INSERTION APPARATUS AND METHOD OF PROVIDING THROUGH THICKNESS REINFORCEMENT IN A LAMINATED MATERIAL

There is disclosed a method of providing through-thickness reinforcement in a laminated material. A guide foot is moved to a datum location relative the laminated material, at which the guide foot abuts a reinforcement zone on a surface of the laminated material. An insertion operation is conducted by inserting an insertion element through the guide foot into the laminated material along an insertion direction when the guide foot is in the datum location. The insertion element comprises a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; or a tamping pin for tamping a reinforcement rod received in the laminated material. A corresponding insertion apparatus is disclosed.

FIELD

The disclosure relates to an insertion apparatus for inserting an insertion element into a reinforcement zone of a laminated material, and a corresponding method.

BACKGROUND

It is known to provide materials having desirable combinations of material properties by building the material in multiple layers, to form a laminated material. Examples of laminated materials are composite structures comprising a fibre reinforced matrix layered in a succession of plies, where the matrix may be a resin matrix and the fibres may be carbon fibre, such as plies of carbon fibre reinforced plastic (CFRP). Such materials are anisotropic owing to their laminated construction.

It is known to provide through-thickness reinforcement in such laminated materials by inserting reinforcing rods into holes in the laminated material. Such insertion techniques are often referred to as “Z-pinning”, with “Z” referring to the thickness direction of a material having plies extending in orthogonal “X” and “Y” directions. Through-thickness reinforcement may improve the resistance of the laminated material to delamination.

In previously considered methods, a first robotic arm may be provided with an end effector for forming a hole, and a second robotic arm may be provided with an end effector for feeding a reinforcing rod into the hole. With high accuracy control over the movement of the end effectors, reinforcing rod may be aligned with and fed into the respective holes.

BRIEF SUMMARY

According to a first aspect there is provided a method of providing through-thickness reinforcement in a laminated material, the method comprising: moving a guide foot to a datum location relative the laminated material, at which the guide foot abuts a reinforcement zone on a surface of the laminated material; conducting an insertion operation by inserting an insertion element, having a principal axis which is linear, through the guide foot into the laminated material along an insertion direction when the guide foot is in the datum location, wherein the insertion element comprises: a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; or a tamping pin for tamping a reinforcement rod received in the laminated material.

The method may further comprise moving a carrier for the insertion element relative the guide foot to align the insertion element for insertion through the guide foot when the guide foot is at the datum location, whereby the carrier may be translated relative the guide foot along an axis orthogonal to the insertion direction.

The carrier and the guide foot may be coupled to a common support. Moving the guide foot to the datum location may comprise moving the common support so that the guide foot is at the datum location. Moving the carrier to align the insertion element with the guide foot may comprise moving the carrier relative the common support.

The position of the guide foot along any axis orthogonal to the insertion direction may be fixed with respect to the common support.

The guide foot may be moveable relative the common support along an insertion axis parallel with the insertion direction. The method may further comprise determining displacement of the guide foot along the insertion axis relative the common support when the guide foot is in the datum location relative the laminated material.

The method may further comprise controlling movement of the carrier along the insertion direction for an insertion operation based on the displacement of the guide foot along the insertion axis to compensate for corresponding displacement of the surface of the laminated material. For example, the controller may adjust or determine a start position, and end position or depth along the insertion axis for a hole-forming operation, a rod-insertion operation or a tamping operation based on the displacement of the guide foot along the insertion axis.

The method may further comprise actively controlling a biasing force urging the guide foot against the laminated material based on the displacement of the guide foot.

The method may further comprise moving a plurality of carriers relative the guide foot in sequence to interchange which one of a corresponding plurality of insertion elements is aligned for insertion through the guide foot when the guide foot is at the datum location, whereby each carrier may be translated relative the guide foot along an axis orthogonal to the insertion direction.

The insertion operation may comprise: inserting a needle through the guide foot to form a hole in the laminated material. The insertion operation may comprise inserting a reinforcement rod through the guide foot into the hole. The insertion operation may comprise inserting a tamping pin through the guide foot to tamp the reinforcement rod in the hole.

The insertion operation may comprise simultaneously inserting a plurality of insertion elements of the same type through the guide foot along the insertion direction into respective hole locations in the reinforcement zone by movement of a common carrier for the plurality of insertion elements along the insertion direction.

The guide foot may comprise a plurality of subsets of guide holes. The method may comprise a corresponding plurality of insertion operations whilst the guide foot is at the datum location. In each insertion operation a insertion element may be inserted through a respective subset of the guide holes corresponding to a respective subset of the hole locations in the reinforcement zone.

Each insertion operation may comprise simultaneously inserting a plurality of insertion elements of the same type through the guide foot along the insertion direction into a respective subset of the hole locations in the reinforcement zone by movement of a common carrier for the plurality of insertion elements along the insertion direction. Two subsets of hole locations which receive a insertion element in two separate insertion operations may overlap. For example, a pitch between insertion elements and respective hole locations in an insertion operation may be greater than a minimum pitch between holes locations in the reinforcement zone.

According to a second aspect there is provided a method of providing through-thickness reinforcement in a laminated material, the method comprising: moving a guide foot to a datum location relative the laminated material, at which the guide foot abuts a reinforcement zone on a surface of the laminated material; conducting an insertion operation by inserting an insertion element, having a principal axis which is linear, through the guide foot into the laminated material along an insertion direction when the guide foot is in the datum location, wherein the insertion element comprises: a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; or a tamping pin for tamping a reinforcement rod received in the laminated material. The method further comprises moving a carrier for the insertion element relative the guide foot to align the insertion element for insertion through the guide foot when the guide foot is at the datum location, whereby the carrier is translated relative the guide foot along an axis orthogonal to the insertion direction.

The carrier and the guide foot may be coupled to a common support. Moving the guide foot to the datum location may comprise moving the common support so that the guide foot is at the datum location. Moving the carrier to align the insertion element with the guide foot may comprise moving the carrier relative the common support.

The position of the guide foot along any axis orthogonal to the insertion direction may be fixed with respect to the common support.

The guide foot may be moveable relative the common support along an insertion axis parallel with the insertion direction. The method may further comprise determining displacement of the guide foot along the insertion axis relative the common support when the guide foot is in the datum location relative the laminated material.

The method may further comprise controlling movement of the carrier along the insertion direction for an insertion operation based on the displacement of the guide foot along the insertion axis to compensate for corresponding displacement of the surface of the laminated material. For example, the controller may adjust or determine a start position, and end position or depth along the insertion axis for a hole-forming operation, a rod-insertion operation or a tamping operation based on the displacement of the guide foot along the insertion axis.

The method may further comprise actively controlling a biasing force urging the guide foot against the laminated material based on the displacement of the guide foot.

The method may further comprise moving a plurality of carriers relative the guide foot in sequence to interchange which one of a corresponding plurality of insertion elements is aligned for insertion through the guide foot when the guide foot is at the datum location, whereby each carrier may be translated relative the guide foot along an axis orthogonal to the insertion direction.

The insertion operation may comprise: inserting a needle through the guide foot to form a hole in the laminated material. The insertion operation may comprise inserting a reinforcement rod through the guide foot into the hole The insertion operation may comprise inserting a tamping pin through the guide foot to tamp the reinforcement rod in the hole.

The insertion operation may comprise simultaneously inserting a plurality of insertion elements of the same type through the guide foot along the insertion direction into respective hole locations in the reinforcement zone by movement of a common carrier for the plurality of insertion elements along the insertion direction.

The guide foot may comprise a plurality of subsets of guide holes. The method may comprise a corresponding plurality of insertion operations whilst the guide foot is at the datum location. In each insertion operation a insertion element may be inserted through a respective subset of the guide holes corresponding to a respective subset of the hole locations in the reinforcement zone.

Each insertion operation may comprise simultaneously inserting a plurality of insertion elements of the same type through the guide foot along the insertion direction into a respective subset of the hole locations in the reinforcement zone by movement of a common carrier for the plurality of insertion elements along the insertion direction. Two subsets of hole locations which receive a insertion element in two separate insertion operations may overlap. For example, a pitch between insertion elements and respective hole locations in an insertion operation may be greater than a minimum pitch between holes locations in the reinforcement zone.

According to a third aspect, there is provided a method of providing through-thickness reinforcement in a laminated material, the method comprising: moving a guide foot to a datum location relative the laminated material, at which the guide foot abuts a reinforcement zone on a surface of the laminated material; conducting an insertion operation by inserting an insertion element, having a principal axis which is linear, through the guide foot into the laminated material along an insertion direction when the guide foot is in the datum location, wherein the insertion element comprises: a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; or a tamping pin for tamping a reinforcement rod received in the laminated material; wherein the insertion operation comprises simultaneously inserting a plurality of insertion elements of the same type through the guide foot along the insertion direction into respective hole locations in the reinforcement zone by movement of a common carrier for the plurality of insertion elements along the insertion direction.

The insertion operation may comprise: inserting a needle through the guide foot to form a hole in the laminated material. The insertion operation may comprise inserting a reinforcement rod through the guide foot into the hole. The insertion operation may comprise inserting a tamping pin through the guide foot to tamp the reinforcement rod in the hole.

The guide foot may comprise a plurality of subsets of guide holes. The method may comprise a corresponding plurality of insertion operations whilst the guide foot is at the datum location. In each insertion operation a insertion element may be inserted through a respective subset of the guide holes corresponding to a respective subset of the hole locations in the reinforcement zone.

According to a fourth aspect there is provided insertion apparatus for inserting an insertion element into a laminated material, comprising: a support; a guide foot coupled to the support and moveable to a datum location relative a laminated material to abut a reinforcement zone on a surface of the laminated material; wherein the guide foot is configured to guide insertion of an insertion element into the laminated material along an insertion direction; a carrier for an insertion element, wherein the carrier is coupled to the support and moveable relative the support along a translation axis orthogonal to the insertion direction to align the insertion element for insertion through the guide foot into the reinforcement zone along the insertion direction; wherein the carrier is configured to carry one of: a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; and a tamping pin for tamping a reinforcement rod received in the laminated material.

The insertion apparatus may comprise an actuator (or manipulator) configured to move the support along a translation axis orthogonal to the insertion direction, so as to move the guide foot to the datum location.

The position of the guide foot along any axis orthogonal to the insertion direction may fixed with respect to the support.

The guide foot may be moveable relative the support along an insertion axis parallel with the insertion direction.

The insertion apparatus may comprise a displacement meter configured to determine displacement of the guide foot along the insertion axis relative the common support when the guide foot is at the datum location.

The insertion apparatus may comprise a controller configured to control movement of the carrier along the insertion direction based on the displacement of the guide foot along the insertion axis to compensate for corresponding displacement of the surface of the laminated material.

The insertion apparatus may comprise a biasing member configured to apply a biasing force to bias the guide foot against the laminated material. For example, the biasing member may be a member coupling the guide foot to the support. The insertion apparatus may comprise a controller configured to control the biasing force based on the determined displacement.

There may be a plurality of carriers coupled to the support and configured to carry a respective plurality of insertion elements of different types. Each carrier may be moveable relative the support along a translation axis orthogonal to the insertion direction to align the respective insertion element for insertion through the guide foot into the reinforcement zone. Each carrier may be configured to carry one of: a needle for forming a hole in the laminated material; a reinforcement rod to be received in the laminated material; and a tamping pin for tamping a reinforcement rod received in the laminated material.

The insertion apparatus may comprise a controller configured to control execution of an insertion operation when the guide foot is at the datum location by: moving a carrier for a needle to insert the needle through the guide foot to form a hole in the laminated material; and/or moving a carrier for a reinforcement rod to insert the reinforcement rod through the guide foot into the hole; and/or moving a carrier for a tamping pin to insert the tamping through the guide foot to tamp the reinforcement rod in the hole.

The carrier may be configured to carry a plurality of insertion elements of the same type for simultaneous insertion through the guide foot into respective hole locations in the reinforcement zone.

The guide foot may comprise a plurality of guide holes.

The carrier may be configured to carry a first plurality of insertion elements. The guide foot may comprise a plurality of subsets of guide holes. Each subset may comprise a plurality of guide holes equal to the first plurality, so that a minimum number of insertion operations to insert insertion elements through each of the guide holes of the guide foot using the carrier is two or more.

The carrier may be configured to carry a first plurality of insertion elements at a first pitch. The guide foot may comprise a second plurality of guide holes at a second pitch which is lower than the first pitch.

The insertion apparatus may comprise a controller configured to carry out a method in accordance with the first aspect, the second aspect or the third aspect.

According to a fifth aspect, there is provided a method of making a composite component comprising: laying up a succession of plies of fibre reinforced matrix to form a laminated material; and performing a method in accordance with the first aspect, the second aspect or the third aspect to provide through-thickness reinforcement to the laminated material.

The composite component may be a fan blade. The composite component may be a casing for a gas turbine engine.

The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive.

DETAILED DESCRIPTION

FIG. 1shows a previously considered example rod insertion device10comprising a support12and a pair of rollers14for feeding reinforcement rod16from a rod supply into a hole18in a laminated material20.

The rod insertion device10may be mounted as an end effector on a manipulator, such as a robotic arm. In use, the rod insertion device10is moved to align with a succession of holes18to insert lengths of rod into the respective holes.

FIG. 2shows a previously considered apparatus for providing through-thickness reinforcement in a laminated material20.FIG. 2shows a top view over an apparatus20having a plurality of hole locations22. Two manipulators24,26are shown. In this example, the first manipulator24carries a needle to form the holes at each of the hole locations in sequence, and the manipulator26carries the rod insertion device10ofFIG. 1.

In use, a controller controls movement of each of the manipulators24,26to firstly position the needle at each of the hole locations22, and subsequently align the hole insertion device with the holes18formed at the hole locations. A high degree of accuracy is required for each of the manipulators to place the respective end effectors (i.e. the needle and the rod insertion device) at the same hole location.

FIG. 3shows an example insertion apparatus100and a laminated material20including a hole location22. The insertion apparatus100comprises a support102which may be provided as an end effector on a robotic arm, gantry system or other manipulator device for movement relative the laminated material20.

A guide foot104is suspended from the support102by a suspension member106which in this example comprises a pneumatic cylinder configured to permit relative movement between the guide foot104and the support102along an insertion axis108normal to a base of the guide foot. The position of the guide foot104relative the support102is fixed along axes (i.e. any axis) perpendicular to the insertion axis. As shown inFIG. 3, the base of the guide foot104is seated on the laminated material20. The guide foot104comprises a plurality of hole guides105, although a single hole guide is shown inFIG. 3for clarity.

The example insertion apparatus100comprises a needle carrier110and a rod carrier120for carrying a needle112for forming holes in the laminated material and a reinforcement rod122for inserting into such holes respectively. In this example, both carriers110are mounted on a common carriage130which is moveable relative the support102to align either one of the carriers with the guide foot104for an insertion operation, as will be described in detail below. In other examples, each carrier may comprise or be provided on a separate carriage.

The common carriage130comprises a rail114for the needle carrier110having an elongate extent parallel with the insertion axis108. The needle carrier110is slidably mounted on the rail114for movement along the insertion axis relative the support102(and relative the common carriage130). The needle carrier110comprises an actuator unit116to which the needle112is rotatably mounted.

The common carriage130further comprises a rail124for the rod carrier120having an elongate extend parallel with the insertion axis108. The rod carrier120is slidably mounted on the rail124for movement along the insertion axis relative the support102(and relative the common carriage130). The rod carrier120comprises a guide head126disposed towards the lower end of the rod carrier120(as oriented inFIG. 3) and a pair of rollers128configured to feed the reinforcement rod along a feed path through the rollers128and the guide head126.

The insertion apparatus100is provided with a controller140for controlling operation of the insertion apparatus100, for example movement of the common carriage130and operation of the carriers110,120. In this example, the controller140is provided together with the apparatus (for example, in a computer separate from the physical apparatus but coupled by control wires to the apparatus). In other examples, the controller may be integrated in the apparatus (for example, mounted on the support102), or may be remote from the apparatus100and configured to control it by a wired or wireless link.

As shown inFIG. 4, the insertion apparatus100further comprises a displacement meter150coupled to the suspension member106to determine displacement A of the guide foot104relative the support102. For example, the displacement meter may be a contact or non-contact sensor (such as a laser displacement sensor).

An example method of providing through-thickness reinforcement in a laminated material will now be described with reference toFIGS. 3-6.

In this example, the insertion apparatus100is provided as an end effector on a manipulator (such as a robotic arm). The controller140controls the manipulator to move the insertion apparatus100relative the laminated material so that the guide foot104engages a reinforcement zone on a surface of the laminated material. In this example, the reinforcement zone is a portion of the surface of the laminated material corresponding to a plurality of hole locations including the hole location22depicted inFIGS. 3-6. A hole location22is merely a virtual reference location for where a hole is to be formed. As will become apparent from the following description, holes will be formed at locations corresponding to the hole guides105of the guide foot.

When the guide foot104is seated on the reinforcement zone, the controller140stops movement of the insertion apparatus100(i.e. as an end effector on the manipulator) so that the insertion apparatus100is held in fixed registration with respect to the laminated material. The controller140may monitor an output of the displacement meter150to determine when any movement of the support102relative the guide foot104settles.

With the insertion apparatus100in fixed registration with respect to the laminated material20, the guide foot can be described as at a datum location relative the laminated material. The term “datum location” is used as the controller140can control movement of the carriers110,120for various insertion operations at the hole locations22relative the position of the guide foot104. As the position of the guide foot104relative the support102is fixed in directions perpendicular to the insertion direction, and monitored by the displacement meter along the insertion direction, the position of the carriers110,120relative the guide foot104can be readily determined.

As the guide foot104is provided together with the insertion apparatus, a travel of the carriers110,120(i.e. an extent of relative movement) to align with the guide foot is relatively small. Accordingly, high accuracy actuators and control equipment for aligning the carriers110,120with the holes105in the guide foot may be relatively inexpensive, for example when compared with actuators and control equipment for relatively large travel manipulators, such as the robotic arms ofFIG. 2. In particular, rather than providing high-accuracy large-travel manipulators for the needle and rod carriers110,120, only small-travel manipulators (i.e. the carriage130, in the above example) is provided. Further, the manipulator for the insertion apparatus itself need not be highly accurate to align the guide foot104with a reinforcement zone on a laminated material. The locations of the holes in the reinforcement zone are determined by where the guide foot104engages the laminated material, and the guide foot104need not be precisely aligned with a predetermined virtual hole location.

With the guide foot104at the datum location, the controller140causes the carriage130to move laterally (i.e. along axes perpendicular to the insertion axis) to align the needle112with a predetermined guide hole105in the guide foot104. The controller140executes an insertion operation in which the needle carrier110is caused to move along an insertion direction (along the insertion axis) towards the guide foot104an the laminated material20until the needle112is located in the guide hole105and at a location corresponding to abutment of the needle112with the surface of the laminated material. The insertion operation continues by causing the needle carrier110to move along the insertion direction to insert the needle into the laminated material by a predetermined hole depth to form a hole23, as shown inFIG. 5. The needle carrier110is then caused to move along a return direction away from the laminated material.

The guide foot104remains at the datum location as a similar operation is conducted to insert reinforcing rod into the hole23. The controller140causes the carriage130to move laterally to align the rod122within the rod carrier120with the guide hole105. The controller140executes an insertion operation in which the rod carrier120is caused to move along the insertion direction so that the guide head126abuts the guide foot104so that a guide hole in the guide head126aligns with the guide hole105of the guide foot104. The controller140causes the rollers128to turn to feed the rod122through the guide head126and the guide foot104into the hole23by an amount corresponding to the hole depth, as shown inFIG. 6.

The rod may then be cut, for example by a cutter integral with the guide foot104.

In this example, the hole forming and rod insertion steps described above are repeated for further hole locations corresponding to other hole guides of the guide foot. The guide foot remains at the datum location, and the controller controls the carriage130to move the needle carrier110and the rod carrier120to align with the other hole guides in succession in the manner described above, until each of the hole guides is provided with a reinforcement rod.

In this example, the controller140causes the insertion apparatus100to move away from the laminated material so that the guide foot104is lifted from the laminated material.

The insertion apparatus100is repositioned so that the guide foot104engages a further reinforcement zone at a further datum location, and the process described above is repeated.

In this example, when the guide foot is lifted from the laminated apparatus, a tamper block is pressed over the holes23to tamp the respective lengths of reinforcing rod into the holes.

FIG. 7shows a further example insertion apparatus200similar to that described above which differs in that the carriage130additionally supports a tamp carrier210. A tamp pin212is mounted on the tamp carrier210for insertion through the guide foot104to tamp a length of reinforcing rod in a hole in the laminated material.

The common carriage130of this example comprises a rail214for the tamp carrier having an elongate extent parallel with the insertion axis108. The tamp210is slidably mounted on the rail213for movement along the insertion axis relative the support102(and relative the common carriage130).

In use, hole forming and rod insertion steps as described above are followed by the controller140causing the common carriage130to move laterally to align the tamp pin212carrier with a predetermine guide hole105of the guide foot104. An insertion operation is executed in which the tamp carrier210moves along the insertion direction so that the tamp pin212extends through the guide hole105and tamps the reinforcing rod received in the respective hole23.

The tamp carrier is withdrawn along a return direction opposite the insertion direction.

Hole forming, rod insertion and tamping is then repeated through other guide holes of the guide foot whilst the guide foot104remains in the datum location.

The controller140controls a manipulator222, which is a three axis gantry system in this example (as shown inFIG. 7), to lift the insertion apparatus200so that the guide foot104separates from the laminated material. The manipulator222then moves the insertion apparatus200so that the guide foot104engages the laminated material at a further reinforcement zone for further insertion operations as described above.

The above examples have been described for simplicity with respect to needle carriers, rod carriers and tamp carriers comprising one needle, one reinforcement rod (or means for feeding one reinforcement rod) and one tamp pin.FIG. 8shows an example reinforcement zone300of a laminated material showing a regular four by four array of virtual hole locations22and a single hole23that has been formed, filled with reinforcement rod and tamped using an insertion apparatus comprising one needle, one reinforcement rod and on tamp pin on the respective carriers.

The disclosure extends to insertion apparatus as described above with respect toFIGS. 3-7but provided with carriers that are each configured to carry multiple insertion elements (needles, reinforcement rods, tamp pins) respectively. For clarity, a single such insertion element is shown in theFIGS. 3-7.

Inserting a plurality of insertion elements at once increases efficiency of manufacture. By using a plurality of tamp pins as opposed to a tamp block configured to act on a plurality of reinforcement rods, the reinforcement rods may be tamped with an equal tamping force. In particular, the tamp pins may comprise a compressible element, such as a spring or compressible material. Accordingly, if a reinforcement rod is stuck, irregularly long or located in a shallow hole (for example), a respective tamp pin may compress when pressed against the reinforcement rod, thereby permitting neighbouring tamp pins to continue pressing against their respective reinforcement rods. In contrast, when using a tamp block, a protruding reinforcement rod may absorb all the force exerted through the tamp block, such that it either breaks or the neighbouring reinforcement rods are inadequately tamped (or not tamped).

FIG. 9shows a further example reinforcement zone302of a laminated material showing a regular eight by eight array of virtual hole locations22of which sixteen are formed, filled and tamped holes23by an example insertion apparatus as described above comprising carriers each carrying sixteen multiple insertion elements (needles, reinforcement rods, tamp pins) in a regular four by four array. As shown inFIG. 9, the pitch between the regular four by four array of the carriers (and thereby of the holes23) is double that of the pitch between the hole locations22. This may permit simpler manufacture of the carriers as the insertion elements can be spaced relatively far apart. The carriers may be moved by an amount corresponding to the pitch of the hole locations22to form, fill and tamp the intervening hole locations shown inFIG. 9.

FIG. 10is a flowchart of an example method400of providing through-thickness reinforcement in a laminated material. In block402a guide foot is moved to a datum location relative the laminated material so that the guide foot abuts a reinforcement zone on a surface of the material.

In blocks404to414, a succession of insertion elements are aligned with the guide foot and inserted through the guide foot into the laminated material in respective insertion operations. The insertion elements are aligned with a subset of guide holes of the guide foot. In this example, the subset is one guide hole, but in other examples multiple insertion elements of the same type may be aligned with and inserted through a respective plurality of guide holes within a subset.

In blocks404and406, a needle is moved into alignment with the guide foot and inserted through the guide foot into the laminated material to form a hole in the laminated material.

In blocks408and410, a carrier for a reinforcement rod is moved to align the reinforcement rod with the guide foot, and the reinforcement rod is inserted through the guide foot into the hole formed in the laminated material. The reinforcement rod is subsequently cut to leave a length of reinforcement rod in the hole.

In blocks412and414, a tamp pin is moved into alignment with the guide foot and inserted through the guide foot to tamp the length of reinforcement rod received in the hole.

In block416, a next subset of guide holes is determined, and the alignment and insertion steps of blocks404to414are repeated for the respective subset, and further until all subsets of guide holes have been completed.

In block418, a next datum location for the guide foot is determined, corresponding to a further reinforcement zone on the surface of the laminated material. The method may be repeated from block402for the next datum location, until all datum locations are complete.

As described above with respect to the insertion apparatus100ofFIGS. 3-6, a displacement meter150is provided to determine displacement of the guide foot104along the insertion axis108relative the support102—i.e. away from the datum location.

Referring back toFIG. 4, such displacement may occur owing to outward deflection of the surface of the laminated material in the reinforcement zone owing to insertion operations, which may be referred to as “pillowing”. When such pillowing is detected, it may be compensated for in one of at least two ways. A first way is to apply a compressive force against the reinforcement zone by actively controlling a biasing force exerted by the suspension member106on the guide foot104. A second way is to control insertion operations to compensate, for example by increasing a hole depth, length of reinforcement rod inserted or tamping force, for example. In the example insertion apparatus100, the controller periodically monitors an output of the displacement meter150to determine if pillowing is occurring (i.e. by determining if there is displacement of the guide foot relative the support).

FIG. 11is a flowchart of a sub method500of compensating for pillowing. The sub method may run in parallel and/or continuously with the method described with respect toFIG. 10.

In block502, displacement of the guide foot relative the support is determined. In block504, the controller controls movement of the carriers along the insertion direction in subsequent insertion operations based on the displacement of the guide foot to compensate for corresponding displacement of the surface of the laminated material.

FIG. 12is a flowchart of a sub method600of compensating for pillowing. The sub method may run in parallel and/or continuously with the method described with respect toFIG. 10. The sub method is described with respect to the insertion apparatus100ofFIGS. 3-6.

In block602, displacement of the guide foot relative the support is determined. As described above with respect toFIGS. 3 and 4, the suspension member comprises a pneumatic cylinder configured to apply a controllable biasing force urging the guide foot to engage the surface of the laminated material. In block604of the flowchart ofFIG. 12, the controller actively controls the biasing force through the suspension member based on the determined displacement. For example, the controller may cause the pneumatic pressure to increase to increase the biasing force in response to pillowing of the laminated material. As will be appreciated, the suspension member may comprise any suitable device or arrangement for applying a biasing force, in alternative to a pneumatic cylinder.

An example laminated material is carbon fibre reinforced polymer, layered in a succession of plies. An example reinforcement rod is carbon fibre.