SYSTEM AND METHOD FOR MANUFACTURING A TOWER STRUCTURE

A system and method are provided for manufacturing a tower structure. Accordingly, a first printed layer of a wall element is deposited with a printhead assembly, and an actual midline perimeter length of the first printed layer is determined. A horizontal reinforcement assembly is then formed based, at least in part, on the actual midline perimeter length. The formed horizontal reinforcement assembly is positioned in a horizontal orientation on the first printed layer and in axial alignment with the vertical axis of the tower structure. With the horizontal reinforcement assembly positioned on the first printed layer, a second printed layer of the wall element is deposited via the printhead assembly on the horizontal reinforcement layer.

FIELD

The present disclosure relates in general to tower structures, and more particularly to systems and methods for additively manufacturing tower structures, such as for supporting wind turbines.

BACKGROUND

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The nacelle includes a rotor assembly coupled to the gearbox and to the generator. The rotor assembly and the gearbox are mounted on a bedplate support frame located within the nacelle. The one or more rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy and the electrical energy may be transmitted to a converter and/or a transformer housed within the tower and subsequently deployed to a utility grid. Modern wind power generation systems typically take the form of a wind farm having multiple such wind turbine generators that are operable to supply power to a transmission system providing power to an electrical grid.

Tower structures, and in particular wind turbine towers, are often constructed of steel tubes, pre-fabricated concrete sections, or combinations thereof. Further, the tubes and/or concrete sections are typically formed off-site, shipped on-site, and then arranged together to erect the tower. For example, one manufacturing method included forming pre-cast concrete rings, shipping the rings to the site, arranging the rings atop one another, and then securing the rings together. As tower heights increase, however, conventional manufacturing methods are limited by transportation regulations that prohibit shipping of tower sections having a diameter greater than about 4 to 5 meters. Thus, certain tower manufacturing methods include forming a plurality of arc segments and securing the segments together on site to form the diameter of the tower, e.g. via bolting and/or welding. Such methods, however, require extensive labor and can be time-consuming.

Thus, the art is continuously seeking new and improved methods for manufacturing towers. Accordingly, the present disclosure is directed to systems and methods for manufacturing towers that address the aforementioned issues. In particular, the present disclosure is directed to methods for additively manufacturing the tower structures on-site using automated additive printing devices and reinforcing the tower structure.

BRIEF DESCRIPTION

In one aspect, the present disclosure is directed to a method for manufacturing a tower structure. The method may include depositing, via an additive printing system, a first printed layer of a wall element with a printhead assembly. The wall element may circumscribe a vertical axis of the tower structure. A controller of the additive printing system may determine an actual midline perimeter length of the first printed layer. The method may also include forming a horizontal reinforcement assembly based, at least in part, on the actual midline perimeter length. The horizontal reinforcement assembly may be positioned in a horizontal orientation on the first printed layer and in axial alignment with the vertical axis. Additionally, the method may include depositing, via the additive printing system, a second printed layer of the wall element with the printhead assembly on the horizontal reinforcement assembly.

In another aspect, the present disclosure is directed to an additive printing system for manufacturing a tower structure. The tower structure may include a wall element circumscribing a vertical axis of the tower structure. The additive printing system may include a support structure and an optical scanner. The additive printing system may also include a printhead assembly operably coupled to the support structure. Further, the additive printing system may include a controller communicatively coupled to the printhead assembly and the optical scanner. The controller may include at least one processor configured to perform or direct a plurality of operations. The plurality of operations may include any of the operations and/or features described herein.

DETAILED DESCRIPTION

Generally, the present disclosure is directed to an additive printing system and methods for manufacturing a tower structure, such as a wind turbine tower. Additively printed tower structures are typically formed via the deposition of sequential layers (e.g., print layers) of a cementitious material, such as concrete. However, in order to achieve the desired structural strength, additively printed towers generally require reinforcement. Known methods for reinforcing towers often utilize vertical rebar and/or a rebar cage. For example, a common construction practice is to manually place a prefabricated rebar cage in the desired location prior to pouring concrete. While such approaches may reinforce the tower structure, they are often labor intensive and costly, and may not be compatible with construction via additive printing. Additionally, known methods of reinforcing an additively printed tower structure may not accurately place the reinforcing elements in an optimal position within the structure. Accordingly, the present application presents novel methods for forming and positioning a horizontal reinforcement assembly of the tower structure that are simple, accurate, non-labor-intensive, and cost-effective.

In order to provide simple, accurate, non-labor-intensive, and cost-effective reinforcement to an additively printed tower structure, the present application utilizes a ring-shaped horizontal reinforcement assembly that is accurately sized and placed upon a printed layer of the tower structure before an additional printed layer is added on top. To that end, the actual midline perimeter length of the first printed layer may be determined. The horizontal reinforcement assembly may then be formed based, at least in part, on the actual midline perimeter. In other words, the dimensions of the horizontal reinforcement assembly may be tailored to the actual physical dimensions of the first printed layer deposited by the additive printing system prior to placement on the first printed layer.

Referring now to the drawings,FIG.1illustrates a perspective view of an embodiment of a tower structure500according to the present disclosure. As depicted inFIG.1, the tower structure may be a component of a wind turbine100. As shown, the wind turbine100generally includes a tower structure500extending from a support surface104, a nacelle106, mounted on the tower structure500, and a rotor108coupled to the nacelle106. The rotor108includes a rotatable hub110and at least one rotor blade112coupled to and extending outwardly from the hub110. For example, in the illustrated embodiment, the rotor108includes three rotor blades112. However, in an alternative embodiment, the rotor108may include more or less than three rotor blades112. Each rotor blade112may be spaced about the hub110to facilitate rotating the rotor108to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy. For instance, the hub110may be rotatably coupled to an electric generator (not shown) positioned within the nacelle106to permit electrical energy to be produced.

It should be appreciated that while discussed herein in reference to a wind turbine tower, the present disclosure is not limited to wind turbine towers but may be utilized in any application having concrete construction and/or tall tower structures. For example, the present disclosure may be utilized in the additive manufacturing of homes, buildings, portions of buildings, bridges, towers, poles, and other aspects of the concrete industry. Further, the methods described herein may also apply to manufacturing any similar structure that benefits from the advantages described herein.

Referring now toFIGS.2-9, wherein multiple embodiments of the tower structure500, and the additive printing system300for forming the same, are depicted in accordance with the present disclosure. As shown the tower structure500may be formed by depositing one or more layers of a wall element502with a printhead assembly302of the additive printing system300. In an embodiment, the wall element502may circumscribe a vertical axis (VA) of the tower structure500. Each wall element502may for example, be one of a plurality of print layers in an axially aligned arrangement to form the tower structure500. As shown, the wall element502may generally define a hollow interior504that may, in a wind turbine100, be employed to house various turbine components. In addition, as will be described in more detail below, the tower structure500may be formed using additive manufacturing. It should be appreciated that, the tower structure500may be formed from at least one cementitious material506.

It should be appreciated that the tower structure500may include a structure having a height that is greater than a maximal horizontal dimension. By way of non-limiting illustrations, the tower structure500may include a wind turbine support tower, a cooling tower, a communications tower, a bridge pylon, a smokestack, a transmission tower, an observation tower, a dwelling, an office, an ornamental tower, a water tower, and/or other similar structures.

As used herein, the cementitious material506may include any suitable workable paste that may be configured to bind together after curing to form a structure. Suitable cementitious materials may include, for example, concrete, pitch resin, asphalt, clay, cement, mortar, cementitious compositions, or other similar materials or compositions.

As depicted in the overhead view (e.g., layer view) of the tower500illustrated inFIG.2, the wall element502may, in an embodiment, have an outer circumferential face508corresponding to each layer of the wall element502. The outer circumferential face508may have a maximal radial distance from the vertical axis (VA). The outer circumferential face508may, for example, be generally circular, circumscribing the vertical axis (VA).

In an embodiment, the wall element502may have an inner circumferential face510corresponding to each layer of the wall element502. The inner circumferential face510may have a minimal radial distance from the vertical axis (VA). The inner circumferential face510may, for example, be generally circular, circumscribing the vertical axis (VA).

As particularly depicted inFIGS.2and7, in an embodiment, a midline reference curve (CM) may be defined for each layer of the tower structure500. The midline reference curve (CM) may be equidistant between the outer circumferential face508and the inner circumferential face510for the layer. Accordingly, the midline reference curve (CM) may be generally circular, circumscribing the vertical axis (VA). It should be appreciated that the midline reference curve (CM) may represent a radial neutral point corresponding to the width/thickness (W) of the wall element502.

According to aspects of the present disclosure, the tower structure500may be additively manufactured via the additive printing system300. Notably, all or part of the tower structure500, in particular, the wall element502, may be printed layer-by-layer, using the additive printing system300. The additive printing system300may use any suitable means for depositing layers of additive material, such as concrete, to form the tower structure500. Thus, aspects of the present subject matter are directed to methods for manufacturing a tower structure500, such as a wind turbine tower, via additive manufacturing.

As used herein, “additive manufacturing” may generally be understood to encompass processes used to synthesize three-dimensional objects in which successive layers of material are formed under computer control to create the objects as such, objects of any size and/or shape can be produced from digital model data. It should be further understood that the additive manufacturing methods of the present disclosure may encompass three degrees of freedom, as well as more than three degrees of freedom, such that the printing techniques are not limited to printing stacked two-dimensional layers but are also capable of printing curved and/or irregular shapes.

As particularly depictedFIGS.3and7, in an embodiment, the additive printing system300may include a support structure304. The support structure304may extend from the ground and/or from the support surface104along a generally vertical direction (V). In an embodiment, the support structure304may include at least one vertical support component306. As depicted, in an embodiment, the vertical support component(s)306may be located radially outward of the tower structure500. However, in an additional embodiment, the vertical support component(s)306may be located radially inward of the wall element502.

The vertical support component(s)306may, in an embodiment, support a horizontal support component308. The vertical support component(s)306and the horizontal support component308may, in an embodiment, be a truss-like structure (e.g., similar to a tower crane). However, the vertical support component(s)306and the horizontal support component308may be formed in the other suitable manner or have any other configuration according to alternative embodiments. The horizontal support component308may, in an embodiment, be rotatable about the vertical support component(s)306. In an additional embodiment, the horizontal support component308may be movably coupled to the vertical support component(s)306so as to permit the horizontal support component308to move in the vertical direction (V).

In at least one embodiment, the vertical support component(s)306may be configured to have a height that increases in step with the tower structure500during the manufacturing thereof. In such an embodiment, additional segments may be combined with the vertical support component(s)306to raise the vertical support structure using a jacking system. In general, the jacking system may be positioned proximate the support surface104and may be configured for raising the vertical support component(s)306and inserting additional segments.

The support structure304may be configured to support at least one support arm310movably coupled thereto. The support arm(s)310may be configured to position at least one component of the additive printing system300adjacent to the tower structure500. The support arm(s)310may also be configured to deliver power, air, cementitious material, form material, or other resources to the supported component. In an additional embodiment, the support arm(s)310may also be equipped with at least one sensor311for detecting a position of the support arm(s)310relative to the tower structure500.

The additive printing system300may include the printhead assembly302supported by the support structure304. The printhead assembly302may be positioned over the support surface104or preceding layers of the wall element502by at least one of the horizontal support component308and/or the support arm(s)310. The printhead assembly302may include a print nozzle312. The print nozzle312may be configured to direct and/or shape a flow of cementitious material506during the additive printing of the tower structure500.

Referring again toFIGS.2-9in general, in an embodiment, the additive printing system300may be employed to deposit a first printed layer512of the wall element502. The first printed layer512may be deposited with the printhead assembly302. A controller200of the additive printing system300may then be utilized to determine an actual midline perimeter length of the first printed layer512. The actual midline perimeter length may correspond to the circumferential length of the midline reference curve (CM). Based, at least in part, on the actual midline perimeter length of the first printed layer512, a horizontal reinforcement assembly514may be formed. The fully assembled/formed horizontal reinforcement assembly514may then be positioned in a horizontal (H) orientation on the first printed layer512and in axial alignment with the vertical axis (VA). Following the positioning of the fully assembled/formed horizontal reinforcement assembly514on the first printed layer512, the additive printing system300may deposit a second printed layer516of the wall element502with the printhead assembly302on the horizontal reinforcement assembly514. It should be appreciated that forming the horizontal reinforcement assembly514may, for example, include establishing an inner circumference (CI) and/or an outer circumference (CO) of the horizontal reinforcement assembly514that is proportional to the actual midline perimeter length.

FIG.2depicts a portion of a method400for manufacturing the tower structure500prior to positioning the horizontal reinforcement assembly514on the first printed layer512. According to the method400, the horizontal reinforcement assembly514may be positioned on the first printed layer512as depicted by arrow A1.FIG.3, therefore, depicts a portion of the method400following the positioning of the horizontal reinforcement assembly514on the first printed layer512.FIG.3also illustrates a portion of the second printed layer516deposited on the horizontal reinforcement assembly514.

The horizontal reinforcement assembly514may, in an embodiment, include an inner rail518. The inner rail518may have a length that is less than the actual midline perimeter length. In an embodiment, the horizontal reinforcement assembly514may include an outer rail520. The outer rail520may have a length that is greater than the actual midline perimeter length. Additionally, in an embodiment, the horizontal reinforcement assembly514may include a plurality of transverse members522. Each transverse member of the plurality of transverse members522may have a first end524coupled to the inner rail518. In an embodiment, each transverse member of the plurality of transverse members522may have a second end526coupled to the outer rail520.

It should be appreciated that the inner rail518and/or the outer rail520may have a shape corresponding to a horizontal shape of the first printed layer. For example, in an embodiment wherein the tower structure500has a generally cylindrical or conical shape, the horizontal shape may be generally circular. In such an embodiment, the inner rail518and/or the outer rail520may have a generally circular shape. By way of an additional example, in an embodiment wherein the tower structure500has a generally polygonal shape, the horizontal shape may include a plurality of angles/corners joined by a plurality of straight and/or curved sections. In such an embodiment, the inner rail518and/or the outer rail520may have a shape which mirrors the plurality of angles/corners joined by the plurality of straight and/or curved sections.

As particularly the depicted inFIG.4, in an embodiment, the horizontal reinforcement assembly514may include a plurality of prefabricated reinforcement segments528. For example, in an embodiment, the horizontal reinforcement assembly514may include three prefabricated reinforcement segments528, with each prefabricated reinforcement segment528covering a 120-degree arc of the midline reference curve (CM). In an additional embodiment, the horizontal reinforcement assembly514may include four prefabricated reinforcement segments528, with each prefabricated reinforcement segment528covering a 90-degree arc of the midline reference curve (CM). In a further embodiment, the horizontal reinforcement assembly514may include six prefabricated reinforcement segments528, with each prefabricated reinforcement segment528covering a 60-degree arc of the midline reference curve (CM). It should, therefore, be appreciated that in an embodiment, forming the horizontal reinforcement assembly514may include receiving the plurality of prefabricated reinforcement segments528.

Each of the plurality of prefabricated reinforcement segments528may, in an embodiment, include an inner rail segment530coupled to an outer rail segment532via a portion of the plurality of transverse members522. Each of the plurality of prefabricated reinforcement segments528may have a first segment end534and a second segment end536opposite thereof. The first segment end534and the second segment end536may be defined by the inner and outer rail segments530,532.

It should be appreciated that the midline reference curves (CM) of the print layers of the wall element502may have different actual midline perimeter lengths at various heights of the tower structure500. For example, the tower structure500may taper with an increase in height. As a result, a midline reference curve (CM) of a print layer near the support surface104may have a greater actual midline perimeter length than the actual midline perimeter length of a midline reference curve (CM) adjacent the ultimate height of the tower structure500. However, in an embodiment each of the plurality of prefabricated reinforcement segments528of the tower structure500may be pre-formed/manufactured to with a fixed length (e.g., arc length). Therefore, the fixed length of the prefabricated reinforcement segments528may be accommodated as further described below in order to form the horizontal reinforcement assembly514in accordance with the actual midline perimeter of the print layer upon which it is positioned prior to the deposition of the second printed layer516.

In order to form (e.g., tailor) the horizontal reinforcement assembly514to coincide with the actual midline perimeter length of the first printed layer512, at least one overlap538between adjacent prefabricated reinforcement segments528of the plurality of prefabricated reinforcement segments528may be established. The magnitude (M) of the overlap538may facilitate the establishment of the inner circumference (CI) and/or the outer circumference (CO) at a value that is proportional to the midline reference curve (CM). In other words, the overlap548may facilitate the establishment of a reinforcement assembly midline perimeter length based on the actual midline perimeter length of the first print layer512. For example, in an embodiment, the reinforcement assembly midline perimeter length may equal the actual midline perimeter length. It should be appreciated that the reinforcement assembly midline perimeter length may represent a length of an assembly midline reference curve (AM) that is radially equidistant between the inner and outer rail segments530,532.

In an embodiment, each of the plurality of prefabricated reinforcement segments528may be coupled to an adjacent segment in order to form the horizontal reinforcement assembly514. For example, the first segment end534of each of the plurality of prefabricated reinforcement segments528and the second segment end536of each adjacent segment may be coupled. The coupling of the adjacent segments may establish the overlap538based on the determined magnitude (M). In an embodiment, the magnitude (M) of the overlap538may correspond to a determined quantity of degrees of arc that the respective first and second segment ends534,536may be in direct contact with one another and may be fixedly coupled thereto. In an additional embodiment, the magnitude (M) of the overlap538may correspond to zero degrees of arc and the adjacent segments may be coupled to one another via a coupler unit540. In a further embodiment, the magnitude (M) may correspond to a gap/separation (G) (e.g., as depicted inFIG.5B) between adjacent segments, therefore necessitating the employment of the coupler unit540to couple of the adjacent sections to one another. It should be appreciated that the coupler unit540may be configured to establish the reinforcement assembly midline perimeter length based on the actual midline perimeter length

As depicted inFIGS.5A-5C, in an embodiment, the coupler unit540may include a first channel542configured to receive a portion of the inner rail518. The coupler unit540may also, in an embodiment include a second channel544configured to receive a portion of the outer rail520. The first channel542and the second channel544may be generally parallel to one another. In an embodiment, the first and second channels542,544may facilitate the coupling of the coupler unit540to adjacent prefabricated reinforcement segments528. In other words, the corresponding portions of the first and second ends534,536of the prefabricated reinforcement segments528may be secured within the first and second channels542,544via crimping (e.g., as depicted inFIGS.5A and5B), welding, adhesives, fasteners, and/or other means suitable for establishing a fixed connection between the prefabricated reinforcement segments528and the coupler unit540.

As further depicted inFIGS.5A-5C, in an embodiment, the coupler unit540may include a plate structure546. The plate structure546may extend in a radial direction so as to establish a radial position of the first channel542and a radial position of the second channel544. The plate structure546may also define a guide orifice548. The guide orifice may, for example, facilitate the positioning of cables, conduits, and/or tensioning elements of the tower structure500.

Referring still toFIGS.5A and5C, in an embodiment, the coupler unit540may include a lifting interface550. The lifting interface550may be configured to couple to at least one lifting element326in order to facilitate the positioning of the fully assembled horizontal reinforcement assembly514on the first print layer512. The lifting interface550may be a flexible element configured to translate from a generally vertical orientation to a generally horizontal orientation when the horizontal reinforcement assembly514is positioned on the first print layer512and the lifting element(s)326is decoupled. For example, in an embodiment, the lifting interface550may be a cable, a hinged element, and/or a deformable plate element. It should be appreciated that transitioning the lifting interface550to a generally horizontal orientation may mitigate a disruption of the second print layer516resulting from the lifting interface550.

As depicted inFIG.5C, in an embodiment, an operable coupling may be established between the lifting element(s)326and the horizontal reinforcement assembly514via the lifting interface550. The lifting element(s)326may be positioned so as to establish a separation328relative to the first printed layer512when the horizontal reinforcement assembly514is positioned thereon. Following the positioning of the horizontal reinforcement assembly514on the first printed layer512, the lifting element(s)326may be released. Accordingly, the lifting element(s)326may be separated from the horizontal reinforcement assembly514while the separation328is maintained or increased relative to the first print layer512. By at least maintaining the separation328, contact between the lifting element(s)326and the first printed layer512may be precluded. Precluding contact between the lifting element(s)326and the cementitious material506of the first printed layer512, which may remain soft/uncured during the positioning of the horizontal reinforcement assembly514, may mitigate/preclude damage to the first printed layer512. It should be appreciated that precluding damage to the first printed layer512may increase the structural integrity of the tower structure500relative to that obtainable in the presence of a damaged first printed layer512.

As depicted inFIG.4, in an embodiment, the additive printing system300may include a jig table316. The jig table316may be positioned on the ground/support surface104at the installation location of the tower structure500. For example, the jig table316may be positioned adjacent to the tower structure500. The jig table316may be configured to receive (e.g., as shown by arrow A2) the plurality of prefabricated reinforcement segments528. In an embodiment, the jig table316may be sized to support the horizontal reinforcement assembly514when fully formed (e.g., with the adjacent segments of the plurality of prefabricated reinforcement segments528being coupled to one another) and in a horizontal orientation.

The jig table316may, in an embodiment, include a plurality of movable stops318. The plurality of movable stops318may, for example, be configured to orient/position the plurality of prefabricated reinforcement segments528in order to form the horizontal reinforcement assembly514. Accordingly, in an embodiment, the plurality of movable stops318may be positioned based on the reinforcement assembly midline perimeter length. At least a portion of the plurality of prefabricated reinforcement segments528may be positioned via the plurality of movable stops318. Such positioning may establish the overlap538between each adjacent segment of the plurality of prefabricated reinforcement segments528.

In an embodiment, the jig table316may include at least one servo320. The servo(s)320may be operably coupled to a portion of the plurality of movable stops318, such as via a linkage322. In such an embodiment, the servo(s)320may be actuated in order to alter a location of at least one of the plurality of movable stops318relative to a support surface324of the jig table316.

The jig table316may be communicatively coupled to the controller200in an embodiment. In such an embodiment, the controller200of the additive printing system300may determine a required position for each of the plurality of movable stops318. The required position may correspond to the positioning of the plurality of movable stops318that establishes the magnitude (M) of the overlap538between adjacent prefabricated reinforcement segments528of the plurality of prefabricated reinforcement segments528. In an embodiment, the controller200may then generate a setpoint for the servo(s)320calculated to position each of the movable stops318at the required position.

As depicted inFIG.6, in an embodiment, forming the horizontal reinforcement assembly514may include determining a required reinforcement assembly midline perimeter length based on the actual midline perimeter length. A required inner rail radius552may then be determined based on the required reinforcement assembly midline perimeter length. In an embodiment, a required outer rail radius554may similarly be determined based on the required reinforcement assembly midline perimeter length. The required inner and outer rail radius is552,554may then be formed via a material working apparatus330of the additive printing system300. For example, the material working apparatus330may apply a bend corresponding to the required inner rail radius552to first portion of rail stock556. The first portion of rail stock556may have a length corresponding to the inner rail length. Similarly, in an embodiment, the material working apparatus330may apply a bend corresponding to the required outer rail radius554a second portion of rail stock556. The second portion of rail stock556may have a length corresponding to the outer rail length. Additionally, in an embodiment, the material working apparatus330may be configured to couple (e.g., weld, adhere, or otherwise secure) the plurality of transverse members522between the inner and outer rails518,520.

Referring again toFIGS.3and7, in order to determine the actual midline perimeter length of the first printed layer512, the controller200may, in an embodiment, record an actual print path332of the printhead assembly302. The actual print path332may be recorded by the controller200during the deposition of the first printed layer512. For example, in an embodiment, the sensor(s)311may be utilized to continuously monitor the position of the support arm(s)310. The position of the printhead assembly302, and thus the print path332, may be derived from the monitored positions of the support arm(s)310. Accordingly, the actual midline perimeter length of the first printed layer512may be determined based on the actual print path332of the printhead assembly302.

As particularly depicted inFIG.7, the additive printing system300may include at least one optical scanner334. The optical scanner(s)334may be a 3D scanner. As such, the optical scanner(s)334may be a non-contact scanner that utilizes cameras (e.g., a stereoscopic system) and/or lasers (e.g., a triangulation-based 3D laser scanner) to capture physical characteristics of the tower structure500. In an embodiment, the optical scanner(s)334may be integrated with the printhead assembly302. However, in an additional embodiment, the optical scanner(s)334may be an independent element supported by the support structure304.

Following the deposition of the first printed layer512, the optical scanner(s)334may, in an embodiment, be employed to optically scan the first printed layer512. The controller200may then generate (as depicted by arrow A3) a three-dimensional map336of the first printed layer512based on the optical scan. The controller200may, in an embodiment, determine the actual midline perimeter length of the first printed layer512based on the three-dimensional map336of the first printed layer512.

Referring still toFIG.7, in an embodiment, the additive printing system300may include at least one laser emitter338. The laser emitter(s)338may be supported by the support structure304and/or the support arm(s)310. In an embodiment, the laser emitter(s)338may project at least one placement guide onto the first printed layer512. The placement guide(s) may be configured to facilitate the positioning of the horizontal reinforcement assembly514on the first printed layer512. The placement guide(s) may, for example, be an illuminated ring, a plurality of alignment marks, an orientation point, and/or other similar features. It should be appreciated that the accurate placement of the horizontal reinforcement assembly514may facilitate the maximization of the structural integrity of the tower structure500as well as the placement of the second print layer516.

Referring now toFIG.8, in an embodiment, the printhead assembly302may include an actuatable roller340. The actuatable roller340may be positioned to precede the print nozzle312during a deposition operation. In other words, the actuatable roller340may proceed along the print path332in advance of the print nozzle312.

Following the positioning of the horizontal reinforcement assembly514on the first printed layer512, the actuatable roller340may, in an embodiment, be utilized to exert a downward force (F) on the horizontal reinforcement assembly514. In response to the downward force (F), the horizontal reinforcement assembly514may be embedded at least partially within the first printed layer512. It should be appreciated that embedding the horizontal reinforcement assembly514at least partially within the first printed layer512while the cementitious material506remains soft/uncured may mitigate an impact of the horizontal reinforcement assembly514on the second print layer516, and any subsequent print layers of the wall element502.

Referring still toFIG.8and also toFIG.9, in an embodiment, the printhead assembly302may include an actuatable groover342. The actuatable groover342may be positioned to trail the print nozzle312. In an embodiment, the actuatable groover may include at least one grooving element344. The grooving element(s)344may be configured to form at least one depression/recess in an upper surface of the first printed layer512that parallels the midline reference curve (CM). Accordingly, in an embodiment, the actuatable groover342may be positioned in contact with a portion of the wet cementitious material506of the first printed layer512. In an embodiment, the actuatable groover342may be utilized to develop the depression/recess in the portion of the wet cementitious material506of the first printed layer512.

In an embodiment, the actuatable groover342may be utilized to form a positioning line (L) in the portion of the wet cementitious material506. The positioning line (L) may be configured to facilitate the accurate placement of the horizontal reinforcement assembly514on the first printed layer512. Accordingly, the positioning line (L) may have a cross-sectional depth (D1) that is less than a cross-sectional maximal width (W1). The cross-sectional maximal width (W1) may, for example, correspond to the maximal diameter of the inner and/or outer rail518,520. It should be appreciated that the cross-sectional depth (D1) being less than a cross-sectional maximal width (W1) may facilitate the positioning of a majority of the horizontal reinforcement assembly514above an upper surface of the first printed layer512.

As depicted inFIG.9, in an embodiment, the actuatable groover342may include at least two grooving elements344. The grooving elements344may be utilized by the additive printing system300to form at least two parallel receiving grooves346(a single receiving groove346is depicted inFIG.9for purposes of illustration) in the first printed layer512. The parallel receiving grooves346may be configured to receive at least the inner and outer rail518,520of the horizontal reinforcement assembly514. In an embodiment, each of the receiving grooves346may have a cross-sectional width (W2) that corresponds to a cross-sectional width of the respective inner and outer rails518,520. Each of the receiving grooves346may, in an embodiment, have a cross-sectional depth (D2) configured to at least partially embed the horizontal reinforcement assembly514in the first printed layer512.

As depicted inFIG.8, in an embodiment, the additive printing system300may include both the actuatable roller340and the actuatable groover342. In such an embodiment, the actuatable groover342may be positioned to engage the first printed layer512during the deposition thereof (as depicted inFIG.9). Following the deposition of the first printed layer512, a separation may be established (as depicted inFIG.8) between the grooving element(s)344and the wet cementitious material506. The horizontal reinforcement assembly514may then be positioned in contact with the resultant positioning line (L) or parallel receiving grooves346. With the horizontal reinforcement assembly514accurately positioned on the first printed layer512, the actuatable roller340may be positioned in contact with the horizontal reinforcement assembly514in order to at least partially embed the horizontal reinforcement assembly514in the first printed layer512. In conjunction with the exertion of the downward force (F) by the actuatable roller340, the printhead assembly may deposit a portion of cementitious material506to print the second printed layer516.

As shown particularly inFIG.10, a schematic diagram of one embodiment of suitable components of a controller200that may control the additive printing system300is illustrated. For example, as shown, the controller200may include one or more processor(s)202and associated memory device(s)204configured to perform a variety of computer-implemented functions (e.g., performing the methods, steps, calculations and the like and storing relevant data as disclosed herein). Additionally, the controller200may also include a communications module206to facilitate communications between the controller200and the various components of the additive printing system300. Further, the communications module206may include a sensor interface208(e.g., one or more analog-to-digital converters) to permit signals transmitted from one or more sensors311to be converted into signals that can be understood and processed by the processors202. It should be appreciated that the sensor(s)311may be communicatively coupled to the communications module206using any suitable means, such as a wired or a wireless connection. Additionally, the communications module206may also be operably coupled to a component of the additive printing system300so as to orchestrate the formation of the tower structure500.

Referring now toFIG.11, a flow diagram of one embodiment of a method400for manufacturing a tower structure is presented. The method400may be implemented using, for instance, the additive printing system300of the present disclosure discussed above with references toFIGS.1-10to manufacture of the tower structure.FIG.11depicts steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that various steps of the method400, or any of the methods disclosed herein, may be adapted, modified, rearranged, performed simultaneously, or modified in various ways without deviating from the scope of the present disclosure.

As shown at (402), the method400may include depositing, via an additive printing system, a first printed layer of a wall element with a printhead assembly. The wall element may circumscribe a vertical axis of the tower structure. As shown at (404), the method400may include determining, via a controller of the additive printing system, an actual midline perimeter length of the first printed layer. As shown at (406), the method400may include forming a horizontal reinforcement assembly based, at least in part, on the actual midline perimeter length. As shown at (408), the method400may include positioning the horizontal reinforcement assembly in a horizontal orientation on the first printed layer and in axial alignment with the vertical axis. As shown at (410), the method400may include depositing, via the additive printing system, a second printed layer of the wall element with the printhead assembly on the horizontal reinforcement assembly.

Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. Similarly, the various method steps and features described, as well as other known equivalents for each such methods and feature, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

Clause 1. A method of manufacturing a tower structure, the method comprising: depositing, via an additive printing system, a first printed layer of a wall element with a printhead assembly, the wall element circumscribing a vertical axis of the tower structure; determining, via a controller of the additive printing system, an actual midline perimeter length of the first printed layer; forming a horizontal reinforcement assembly based, at least in part, on the actual midline perimeter length; positioning the horizontal reinforcement assembly in a horizontal orientation on the first printed layer and in axial alignment with the vertical axis; and depositing, via the additive printing system, a second printed layer of the wall element with the printhead assembly on the horizontal reinforcement assembly.

Clause 2. The method of clause 1, wherein the horizontal reinforcement assembly comprises: an inner rail having a length that is less than the actual midline perimeter length; an outer rail having a length that is greater than the actual midline perimeter length, wherein the inner rail and the outer rail have a shape corresponding to a horizontal shape of the first printed layer; and a plurality of transverse members, each transverse member having a first end coupled to the inner rail and a second end coupled to the outer rail.

Clause 3. The method of any preceding clause, wherein forming the horizontal reinforcement assembly further comprises: receiving a plurality of prefabricated reinforcement segments, each of the plurality of prefabricated reinforcement segments comprising an inner rail segment coupled to an outer rail segment via a portion of the plurality of transverse members, wherein each of the plurality of prefabricated reinforcement segments has a first segment end and a second segment end defined by the inner and outer rail segments; determining a magnitude of an overlap between adjacent prefabricated reinforcement segments of the plurality of prefabricated reinforcement segments configured to establish a reinforcement assembly midline perimeter length based on the actual midline perimeter length; and coupling the first segment end of each of the plurality of prefabricated reinforcement segments and the second segment end of each adjacent segment of the plurality of prefabricated reinforcement segments to establish the overlap therebetween based on the determined magnitude of overlap.

Clause 4. The method of any preceding clause, wherein establishing the overlap further comprises: positioning a plurality of movable stops of a jig table based on the reinforcement assembly midline perimeter length; and positioning a portion of the plurality of prefabricated reinforcement segments via the plurality of movable stops so as to establish the overlap between each adjacent segment of the plurality of prefabricated reinforcement segments.

Clause 5. The method of any preceding clause, wherein positioning the plurality of movable stops of the jig table further comprises: actuating at least one servo operably coupled to the plurality of movable stops; and altering a location of at least one movable stop of the plurality of movable stops relative to a support surface of the jig table.

Clause 6. The method of any preceding clause, wherein actuating the at least one servo further comprises: determining, via the controller, a required position for each of the plurality of movable stops that establishes the magnitude of the overlap between adjacent prefabricated reinforcement segments of the plurality of prefabricated reinforcement segments; and generating, via the controller, a setpoint for the at least one servo calculated to position each of the movable stops at the required position.

Clause 7. The method of any preceding clause, wherein forming the horizontal reinforcement assembly further comprises: receiving a plurality of prefabricated reinforcement segments, each of the plurality of prefabricated reinforcement segments comprising an inner rail segment coupled to an outer rail segment via a portion of the plurality of transverse members; and coupling each pair of adjacent prefabricated reinforcement segments of the plurality of prefabricated reinforcement segments via a coupler unit, wherein the coupler unit is configured to establish a reinforcement assembly midline perimeter length based on the actual midline perimeter length.

Clause 8. The method of any preceding clause, wherein positioning the horizontal reinforcement assembly further comprises: operably coupling at least one lifting element to a lifting interface of the coupler unit.

Clause 9. The method of any preceding clause, wherein forming the horizontal reinforcement assembly further comprises: determining a required reinforcement assembly midline perimeter length based on the actual midline perimeter length; determining a required inner rail radius based on the required reinforcement assembly midline perimeter length; applying, via a material working apparatus, a bend corresponding to the required inner rail radius to a first portion of rail stock, the first portion of rail stock having a length corresponding to the inner rail length; determining a required outer rail radius based on the required reinforcement assembly midline perimeter length; applying, via the material working apparatus, a bend corresponding to the required outer rail radius to a second portion of rail stock, the second portion of rail stock having a length corresponding to the outer rail length; and coupling the plurality of transverse members between the inner and outer rails via the material working apparatus.

Clause 10. The method of any preceding clause, wherein positioning the horizontal reinforcement assembly in the horizontal orientation on the first printed layer further comprises: establishing an operable coupling between at least one lifting element and the horizontal reinforcement assembly, the at least one lifting element being positioned so as to establish a separation relative to the first printed layer when the horizontal reinforcement assembly is positioned thereon; and following the positioning of the horizontal reinforcement assembly on the first printed layer, separating the at least one lifting element from the horizontal reinforcement assembly while maintaining at least the separation relative to the first printed layer, wherein the maintaining of at least the separation precludes a contact between the at least one lifting element and the first printed layer.

Clause 11. The method of any preceding clause, wherein determining the actual midline perimeter length of the first printed layer further comprises: recording, via the controller of the additive printing system, an actual print path of the printhead assembly during the deposition of the first printed layer; and determining the actual midline perimeter length of the first printed layer based on the actual print path of the printhead assembly.

Clause 12. The method of any preceding clause, wherein determining the actual midline perimeter length of the first printed layer further comprises: following the deposition of the first printed layer, optically scanning the first printed layer via an optical scanner of the additive printing system; generating, via the controller of the additive printing system, a three-dimensional map of the first printed layer based on the optical scan; and determining, via the controller of the additive printing system, the actual midline perimeter length of the first printed layer based on the three-dimensional map of the first printed layer.

Clause 13. The method of claim 1, wherein the additive printing system further comprises at least one laser emitter, the method further comprising: projecting at least one placement guide onto the first printed layer via the at least one laser emitter, wherein the at least one placement guide is configured to guide the positioning of the horizontal reinforcement assembly on the first printed layer.

Clause 14. The method of any preceding clause, wherein the printhead assembly further comprises an actuatable roller positioned to precede a print nozzle during a deposition operation, the method further comprising: following the positioning of the horizontal reinforcement assembly on the first printed layer, exerting a downward force on the horizontal reinforcement assembly via the actuatable roller; and in response to the downward force, embedding the horizontal reinforcement assembly at least partially within the first printed layer.

Clause 15. The method of any preceding clause, wherein the printhead assembly further comprises an actuatable groover positioned to trail a print nozzle during a deposition operation, wherein depositing the first printed layer further comprises: positioning the actuatable groover in contact with a portion of wet cementitious material of the first print layer; and developing a depression in the portion of wet cementitious material via the actuatable groover.

Clause 16. The method of any preceding clause, wherein the printhead assembly further comprises an actuatable roller positioned to precede the print nozzle during a deposition operation, the method further comprising: following the positioning of the horizontal reinforcement assembly on the first printed layer, establishing a separation between the actuatable groover and first printed layer; positioning the actuatable roller in contact with the horizontal reinforcement assembly; exerting a downward force on the horizontal reinforcement assembly via the actuatable roller; and in response to the downward force, embedding the horizontal reinforcement assembly at least partially within the first printed layer.

Clause 17. The method of any preceding clause, wherein developing the depression in the portion of wet cementitious material further comprises: forming a positioning line in the portion of wet cementitious material via the actuatable groover, the positioning line having a cross-sectional depth which is less than a cross-sectional maximal width.

Clause 18. The method of any preceding clause, wherein the actuatable groover comprises at least two grooving elements, and wherein developing the depression in the portion of wet cementitious material further comprises: forming at least two parallel receiving grooves in the first printed layer via the at least two grooving elements configured to receive at least an inner rail and an outer rail of the horizontal reinforcement assembly, wherein each of the at least two parallel receiving grooves have a cross-sectional width corresponding to a cross-sectional width of the respective inner and outer rail and a cross-sectional depth configured to at least partially embed the horizontal reinforcement assembly in the first printed layer.

Clause 19. An additive printing system for manufacturing a tower structure, the tower structure comprising a wall element circumscribing a vertical axis of the tower structure, the additive printing system comprising: a support structure; an optical scanner; a printhead assembly operably coupled to the support structure; and a controller communicatively coupled to the printhead assembly and the optical scanner, the controller comprising at least one processor configured to perform or direct a plurality of operations, the plurality of operations comprising: depositing a first printed layer of a wall element with the printhead assembly, optically scanning the first printed layer via the optical scanner, generating a three-dimensional map of the first printed layer based on the optical scan, determining an actual midline perimeter length of the first printed layer based on the three-dimensional map of the first printed layer, forming a horizontal reinforcement assembly based, at least in part, on the actual midline perimeter, wherein the horizontal reinforcement assembly comprises an inner rail having a length that is less than the actual midline perimeter length, an outer rail having a length that is greater than the actual midline perimeter length, and a plurality of transverse members, each transverse member having a first end coupled to the inner rail and a second end coupled to the outer rail, wherein the inner rail and the outer rail have a shape corresponding to a horizontal shape of the first printed layer, positioning the horizontal reinforcement assembly in a horizontal orientation on the first printed layer and in axial alignment with the vertical axis, and depositing a second printed layer of the wall element with the printhead assembly on the horizontal reinforcement layer.

Clause 20. The additive printing system of any preceding clause, wherein forming the horizontal reinforcement assembly further comprises: receiving a plurality of prefabricated reinforcement segments, each of the plurality of prefabricated reinforcement segments comprising an inner rail segment coupled to an outer rail segment via a portion of the plurality of transverse members, wherein each of the plurality of prefabricated reinforcement segments has a first segment end and a second segment end defined by the inner and outer rail segments; determining a magnitude of an overlap between adjacent prefabricated reinforcement segments of the plurality of prefabricated reinforcement segments configured to establish a reinforcement assembly midline perimeter length based on the actual midline perimeter length; receiving, via a controller of a jig table, the actual midline perimeter from the controller of the additive printing system; determining, via the controller of the jig table, a required position for each of a plurality of movable stops that establishes the magnitude of the overlap between adjacent prefabricated reinforcement segments of the plurality of prefabricated reinforcement segments; generating, via the controller of the jig table, a setpoint for at least one servo of the jig table calculated to position each of the movable stops at the required position, the at least one servo being operably coupled to the plurality of movable stops of the jig table so as to position the plurality of movable stops based on the reinforcement assembly midline perimeter length; actuating the at least one servo in accordance with the setpoint; positioning a portion of the plurality of prefabricated reinforcement segments via the plurality of movable stops so as to establish the overlap between each adjacent segment of the plurality of prefabricated reinforcement segments; and coupling the first segment end of each of the plurality of prefabricated reinforcement segments and the second segment end of each adjacent segment of the plurality of prefabricated reinforcement segments.