System and method for additive manufacturing calibration
阅读说明：本技术 用于增材制造校准的系统和方法 (System and method for additive manufacturing calibration ) 是由 布莱恩·斯科特·麦卡锡 苏布拉吉特·罗伊乔杜里 穆罕默德·莎拉比 维克托·彼得罗维什·奥斯特罗 于 2018-12-21 设计创作，主要内容包括：提供了一种增材制造系统,该增材制造系统包括固结装置,构建平台,光学检测器和控制器。固结装置被构造为形成部件的构建层。构建平台被构造为围绕沿着第一方向延伸的构建平台旋转轴线旋转。光学检测器被构造为检测至少两个对准标记的位置。控制器被构造为从光学检测器接收至少两个对准标记的位置。控制器还被构造为基于至少两个对准标记之间的比较来确定构建平台旋转轴线和构建平台旋转中心点的位置,其中,构建平台旋转中心点位于构建平台旋转轴线上。控制器进一步被构造为控制固结装置以在构建平台上固结多个颗粒。(An additive manufacturing system is provided that includes a consolidation device, a build platform, an optical detector, and a controller. The consolidation apparatus is configured to form a build layer of the part. The build platform is configured to rotate about a build platform rotation axis extending along a first direction. The optical detector is configured to detect the positions of at least two alignment marks. The controller is configured to receive the positions of the at least two alignment marks from the optical detector. The controller is further configured to determine a position of a build platform rotation axis and a build platform rotation center point based on a comparison between the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis. The controller is further configured to control the consolidation device to consolidate the plurality of particles on the build platform.)
1. An additive manufacturing system, comprising:
at least one consolidation apparatus configured to form a build layer of a part;
a build platform configured to rotate about a build platform rotation axis extending along a first direction;
an optical detector configured to detect a position of at least two alignment marks on at least one of the build platform and the build layer; and
a controller comprising a processing device and a memory device coupled to the processing device, the controller configured to:
receiving the positions of the at least two alignment marks from the optical detector;
determining a position of the build platform rotation axis and a build platform rotation center point based on a comparison between the positions of the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis; and is
Controlling the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based, at least in part, on the determined build platform axis of rotation and the determined build platform center of rotation point.
2. The additive manufacturing system of claim 1, wherein the consolidation device comprises a laser device, and wherein the controller is further configured to control the laser device to etch the at least two alignment marks on at least one of the build platform and the build layer.
3. The additive manufacturing system of claim 1, wherein at least one of the build platform and the at least one consolidation device is configured to move along the first direction.
4. The additive manufacturing system of claim 1, wherein the at least two alignment marks comprise a first plurality of alignment marks and a second plurality of alignment marks, and wherein the controller is configured to:
approximately translating and rotating the plurality of first alignment marks to align the plurality of first alignment marks with the plurality of second alignment marks;
characterizing the translation and the rotation of the plurality of first alignment marks as a rotation about a build platform rotation axis and a build platform center of rotation point; and is
Determining a position of the build platform rotation axis and the build platform center of rotation based on characterizing the translation and the rotation of the plurality of first alignment marks as rotations about the build platform rotation axis and the build platform center of rotation point.
5. The additive manufacturing system of claim 1, wherein the at least two alignment marks comprise a first side first alignment mark, a second side first alignment mark, a first side second alignment mark, and a second side second alignment mark, wherein the first side first alignment mark is positioned opposite the second side first alignment mark on the build platform, wherein a first line is defined between the first side first alignment mark and the second side first alignment mark, wherein the first side second alignment mark is positioned opposite the second side second alignment mark, wherein a second line is defined between the first side second alignment mark and the second side second alignment mark, and wherein the controller is configured to determine the position of the build platform rotational axis and the build platform rotational center point by determining a position of an intersection of the first line and the second line .
6. The additive manufacturing system of claim 1, wherein the controller is further configured to:
estimating a position of the build platform rotation axis and the build platform center of rotation point based on the image of the build platform received from the optical detector; and is
Controlling the at least one consolidation device to etch the at least two alignment marks located on the build platform.
7. The additive manufacturing system of claim 6, wherein the at least two alignment marks comprise at least two vernier alignment scales, wherein each vernier alignment scale comprises a plurality of graduations.
8. The additive manufacturing system of claim 6, wherein the at least two alignment marks comprise at least two substantially similar sectors extending radially outward from the build platform center of rotation and being adjacently spaced along at least one of the build platform and the component.
9. A controller for use in an additive manufacturing system, the additive manufacturing system comprising at least one consolidation device configured to form build layers of a part, the controller comprising a processing device and a memory device coupled to the processing device, the controller configured to:
receiving positions of at least two alignment marks from an optical detector, the optical detector configured to detect the positions of the at least two alignment marks, the at least two alignment marks being located on at least one of a build platform and the build layer;
determining the position of a build platform rotation axis of the build platform extending along a first direction and a build platform rotation center point based on a comparison between the positions of the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis; and is
Controlling the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based, at least in part, on the determined build platform axis of rotation and the determined build platform center of rotation point.
10. The controller of claim 9, wherein the controller is configured to control a consolidation device comprising a laser device configured to emit an energy beam, and wherein the controller is configured to control the consolidation device to etch the at least two alignment marks on at least one of the build platform and the component.
11. The controller of claim 9, wherein at least one of the build platform and the at least one consolidation apparatus is configured to move along the first direction.
12. The controller of claim 9, wherein the at least two alignment marks comprise a plurality of first alignment marks and a plurality of second alignment marks, and wherein the controller is configured to:
approximately translating and rotating the plurality of first alignment marks to align the plurality of first alignment marks with the plurality of second alignment marks;
characterizing the translation and the rotation of the plurality of first alignment marks as a rotation about a build platform rotation axis and a build platform center of rotation point; and is
Determining a position of the build platform rotation axis and the build platform center of rotation based on characterizing the translation and the rotation of the plurality of first alignment marks as rotations about the build platform rotation axis and the build platform center of rotation point.
13. The controller of claim 9, wherein the controller is configured to:
determining the build platform axis of rotation and the build platform center of rotation based on a comparison between the positions of a first side first alignment mark, a second side first alignment mark, a first side second alignment mark and a second side second alignment mark, wherein the first side first alignment mark is positioned on the build platform opposite the second side first alignment mark, wherein a first line is defined between the first side first alignment mark and the second side first alignment mark, wherein the first side second alignment mark is positioned opposite the second side second alignment mark, and wherein a second line is defined between the first side second alignment mark and the second side second alignment mark; and is
Determining the position of the build platform center of rotation point by determining a position of an intersection of the first line and the second line.
14. The controller of claim 9, wherein the controller is further configured to:
estimating a position of the build platform rotation axis and the build platform center of rotation point based on the image of the build platform received from the optical detector; and is
Controlling the at least one consolidation device to etch the at least two alignment marks located on the build platform.
15. The controller of claim 9, wherein the controller is configured to determine the position of the build platform center of rotation based on a comparison between the positions of a first vernier alignment scale and a second vernier alignment scale, wherein the first vernier alignment scale and the second vernier alignment scale comprise a plurality of scales.
16. The controller of claim 9, wherein the controller is configured to determine the position of the build platform center of rotation based on a comparison between positions of at least two substantially similar sectors extending radially outward from the build platform center of rotation and being adjacently spaced along at least one of the build platform and the component.
17. A method of manufacturing a component using an additive manufacturing system, the method comprising:
rotating the build platform relative to the optical detector about a build platform rotation axis;
detecting, using the optical detector, positions of at least two alignment marks on at least one of a build platform and a build layer of a part on the build platform;
receiving, by a controller, the positions of the at least two alignment marks;
determining, by the controller, a location of the build platform axis of rotation and a build platform center of rotation based on a comparison between the at least two alignment marks; and
controlling, by the controller, at least one consolidation device to consolidate at least a portion of a plurality of particles on the build platform to form at least one build layer of the part based at least in part on the determined build platform axis of rotation and the determined position of a build platform center point of rotation.
18. The method of claim 17, wherein determining the location of the build platform axis of rotation and the build platform center of rotation further comprises determining the build platform axis of rotation and the build platform center of rotation based on a comparison between the locations of a first side first alignment mark, a second side first alignment mark, a first side second alignment mark, and a second side second alignment mark, wherein the first side first alignment mark is positioned on the build platform opposite the second side first alignment mark, wherein a first line is defined between the first side first alignment mark and the second side first alignment mark, wherein the first side second alignment mark is positioned opposite the second side second alignment mark, and wherein, a second line is defined between the first side second alignment mark and the second side second alignment mark.
19. The method of claim 18, wherein determining the location of the build platform axis of rotation and the build platform center of rotation further comprises determining the location of an intersection of the first line and the second line.
20. The method of claim 17, wherein rotating the build platform relative to the optical detector about the build platform rotation axis further comprises:
estimating the position of the build platform axis of rotation and the build platform center of rotation based on the image of the build platform received from the optical detector; and
controlling the at least one consolidation device to etch the at least two alignment marks located on the build platform.
Technical Field
The subject matter described herein relates generally to additive manufacturing systems, and more particularly to rotary additive manufacturing systems that include a calibration apparatus.
Background
At least some additive manufacturing systems involve consolidation of particulate material to manufacture a part. Such techniques facilitate the production of complex parts from expensive materials in a manner that reduces cost and increases manufacturing efficiency. At least some known additive manufacturing systems (e.g., Direct Metal Laser Melting (DMLM), Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS), andsystem) uses a focused energy source (e.g., a laser device or electron beam generator), a build platform, and particles (e.g., without limitation, powdered metal) to manufacture a part. (LaserCusing is a registered trademark of ConceptLaser GmbH, Ridgehog Fisch, Germany). In at least some additive manufacturing systems, the build platform is centered about the build platform relative to the consolidation apparatusThe axis is rotated while the laser beam emitted by the consolidation means scans the build layer of particulate material. However, in at least some known systems, the rotary additive manufacturing system must be calibrated based at least in part on the location of the build platform central axis and a build layer center of rotation point located on the build platform central axis. Consolidation of a part in a rotary additive manufacturing system depends, at least in part, on determination of a build platform central axis and a build layer rotational center point to prevent formation of seams and alignment defects within the part, which may require a significant amount of time.
Disclosure of Invention
In one aspect, an additive manufacturing system is provided. The additive manufacturing system includes at least one consolidation device, a build platform, an optical detector, and a controller. At least one consolidation apparatus is configured to form a build layer of the part. The build platform is configured to rotate about a build platform rotation axis extending along a first direction. The optical detector is configured to detect a position of at least two alignment marks located on at least one of the build platform and the build layer. The controller includes a processing device and a memory device coupled to the processing device. The controller is configured to receive the positions of the at least two alignment marks from the optical detector. The controller is further configured to determine a position of a build platform rotation axis and a build platform rotation center point based on a comparison between the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis. The controller is further configured to control the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based at least in part on the determined build platform axis of rotation and the determined position of the build platform center of rotation point.
In another aspect, a controller for use in an additive manufacturing system is provided. The additive manufacturing system comprises at least one consolidation device and a build platform configured to rotate about a build platform axis of rotation extending along a first direction, wherein the at least one consolidation device is configured to form a build layer of a part. The controller includes a processing device and a memory device coupled to the processing device. The controller is configured to receive the positions of the at least two alignment marks from an optical detector configured to detect the positions of the at least two alignment marks, the at least two alignment marks being located on at least one of the build platform and the build layer. The controller is further configured to determine a position of a build platform rotation axis and a build platform center of rotation point based on a comparison between the positions of the at least two alignment marks, wherein the build platform center of rotation point is located on the build platform rotation axis. The controller is further configured to control the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based at least in part on the determined build platform axis of rotation and the determined position of the build platform center of rotation point.
In yet another aspect, a method of manufacturing a component using an additive manufacturing system is provided. The method comprises rotating the build platform relative to the optical detector about a build platform rotation axis. The method also includes detecting, using an optical detector, positions of at least two alignment marks on at least one of the build platform and a build layer of the component on the build platform. The method further includes receiving, by the controller, positions of at least two alignment marks. The method includes determining, by the controller, a position of a build platform rotation axis and a build platform center of rotation point based on a comparison between the at least two alignment marks. The method also includes controlling, by the controller, at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform to form at least one build layer of the part based at least in part on the determined build platform axis of rotation and the determined position of the build platform center point of rotation.
Drawings
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
fig. 1 is a schematic diagram of an exemplary rotary additive manufacturing system;
fig. 2 is a block diagram of a controller that may be used to operate the rotary additive manufacturing system shown in fig. 1;
FIG. 3 is a schematic plan view of the example rotary additive manufacturing system shown in FIG. 1, illustrating a plurality of example alignment marks;
FIG. 4 is an enlarged schematic plan view of area 3 shown in FIG. 3, showing the plurality of alignment marks shown in FIG. 3 superimposed;
FIG. 5 is a schematic plan view of the rotary additive manufacturing system of FIG. 1 showing another plurality of alignment marks;
FIG. 6 is a schematic plan view of the rotary additive manufacturing system shown in FIG. 1 illustrating exemplary alternative embodiments of the alignment marks shown in FIG. 3;
FIG. 7 is a top view of a portion of the build platform shown in FIG. 6 illustrating a first type of misalignment of the alternative alignment marks shown in FIG. 6;
FIG. 8 is a top view of a portion of the build platform shown in FIG. 6 illustrating a second type of misalignment of the alternative alignment marks shown in FIG. 6;
FIG. 9 is a schematic plan view of the rotary additive manufacturing system shown in FIG. 1 illustrating an alternative embodiment of the alignment marks shown in FIG. 6;
FIG. 10 is an enlarged schematic plan view of the area 9 shown in FIG. 9, showing the alternative alignment mark shown in FIG. 9; and
fig. 11 is a flow diagram of an exemplary method that may be used to manufacture a component using the rotary additive manufacturing system shown in fig. 1.
Unless otherwise indicated, the drawings provided herein are intended to illustrate features of embodiments of the present disclosure. These features are believed to be applicable in a variety of systems including one or more embodiments of the present disclosure. As such, the drawings are not meant to include all of the conventional features known to those of ordinary skill in the art to be required to practice the embodiments disclosed herein.
Detailed Description
In the following specification and claims, reference will be made to a number of terms which shall be defined to have the following meanings.
The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.
"optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about", "substantially" and "approximately", are not to be limited to the precise value specified. In at least some cases, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.
As used herein, the terms "processor" and "computer" and related terms (e.g., "processing device," "computing device," and "controller") are not limited to just those integrated circuits referred to in the art as a computer, but broadly refer to a microcontroller, a microcomputer, a Programmable Logic Controller (PLC) and an application specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein. In the embodiments described herein, memory may include, but is not limited to, a computer-readable medium, such as a Random Access Memory (RAM), a computer-readable non-volatile medium, such as flash memory. Alternatively, a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a Digital Versatile Disc (DVD) may also be used. Also, in the embodiments described herein, additional input channels may be, but are not limited to, computer peripherals associated with operator interfaces (such as a mouse and a keyboard). Alternatively, other computer peripherals may be used, which may include, for example, but are not limited to, a scanner. Further, in the exemplary embodiment, additional output channels may include, but are not limited to, an operator interface monitor.
Further, as used herein, the terms "software" and "firmware" are interchangeable, and include any computer program stored in memory for execution by a personal computer, workstation, client and server.
As used herein, the term "non-transitory computer-readable medium" is intended to mean any tangible computer-based apparatus for the short and long term storage of information (such as computer-readable instructions, data structures, program modules and sub-modules or other data in any device) implemented in any technical method. Thus, the methods described herein may be encoded as executable instructions embodied in a tangible, non-transitory computer-readable medium (including, but not limited to, a storage device and/or a memory device). Such instructions, when executed by a processor, cause the processor to perform at least a portion of the methods described herein. Furthermore, as used herein, the term "non-transitory computer readable medium" includes all tangible computer readable media (including, but not limited to, non-transitory computer storage devices, including, but not limited to, volatile and non-volatile media), as well as removable and non-removable media (e.g., firmware, physical and virtual storage devices, CD-ROMS, DVDs, and any other digital source, such as a network or the internet, and digital means not yet developed, with the sole exception of transitory propagating signals).
Further, as used herein, the term "real-time" refers to at least one of the time of occurrence of the associated event, the time of measurement and collection of the predetermined data, the time of processing the data, and the time of response of the system to the event and environment. In the embodiments described herein, these activities and events occur substantially instantaneously.
Systems and methods described herein include an additive manufacturing system that includes at least one consolidation device, a build platform, an optical detector, and a controller. At least one consolidation apparatus is configured to consolidate at least a portion of the plurality of particles to form a build layer of the component. The build platform is configured to rotate about a build platform rotation axis extending along a first direction. The optical detector is configured to detect a position of at least two alignment marks located on at least one of the build platform and the build layer. The controller includes a processing device and a memory device coupled to the processing device. The controller is configured to receive the positions of the at least two alignment marks from the optical detector and determine a position of a build platform rotation axis and a build platform rotation center point based on a comparison between the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis. The controller is further configured to control the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based at least in part on the determined build platform axis of rotation and the determined build platform center of rotation point. The additive manufacturing systems described herein facilitate increasing system efficiency by reducing setup time, improving part quality by increasing system calibration accuracy, and reducing costs of additive manufactured parts.
Additive manufacturing processes and systems include, for example, but are not limited to, reductive photopolymerization, powder bed melting, binder jetting, material jetting, sheet lamination, material extrusion, directed energy deposition, and mixing systems. These processes and systems include, for example, but are not limited to, SLA-lithography equipment, DLP-digital light processing, 3 SP-scanning, spin and selective photocuring, CLIP-continuous liquid interface production, SLS-selective laser sintering, DMLS-direct metal laser sintering, SLM-selective laser melting, EBM-electron beam melting, SHS-selective heat sintering, MJF-multiple jet melting, 3D printing, Voxeljet, Polyjet, SCP-smooth curvature printing, MJM-multiple jet modeling Projet, LOM-laminate manufacturing, SDL-selective deposition lamination, UAM-ultrasonic additive manufacturing, FFF-melt filament manufacturing, FDM-melt deposition modeling, LMD-laser metal deposition, NS LENS-laser engineering web forming, DMD-direct metal deposition, hybrid systems, and combinations of these processes and systems. These processes and systems may employ, for example, but are not limited to, all forms of electromagnetic radiation, heating, sintering, melting, curing, bonding, consolidating, pressing, embedding, and combinations thereof.
Materials employed in additive manufacturing processes and systems include, for example, but are not limited to, polymers, plastics, metals, ceramics, sand, glass, waxes, fibers, biomass, composites, and mixtures of these materials. These materials may be used in a variety of forms suitable for a given material and process or system, including for example, but not limited to, liquids, solids, powders, flakes, foils, tapes, filaments, granules, liquids, slurries, wires, mists, pastes, and combinations of these forms.
Fig. 1 is a schematic diagram of an exemplary rotary additive manufacturing system 10. The coordinate system 12 includes an X-axis, a Y-axis, and a Z-axis, which are orthogonal to each other. In the exemplary embodiment, rotary additive manufacturing system 10 includes a consolidation apparatus 14, where consolidation apparatus 14 includes a laser apparatus 16 for manufacturing a part 24 using a layer-by-layer manufacturing process, a scan motor 18, a scan mirror 20, and a scan lens 22. Rotary additive manufacturing system 10 also includes an optical detector 23, optical detector 23 configured to detect a position of at least two alignment marks 25 located on at least one of build platform 38 and component 24. Alternatively, the consolidation apparatus 14 may include any component that facilitates the consolidation of a material using any of the processes and systems described herein. The laser device 16 provides a high intensity heat source configured to generate a melt pool 26 (not shown to scale) in the powdered material using an energy beam 28. Laser device 16 is contained within a housing 30 coupled to a mounting system 32. Rotary additive manufacturing system 10 also includes a computer control system or controller 34.
Mounting system 32 is moved by an actuator or actuator system 36, which actuator or actuator system 36 is configured to move mounting system 32 in the X-direction, the Y-direction, and the Z-direction to cooperate with scanning mirror 20 to facilitate the manufacture of layers of component 24 within rotary additive manufacturing system 10. For example, without limitation, mounting system 32 pivots about a center point, moves in a linear path, a curved path, and/or rotates to cover a portion of powder on circular build platform 38 to facilitate directing energy beam 28 along a surface of a plurality of particles 45 of build layer 44 to form a layer of part 24. Alternatively, housing 30 and energy beam 28 are moved in any orientation and manner that enables rotary additive manufacturing system 10 to function as described herein.
Scan motor 18 is controlled by controller 34 and is configured to move mirror 20 such that energy beam 28 is reflected to be incident along a predetermined path (e.g., without limitation, linear and/or rotational scan path 40) along build platform 38. In the exemplary embodiment, the combination of scan motor 18 and scan mirror 20 forms a two-dimensional scanning galvanometer. Alternatively, scan motor 18 and scan mirror 20 may include a three-dimensional (3D) scan galvanometer, a dynamic focus galvanometer, and/or any other method that may be used to deflect energy beam 28 of laser device 16.
In the exemplary embodiment, build platform 38 is rotated by actuator system 36 about build platform rotation axis 39 along rotation direction 42 to facilitate a continuous deposition, distribution, and consolidation of particles 45. As described above with respect to mounting system 32, actuator system 36 is also configured to move consolidation apparatus 14 in the Z-direction (i.e., perpendicular to the top surface of build platform 38) so that build layer 44 may be consolidated on top of a previously consolidated build layer 44. In an exemplary embodiment, one full rotation of the build platform in the rotational direction 42 corresponds to approximately seventy microns of movement of the consolidation means 14 in the Z-direction. In some embodiments, actuator system 36 is also configured to move build platform 38 in the Z-direction and/or XY-plane. For example, and without limitation, in an alternative embodiment in which housing 30 is stationary, actuator system 36 rotates build platform 38 in rotational direction 42 and in the X-direction and/or the Y-direction to cooperate with scan motor 18 and scan mirror 20 to direct energy beam 28 of laser device 16 about build platform 38 along scan path 40. In the exemplary embodiment, actuator system 36 includes, for example and without limitation, a linear motor, a hydraulic and/or pneumatic piston, a screw drive mechanism, and/or a conveyor system.
In the exemplary embodiment, rotary additive manufacturing system 10 is operated to manufacture part 24 from a computer modeled representation of the 3D geometry of part 24. The computer modeling representation may be generated in a Computer Aided Design (CAD) or similar file. The CAD file of component 24 is converted to a layer-by-layer format that includes a plurality of build parameters for each layer of component 24, e.g., build layer 44 of component 24 contains a plurality of particles 45 to be consolidated by rotary additive manufacturing system 10. In the exemplary embodiment, component 24 is modeled at a desired orientation relative to a coordinate system origin used in rotary additive manufacturing system 10. The geometry of the part 24 is cut into a stack of layers of desired thickness such that the geometry of each layer is the profile of a cross-section through the part 24 at that particular layer location. The geometry across the respective layers generates a scan path 40. Build parameters are applied along scan path 40 to fabricate layers of part 24 from particles 45 used to construct part 24. These steps are repeated for each respective layer of the component 24 geometry. Once this process is complete, an electronic representation of scan path 40 is generated, including all layers. The electronic representation of scan path 40 is loaded into controller 34 of rotary additive manufacturing system 10 to control the system during the manufacture of each layer.
After the electronic representation of scan path 40 is loaded into controller 34, rotary additive manufacturing system 10 is operated to consolidate particles 45 by implementing a layer-by-layer manufacturing process (e.g., a direct metal laser melting method) to generate part 24. The exemplary layer-by-layer additive manufacturing process does not use a pre-existing article as a precursor to the final part, but rather the process produces the part 24 from raw materials (e.g., particles 45) in a configurable form. For example, but not limited to, steel powder may be used for additive manufacturing of steel components. Rotary additive manufacturing system 10 is capable of manufacturing components, such as component 24, using a variety of materials, such as, but not limited to, metals, ceramics, glasses, and polymers.
Fig. 2 is a block diagram of a controller 34 that may be used to operate rotary additive manufacturing system 10 (shown in fig. 1). In the exemplary embodiment, controller 34 is any type of controller that is generally provided by a manufacturer of rotary additive manufacturing system 10 to control operations of rotary additive manufacturing system 10. Controller 34 performs operations to control the operation of rotary additive manufacturing system 10 based at least in part on instructions from a human operator. Controller 34 includes, for example, a 3D model of part 24 to be manufactured by rotary additive manufacturing system 10. The operations performed by controller 34 include controlling the power output of laser device 16 (shown in FIG. 1), and adjusting mounting system 32 and/or build platform 38 (all shown in FIG. 1) via actuator system 36 to control the scan speed of energy beam 28. Controller 34 is also configured to control scan motor 18 to direct scan mirror 20 to further control the scan speed of energy beam 28 within rotary additive manufacturing system 10. Controller 34 is further configured to receive the positions of alignment marks 25 from optical detector 23 to determine the position of build platform rotation axis 39 and build platform center of rotation point 27 based on a comparison between alignment marks 25. In alternative embodiments, controller 34 may perform any operations that enable rotary additive manufacturing system 10 to function as described herein.
In the exemplary embodiment, controller 34 includes a memory device 46 and a processor 48 that is coupled to memory device 46. Processor 48 may include one or more processing units, such as, but not limited to, a multi-core configuration. Processor 48 is any type of processor that allows controller 34 to operate as described herein. In some embodiments, the executable instructions are stored in the memory device 46. The controller 34 may be configured to perform one or more of the operations described herein by programming the processor 48. For example, processor 48 may be programmed by encoding an operation as one or more executable instructions and providing the executable instructions in memory device 46. In an exemplary embodiment, the memory device 46 is one or more devices capable of storing and retrieving information (such as executable instructions or other data). The memory device 46 may include one or more computer-readable media such as, but not limited to, Random Access Memory (RAM), dynamic RAM, static RAM, solid state disks, hard disks, Read Only Memory (ROM), erasable programmable ROM, electrically erasable programmable ROM, or non-volatile RAM memory. The above memory types are exemplary only, and are thus not limiting as to the types of memory usable for storage of a computer program.
Memory device 46 may be configured to store any type of data, including, but not limited to, build parameters associated with component 24. In some embodiments, processor 48 removes or "flushes" data from memory device 46 based on the age of the data. For example, processor 48 may overwrite previously recorded and stored data associated with a subsequent time or event. Additionally or alternatively, the processor 48 may remove data that exceeds a predetermined time interval. Additionally, the memory device 46 includes, but is not limited to, sufficient data, algorithms, and commands to facilitate monitoring of build parameters and geometric conditions of the component 24 manufactured by the rotary additive manufacturing system 10.
In some embodiments, the controller 34 includes a presentation interface 50 coupled to the processor 48. Presentation interface 50 presents information, such as operating conditions of rotary additive manufacturing system 10, to user 52. In one embodiment, presentation interface 50 includes a display adapter (not shown) coupled to a display device (not shown) such as a Cathode Ray Tube (CRT), Liquid Crystal Display (LCD), Organic LED (OLED) display, or "electronic ink" display. In some embodiments, presentation interface 50 includes one or more display devices. Additionally or alternatively, presentation interface 50 includes an audio output device (not shown), such as, but not limited to, an audio adapter or speaker (not shown).
In some embodiments, the controller 34 includes a user input interface 54. In the exemplary embodiment, a user input interface 54 is coupled to processor 48 and receives input from user 52. The user input interface 54 may include, for example, but is not limited to, a keyboard, a pointing device, a mouse, a stylus, a touch sensitive panel (such as, but not limited to, a touchpad or a touch screen), and/or an audio input interface (such as, but not limited to, a microphone). A single component, such as a touch screen, may serve as both the display device of the presentation interface 50 and the user input interface 54.
In the exemplary embodiment, communication interface 56 is coupled to processor 48 and is configured to communicatively couple with one or more other devices (e.g., laser device 16) and perform input and output operations with respect to these devices while acting as an input channel. For example, communication interface 56 may include, but is not limited to, a wired network adapter, a wireless network adapter, a mobile telecommunications adapter, a serial communications adapter, or a parallel communications adapter. Communication interface 56 may receive data signals from or transmit data signals to one or more remote devices. For example, in some embodiments, the communication interface 56 of the controller 34 may transmit data signals to the actuator system 36 or receive data signals from the actuator system 36.
Presentation interface 50 and communication interface 56 are each capable of providing information suitable for use with the methods described herein (e.g., providing information to user 52 or processor 48). Accordingly, presentation interface 50 and communication interface 56 may be referred to as output devices. Similarly, the user input interface 54 and the communication interface 56 are capable of receiving information suitable for use with the methods described herein and may be referred to as input devices.
In an exemplary embodiment, the controller 34 is configured to receive the position of the alignment mark 25 from the optical detector 23. Controller 34 is further configured to determine a location of a build platform rotation axis 39 and a build platform center of rotation point 27 based on a comparison between the locations of alignment marks 25, wherein build platform center of rotation point 27 is located on build platform rotation axis 39, as will be described in detail below. Controller 34 is further configured to control consolidation apparatus 14 to consolidate at least a portion of plurality of particles 45 on build platform 38 based at least in part on the determined build platform axis of rotation 39 and the determined position of build platform center of rotation point 27. In alternative embodiments, controller 34 may perform any operations that enable rotary additive manufacturing system 10 to function as described herein.
Fig. 3 is a schematic plan view of rotary additive manufacturing system 10 (shown in fig. 1) showing a plurality of alignment marks 25. Fig. 4 is an enlarged schematic plan view of region 3 (shown in fig. 3) showing a plurality of alignment marks 25 (shown in fig. 3) overlapping. In the exemplary embodiment, particle delivery device 58 is configured to deliver a plurality of particles 45 to build platform 38. Recoating apparatus 60 is configured to distribute a plurality of particles 45 to form build layer 44 on build platform 38. The alignment marks 25 include a plurality of first alignment marks 100 and a plurality of second alignment marks 102. In the exemplary embodiment, first alignment mark 100 is positioned opposite second alignment mark 102 on build platform 38. In alternative embodiments, second alignment mark 102 may be positioned on build platform 38 at any rotational angle of build platform 38 relative to first alignment mark 100 that facilitates operation of rotary additive manufacturing system 10 as described herein.
In the exemplary embodiment, controller 34 controls laser device 16 of consolidation apparatus 14 to project energy beam 28 to be incident on build platform 38 to form first alignment mark 100. In the exemplary embodiment, after forming first alignment mark 100 on build platform 38, controller 34 controls build platform 38 to rotate one hundred eighty degrees in rotational direction 42 while consolidation apparatus 14 remains stationary. In alternative embodiments, controller 34 may control the rotation of build platform by any angle in rotational direction 42, which facilitates the operation of additive manufacturing system 10 as described herein. Controller 34 then controls laser device 16 to project energy beam 28 for incidence on the build platform to form second alignment mark 102. In an alternative embodiment, laser device 16 may project energy beam 28 to be incident on component 24. In further alternative embodiments, consolidation devices 14 may form any alignment marks 25 in any order, which facilitates operation of rotary additive manufacturing system 10 as described herein.
In an exemplary embodiment, the optical detector 23 detects the position of the alignment mark 25 and transmits the position to the controller 34. Controller 34 determines the position of build platform center of rotation point 27 and build platform axis of rotation 39 by comparing the positions of alignment marks 25. In an exemplary embodiment, the controller 34 is configured to determine the position of the first and second alignment marks 100, 102 relative to each other using the position data received from the optical detector 23. In an alternative embodiment, controller 34 determines the positions of first and second alignment marks 100, 102 in any manner that facilitates operation of rotary additive manufacturing system 10 as described herein.
In the exemplary embodiment, using the determined positions of first and second alignment marks 100, 102 relative to each other, controller 34 determines the position of build platform axis of rotation 39 and build platform center of rotation point 27 located on build platform axis of rotation 39 by using a matrix approximation that uses the first and second matrices to find an orthogonal matrix that most closely maps the first matrix to the second matrix. This "best fit" approach approximates translation and rotation of the first alignment mark 100 in homogeneous coordinates to align the first alignment mark 100 with the second alignment mark 102. To characterize the translational and rotational motion of the first alignment mark 100 as rotation about the build platform rotation axis 39 and the build platform center of rotation point 27, the following formula is used:
equation 1A can be simplified to the following equation:
using equation 1B, the coordinates xc and yc may be solved to determine the position of the build platform center of rotation 27 relative to coordinate system 12 for a given build layer 44. In an exemplary embodiment, build platform center of rotation point 27 is movable in the Z-direction along build platform axis of rotation 39 as the overall height of component 24 relative to the Z-direction increases. In alternative embodiments, build platform center of rotation point 27 may be determined using any formula that facilitates operation of additive manufacturing system 10 as described herein.
Fig. 5 is a schematic plan view of rotary additive manufacturing system 10 (shown in fig. 1) illustrating another plurality of alignment marks 25. The alignment marks 25 include a first side first alignment mark 200, a second side first alignment mark 202, a first side second alignment mark 204, and a second side second alignment mark 206. First side first alignment mark 200 is positioned on build platform 38 opposite second side first alignment mark 202, defining a first line 203 therebetween. First side second alignment mark 204 is positioned on build platform 38 opposite second side second alignment mark 206, defining a second line 207 therebetween. In alternative embodiments, first side first alignment mark 200, second side first alignment mark 202, first side second alignment mark 204, and second side second alignment mark 206 may be located in any position that facilitates operation of rotary additive manufacturing system 10 as described herein.
In the exemplary embodiment, controller 34 controls laser device 16 of consolidation apparatus 14 to project energy beam 28 to be incident on build platform 38 to form first side first alignment mark 200 and first side second alignment mark 204. In an alternative embodiment, the consolidation apparatus 14 may project the energy beam 28 to be incident on the part 24, thereby forming the first side first alignment mark 200 and the first side second alignment mark 204. In the exemplary embodiment, after forming first side first alignment mark 200 and second side second alignment mark 204 on build platform 38, controller 34 controls build platform 38 to rotate one hundred eighty degrees in rotational direction 42 while consolidation apparatus 14 remains stationary. Controller 34 then controls laser device 16 to project energy beam 28 for incidence on the build platform to form second side first alignment mark 202 and second side second alignment mark 206. In an alternative embodiment, laser device 16 may project energy beam 28 to be incident on component 24. In further alternative embodiments, consolidation devices 14 may form any alignment marks 25 in any order that facilitates operation of rotary additive manufacturing system 10 as described herein.
In an exemplary embodiment, the optical detector 23 detects the position of the alignment mark 25 and transmits the position to the controller 34. Controller 34 determines the position of build platform center of rotation point 27 and build platform axis of rotation 39 by comparing the positions of alignment marks 25. More specifically, in the exemplary embodiment, controller 34 determines a position of build platform axis of rotation 39 and a build platform center of rotation point 27 located on build platform axis of rotation 39 by determining a position of an intersection 211 of first line 203 and second line 207. The location of intersection point 211 represents the location of build platform center of rotation point 27 for a given build layer 44. In an exemplary embodiment, build platform center of rotation point 27 is movable in the Z-direction along build platform axis of rotation 39 as the overall height of component 24 relative to the Z-direction increases. In an exemplary embodiment, the controller 34 is configured to determine the location of the intersection 211 using the position data received from the optical detector 23 by first determining a first side distance 213 defined between the first side first alignment mark 200 and the first side second alignment mark 204. Controller 34 then determines a second side distance 215 defined between second side-first alignment mark 202 and second side-second alignment mark 206. Then, the controller 34 determines the lengths of the first line 203 and the second line 207. Using a trigonometric relationship, such as sine law, controller 34 determines the location of intersection 211. In alternative embodiments, controller 34 determines the location of intersection 211 in any manner that facilitates operation of rotary additive manufacturing system 10 as described herein.
Fig. 6 is a schematic plan view of rotary additive manufacturing system 10 (shown in fig. 1) illustrating an alternative embodiment of alignment marks 25 (shown in fig. 3). FIG. 7 is a top view of a portion of build platform 38 (shown in FIG. 6) illustrating a first type of misalignment of alternate alignment marks 25. FIG. 8 is a top view of a portion of build platform 38 (shown in FIG. 4) illustrating a second type of alternative alignment mark 25 misalignment. In the exemplary embodiment, alternate alignment marks 25 include a plurality of substantially similar pie-shaped alignment sectors 300 that are adjacently spaced along a surface of build platform 38. In alternative embodiments, alignment sector 300 may be any shape and size that facilitates operation of rotary additive manufacturing machine 10 as described herein.
In the exemplary embodiment, controller 34 receives an image of build platform 38 from optical detector 23 and estimates an estimated approximate position of build platform center of rotation point 304 and an approximate surface area of build platform 38. Based on estimated build platform center of rotation point 304 and the build platform surface area, controller 34 determines the size and location of a plurality of adjacently located estimated alignment sectors 302 relative to build platform 38. The relative positions of the plurality of estimated alignment sectors 302 are determined by controller 34 such that the plurality of estimated alignment sectors 302 are sized and positioned to extend radially outward from the estimated build platform center of rotation point 304 in the XY plane a sufficient amount to cover substantially three hundred sixty degree area of build platform 38 about the estimated build platform center of rotation point 304. In the exemplary embodiment, plurality of estimated alignment sectors 302 includes ten substantially similar triangular estimated alignment sectors 302, each estimated alignment sector 302 having a substantially similar first angle 301. In alternative embodiments, the plurality of estimated alignment sectors 302 may include as many estimated alignment sectors 302 of any shape and size as facilitate operation of the rotary additive manufacturing system 10 as described herein.
In the exemplary embodiment, based on estimated build platform center of rotation point 304 and plurality of estimated alignment sectors 302, controller 34 controls laser device 16 of consolidation apparatus 14 to project energy beam 28 to be incident on build platform 38 to form at least two alignment sectors 300 as build platform 38 is rotated a fixed angle. In an alternative embodiment, the consolidation apparatus 14 may project the energy beam 28 to be incident on the part 24, thereby forming at least two alignment sectors 300 on the part 24. In the exemplary embodiment, controller 34 controls build platform 38 to rotate approximately sixty degrees in rotational direction 42 while consolidation apparatus 14 remains stationary to form two alignment sectors 300 on build platform 38. In alternative embodiments, consolidation apparatus 14 may form as many alignment sectors 300 on build platform 28 as facilitate operation of rotary additive manufacturing system 10 as described herein.
In an exemplary embodiment, referring to fig. 7, the optical detector 23 detects the position of each alignment sector 300 and transmits the position to the controller 34. Controller 34 determines the location of build platform center of rotation point 27 and build platform axis of rotation 39 by comparing the location of alignment sector 300 with the corresponding estimated location of alignment sector 302. More specifically, controller 34 determines the severity of field alignment errors and center point errors resulting from forming alignment sector 300 using estimated build platform center of rotation point 304 and corrects estimated build platform center of rotation point 304 to determine the location of build platform center of rotation point 27. For example, as will be described in more detail below, after determining the values of the field alignment error and the center point error, an error value represented in the associated coordinate system is applied to estimated build platform center of rotation point 304 to determine the position of build platform center of rotation point 27. In an alternative embodiment, controller 34 determines the location of build platform center of rotation point 27 in any manner that facilitates operation of rotary additive manufacturing system 10 as described herein.
In an exemplary embodiment, the scan field offset error 303, t, the scan field radial error 305, r, the center point spacing offset error 307, t, and the center point radial error 309, r are measured using image data received from the optical detector 23 and used to determine the position of the build platform rotational center point 27. The field errors 303 and 305 are related to the center point errors 307 and 309 by the following two equations:
t＝2rsin (theta/2) equation 2A
r＝2tsin (theta/2) equation 2B
Wherein once the field errors 303 and 305 are known, corrections can be applied to the estimated position of the build platform center of rotation point 304 using center point errors 307 and 309 to determine the position of the build platform center of rotation point 27. The applied correction may be in the form of a distance from estimated build platform center of rotation point 304 to build platform center of rotation point 27 and an angle of a line representing the distance between estimated build platform center of rotation point 304 and build platform center of rotation point 27. The applied corrections may then be used to determine coordinates representing the position of the build platform center of rotation point 27. In an exemplary embodiment, the field offset error 303, the field radial error 305, the center point spacing offset error 307, and the center point radial error 309 are measured in a homogeneous coordinate system. In alternate embodiments, any type of coordinate system (such as, but not limited to, a digital line coordinate system, a Cartesian coordinate system, a polar coordinate system, a cylindrical coordinate system, and a spherical coordinate system) may be used to calculate any type of field error and center point error. In further alternative embodiments, any formula may be used to determine the location of build platform center of rotation point 27 that facilitates operation of rotary additive manufacturing system 10 as described herein.
Fig. 9 is a schematic plan view of rotary additive manufacturing system 10 (shown in fig. 1) illustrating an alternative embodiment of alignment marks 25 (shown in fig. 6). FIG. 10 is an enlarged plan view of region 9 (shown in FIG. 9) illustrating overlapping pairs of an alternative embodiment of alignment marks 25 (shown in FIG. 6). The embodiment shown in fig. 9 and 10 is substantially the same as the embodiment shown in fig. 6, except that the alignment mark 25 is a vernier alignment scale 400. In the exemplary embodiment, build platform 38 includes two vernier alignment scales 400, each vernier alignment scale 400 including a plurality of graduations 402. A cursor angle 403 is defined between each cursor alignment scale 400 relative to the build platform center of rotation point 27. In an exemplary embodiment, cursor angle 403 is approximately fourteen degrees. In the exemplary embodiment, controller 34 determines the position of build platform axis of rotation 39 and build platform center of rotation 27 using substantially the same method as described for the embodiment shown in FIGS. 7 and 8, except that the vernier alignment scale 400 scale 402 is used to determine the field errors 303 and 305 and the center point errors 307 and 309. In alternative embodiments, build platform 38 may include any configuration of any number of vernier alignment scales 400 that facilitate operation of rotary additive manufacturing system 10 as described herein.
Fig. 11 is a flow diagram of an example method that may be used to manufacture part 24 using rotary additive manufacturing system 10. Referring to fig. 1-10, method 500 includes, at 502, rotating build platform 38 relative to optical detector 23 about build platform rotation axis 39. Method 500 further includes, at 504, detecting, using optical detector 23, a position of at least two alignment marks 25, the at least two alignment marks 25 being on at least one of build platform 38 and build layer 44 of part 24 on build platform 38. Method 500 further includes receiving, by controller 34, the positions of at least two alignment marks 25 at 506. Method 500 includes determining, by controller 34, a position of build platform axis of rotation 39 and a build platform center of rotation point 27 based on a comparison between the at least two alignment marks 25, at 508. Finally, method 500 includes controlling, by controller 34, at least one consolidation device 14 to consolidate at least a portion of the plurality of particles on build platform 38 to form at least one build layer 44 of part 24 based at least in part on the determined build platform axis of rotation 39 and the determined position of build platform center of rotation point 27, at 510.
Embodiments described herein include an additive manufacturing system comprising at least one consolidation device, a build platform, an optical detector, and a controller. At least one consolidation apparatus is configured to consolidate at least a portion of the plurality of particles to form a build layer of the component. The build platform is configured to rotate about a build platform rotation axis extending in a first direction. The optical detector is configured to detect a position of at least two alignment marks located on at least one of the build platform and the build layer. The controller includes a processing device and a memory device coupled to the processing device. The controller is configured to receive the positions of the at least two alignment marks from the optical detector and determine a position of a build platform rotation axis and a build platform rotation center point based on a comparison between the at least two alignment marks, wherein the build platform rotation center point is located on the build platform rotation axis. The controller is further configured to control the at least one consolidation device to consolidate at least a portion of the plurality of particles on the build platform based at least in part on the determined build platform axis of rotation and the build platform center of rotation point. Additive manufacturing systems are beneficial for increasing system efficiency by reducing setup time, improving component quality by increasing system calibration accuracy, and reducing the cost of additive manufactured components.
Exemplary technical effects of the methods, systems, and apparatus described herein include at least one of: a) increasing an efficiency of an additive manufacturing system, b) reducing a calibration time of a rotating additive manufacturing system, c) reducing a build time required for additive manufacturing a component, d) increasing a productivity of the additive manufacturing component, e) increasing a quality of the additive manufacturing component, f) reducing a cost of the additive manufacturing component.
Exemplary embodiments of a rotary additive manufacturing system including a calibration apparatus are described above in detail. Additive manufacturing systems and methods of using such systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the methods may also be used in combination with other additive manufacturing systems, and are not limited to practice with only the rotary additive manufacturing systems and methods as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other additive manufacturing systems.
Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.