator 102 along two degrees of freedom of the three rotational dimensions. Such rotation may reduce torsional stresses in the layer. One or more rotary actuators may move the layer manipulator 102 within the arcuate track 136 and around the disk 134.

[0050] As illustrated in [Fig.6B], the layer manipulator 102 is rotating in two rotational dimensions and translating along two translational dimensions. More specifically, the inner portion 130 of the platform 114 moves in the platform track 124, the rod 132 moves in the second platform track 126, the disc 134 is rotating, and the layer manipulator 102 moves in the arcuate track 136. The movement of the layer manipulator 102 along two dimensions of rotation and two dimensions of translation (4 DOF) can reduce torsional stresses in the layer.

[0051] As illustrated in 6C, the layer manipulator 102 rotates in three rotational dimensions and moves along two translational dimensions. More specifically, the inner portion 130 of the platform 114 moves in the platform track 124, the rod 132 moves in the second platform track 126, the disk 134 is rotated, the layer manipulator 102 moves in the arcuate track 136, and the layer manipulator 102 moves in the second arcuate track 138. Moving the layer manipulator 102 along three rotational dimensions and two translational dimensions (5 DOF) can reduce torsional stresses in the layer. It will be appreciated that moving the layer manipulator 102 along the three rotational dimensions can also help shape the layer into a shape that facilitates layup on a mold surface.

[0052] Referring to [Fig. 7], a block diagram of a system 200 for controlling a first robotic arm 18, a second robotic arm 20, and an end effector 100 for the first robotic arm 18 is illustrated. The system 200 includes a controller 202 and an end effector module 204. The controller 202 and the end effector module 204 communicate via a suitable wired or wireless network. More specifically, the end effector module 204 provides data to the controller 202, and the controller 202 provides instructions to the end effector module 204 and a layer manipulator 102 based on the collected data.

[0053] With particular reference to the operation of the controller 202, in at least some embodiments, the controller 202 may include one or more processors 206 and one or more memory devices 208. The one or more processors 206 may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or another suitable processing device. The one or more memory devices 208 may include one or more computer-readable media, including, but not limited to, non-transitory computer-readable media, RAM, ROM, hard drives, flash drives, and / or other memory devices.

[0054] The one or more memory devices 208 may store information accessible by the one or more processors 206, including computer-readable instructions that may be executed by the one or more processors 206. The instructions may be any set of instructions that when executed by the one or more processors 206, cause the one or more processors 206 to perform operations. In some embodiments, the instructions may be executed by the one or more processors 206 to cause the one or more processors 206 to perform operations, such as any of the operations and functions for which the controller 202 is configured, the operations for laying a layer 30 (such as the method 300 of [Fig. 7]), as described herein, any other operations or functions of the one or more processors 206, or combinations thereof. The instructions may be software written in any suitable programming language or may be implemented in hardware. Additionally, and / or alternatively, the instructions may be executed in logically and / or virtually separate threads on the one or more processors 206.The one or more memory devices 208 may further store data that may be accessed by the one or more processors 206.

[0055] The controller 202 is configured to actuate the layer manipulator 102 to secure one end of the layer 30. More specifically, the controller 202 provides instructions to the layer manipulator 102 to engage or release a first end 32 of the layer 30 ([Fig. 2]). The layer manipulator 102 may include an actuator or other mechanical device that, upon receiving instructions from the controller 202, engages or releases the first end 32 of the layer 30 ([Fig. 2]).

[0056] The controller 202 is configured to move the layer 30 to a specified position in a three-dimensional coordinate system. In order to lay the layer 30, the controller 202 identifies an initial position of the layer 30, an overlay destination of the layer 30, and a trajectory from the initial position to the overlay destination that may include multiple intermediate positions. The initial position, the intermediate positions, and the overlay destination are each a respective set of coordinates and angles in the three-dimensional coordinate system that fully define the location and orientation of the layer input to the controller 202, and the trajectory is a set of coordinates and angles in the three-dimensional coordinate system along which the robotic arms move the layer 30.As described above, the stacking of tolerances may cause the layer 30 to deviate from the initial position, causing mechanical stresses in the layer 30.

[0057] The end effector module 204 is configured to adjust the layer 30 to a nominal position, reducing stresses in the layer 30. More specifically, the end effector module 204 receives data from the device command 202 indicating that the layer manipulator 102 has engaged the end of the layer 30 and instructions from the controller 202 to adjust the position of the layer 30 to the nominal position. The nominal position of the layer 30 input to the controller 202 may be defined as a combination of one or more of: its area, its perimeter, its major dimension length, its minor dimension length, or combinations thereof. For example, the nominal position of the layer 30 may be the set of coordinates of the coordinate system defining the perimeter of the layer 30.

[0058] Upon receiving instructions from the controller 202, the end effector module 204 collects data from a force sensor 104 indicative of the force acting on the layer 30. The force data may include data indicative of forces applied in three translational dimensions (e.g., X, Y, Z axes) and in three rotational dimensions (e.g., y / , 0, 0 directions). When the forces in one or more translational or rotational dimensions exceed a force threshold, the end effector module 204 instructs a rotator module 210 to rotate the layer manipulator 102 and a translator module 212 to translate the layer manipulator 102 in a specified direction to reduce the forces as detected by the force sensor 104 to a specified force less than the force threshold.The rotator module 210 directs one or more of the actuators or the rotator 110 to rotate components of the end effector 100, such as the disk 134, the arcuate track 136, or the second arcuate track 138, as described above. The translator module 212 directs one or more actuators of the translator 108 to translate components of the end effector 100, such as a platform 114 or a rod 132 as described above. After rotation and translation of the layer 30, the end effector controller 204 collects additional data from the force sensor 104 to determine the force experienced by the layer 30. When the data from the force sensor 104 indicates that the forces in the layer 30 are below the force threshold, the end effector controller 204 sends instructions to the controller 202.Although one force sensor 104 is described herein, it will be appreciated that the end effector module 204 may collect data from more than one force sensor 104.

[0059] Upon receiving instructions from the end effector module 204, the controller 202 actuates the first robotic arm 18 and the second robotic arm 20 to move the layer 30 along the trajectory to the overlay destination. Since the end effector controller end 204 moved the layer manipulator 102 with improved precision to reduce stresses in the layer 30, the layer 30 is laid on the overlay destination with less deviation than the robotic arms 18, 20 can move the layer 30 alone.

[0060] Additional instructions may be provided to the end effector controller 204 to rotate along the three rotational directions (e.g., the 0 directions) to achieve a state that enhances the layup of the layer 30. In one example, this may include translating and rotating the layer 30 to a predetermined intermediate position selected to move the layer 30 to a mold surface without unspecified contact with other portions of the mold surface. The "intermediate position" is a position between the nominal position and the mold surface that allows movement of the layer 30 to the mold surface without unspecified contact with other surfaces or to control the order in which one or more regions of the layer 30 contact the mold surface.In another example, this may include translations and rotations of the layer 30 as the layer 30 is placed on the mold surface to control the order in which various regions of the surface of the layer 30 contact the mold surface, thereby reducing or preventing disturbances of the layer 30.

[0061] Referring now to [Fig. 8], a flow diagram of a method 300 for laying a layer of a composite material according to an exemplary aspect of the present invention is provided. The method 300 of [Fig. 8] may be used to lay one or more of the exemplary CMC layers described above. Accordingly, it will be appreciated that the method 300 may generally be used to lay layers for any suitable composite material.

[0062] The method 300 begins at a step (302), in which a first robotic arm secures a first end of the layer of the composite material. The controller instructs a layer manipulator to secure the first end of the layer at a securing location. More specifically, the first robotic arm includes an end effector, and the layer manipulator extends from the end effector to engage the first end of the layer. The end effector is movable in at least two translational dimensions and at least two rotational dimensions.

[0063] The method 300 continues to a step (304), in which a second robotic arm secures a second end of the layer. The controller instructs a layer manipulator attached to the second robotic arm to secure the second end of the layer at a securing location.

[0064] The method 300 continues to a step (306), in which a force sensor detects a force between the first end of the layer and the end effector. The force sensor collects force data indicating the magnitudes and directions of the forces experienced by the layer. The source sensor transmits the collected force data to an end effector module of the end effector.

[0065] The method 300 continues to a step (308), in which the end effector controller determines a translation and rotation of the layer to reduce the detected force to a specified force less than a force threshold. More specifically, the end effector controller determines a specified position to move the attachment location of the layer to reduce the detected force to the specified force. Based on the direction and magnitude of the force data, the end effector controller determines the specified position such that moving the layer to the specified position causes the layer to experience lower forces, reducing stresses in the layer.To achieve the specified position, the end effector controller determines translation in up to three translation dimensions and rotation in up to three rotation dimensions, as described above.

[0066] The method 300 continues to a step (310), in which the end effector controller actuates the translator to translate the layer and the rotator to rotate the layer to the specified position according to the determined translation and rotation. As described above, the translator includes one or more components (such as a platform and a rod) that move the layer manipulator along three translation dimensions, and the rotator includes one or more components (such as an arcuate track and a disk) that move the layer manipulator along three rotation dimensions. To effect the translation and rotation, the end effector controller actuates one or more linear actuators of the translator and one or more rotary actuators of the rotator to move the layer manipulator to the specified position.

[0067] The method 300 continues to a step (312), in which the controller operates the first robotic arm and the second robotic arm to move the layer along a predetermined trajectory to the overlay destination. After performing the translation and rotation, the end effector controller sends an instruction to the controller to move the layer. The controller has the predetermined trajectory from an initial position to the overlay destination that the layer travels. The controller instructs the first robotic arm and the second robotic arm to move the layer along the predetermined trajectory, placing the layer at the overlay destination. After step (312), the method 300 may return to step (302) to move another layer. Otherwise, the method 300 terminates.

[0068] Other aspects are provided by the subject matter of the following clauses:

[0069] Apparatus for controlling a layer of a composite material, the apparatus comprising a robotic arm and an end effector mounted on the robotic arm. The end effector comprises a base attached to the robotic arm, the base comprising a base track extending along a first translational dimension, a platform supported by the base and movable along the base track, the platform comprising a platform track extending along a second translational dimension, a disk supported by the platform and movable along the platform track, the disk being rotatable about a first rotational dimension, an arcuate track supported by the disk, the arcuate track extending along a second rotational dimension, and a layer manipulator extending from the arcuate track and movable along the arcuate track.

[0070] Apparatus according to any preceding clause, wherein the end effector further comprises a second arcuate track extending along a third rotational dimension, wherein the second arcuate track is supported by the disc and the arcuate track is supported by the second arcuate track.

[0071] Apparatus according to any preceding clause, wherein the end effector further comprises a first actuator configured to rotate the disc about the first rotational dimension and a second actuator configured to move the layer manipulator along the arcuate track.

[0072] Apparatus according to any preceding clause, wherein the platform comprises a second platform track extending along a third translational dimension, and the disc is movable along the second platform track.

[0073] Apparatus according to any preceding clause, wherein the end effector further comprises a spring having a first end attached to the base and a second end attached to the platform.

[0074] Apparatus according to any one of the preceding clauses, wherein the end effector further comprises a linear actuator having a first end attached to the base and a second end attached to the platform.

[0075] Apparatus according to any one of the preceding clauses, wherein the end effector further comprises a spring having a first end attached to the platform and a second end attached to the disc.

[0076] Apparatus according to any preceding clause, wherein the end effector further comprises a rod slidable along the platform track, wherein the disc is rotatably supported by the rod.

[0077] Apparatus according to any preceding clause, further comprising a controller configured to operate the layer manipulator to fix one end of the layer and rotate the disk and the arcuate track to move the layer to a specified position in the first translational dimension and the second translational dimension and the first rotational dimension and the second rotational dimension, the specified position being defined by a set of coordinates in the first translational dimension and the second translational dimension and the first rotational dimension and the second rotational dimension.

[0078] Apparatus according to any preceding clause, wherein the end effector defines an origin in a three-dimensional coordinate system and the first translation dimension and the second translation dimension define a first axis and a second axis of the three-dimensional coordinate system, the first axis being orthogonal to the second axis.

[0079] Apparatus according to any preceding clause, wherein the end effector is movable along a third translational dimension defining a third axis of the three-dimensional coordinate system, the third axis being orthogonal to the first axis and the second axis.

[0080] Apparatus according to any one of the preceding clauses, wherein the platform is movable along two of the first axis, the second axis, and the third axis of the three-dimensional coordinate system, and wherein the base is movable along one of the first axis, the second axis, and the remaining third axis of the three-dimensional coordinate system.

[0081] A method of laying a layer of a composite material, the method comprising securing a first end of the layer with an end effector of a first robotic arm, the end effector being movable in at least two translational dimensions and at least two rotational dimensions, securing a second end of the layer with a second robotic arm, translating and rotating the first end of the layer with the end effector to a specified position in the at least two translational dimensions and the at least two rotational dimensions, and moving the layer with the first robotic arm and the second robotic arm along a predetermined path to a layup destination.

[0082] A method according to any one of the preceding clauses, wherein the end effector comprises a linear portion and a rotary portion, wherein translating the first end of the layer further comprises translating the first end of the layer in the at least two translation dimensions with the linear portion and the rotation of the first end of the layer in the at least two rotational dimensions with the rotating portion.

[0083] A method according to any one of the preceding clauses, further comprising actuating a linear actuator to translate the linear portion and actuating a rotation actuator to rotate the rotary portion.

[0084] A method according to any preceding clause, further comprising detecting a force between the first end of the layer and the end effector and determining the specified position to reduce the detected force below a force threshold.

[0085] A method according to any preceding clause, further comprising determining the specified position to reduce the detected force to a specified force, the specified force being less than the force threshold.

[0086] A method according to any preceding clause, wherein detecting force further comprises collecting force data from a force sensor.

[0087] A method according to any preceding clause, further comprising translating and rotating the first end of the layer with the end effector to the specified position in three translational dimensions and three rotational dimensions, the specified position being defined by a set of coordinates in the three translational dimensions and the three rotational dimensions.

[0088] An apparatus for controlling a layer of a composite material, the apparatus comprising a first robotic arm configured to control a position of a first location of the layer in multiple degrees of freedom, the multiple degrees of freedom comprising one or more translational degrees of freedom and one or more rotational degrees of freedom, and a second robotic arm configured to control a position of a second location of the layer in the multiple degrees of freedom, the first robotic arm and the second robotic arm being configured to place the layer at a layup destination, wherein the first robotic arm further comprises an end effector,the end effector comprising a translator configured to control the position of the first location of the layer in the one or more translational degrees of freedom and a rotator configured to control the position of the first location of the layer in the one or more rotational degrees of freedom.

[0089] This written description uses examples to describe the present invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and carrying out any methods incorporated therein. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

Claims

1. An apparatus for controlling a layer of a composite material, the apparatus comprising: a robotic arm (18); and an end effector (100) mounted on the robotic arm, the end effector (100) comprising: a base (112) attached to the robotic arm (18), the base (112) having a base track (116) extending along a first translational dimension; a platform (114) supported by the base (112) and movable along the base track (116), the platform (114) having a platform track (124) extending along a second translational dimension; a disk (134) supported by the platform (114) and movable along the platform track (124), the disk (134) being rotatable about a first rotational dimension; an arcuate track (136) supported by the disc (134), the arcuate track (136) extending along a second rotational dimension;and a layer manipulator (102) extending from the arcuate track (136) and movable along the arcuate track (136).;

2. The apparatus of claim 1, wherein the end effector (100) further comprises a second arcuate track (138) extending along a third rotational dimension, wherein the second arcuate track (138) is supported by the disc (134) and the arcuate track (136) is supported by the second arcuate track (138).

3. Apparatus according to any preceding claim, wherein the end effector (100) further comprises a first actuator configured to rotate the disc (134) about the first rotational dimension and a second actuator configured to move the layer manipulator (102) along the arcuate track (136).

4. Apparatus according to any preceding claim, wherein the platform (114) has a second platform track (126) extending along a third translational dimension, and the disc (134) is movable along the second platform track (126).

5. Apparatus according to any preceding claim, wherein the end effector (100) further comprises a spring having a first end attached to the base (112) and a second end attached to the platform (114).

6. Apparatus according to any preceding claim, wherein the end effector (100) further comprises a linear actuator having a first end attached to the base (112) and a second end attached to the platform (114).

7. Apparatus according to any preceding claim, wherein the end effector (100) further comprises a spring having a first end attached to the platform (114) and a second end attached to the disc (134).

8. Apparatus according to any preceding claim, wherein the end effector (100) further comprises a rod (132) slidable along the platform track (124), wherein the disc (134) is rotatably supported by the rod (132).

9. The apparatus of any preceding claim, further comprising: a controller (202) configured to operate the layer manipulator (102) to fix one end of the layer and to rotate the disk (134) and the arcuate track (136) to move the layer to a specified position in the first and second translational dimensions and the first and second rotational dimensions, the specified position being defined by a set of coordinates in the first and second translational dimensions and the first and second rotational dimensions.

10. Apparatus according to any preceding claim, wherein the end effector (100) defines an origin in a three-dimensional coordinate system and the first translation dimension and the second translation dimension define a first axis and a second axis of the three-dimensional coordinate system, the first axis being orthogonal to the second axis.

11. Apparatus according to any preceding claim, wherein the end effector (100) is movable along a third translational dimension defining a third axis of the three-dimensional coordinate system, the third axis being orthogonal to the first and second axes.

12. Apparatus according to any preceding claim, wherein the platform (114) is movable along two of the first, second, and third axes of the three-dimensional coordinate system, and wherein the base (112) is movable along one of the remaining first, second, and third axes of the three-dimensional coordinate system.

13. A method for laying a layer of a composite material, the method comprising: securing a first end (32) of the layer with an end effector (100) of a first robotic arm (18), the end effector (100) being movable in at least two translational dimensions and at least two rotational dimensions; securing a second end (36) of the layer with a second robotic arm (20); translating and rotating the first end (32) of the layer with the end effector (100) to a specified position in the at least two translational dimensions and the at least two rotational dimensions; and moving the layer with the first robotic arm (18) and the second robotic arm (20) along a predetermined trajectory to a layup destination (16).

14. The method of claim 13, wherein the end effector (100) comprises a linear portion and a rotatable portion, wherein translating the first end (32) of the layer further comprises translating the first end (32) of the layer in the at least two translational dimensions with the linear portion and rotating the first end (32) of the layer in the at least two rotational dimensions with the rotatable portion.

15. The method of any one of claims 13 to 14, further comprising translating and rotating the first end (32) of the layer with the end effector (100) to the specified position in three translational dimensions and three rotational dimensions, the specified position being defined by a set of coordinates in the three translational dimensions and the three rotational dimensions.

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