Patent Description:
It may be desirable to perform a plurality of operations on a large part, such as an aircraft and/or a component thereof. However, it may be difficult to precisely perform the plurality of operations at desired locations on the composite part in an automated fashion and/or utilizing conventional robotic systems, which may determine a location for each operation based upon and/or within a global coordinate system. Thus, there exists a need for layup mandrels with embedded textured pins, for methods of manufacturing layup mandrels, for methods of repairing layup mandrels, for systems for forming composite parts, for methods of forming composite parts, for robotic systems, and for methods of operating robotic systems, according to the present disclosure. <CIT> discloses a boundary between a grained surface and a smooth surface to be seen in a resin molded product facilitating manufacture and grinding of a mold for molding a resin. A resin molded product has a smooth surface adjacent to a grained surface on which microscopic asperities are formed. A step surface protruding toward the grained surface is formed on a boundary between the grained surface and the smooth surface.

Systems for forming composite parts, methods of forming composite parts, and methods of precisely performing a plurality of operations on a composite part are disclosed herein. The systems include a layup mandrel that includes a mandrel body and a plurality of regions of isotropic surface finish. The mandrel body defines a layup surface that defines a layup surface finish roughness. The each region of isotropic surface finish defines an isotropic surface finish roughness that is greater than the layup surface finish roughness. A location of each region of isotropic surface finish corresponds to a desired location for a fastener hole within a composite part.

The methods of forming the composite part include positioning a plurality of plies of composite material on a layup mandrel, conforming the plurality of plies of composite material to a layup surface shape of the layup mandrel, and curing the plurality of plies of composite material to define the composite part. The layup mandrel includes a mandrel body that defines a layup surface that defines a layup surface finish roughness. The layup mandrel also includes a plurality of regions of isotropic surface finish spaced-apart on the layup surface. The isotropic surface finish defines an isotropic surface finish roughness that is greater than the layup surface finish roughness, and a location of each region of isotropic surface finish of the plurality of regions of isotropic surface finish corresponds to a desired location for a fastener hole within the composite part. The conforming includes imprinting, within at least a mandrel-contacting ply of the plurality of plies of composite material, the layup surface finish roughness within regions of the mandrel-contacting ply that contact the layup surface and the isotropic surface finish roughness within regions of the mandrel-contacting ply that contact the plurality of regions of isotropic surface finish. Subsequent to the curing, the composite part includes a plurality of spaced-apart imprinted features, and a location of each spaced-apart imprinted feature of the plurality of spaced-apart imprinted features corresponds to a location of a corresponding region of isotropic surface finish of the plurality of regions of isotropic surface finish.

The methods of precisely performing the plurality of operations on a composite part include detecting a corresponding imprinted feature of a plurality of imprinted features, aligning an operating assembly of an end effector of a robotic system relative to the corresponding imprinted feature, and performing a corresponding operation of the plurality of operations on the composite part. The detecting includes detecting with a vision system of the end effector, and the corresponding imprinted feature has an isotropic feature surface finish with a roughness that is greater than a surface roughness of a remainder of the composite part. The aligning includes aligning with a positioning system of the robotic system. The performing includes performing with the operating assembly of the robotic system.

<FIG> provide illustrative, non-exclusive examples of composite part assemblies <NUM>, of systems <NUM> for forming a composite part, of robotic systems <NUM>, of layup mandrels <NUM>, and/or of methods <NUM>, <NUM>, <NUM>, and <NUM>, according to the present disclosure. Elements that serve a similar, or at least substantially similar, purpose are labeled with like numbers in each of <FIG>, and these elements may not be discussed in detail herein with reference to each of <FIG>. Similarly, all elements may not be labeled in each of <FIG>, but reference numerals associated therewith may be utilized herein for consistency. Elements, components, and/or features that are discussed herein with reference to one or more of <FIG> may be included in and/or utilized with any of <FIG> without departing from the scope of the present disclosure.

In general, elements that are likely to be included in a given (i.e., a particular) embodiment are illustrated in solid lines, while elements that are optional to a given embodiment are illustrated in dashed lines. However, elements that are shown in solid lines are not essential to all embodiments, and an element shown in solid lines may be omitted from a particular embodiment without departing from the scope of the present disclosure.

<FIG> is a schematic illustration of an example of a composite part assembly <NUM>, in the form of an aircraft <NUM>, that may include, utilize, be formed from, and/or be formed utilizing layup mandrels <NUM>, systems <NUM> for forming a composite part, robotic systems <NUM>, and/or methods <NUM>, <NUM>, <NUM>, and/or <NUM>, according to the present disclosure. Composite part assembly <NUM>, in the form of aircraft <NUM> includes a plurality of components, including a fuselage <NUM>, a wing <NUM>, a tail <NUM>, an engine <NUM>, a skin <NUM>, and a frame <NUM>. At least one component of composite part assembly <NUM> may include and/or be a composite part <NUM>, which may be formed from and/or defined by a plurality of plies <NUM> of composite material. In some examples, composite part <NUM> may include a plurality of fastener holes <NUM> and/or may be operatively attached to at least one other component of composite part assembly <NUM> with, via, and/or utilizing a plurality of fasteners <NUM>.

During fabrication of large and/or complex composite part assemblies <NUM>, such as during fabrication of aircraft <NUM>, it may be important to precisely and/or accurately position fastener holes <NUM>, and corresponding fasteners <NUM>, relative to a remainder of the composite part assembly. As discussed in more detail herein, systems <NUM>, robotic systems <NUM>, layup mandrels <NUM>, and/or methods <NUM>, <NUM>, <NUM>, and <NUM>, according to the present disclosure, may permit and/or facilitate this accurate and/or precise positioning. More specifically, and also discussed in more detail herein, systems <NUM>, layup mandrels <NUM>, and/or methods <NUM>, <NUM>, and/or <NUM> may be utilized to form and/or define composite parts <NUM> that include imprinted features <NUM>, as illustrated in <FIG>. In addition, robotic systems <NUM> and/or methods <NUM> may utilize and/or reference imprinted features <NUM> to precisely position fastener holes <NUM> within which fasteners <NUM> may be positioned.

<FIG> is a schematic illustration of examples of systems <NUM> for forming a composite part and/or of layup mandrels <NUM> that may be utilized therein, according to the present disclosure. <FIG> are less schematic illustrations of examples of a regions of layup mandrels <NUM>, according to the present disclosure. <FIG> is an image illustrating an example of a composite part <NUM> that includes an unprimed imprinted feature <NUM> that includes an isotropic surface finish as viewed by a vision system of a robotic system, according to the present disclosure, such as a vision system <NUM> of robotic system <NUM> of <FIG>. <FIG> is an image illustrating an example of composite part <NUM> that includes a primed, or painted, imprinted feature <NUM> that includes an isotropic surface finish as viewed by vision system <NUM>.

As illustrated in <FIG>, systems <NUM>, which are configured for forming composite parts <NUM> that include imprinted features <NUM>, include a layup mandrel <NUM>. Layup mandrel <NUM> includes a mandrel body <NUM> that includes and/or defines a layup surface <NUM>. Layup surface <NUM> has and/or defines a layup surface finish roughness. Layup mandrel <NUM> also includes a plurality of regions <NUM> of isotropic surface finish. Regions <NUM> are spaced-apart on layup surface <NUM>, and each region <NUM> defines an isotropic surface finish roughness that is greater than the layup surface finish roughness. In addition, a location of each region <NUM> corresponds to a desired location for a fastener hole within the composite part, such as fastener hole <NUM> in composite part <NUM> of <FIG>.

Regions <NUM> may have and/or define any suitable isotropic surface finish roughness. As used herein, the phrase "isotropic surface finish roughness" refers to a surface finish roughness that is non-directional, that is omnidirectional, and/or that is the same, or at least substantially the same, as measured within, parallel to, and/or a least substantially parallel to a plane of layup surface <NUM>. Stated differently, the isotropic surface finish roughness of regions <NUM> is uniform within regions <NUM> and/or does not vary with direction within regions <NUM>. Such a configuration has been shown to produce and/or to generate imprinted features <NUM> that are durable and/or that readily may be recognized by vision systems <NUM> of robotic systems <NUM> of <FIG>. In addition, such a configuration also permits imprinted features <NUM> to be "fly away" features that need not be removed prior to placing an aircraft <NUM>, as illustrated in <FIG>, that includes such features into service. Stated differently, a size, an extent, and/or a roughness of imprinted features <NUM> may be such that imprinted features <NUM> comply with applicable manufacturing standards for inclusion within aircraft <NUM>.

Examples of the isotropic surface finish roughness include roughness average (Ra) roughnesses of at least <NUM> micrometer (µm), at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM> , at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>.

In some examples, the isotropic surface finish roughness of regions <NUM> may be a threshold roughness multiple of the layup surface finish roughness of layup surface <NUM>. Stated differently, the isotropic surface finish roughness may be a product of the threshold roughness multiple and the layup surface finish roughness. Examples of the threshold roughness multiple include at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>.

In some examples, and as discussed in more detail herein, regions <NUM> may be formed and/or defined by a plurality of isotropically textured pin end surfaces of a plurality of textured pin ends <NUM> of a plurality of textured pins <NUM>. As an example, and as also discussed in more detail herein, mandrel body <NUM> may define a plurality of pin-receiving holes <NUM>. In such a configuration, each textured pin <NUM> may be positioned within a corresponding pin-receiving hole <NUM> such that the isotropically textured pin end surface of textured pin end <NUM> faces away from the layup mandrel.

As illustrated in dashed lines in <FIG>, system <NUM> may include and/or may be utilized with a plurality of plies <NUM> of composite material. As an example, and as discussed in more detail herein, plies <NUM> may be positioned on layup mandrel <NUM> and/or on layup surface <NUM> thereof, such as to form and/or define an uncured composite part <NUM>.

As also illustrated in dashed lines in <FIG>, system <NUM> may include and/or may be utilized with a cure oven <NUM>. As an example, cure oven <NUM> may be utilized to heat uncured composite part <NUM>, such as to cure uncured composite part <NUM> and/or to define composite part <NUM> that includes imprinted features <NUM>.

During operative use of systems <NUM> to form and/or to define composite part <NUM>, and as discussed in more detail herein with reference to methods <NUM> of <FIG>, plies <NUM> may be positioned on layup surface <NUM> of layup mandrel <NUM>. Plies <NUM> then may be conformed to a layup surface shape of layup surface <NUM> to define uncured composite part <NUM>. This may include conforming such that at least a mandrel-contacting ply of plies <NUM> is imprinted with the layup surface finish roughness in regions of the mandrel-contacting ply that contact layup surface <NUM>. In addition, regions of the mandrel-contacting ply that contact regions <NUM> of isotropic surface finish are imprinted with the isotropic surface finish roughness. This is illustrated, for example, in <FIG>, where regions <NUM> of composite part <NUM> that contacted layup surface <NUM> of <FIG> during formation of composite part <NUM> visually contrast with regions <NUM> of composite part <NUM> that contacted regions <NUM> of isotropic surface finish.

Subsequently, uncured composite part <NUM> may be cured within and/or by cure oven <NUM>. Thus curing may form and/or define composite part <NUM> with corresponding imprinted features <NUM>.

Turning more generally to <FIG>, layup mandrels <NUM>, according to the present disclosure, include any suitable structure that defines layup surface <NUM>, which has the corresponding layup surface finish roughness, and that also defines regions <NUM> of isotropic surface finish, which have the corresponding isotropic surface finish roughness. As an example, regions <NUM> of isotropic surface finish simply may be roughened regions of mandrel body <NUM>. As another example, layup mandrels <NUM> may include mandrel body <NUM> and textured pins <NUM>. In such examples, mandrel body <NUM> defines layup surface <NUM>, which is configured to receive plies <NUM> to define a surface contour of composite part <NUM>. In addition, mandrel body <NUM> also defines pin-receiving holes <NUM>, which extend from layup surface <NUM> and/or into the mandrel body. Textured pins <NUM> are positioned within corresponding pin-receiving holes <NUM> and have textured pin ends <NUM> that define the isotropically textured pin end surface and that face away from layup mandrel <NUM>. Stated differently, and in such examples, textured pin ends <NUM> may form, at least partially define, or even completely define regions <NUM> of isotropic surface finish and/or the corresponding isotropic surface finish roughness.

Textured pins <NUM> may include and/or be any suitable structure that may be adapted, configured, sized, finished, and/or constructed to be positioned within pin-receiving holes <NUM> and/or to define textured pin ends <NUM> with the corresponding isotropically textured pin end surface. In some examples, textured pins <NUM> may be sized for a friction fit within corresponding pin-receiving holes <NUM>. In some examples, and as illustrated in dashed lines in <FIG>, textured pins may be sized for a slip fit within pin-receiving holes <NUM> and/or layup mandrels <NUM> may include an adhesive material <NUM> that may be positioned within pin-receiving holes <NUM> and/or that may be configured to adhesively retain textured pins <NUM> within corresponding pin-receiving holes <NUM>. Additionally or alternatively, textured pins <NUM> may be threaded into pin-receiving holes <NUM> and/or may be retained within pin-receiving holes <NUM> with a corresponding fastener.

Textured pins <NUM> may have and/or define any suitable size and/or shape. As an example, textured pins <NUM> may include a cylindrical, or at least substantially cylindrical, pin region. Stated differently, textured pins <NUM> may include and/or be cylindrical, or at least partially cylindrical.

As another example, textured pins <NUM> may define a pin diameter <NUM>, an average pin diameter, and/or an effective pin diameter. Examples of pin diameter <NUM> include at least <NUM> millimeters (mm), at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>. A more specific example of pin diameter <NUM> is <NUM>/<NUM> inches, or <NUM>. A particular pin diameter <NUM> may be selected based upon a preferred size, or diameter, for imprinted features <NUM> that may be formed utilizing a given textured pin <NUM>.

As yet another example, textured pins <NUM> may define a pin length <NUM>, or an average pin length. Examples of pin length <NUM> include at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>. A given pin length <NUM> may be selected based, at least in part, upon a thickness of mandrel body <NUM> and/or a desired retention force for textured pins <NUM> within mandrel body <NUM>.

In some examples, textured pin end <NUM> may include and/or be a circular, or at least substantially circular, textured pin end <NUM>. In some examples, textured pin end <NUM> may include and/or be a planar, or at least substantially planar, textured pin end. In some examples, textured pin end <NUM> may extend perpendicular, or at least substantially perpendicular, to an elongate axis, or to a cylindrical axis, of each textured pin <NUM>.

In some examples, textured pin end <NUM> is an abrasive grit blasted textured pin end. Examples of the roughness of textured pin end <NUM> are disclosed herein with reference to the isotropic surface finish roughness imprinted features <NUM>. Examples of a roughness ratio of the Ra roughness of textured pin end <NUM> to the Ra roughness of the layup surface are disclosed herein with reference to the roughness ratio of the Ra roughness of imprinted features <NUM> to the Ra roughness of the remainder of composite part <NUM>.

In some examples, and as illustrated in <FIG>, textured pin end <NUM> may be coplanar, or at least substantially coplanar, with a region of layup surface <NUM> that defines the corresponding pin-receiving hole <NUM>. Additionally or alternatively, textured pin end <NUM> may be coplanar, or at least substantially coplanar, with an opening into the corresponding pin-receiving hole <NUM> that is defined by layup surface <NUM>.

In some examples, and as illustrated in <FIG>, textured pin end <NUM> may be within a threshold pin end offset distance <NUM> of the region of layup surface <NUM> that defines the corresponding pin-receiving hole <NUM> and/or the opening into the corresponding pin-receiving hole <NUM> that is defined by layup surface <NUM>. Examples of threshold pin end offset distance <NUM> include at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, or at most <NUM>. Pin end offset distance <NUM> may, in some examples, simply be based upon a manufacturing tolerance for layup mandrels <NUM>. Additionally or alternately, and in some examples, pin end offset distance <NUM> may be selected to provide a desired visibility, height, and/or depth of imprinted features <NUM> that are formed therefrom.

Mandrel body <NUM> may include any suitable structure that may define layup surface <NUM> and/or pin-receiving holes <NUM>. In addition, pin-receiving holes <NUM> may have and/or define any suitable size and/or shape, such as may be sized for the friction-fit or for the slip-fit with textured pins <NUM>. As an example, pin-receiving holes <NUM> may define a hole diameter <NUM>, an average hole diameter, and/or an effective hole diameter. Examples of hole diameter <NUM> include at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>. A more specific example of hole diameter <NUM> is <NUM>.

When pin-receiving holes <NUM> are sized for the friction-fit with textured pins <NUM>, hole diameter <NUM> may be less, or slightly less, than pin diameter <NUM>. Alternatively, when pin-receiving holes <NUM> are sized for the slip-fit with textured pins <NUM>, hole diameter <NUM> may be greater, or slightly greater, than pin diameter <NUM>. Examples of a magnitude of a difference between hole diameter <NUM> and pin diameter <NUM> include at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, or at most <NUM>.

Similarly, pin-receiving holes <NUM> may have and/or define any suitable hole depth <NUM>, or average hole depth. Examples of hole depth <NUM> include at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>. In some examples, hole depth <NUM> may correspond to, or equal, pin length <NUM>. In some examples, a shape of pin-receiving holes <NUM> may correspond to a shape of textured pins <NUM>.

It is within the scope of the present disclosure that at least one material property of mandrel body <NUM> may differ from a corresponding material property of textured pins <NUM>. Such a configuration may provide improved durability for layup mandrels <NUM>, may facilitate cleaning of layup mandrels <NUM>, and/or may facilitate repair of layup mandrels <NUM>. As an example, mandrel body <NUM> may be defined by a mandrel body material, textured pins <NUM> may be defined by a textured pin material, and/or the mandrel body material may differ from the textured pin material. Examples of the mandrel body material include a polymer, a carbon-fiber-reinforced polymer, a metal, aluminum, an aluminum alloy, structural steel, a nickel-iron alloy, and/or 64FeNi (Invar). Examples of the textured pin material include a thermoplastic, a polyetheretherketone, a metal, a steel, a mild steel, and/or a stainless steel.

In some examples, the textured pin material may define a textured pin hardness that is greater than a mandrel body material hardness of the mandrel body material. As examples, a ratio of the textured pin material hardness to the mandrel body material hardness may be at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>. In some examples, the textured pin material may define a textured pin material durability that is greater than a mandrel body material durability of the mandrel body material.

<FIG> are schematic illustrations of examples of robotic systems <NUM>, according to the present disclosure. Robotic systems <NUM> may be configured to accurately and/or precisely perform a plurality of operations on a composite part <NUM> that includes a plurality of imprinted features <NUM>.

As illustrated in <FIG>, robotic systems <NUM> include an end effector <NUM>. End effector <NUM> includes a vision system <NUM>, which is configured to detect a corresponding imprinted feature <NUM> on a surface <NUM> of composite part <NUM>. The corresponding imprinted feature <NUM> has an isotropic feature surface finish with a roughness that is greater than a surface roughness of a remainder of composite part <NUM>. End effector <NUM> also includes an operating assembly <NUM>, which is configured to perform the plurality of operations on composite part <NUM>.

Robotic systems <NUM> also include a positioning system <NUM>. Positioning system <NUM> is configured to position end effector <NUM> relative to composite part <NUM>.

Robotic systems <NUM> also include a controller <NUM>. Controller <NUM> is programmed to control the operation of robotic systems <NUM> such that robotic systems <NUM> perform each operation of the plurality of operations at a corresponding operation location <NUM> that corresponds to a location of the corresponding imprinted feature <NUM>. In some examples, and as illustrated in <FIG>, controller <NUM> may control robotic systems <NUM> such that the corresponding operation location <NUM> is on and/or at the corresponding imprinted feature <NUM>. In some examples, controller <NUM> may control robotic systems <NUM> such that the corresponding operation location <NUM> is offset from, or has a consistent offset from, the corresponding imprinted feature <NUM>.

In some examples, and as illustrated in dashed lines in <FIG>, positioning system <NUM> may include a rough positioning system <NUM> and a fine positioning system <NUM>. In such examples, controller <NUM> may be programmed to position end effector <NUM> proximate corresponding imprinted feature <NUM> utilizing rough positioning system <NUM> and to, or then to, refine the position of end effector <NUM> relative to corresponding imprinted feature <NUM> utilizing fine positioning system <NUM>. Examples of rough positioning system <NUM> and/or of fine positioning system <NUM> include a mechanical positioning device, an electromechanical positioning device, an electrical positioning device, a linear actuator, a rack and pinion assembly, a lead screw and nut assembly, a ball screw and nut assembly, a motor, a linear motor, a stepper motor, a servo motor, and/or a piezoelectric element. In some examples, positioning system <NUM>, rough positioning system <NUM>, and/or fine positioning system <NUM> may be configured to position, to move, and/or to rotate end effector <NUM> along and/or about one axis, along and/or about two perpendicular axes, and/or along and/or about three orthogonal axes.

Rough positioning system <NUM> and fine positioning system <NUM> may have and/or define any suitable relative accuracy. As examples, rough positioning system <NUM> may have a positioning accuracy of at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>. As additional examples, fine positioning system <NUM> may have a positioning accuracy of at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>. In some examples, a ratio of a positioning accuracy of fine positioning system <NUM> to a positioning accuracy of rough positioning system <NUM> may be at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, or at least <NUM>.

In some examples, operating assembly <NUM> may include and/or be a drilling assembly <NUM>. Drilling assembly <NUM> may include a drill bit <NUM> and/or may be configured to define a plurality of fastener holes <NUM> within composite part <NUM>. Stated differently, and when operating assembly <NUM> includes drilling assembly <NUM>, the plurality of operations performed by robotic system <NUM> may include drilling the plurality of fastener holes <NUM> within composite part <NUM>.

In some such examples, vision system <NUM> may be configured to view corresponding imprinted feature <NUM> along an optical axis <NUM>, as illustrated in <FIG>. Also in some such examples, drilling assembly <NUM> may be configured to define a corresponding fastener hole <NUM> by extending drill bit <NUM> along a drilling axis <NUM>, as illustrated by the transition from the configuration that is illustrated in <FIG> to the configuration that is illustrated in <FIG>. Also in some such examples, optical axis <NUM> may be coaxial, or at least substantially coaxial, with drilling axis <NUM>, at least when vision system <NUM> views corresponding imprinted feature <NUM> and/or when vision system <NUM> is utilized to align operating assembly <NUM> with corresponding imprinted feature <NUM>. To permit and/or to facilitate such a configuration, vision system <NUM> may be configured to move and/or to pivot such that optical axis <NUM> is coaxial with drilling axis <NUM> during the alignment and also to move and/or pivot such that optical axis <NUM> is spaced-apart from drilling axis <NUM> when drill bit <NUM> is extended into composite part <NUM>, as illustrated by the transition between the configuration that is illustrated in <FIG> and the configuration that is illustrated in <FIG>. This motion and/or pivoting of vision system <NUM> may be performed utilizing a pivot mechanism <NUM> of vision system <NUM>.

In some examples, and as illustrated in dashed lines in <FIG>, robotic system <NUM> may include a normality detection system <NUM>. Normality detection system <NUM> may be configured to detect an orientation, or an angular orientation, of operating assembly <NUM> and/or of drilling assembly <NUM> relative to surface <NUM> of composite part <NUM>. In some examples, normality detection system <NUM> and/or controller <NUM> may align operating assembly <NUM> and/or drilling assembly <NUM> normal to surface <NUM> utilizing information from normality detection system <NUM>. In some examples, normality detection system <NUM> and/or controller <NUM> may align operating assembly <NUM> and/or drilling assembly <NUM> at a specified and/or predetermined angle relative to surface <NUM>. Examples of normality detection system <NUM> include at least three spaced-apart lasers and/or at least three spaced-apart mechanical actuators, which may be utilized to detect alignment and/or normality between surface <NUM> and operating assembly <NUM>.

As discussed, robotic systems <NUM> and/or vision systems <NUM> thereof may be adapted, configured, designed, and/or constructed to detect imprinted features <NUM> that have an isotropic feature surface finish with a roughness that is greater than a roughness of a remainder of composite part <NUM>, such as a region of surface <NUM> that is external imprinted features <NUM>. It is within the scope of the present disclosure that the roughness of imprinted features <NUM> may have and/or define any suitable roughness value. As examples, imprinted features <NUM> may define a roughness average (Ra) roughness of at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM> , at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>.

It is also within the scope of the present discourse that the roughness of imprinted features <NUM> may differ from the roughness of the remainder of composite part <NUM> in any suitable manner. As examples, a roughness ratio of the Ra roughness of imprinted features <NUM> to the Ra roughness of the remainder of composite part <NUM> may be at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, at most <NUM>, and/or at most <NUM>. The roughness of imprinted features <NUM> may include and/or be an isotropic surface finish roughness, examples of which are disclosed herein.

<FIG> is a flowchart depicting examples of methods <NUM> of manufacturing a layup mandrel for a composite part, according to the present disclosure. Examples of the layup mandrel are disclosed herein with reference to layup mandrel <NUM>. Examples of the composite part are disclosed herein with reference to composite part <NUM>.

Methods <NUM> include providing a mandrel body at <NUM> and defining pin-receiving holes at <NUM>. Methods <NUM> also may include grit blasting textured pins at <NUM> and/or positioning adhesive at <NUM> and inserting textured pins at <NUM>.

Providing the mandrel body at <NUM> may include providing any suitable mandrel body that defines a layup surface. The layup surface may be configured to receive a plurality of plies of composite material and/or to define a surface contour for the composite part. Examples of the mandrel body are disclosed herein with reference to mandrel body <NUM>.

Defining the pin-receiving holes at <NUM> may include forming, defining, and/or establishing a plurality of pin-receiving holes within the mandrel body. Each pin-receiving hole may extend from the layup surface into the mandrel body. Examples of the pin-receiving holes are disclosed herein with reference to pin-receiving holes <NUM>.

The defining at <NUM> may be performed in any suitable manner, such as via any suitable additive and/or subtractive machining and/or manufacturing process. In a specific example, the defining at <NUM> may include drilling the plurality of pin-receiving holes in and/or within the mandrel body. In some examples, the defining at <NUM> may include defining a plurality of blind pin-receiving holes.

As discussed in more detail herein, the composite part may be configured to be utilized within a composite part assembly. In such examples, within the composite part assembly, the composite part may include a plurality of fastener holes, and a corresponding fastener may extend within each fastener hole to retain the composite part within the composite part assembly. Also in such examples, the defining at <NUM> may include positioning the plurality of pin-receiving holes such that, subsequent to the inserting, a location of each textured pin of the plurality of textured pins corresponds to a location of, or to a desired location for, a fastener hole of the plurality of fastener holes.

Grit blasting the textured pins at <NUM> may include grit blasting the plurality of textured pins, such as the end surfaces thereof, to form and/or define the isotropically textured pin end surface. This may include grit blasting the plurality of textured pins prior to the inserting at <NUM>.

Positioning the adhesive at <NUM> may include positioning any suitable adhesive, or adhesive material, in and/or within each pin-receiving hole. This may include positioning the adhesive material such that the adhesive material adhesively retains each textured pin of the plurality of textured pins within the corresponding pin-receiving hole. The positioning at <NUM> may be performed prior to the inserting at <NUM>.

Inserting the textured pins at <NUM> may include inserting a textured pin of a plurality of textured pins into a corresponding pin-receiving hole of the plurality of pin-receiving holes. The textured pin may include a textured pin end. The textured pin end may define an isotropically textured pin end surface, and the inserting at <NUM> may include inserting such that the isotropically textured pin end surface faces away from the layup mandrel. Examples of the textured pin are disclosed herein with reference to textured pin <NUM>. Examples of the textured pin end are disclosed herein with reference to textured pin end <NUM>.

In some examples, the inserting at <NUM> may include inserting such that the textured pin end is coplanar, or at least substantially coplanar, with a region of the layup surface that defines the corresponding pin-receiving hole and/or with an opening into the corresponding pin-receiving hole that is defined by the layup surface. In some examples, the inserting at <NUM> may include inserting such that the corresponding textured pin end is within a threshold pin end offset distance of the region of the layup surface that defines the corresponding pin-receiving hole and/or of the opening into the corresponding pin-receiving hole that is defined by the layup surface. Examples of the threshold pin end offset distance are disclosed herein with reference to threshold pin end offset distance <NUM>.

In a specific example of methods <NUM>, the textured pins already may be formed and may be configured for a friction fit within the pin-receiving holes. In such an example, methods <NUM> include providing the mandrel body via the providing at <NUM>, defining the pin-receiving holes via the defining at <NUM>, and inserting the textured pins into the pin-receiving holes via the inserting at <NUM>. In another specific example of methods <NUM>, pins without textured ends may be provided and these pins may be configured for a slip-fit within the pin-receiving holes. In such an example, methods <NUM> include providing the mandrel body via the providing at <NUM>, defining the pin-receiving holes via the defining at <NUM>, grit blasting to define the textured pin ends via the grit blasting at <NUM>, positioning adhesive within the pin-receiving holes via the positioning at <NUM>, and inserting the textured pins into the pin-receiving holes via the inserting at <NUM>. Other combinations of the steps of methods <NUM> also are within the scope of the present disclosure.

<FIG> is a flowchart depicting examples of methods <NUM> of repairing a damaged layup mandrel, according to the present disclosure. Examples of the layup mandrel are disclosed herein with reference to layup mandrel <NUM>.

Methods <NUM> may include manufacturing the layup mandrel at <NUM>, utilizing the layup mandrel at <NUM>, and/or evaluating the layup mandrel at <NUM>. Methods <NUM> further include removing an installed textured pin at <NUM> and inserting a replacement textured pin at <NUM>.

Manufacturing the layup mandrel at <NUM> may include forming, defining, and/or creating the layup mandrel in any suitable manner. As an example, the manufacturing at <NUM> may include performing any suitable step and/or steps of methods <NUM>, which are disclosed herein.

Utilizing the layup mandrel at <NUM> may include utilizing the layup mandrel to form and/or define a composite part. As an example, the utilizing at <NUM> may include performing any suitable step and/or steps of methods <NUM>, which are disclosed herein. Examples of the composite part are disclosed herein with reference to composite part <NUM>. The utilizing at <NUM> may be performed subsequent to the manufacturing at <NUM> and/or prior to the evaluating at <NUM>, prior to the removing at <NUM>, and/or prior to the inserting at <NUM>.

Evaluating the layup mandrel at <NUM> may include evaluating and/or scrutinizing the layup mandrel in any suitable manner and/or based upon any suitable criteria. As an example, the evaluating at <NUM> may include establishing that the layup mandrel fails to meet at least one specification, such as may be subsequent to the manufacturing at <NUM> and/or subsequent to the utilizing at <NUM>. As another example, the evaluating at <NUM> may include quantifying wear of the layup mandrel, such as may be caused by the utilizing at <NUM>. Stated differently, and during the utilizing at <NUM>, one or more components of the layup mandrel may become worn and/or damaged, thereby causing the one or more components of the layup mandrel to be outside an applicable specification, and the evaluating at <NUM> may be utilized to detect, to quantify, and/or to determine the extent of this wear and/or damage. When methods <NUM> include the evaluating at <NUM>, the removing at <NUM> may be performed at least partially responsive to the evaluating at <NUM>. As examples, the removing at <NUM> may be performed responsive to the layup mandrel failing to meet the at least one specification and/or responsive to the wear of the layup mandrel.

Removing the installed textured pin at <NUM> may include removing the installed textured pin from a corresponding pin-receiving hole that extends from a layup surface of the damaged layup mandrel into a mandrel body of the damaged layup mandrel. Examples of the installed textured pin are disclosed herein with reference to textured pin <NUM>. Examples of the pin-receiving hole are disclosed herein with reference to pin-receiving hole <NUM>. Examples of the layup surface are disclosed herein with reference to layup surface <NUM>. Examples of the mandrel body are disclosed herein with reference to mandrel body <NUM>.

The removing at <NUM> may be performed in any suitable manner. As an example, the removing at <NUM> may include pulling the installed textured pin from the corresponding pin-receiving hole. As another example, the removing at <NUM> may include drilling an extraction hole within the installed textured pin, positioning a pin extractor within the extraction hole, and pulling the installed textured pin from the corresponding pin-receiving hole, such as via utilizing the pin extractor.

Inserting the replacement textured pin at <NUM> may include inserting the replacement textured pin into the corresponding pin-receiving hole to define a repaired layup mandrel. The replacement textured pin may have a textured pin end that defines an isotropically textured pin end surface, and the inserting at <NUM> may include inserting such that the isotropically textured pin end faces away from the layup mandrel. Examples of the repaired layup mandrel are disclosed herein with reference to layup mandrel <NUM>. Examples of the replacement textured pin are disclosed herein with reference to textured pin <NUM>. The inserting at <NUM> may be performed in any suitable manner, including manners that are disclosed herein with reference to the inserting at <NUM> that is described with reference to methods <NUM>.

<FIG> is a flowchart depicting examples of methods <NUM> of forming a composite part, according to the present disclosure. The composite part includes a plurality of imprinted features, which is configured to indicate, to a robotic drilling system, a location for a fastener hole within the composite part. Examples of the composite part are disclosed herein with reference to composite part <NUM>. Examples of the imprinted features are disclosed herein with reference to imprinted features <NUM>. Examples of the robotic drilling system are disclosed herein with reference to robotic system <NUM>. Examples of the fastener hole are disclosed herein with reference to fastener hole <NUM>. Methods <NUM> include positioning plies at <NUM>, conforming the plies at <NUM>, and curing the plies at <NUM>.

Positioning the plies at <NUM> may include positioning a plurality of plies of composite material on a layup mandrel. The layup mandrel may include a mandrel body that defines a layup surface. The layup surface may define a layup surface finish roughness. The layup mandrel also may include a plurality of regions of isotropic surface finish spaced-apart on the layup surface. The isotropic surface finish may define an isotropic surface finish roughness that is greater than the layup surface finish roughness, and a location of each region of isotropic surface finish may correspond to a desired location for a corresponding fastener hole within the composite part. Examples of the plurality of plies are disclosed herein with reference to plies <NUM>. Examples of the layup surface are disclosed herein with reference to layup surface <NUM>. Examples of the plurality of regions of isotropic surface finish are disclosed herein with reference to regions <NUM>.

Conforming the plies at <NUM> may include conforming the plurality of plies of composite material to a layup surface shape of the layup surface. This may be performed in any suitable manner. As an example, the conforming at <NUM> may include vacuum bagging the plurality of plies of composite material to compress the plurality of plies of composite material to the layup surface.

The conforming at <NUM> also includes imprinting, within at least a mandrel-contacting ply of the plurality of plies of composite material. The imprinting includes imprinting the layup surface finish roughness within regions of the mandrel-contacting ply that contact the layup surface. The imprinting also includes imprinting the isotropic surface finish roughness within regions of the mandrel-contacting ply that contact the plurality of regions of isotropic surface finish.

Curing the plies at <NUM> may include curing the plurality of plies of composite material to form and/or define the composite part. Subsequent to the curing, the composite part may include the plurality of spaced-apart imprinted features, and a location of each spaced-apart imprinted feature may correspond to a location of a corresponding region of isotropic surface finish of the plurality of regions of isotropic surface finish.

<FIG> is a flowchart depicting examples of methods <NUM> of precisely performing a plurality of operations on a composite part, according to the present disclosure. The composite part includes a plurality of imprinted features defined on a surface of the composite part. Examples of the composite part are disclosed herein with reference to composite part <NUM>. Examples of the imprinted features are disclosed herein with reference to imprinted features <NUM>. Examples of the surface of the composite part are disclosed herein with reference to surface <NUM>.

Methods <NUM> may include forming the composite part at <NUM>, detecting an imprinted feature at <NUM>, and aligning an operating assembly at <NUM>. Methods <NUM> further may include retracting a vision system at <NUM> and performing an operation at <NUM>. Methods <NUM> also may include repeating at <NUM>.

Forming the composite part at <NUM> may include forming and/or defining the composite part in any suitable manner. As an example, the forming at <NUM> may include performing any suitable step and/or steps of methods <NUM>, which are disclosed herein.

Detecting the imprinted feature at <NUM> may include detecting a corresponding imprinted feature of the plurality of imprinted features. The imprinted feature has an isotropic surface finish with a roughness that is greater than a surface roughness of a remainder of the composite part. The detecting at <NUM> may be performed utilizing a vision system of an end effector of a robotic system. Examples of the vision system are disclosed herein with reference to vision system <NUM>. Examples of the end effector are disclosed herein with reference to end effector <NUM>. Examples of the robotic system are disclosed herein with reference to robotic system <NUM>.

Aligning the operating assembly at <NUM> may include aligning an operating assembly of the end effector relative to the corresponding imprinted feature and may be based, at least in part, on the detecting at <NUM>. This may include aligning the operating assembly utilizing a positioning system of the robotic system. Examples of the positioning system are disclosed herein with reference to positioning system <NUM>.

In some examples, the aligning at <NUM> may include roughly positioning the end effector relative to the corresponding imprinted feature utilizing a rough positioning system of the positioning system. In some such examples, the aligning at <NUM> also may include finely positioning the end effector relative to the corresponding imprinted feature utilizing a fine positioning system of the positioning system. Examples of the rough positioning system are disclosed herein with reference to rough positioning system <NUM>. Examples of the fine positioning system are disclosed herein with reference to fine positioning system <NUM>.

In some examples, the aligning at <NUM> may include utilizing the vision system to view the corresponding imprinted feature. In some examples, the operating assembly may include a drilling assembly configured to define a plurality of fastener holes in the composite part. In some such examples, the aligning at <NUM> may include aligning such that a drilling axis of the drilling assembly is normal to the surface of the composite part, is at a predetermined angle relative to the surface of the composite part, and/or is coaxial with an optical axis of the vision system. In some such examples, the aligning at <NUM> may include utilizing a normality detection system of the end effector to determine an angle between the drilling axis and the surface of the composite part. Examples of the drilling assembly are disclosed herein with reference to drilling assembly <NUM>. Examples of the drilling axis are disclosed herein with reference to drilling axis <NUM>. Examples of the optical axis are disclosed herein with reference to optical axis <NUM>. Examples of the normality detection system are disclosed herein with reference to normality detection system <NUM>.

Retracting the vision system at <NUM> may include moving the vision system away from the drilling axis. Stated differently, and when the aligning at <NUM> includes aligning such that the optical axis of the vision system is coaxial with the drilling axis of the drilling assembly, the vision system may be positioned between the drilling assembly and the surface of the composite part during the aligning at <NUM>. In such examples, the retracting at <NUM> may be utilized to permit, or to provide space for, the performing at <NUM>. In addition, and in such examples, the retracting at <NUM> may permit transitioning from the aligning at <NUM> to the performing at <NUM> without moving the drilling assembly, thereby improving an overall accuracy of methods <NUM>.

Performing the operation at <NUM> may include performing a corresponding operation of the plurality of operations on the composite part and/or proximate the corresponding imprinted feature. When the operating assembly includes the drilling assembly, the performing at <NUM> may include drilling a corresponding hole in the composite part. In some examples, the performing at <NUM> may include performing the corresponding operation on and/or within the corresponding imprinted feature. In some such examples, the performing at <NUM> may include removing the corresponding imprinted feature from the composite part. In other examples, the performing at <NUM> may include performing the corresponding operation at a predetermined location relative to the corresponding imprinted feature. In some such examples, the corresponding imprinted feature may include and/or be a fly-away feature that may be acceptable in the finished composite part and/or in a composite part assembly that includes and/or utilizes the composite part.

Repeating at <NUM> may include repeating any suitable step and/or steps of methods <NUM> in any suitable manner and/or for any suitable purpose. As an example, the repeating at <NUM> may include repeating to perform the plurality of operations on the composite part and/or to perform the plurality of operations at locations of the plurality of imprinted features on the composite part.

As used herein, the terms "selective" and "selectively," when modifying an action, movement, configuration, or other activity of one or more components or characteristics of an apparatus, mean that the specific action, movement, configuration, or other activity is a direct or indirect result of user manipulation of an aspect of, or one or more components of, the apparatus.

As used herein, the phrase "at least one," in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entity in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase "at least one" refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases "at least one," "one or more," and "and/or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C" and "A, B, and/or C" may mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and optionally any of the above in combination with at least one other entity.

The various disclosed elements of apparatuses and steps of methods disclosed herein are not required to all apparatuses and methods according to the present disclosure, and the present disclosure includes all novel and non-obvious combinations and subcombinations of the various elements and steps disclosed herein. Moreover, one or more of the various elements and steps disclosed herein may define independent inventive subject matter that is separate and apart from the whole of a disclosed apparatus or method. Accordingly, such inventive subject matter is not required to be associated with the specific apparatuses and methods that are expressly disclosed herein, and such inventive subject matter may find utility in apparatuses and/or methods that are not expressly disclosed herein.

As used herein, the phrase, "for example," the phrase, "as an example," and/or simply the term "example," when used with reference to one or more components, features, details, structures, embodiments, and/or methods according to the present disclosure, are intended to convey that the described component, feature, detail, structure, embodiment, and/or method is an illustrative, non-exclusive example of components, features, details, structures, embodiments, and/or methods according to the present disclosure. Thus, the described component, feature, detail, structure, embodiment, and/or method is not intended to be limiting, required, or exclusive/exhaustive; and other components, features, details, structures, embodiments, and/or methods, including structurally and/or functionally similar and/or equivalent components, features, details, structures, embodiments, and/or methods, are also within the scope of the present disclosure.

Claim 1:
A system (<NUM>) for forming a composite part (<NUM>) with an imprinted feature (<NUM>), the system (<NUM>) comprising:
a layup mandrel (<NUM>) that includes:
(i) a mandrel body (<NUM>) that defines a layup surface (<NUM>) that defines a layup surface finish roughness; and
(ii) a plurality of regions (<NUM>) of isotropic surface finish spaced-apart on the layup surface (<NUM>), wherein each region (<NUM>) of isotropic surface finish of the plurality of regions (<NUM>) of isotropic surface finish defines an isotropic surface finish roughness that is greater than the layup surface finish roughness, and further wherein a location of each region (<NUM>) of isotropic surface finish corresponds to a desired location for a fastener hole (<NUM>) within the composite part (<NUM>).