BE1022947B1 - Systems and methods for avoiding the interlocking of parts in 3d nesting - Google Patents

Abstract

Methods and devices for improved three-dimensional printing are described. A system for avoiding interlocking parts in 3D object nesting may include a nesting module that generates modified versions of any objects with a risk characteristic such as a tunnel or a cavity. The system can determine an ordering of nesting based on a modified set of objects containing the modified versions. Once the nesting order has been determined, the modified versions can be replaced with their original counterparts, and the objects printed without any interlocking or embedded objects.

Description

Systems and methods for avoiding the interlocking of parts in 3d nesting

BACKGROUND OF THE INVENTION

Methods of additive manufacturing can be accompanied by layer after layer formation of objects, for example by means of laser sintering (LS) or selective laser melting (SLM). In these applications, it is desirable to specify the three-dimensional placement and orientation of the parts by virtual representation of these objects before forming them, so as to efficiently use the raw materials and maximize the yield per mold volume. This process is known as "3d nesting".

Methods for automatic nesting of parts are known which are associated with analyzing the size and shape of the parts and placing them within the mold volume, in order to stack as many parts as possible in the mold volume. Certain forms of sharing may, however, present a problem for these programs. For example, smaller parts can be unwittingly nested within larger, hollow parts with small openings, making it impossible to remove the smaller parts from the larger parts after printing (i.e. after forming is completed). Parts with loops or other openings can also interlock, making separation of these parts after molding impossible. Existing 3d-nesting programs can detect embedded or interlocking parts before starting to form, but these problems must then be solved manually by the user.

Accordingly, there is a need for improved devices and methods for nesting three-dimensional parts to avoid these problems.

Summary

This application describes methods and apparatus for improved three-dimensional printing by resolving and / or avoiding error states by interlocking in an arrangement of 3d nesting.

Brief description of the drawings

Figure 1 illustrates an example of 3d nesting of a series of objects.

Figure 2A illustrates an example of two models, shown next to a shape volume.

Figure 2B illustrates an example of an arrangement of 3d nesting for the three-dimensional objects containing the models of Figure 2A. FIGURE 3 illustrates an example of nested objects where an error state of interlocking is represented.

Figure 4 illustrates another example of nested objects where a different error state of interlocking is represented.

Figure 5 illustrates an example of a modified version of an object in accordance with an embodiment.

Figure 6 illustrates an example of a method for resolving error states in an arrangement of 3D nesting.

Figure 7 illustrates an example of a method for avoiding error states in an arrangement of 3D nesting.

Figure 8 illustrates an example of a system for designing and producing an object through additive manufacturing. Figure 9 illustrates a functional block diagram of one example of a computer from Figure 8.

Figure 10 illustrates a method for the production of a three-dimensional object.

Figure 11 is a high-level system diagram of a computer system that can be used in one or more embodiments.

Detailed description of certain embodiments of the invention

This application describes methods and apparatus for improved three-dimensional printing by resolving and / or avoiding error states by interlocking in an arrangement of 3d nesting. In embodiments, a series of objects to be printed can be analyzed to identify any objects that may be problematic for a nesting operation - for example, objects with tunnels or cavities that can enclose other objects or that can engage in other objects after the nesting operation has been performed . Once these potentially problematic objects have been identified, secure counterparts of these objects can be generated against interlocking. The counterparts secured against interlocking can have the same dimensions as the original versions, except that potentially problematic features (such as tunnels or cavities) can be closed or filled to such an extent that the ability to enclose or enclose other objects grasping is reduced or eliminated. Subsequently, a nesting operation can be performed on a modified set of objects, including original versions of any objects without problematic features and against interlocking protected versions of any objects with potentially problematic features. Once the modified set has been nested satisfactorily (for example, to a desired density in terms of nests and / or shape height) any interlocked versions can be replaced with their original counterparts, and then the printing or printing operation can be commenced. to shape.

Various technologies of additive manufacturing are known in the art, for example stereolithography (SL), laser sintering (LS) and selective laser melting (SLM). In cases where a laser transmitter is used in SL, LS or SLM, the method can generally be called Laser Additive Manufacturing (LAM).

Stereolithography (SLA) is an optical technique of additive manufacturing that is used for layer after layer "printing" of three-dimensional objects. An SL device can use, for example, a UV laser to cure a photo-reactive substance by means of emitted radiation. In a number of embodiments, the SL device guides the UV laser through a surface of a photo-reactive substance such as, for example, a UV-curable photopolymer ("resin") for the purpose of layer-by-layer forming of an object. For each layer, the laser beam follows a cross-section of the object on the surface of the liquid resin, whereby the cross-section hardens and solidifies and is deposited on the layer below. Upon completion of a layer, the SL device lowers a production platform with a distance equal to the thickness of a single layer and deposits a new surface of unhardened resin (or a similar photoactive material) on the previous layer. A new pattern is followed on this surface and a new layer is formed in this way. By repeating this process layer after layer, a complete three-dimensional component can be formed.

Laser sintering (LS) is another optical technique of additive manufacturing that is used for printing three-dimensional objects. LS devices often use a powerful laser (for example, a carbon dioxide laser) to "sinter" small particles of plastic, metal, ceramic, or glass powder into a three-dimensional object. As with SL, the LS device can use a laser to scan sections on the surface of a powder bed in accordance with a CAD design. Similarly to SL, the LS device can lower a production platform by the thickness of one layer after a layer has been completed, and supply a new layer of material so that a new layer can be formed. In some embodiments, an LS device may pre-heat the powder to make it easier for the laser to raise the temperature during the course of the sintering process.

Selective laser melting (SLM) is another optical technique of additive manufacturing that is used for printing three-dimensional objects. Like LS, an SLM device generally uses a powerful laser to selectively melt thin layers of metal powder to form solid metal objects. Even though SLM is a process similar to LS, it is different because it generally uses materials with much higher melting points. When forming objects by means of SLM, thin layers of metal powder can be distributed using different coating mechanisms. As with SL and LS, a production surface moves up and down to allow individual layers to be formed.

Using these different technologies of additive manufacturing, in a number of cases one three-dimensional object is printed in one go and in a number of cases several three-dimensional objects are printed in one go. For example, LS can be used by an additive manufacturing device to print multiple three-dimensional objects at a given time, multiple versions of the same object, or multiple different objects, that can be mounted to form a larger object. The multiple three-dimensional objects can be nested in 3D in the total volume that the device of additive manufacturing can print, also called the shape volume in this text. That is, the multiple three-dimensional objects are placed in the total volume in such a way that they all fit into the total volume. It is generally desirable to maximize the number of objects in the mold volume while also minimizing the height of the order of objects in the mold volume, in order to reduce raw material consumption and production costs.

When printing multiple three-dimensional objects, the three-dimensional design to be printed or the 3d-nesting arrangement to be printed (wherein the 3d-nesting arrangement consists of the three-dimensional ordered three-dimensional objects to be printed by the additive manufacturing device) or presented as a digital three-dimensional representation (e.g., CAD, STL, etc.). Objects can be arranged or nested manually or automatically in the form volume, for example using an application such as MAGICS® 3D nesting software.

Figure 1 illustrates one example of 3d nesting of a series of three-dimensional objects in a shape volume. The left-hand hatch of Figure 1 shows the series of objects that will be printed, and the right-hand hatch of Figure 1 shows the objects nested in the mold volume and compressed to lower the mold height and increase the nesting density.

Figure 2A illustrates an example of two motorcycle models, shown next to a shape volume. Figure 2B illustrates an example of an arrangement of 3d nesting for the series of three-dimensional objects containing the motorcycle models of Figure 2A. As illustrated in Figure 2B, the individual objects that make up the models are nested compactly in the shape volume.

Certain types of object shapes can pose problems in the course of nesting operations. By way of example, Fig. 4 illustrates an object forming a hollow bottle 300 nested in a mold volume together with spherical objects 304. As illustrated in Fig. 4, the spherical objects 304 were nested in the bottle 300 and will thus be nested as soon as the operation of the forming starts in the bottle 300 can be printed. However, if the diameter of the spherical objects 304 is larger than the opening 302 of the bottle 300, the spherical objects 304 will be enclosed in the internal cavity of the bottle 300 and it will be impossible to recover the spherical objects 304 without the bottle 300 to break.

Figure 5 illustrates another example of the possible processing of nesting problematic forms of objects. Figure 5 shows two objects forming spectacle frames 400, each with two apertures 402. As a result of these apertures 402, if several of these spectacle frames 400 are nested in the same shape volume, there is a risk that they will interlock as illustrated in Figure 5. If they are nested in this way, it will be impossible after printing to separate the interlocking objects 400 without breaking one of them.

According to various embodiments, the arrangement of 3d nesting and / or the objects that are part of this arrangement can be manipulated to solve any potential enclosing or interlocking problems before starting printing or forming processing, thereby increasing efficiency and the production costs decrease. In embodiments, once a problematic object (e.g., an object with an opening and / or an internal cavity) has been identified, the problematic object can be replaced by a modified version of that object from which any openings, internal cavities or other problematic features have been effectively closed or filled to exclude the possibility of inclusion or interlocking. Figure 5 illustrates an example of a modified version 500 of one of the spectacle frames 400 of Figure 4, with closed openings 402 (reference numeral 502). The modified version 500 can otherwise have the same dimensions as the original version 400. The modified versions of the problematic objects can also be referred to in this text against interlocking secured counterparts.

Once the problematic object (s) has been replaced with its corresponding modified version (s), the modified set of objects (including the original versions of the non-problematic objects and the modified versions of the problematic or potentially problematic objects) are nested as desired (for example, to achieve an appropriate nesting density) without interfering with any error conditions such as enclosed or interlocking parts. After such nesting, but before the shaping operation starts, the modified objects can be replaced with their corresponding originals.

Referring to Figure 6, an example of a method 600 for resolving error states by interlocking in an arrangement of 3D nesting using a computer device is illustrated. In block 602, a first order of nesting is determined for a series of objects, including all objects to be printed. The order of nesting can be determined automatically based on the size and size of the objects to be printed, for example using an application for two-dimensional or three-dimensional nesting such as MAGICS® 3D nesting software. In a number of embodiments, nesting can be performed with manual control or user intervention through an application to the computer device. While the nesting operation can be performed directly on the objects, in some embodiments the nesting operation can be performed on other virtual representations of the objects, including simplified or parameterized representations of the objects, for example parts with reduced triangles or on another reduced complexity in a way that reduces computer capacity requirements. For example, in a number of embodiments, the nesting operation can be performed using volumetric representations of the objects to be printed. It will be understood that the various other analytical operations and manipulations described in this text as performed on "objects" mean that the operations can be performed directly on the objects themselves or on volumetric or other virtual representations of the objects. Performing these operations on mathematically simpler versions of the objects can significantly improve the speed and efficiency of these operations.

In block 602, one or more objects that respond to an error state due to interlocking can be identified. Figures 3 and 4 illustrate examples of such objects. In block 602, the objects corresponding to an error condition due to interlocking can be identified by an interlocking test or any other appropriate method.

In block 604, versions of the interlocking objects can be generated that have been modified to exclude or correct any problematic or potential problematic features such as tunnels or cavities. Figure 5 illustrates an example of such a modified version. The modified versions can be generated by any suitable method. Although the term "generated" is used to describe the creation of a modified version of an object, it should be understood that the generation of a modified version does not necessarily require the modified version to be generated for display or otherwise visible to an user. Instead, the modified version can simply be a transformation of the original object used by the computer device to position the object (e.g., to develop an order of nesting). Each visual representation of an order of nesting can, if desired, contain the original version or the modified version of an object.

In block 606, a second order of nesting can be determined based on a modified set of objects. The modified set of objects may contain the original versions of all objects in the set, except that any problematic or potentially problematic objects identified in block 602 may be replaced with modified versions thereof as generated in block 604.

In a number of embodiments, the processes in blocks 602 to 606 can be repeated to identify any other objects that respond to an error condition due to interlocking, generate interlocking protected counterparts of these objects, and generate an arrangement of nesting on the basis of a modified set of objects, including the newly generated counter-secure counterparts of problematic or potentially problematic objects.

Also, in a number of embodiments, after block 606, the general three-dimensional design to be printed can be finalized and sent to an additive manufacturing device for production. Such finalization may include the replacement of any modified versions of the objects in the second order of nesting by their original counterparts (or the restoration of the modified versions in a different way to restore their original topological characteristics). Subsequently, an operation of shapes can be started that will produce all objects in the series using an additive manufacturing device, without any interlocking or enclosed parts. Referring to Figure 7, an example of a method 700 for avoiding error states in an arrangement of 3D nesting using a computer device is illustrated. In block 702, the method 700 may involve generating a modified version of at least one object with a risk characteristic. The risk characteristic can be any topological characteristic that may be problematic for a nesting operation, such as, for example, any tunnels (e.g., openings, holes, cavities or any other similar shapes) that may occur after the nesting operation result in enclosed or interlocking parts. In a number of embodiments, the risk characteristic objects can be manually identified with user input identifying potentially problematic objects and received at the computer device. In other embodiments, the or risk-identified objects can be automatically identified by the computer device. To identify objects with a risk characteristic, the geometry of the parts can be analyzed by appropriate metric to detect openings, holes, cavities or any properties that can be problematic and result in inclusions or interlocking with other objects . As another possibility, in a number of embodiments, an object with a risk characteristic can be identified by analyzing a given order of nesting and identifying any objects that respond to an error condition due to interlocking. In such an example, any objects that respond to an error condition due to interlocking can be considered as having a risk characteristic.

In a number of embodiments, modified versions of all objects can be generated in a series without first identifying any specific items with a risk characteristic. By generating modified versions of all objects in a series, all objects will be secured against interference.

The modified version (s) of the object (s) can be generated by any method of closing, filling or otherwise remedying (at least for the purpose of performing the nesting operation) of the problematic objects or their problematic characteristics.

In block 704, an order of nesting for the set of objects can be determined based on a modified set of objects. The modified set of objects may contain the original versions of all objects in the set, except that the modified version of an optional object as generated in block 702 replaces the original version of an optional object corresponding to a risk characteristic. In an embodiment in which all objects in the series are modified to create interlocking secured counterparts (regardless of whether the original object exhibits a tunnel, cavity or other risk characteristic), the modified series of objects may be a modified version of each of contain the objects.

In a number of embodiments, after block 704, the general three-dimensional design to be printed can be finalized and sent to an additive manufacturing device for production. Such finalization may include the replacement of any modified versions of the objects in their nesting order by their original counterparts (or the restoration of modified versions to return their original topological characteristics). Subsequently, an operation of shapes can be started that will produce all objects in the series using an additive manufacturing device, without any interlocking or enclosed parts.

It should be noted that the methods described in this text with reference to certain figures are merely illustrative embodiments, and that some of the blocks and steps of the methods may be executed in a different order, removed, and / or additional blocks and steps on the methods can be added without departing from the scope of the invention.

Figure 8 illustrates one example of a system 1100 for designing and producing objects by means of additive manufacturing including, by way of example, three-dimensional designs. The system 1100 can be configured to support the techniques described in this text.

In a number of embodiments, the system 1100 may include one or more computers 1102a-1102d. The computers 1102a-1102d can take various forms, such as, for example, any workstation, any server or any other computer device that can process information. The computers 1102a-1102d can be connected by means of a computer network 1105. The computer network 1105 can, for example, be the internet or a LAN (local area network), a WAN (wide area network), or any other another type of network capable of digital communication between electronic devices. The computers 1102a-1102d may furthermore communicate with each other over the computer network 1105 by means of any suitable communication technology or any suitable communication protocol. The computers 1102a-1102d can, for example, exchange data by sending and receiving information, for example software, digital representations of three-dimensional objects and designs, commands and / or instructions to operate an additive manufacturing device, etc.

The system 1100 may further comprise one or more devices of additive manufacturing 1106a and 1106b. These additive manufacturing devices may contain 3D printers or any other production devices as known in the art. In the example illustrated in Figure 8, the device of additive manufacturing 1106a is directly connected to the computer 1102d. The device of additive manufacturing 1106a is also connected to the computers 1102a-1102c by means of the network 1105 which further connects the computers 1102a-1102d to each other. The device of additive manufacturing 1106b is also connected by means of the network 1105 to the computers 1102a-1102d. Those skilled in the art will appreciate that an additive manufacturing device such as devices 1106a and 1106b can be directly connected to a computer, connected to a computer, and / or connected to a computer through another computer.

Although a specific computer and network configuration is described in Figure 8, those skilled in the art will also appreciate that the techniques of additive manufacturing described in this text can be implemented using a single-computer configuration that incorporates the additive manufacturing device 1106 checks and / or supports, without the need for a computer network.

Figure 9 provides a more detailed illustration of the computer 1102a of Figure 8. The computer 1102a contains a processor 1210. The processor 1210 is in data communication with various computer components. These components may include a memory 1220 as well as an input device 1230 and an output device 1240. In some embodiments, the processor may also communicate with a network interface card 1260. Although described as a separate component, it should be understood that the functional blocks described are no different structural elements with respect to computer 1102a. By way of example, the processor 1210 and the network interface card 1260 can be included in a single chip or a single board.

The processor 1210 can be a universal processor or a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field-programmable gate array (field programmable gate array, FPGA) or another programmable logic unit, a separate port or transistor, separate hardware components, or any combination thereof, to perform the functions described in this text. A processor can also be implemented as a combination of computer equipment, for example a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

The processor 1210 can be coupled, via one or more data buses, to read information from, or write to, the memory 1220. The processor can additionally, or as another possibility, contain memory, for example processor registers. The memory 1220 may contain processor cache, including a multi-level hierarchical cache in which different levels have different options and different access speeds. This memory 1220 may further comprise a random access memory (RAM), as well as other devices with a volatile memory or devices with a non-volatile memory. The data storage can consist of hard disks, optical disks such as compact disks (CDs) or digital video disks (DVDs), flash memory, diskettes, magnetic tape, Zip drives, USB drives, and other components known in the art.

The processor 1210 can also be coupled to an input device 1230 and an output device 1240 for resp. get input from, and deliver output to, a user of computer 1102a. Suitable input devices include, but are not limited to, a keyboard, a rollerball, buttons, keys, switches, pointing devices, a mouse, a joystick, a remote control device, an infrared detector, a voice recognition system, a barcode reader, a scanner, a video camera ( possibly coupled to image processing software to detect, for example, hand or face movements, a motion detector, a microphone (possibly coupled to sound processing software to detect, for example, voice commands), or any other device capable of transmitting data from a user to a computer. The input device may also take the form of a touchscreen associated with the display, in which case a user responds to information displayed on the display by touching the screen. The user can enter information in the form of text by means of an input device such as a keyboard or the touchscreen. Suitable output devices include, but are not limited to, visual output devices, including screens and printers, audio output devices, including speakers, headphones, earphones and alarms, additive manufacturing devices, and haptic output devices.

The processor 1210 may further be coupled to a network interface card 1260. The network interface card 1260 prepares data generated by the processor 1210 for transmission over a network in accordance with one or more data transmission protocols. The network interface card 1260 can also be configured for decoding data received by the network. In a number of embodiments, the network interface card 1260 may include a transmitter, a receiver, or both a transmitter and a receiver. Based on the specific embodiment, the transmitter and the receiver may consist of a single integrated component or may be two separate components. The network interface card 1260 may be in the form of a universal processor or a DSP, an ASIC, an FPGA, or other programmable logic unit, a separate port or transistor, separate hardware components, or any combination thereof to perform the functions described in this text.

Figure 10 illustrates a general method 1300 for producing an object using an additive manufacturing device, such as 1106a or 1106b from Figure 8.

The process starts at step 1305, where a digital representation of the three-dimensional object to be produced is designed using a computer, for example, the computer 1102a of Figure 8. In a number of embodiments, a two-dimensional representation of the device can be used to create the three-dimensional model of the device. Alternatively, three-dimensional data may be entered into the computer 1102a to assist in designing the digital representation of the three-dimensional design. Additionally or as another possibility, the three-dimensional design is generated using embodiments of the methods described with reference to Figure 6 and / or Figure 7. In a number of embodiments, the computer 1102a is the computer device as described with reference to Figure 8. The process continues to step 1310, where information is sent from the computer 1102a to an additive manufacturing device, e.g., the additive manufacturing devices 1106a and 1106b. Then, at step 1315, the additive manufacturing device begins production of the three-dimensional device by performing a process of additive manufacturing using appropriate materials as described above. Using the appropriate materials, the additive manufacturing device then ends the process at step 1320 where the three-dimensional object is completed.

To produce objects by a method such as that of figure 10, various techniques of additive manufacturing can be applied. As described above, these techniques include SL, LS and SLM, and others.

Referring to Figure 11, a computer-based system 1400 is described for three-dimensional printing of a series of objects in accordance with an embodiment. The system 1400 may consist of one or more computers such as computer 1102a as described above. The system 1400 may include a nesting module 1402 that can be configured for performing various functions within the system 1400 such as, for example, generating a modified version of at least one object with a risk characteristic. The nesting module 1402 may further be configured for determining a nesting arrangement for the set of objects based on a modified set of objects, the modified set including the modified version of at least one object having a risk characteristic such as, for example, a tunnel or a cavity. As illustrated in Figure 11, the system 1400 can optionally also include an analysis module 1404 that is configured for the purpose of identifying at least one object with a risk characteristic. The nesting module 1402 and the optional analysis module 1404 may consist largely or completely of software, or may consist of a combination of hardware and software, or in yet other embodiments specialized hardware such as an ASIC or other types of microprocessors. In some embodiments, certain functionality for nesting and / or analysis can be provided by one software application, while other functionality for nesting and / or analysis can be provided by one or more separate computer applications. As another possibility, full functionality can be provided by a single computer program.

The embodiments described in this text can be implemented in the form of a method, a device, a produced article, using standard programming or engineering techniques to produce software, firmware, hardware or any combination thereof. The term "produced article" as used herein refers to code or logic implemented in hardware or permanent computer readable media such as optical disks, and volatile or non-volatile memory devices or temporary computer readable media such as signals, carriers, etc. Such hardware may include, but is not limited to, FPGAs, ASICs, complex programmable logic devices (complex programmable logic devices, CPLDs), programmable logic arrays (programmable logic arrays, PLAs), microprocessors, or other similar processing devices .

Those skilled in the art will appreciate that numerous variations and / or modifications to the invention can be made without departing from the spirit or scope of the invention as extensively described. The embodiments described above must therefore always be regarded as illustrative and non-limiting. in the drawings:

FIG. 1

Prior art The prior art

FIG. 6

FIG. 8

Computer Computer

FIG. 9

FIG. 11

Claims (11)

CONCLUSIONS A method for improved three-dimensional printing of a series of objects, the method comprising: - determining a first order of nesting for a series of objects; - identifying at least one object that corresponds to an error condition due to interlocking; - generating a modified version of the at least one object that corresponds to an error state due to interlocking; and - determining a second order of nesting based on a modified set of objects, the modified set comprising the modified version of the at least one object corresponding to an error condition due to interlocking. The method of claim 1, further comprising: - identifying at least one second object that responds to an error condition due to interlocking; - generating a modified version of the at least one second object that responds to an error condition due to interlocking; and - determining a third order of nesting based on a modified set of objects, wherein the second modified set of objects contains the modified version of the at least one object that responds to an error condition due to interlocking as well as the modified version of the at least one second object corresponding to an error condition due to interlocking. A method for the improved three-dimensional printing of a series of objects, the method comprising: - generating a modified version of at least one object, wherein the at least one object has a risk characteristic; and - determining an order of nesting for the set of objects based on a modified set of objects, wherein the modified set contains the modified version of the at least one object that exhibits a risk characteristic. The method of claim 3, wherein the risk feature includes at least one of a tunnel or a cavity. The method of claim 3, further comprising receiving input identifying the at least one object with a risk attribute. The method of claim 3, further comprising identifying the at least one object with a risk characteristic. The method of claim 3, further comprising identifying at least one object that responds to an error condition due to interlocking. The method of claim 3, further comprising replacing the modified version of the at least one object with an original version of the at least one object. 9. A system for three-dimensional printing of a series of objects, which system comprises: - a nesting module configured to generate a modified version of at least one object, the at least one object exhibiting a risk characteristic, wherein the nesting module is further configured for determining a nesting arrangement for the set of objects based on a modified set of objects, the modified set comprising the modified version of the at least one object having a risk characteristic. The system of claim 9, further comprising an analysis module, wherein the analysis module is configured for the purpose of identifying the at least one object with a risk characteristic. The system of claim 10, wherein the risk feature includes at least one of a tunnel or a cavity.