The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2019-034664, filed on Feb. 27, 2019. The contents of which are incorporated herein by reference in their entirety.
The present invention relates to a shaping device, a system, and a method.
A shaping device (what is called a “three-dimensional (3D) printer”) that shapes a three-dimensional shaped object based on input data has been developed. As a method of shaping a three-dimensional object, various methods have been proposed, such as Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), Material Jetting (MJ), Electron Beam Melting (EBM), and a stereolithography apparatus (SLA).
However, in some cases, it is difficult to shape a desired three-dimensional shaped object due to contraction of a shaping material.
For example, Japanese Patent No. 6077717 discloses a technology for adding a contraction control structure in order to prevent contraction of a shaped object due to reduction in temperature.
However, in Japanese Patent No. 6077717, if a three-dimensional shaped object has a complex shape, it is difficult to add the contraction control structure, and therefore, in some cases, it is still difficult to shape a desired three-dimensional shaped object.
According to an aspect of the present invention, a shaping device is configured to shape a three-dimensional shaped object. The shaping device includes a measuring unit and a correcting unit. The measuring unit is configured to measure a shape of a shaping layer. The correcting unit is configured to correct operation of shaping a shaping layer, according to a first correction amount based on a measurement result of the measuring unit and a second correction amount in accordance with a past correction.
The accompanying drawings are intended to depict exemplary embodiments of the present invention and should not be interpreted to limit the scope thereof. Identical or similar reference numerals designate identical or similar components throughout the various drawings.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In describing preferred embodiments illustrated in the drawings, specific terminology may be employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
An embodiment of the present invention will be described in detail below with reference to the drawings.
An embodiment has an object to provide a shaping device, a system, and a method for shaping a desired three-dimensional shaped object.
Hereinafter, first to fourth embodiments of the present invention will be described, but the present invention is not limited to each of the embodiments described below. In the drawings to be referred to in the following description, the same components are denoted by the same reference symbols, and explanation thereof will be appropriately omitted. Further, in the following, the present invention will be described mainly using a shaping device based on an FFF method, but embodiments are not limited thereto, and the present invention is applicable to shaping devices using methods other than the FFF method.
Furthermore, in the following, for convenience of explanation, a height direction of a three-dimensional shaped object is referred to as a z-axis direction, and a plane perpendicular to the z-axis is referred to as an xy plane.
As illustrated in
Further, the shaping device 100 of the present embodiment includes a sensor 130 that measures a shape of a shaping layer during shaping or a shape of a three-dimensional shaped object after shaping. The sensor 130 may measure the xy plane of the shaping layer. As illustrated in
A hardware configuration of the shaping device 100 will be described below.
The CPU 201 is a device that executes a program for controlling operation of the shaping device 100 and performs a predetermined process. The RAM 202 is a volatile storage device for providing an execution space for the program to be executed by the CPU 201, and is used for storing and loading programs and data. The ROM 203 is a non-volatile storage device for storing the program executed by the CPU 201 and firmware.
The storage device 204 is a rewritable non-volatile storage device for storing an operating system (OS) that enables the shaping device 100, various applications, setting information, various kinds of data, and the like. The interface 205 is a device for connecting the shaping device 100 to other apparatuses. The interface 205 is able to connect to, for example, the information processing terminal 150, a network, an external storage device, and the like, and it is possible to receive control data for shaping operation, shape data of a three-dimensional shaped object, and the like via the interface 205.
The shaping unit 206 is a device that serves as a shaping means and shapes a shaping layer based on shaping data. The shaping unit 206 includes the head 110, the stage 120, and the like, and is configured in accordance with a shaping method. For example, the shaping unit 206 based on the FFF method includes a heating mechanism that melts the shaping material 140, a nozzle for ejecting the shaping material 140, and the like. The shaping unit 206 based on an SLS method includes a laser light source and the like.
The shape sensor 207 is a device that measures a shape of a shaping layer during shaping or a shape of a three-dimensional shaped object after shaping. The shape sensor 207 may measure the xy plane of a shaping layer. Further, the shape sensor 207 may measure dimensions of a three-dimensional shaped object in an x-axis direction, a y-axis direction, and the z-axis direction. Examples of the shape sensor 207 include an infrared sensor, a camera, and a 3D measurement sensor (for example, a light-sectioning profile sensor).
Functional means implemented by each piece of hardware according to the present embodiment will be described below with reference to
The shaping device 100 includes a data input unit 310, a shaping data generating unit 320, a shaping unit control unit 330, a shaped object shape measuring unit 340, a feedback (FB) correction vector output unit 350, a feedforward (FF) correction vector output unit 360, a correcting unit 370, and a storage unit 380.
The data input unit 310 is a means that receives input of shape data for shaping a three-dimensional shaped object, or the like. As one example, the shape data is generated by the information processing terminal 150 or the like, and input to the data input unit 310 via the interface 205.
The shaping data generating unit 320 is a means that divides the shape data, which is input to the data input unit 310, in a height direction of the three-dimensional shaped object, and generates pieces of shaping data (what is called slice data) of a plurality of shaping layers. The shaping data is generated by dividing a target three-dimensional shaped object by the deposition pitch, as data that indicates a shape of a shaping layer and that is used to shape each of layers to be deposited. The shaping data may be binary data that indicates whether shaping is performed or not at a coordinate on the xy plane of each of layers. Further, in a preferred embodiment, it may be possible to include not only information on whether to perform shaping at each of coordinates, but also a shaping amount and an ejection amount of the shaping material 140 at each of the coordinates. In
The shaping unit control unit 330 is a means that controls shaping operation performed by the shaping unit 206, on the basis of the shaping data. The shaping unit control unit 330 is able to perform shaping while controlling algorithms and various parameters, such as a shaping speed and a deposition pitch, by adjusting the position of the head 110 and the height of the stage 120 on the basis of the shaping data. Further, the shaping unit control unit 330 is able to control a shaping amount on the basis of the shaping data. For example, in the FFF method, it is possible to control the ejection amount of the shaping material 140, and, in the SLS method, it is possible to control intensity of laser. Meanwhile, the shaping unit control unit 330 may control the shaping unit 206 on the basis of the shaping data output by the shaping data generating unit 320, or may control the shaping unit 206 on the basis of shaping data (corrected shaping data) for which a shaping shape is corrected by the correcting unit 370.
The shaped object shape measuring unit 340 is a means, as a measuring means, that controls the shape sensor 207 and measures measurement data, such as a dimension and a height, as a shape of a shaping layer during shaping or a shape of a three-dimensional shaped object after shaping. The shaped object shape measuring unit 340 acquires a measurement result as the measurement data.
The FB correction vector output unit 350 serves as a calculation means and outputs, as a feedback (FB) correction vector, the measurement data and a first correction amount that is calculated based on the shaping data. The FB correction vector output unit 350 includes a deviation amount calculating unit 351, a correction amount calculating unit 352, a delay unit 353, and a layer conversion processing unit 354. The deviation amount calculating unit 351 calculates, as a deviation amount, a difference between the shaping data and the measurement data, and outputs a difference vector. The correction amount calculating unit 352 calculates a correction vector corresponding to the measured shaping layer on the basis of the difference vector. The delay unit 353 is a means that outputs input shaping data in a one-layer delayed manner. The delay unit 353 is configured with, for example, a buffer memory. The layer conversion processing unit 354 calculates a first correction amount that is needed to shape a desired shape, on the basis of the correction vector calculated by the correction amount calculating unit 352 and shaping data of an n-th layer. The first correction amount is output, as an FB correction vector, to the correcting unit 370. Meanwhile, the FB correction vector may be stored in the storage unit 380.
The FF correction vector output unit 360 serves as a calculation means and outputs a feedforward (FF) correction vector. The FF correction vector output unit 360 includes an FF correction data generating unit 361 that generates FF correction data. The FF correction data generating unit 361 analyzes the FB correction vector of a shaping layer that has been shaped in the past or information on other kinds of correction, and generates FF correction data, as a second correction amount, for correcting a shaping layer that is to be shaped next or later. Further, the generated FF correction data is stored in the storage unit 380. The FF correction vector output unit 360 reads the FF correction data from the storage unit 380 at a timing at which a correction process is performed, multiplies the FF correction data by an FF gain, and outputs the second correction amount, as an FF correction vector, to the correcting unit 370. Meanwhile, as one example, the FF gain may be a parameter that determines a weight of FF correction in a series of correction processes. For example, if a storage amount of pieces of FF correction data is small and reliability is not adequate, it is possible to perform more appropriate correction by reducing the FF gain and reducing the degree of FF correction in the correction processes.
The correcting unit 370 is a means that corrects the shaping data to achieve a desired shape of a shaping layer, on the basis of the FB correction vector and the FF correction vector. Accordingly, it is possible to improve accuracy of the shaping layer. The correcting unit 370 includes a first adding unit 371 and a second adding unit 372. The first adding unit 371 adds the FB correction vector and the FF correction vector, and outputs, as a third correction amount, a correction vector. Meanwhile, the correction vector may be stored in the storage unit 380. The second adding unit 372 corrects the shaping data on the basis of the correction vector. Accordingly, the shaping operation is corrected based on the shaping data that has been corrected. In other words, the shaping data that has been corrected is output, as the corrected shaping data, to the shaping unit control unit 330.
The storage unit 380 is a means that controls the storage device 204 and stores therein various kinds of data. The storage unit 380 includes a correction information storage unit 381 and an FF correction data storage unit 382. The correction information storage unit 381 is able to store therein the correction vector, the FB correction vector, the difference vector, and the like. The FF correction data storage unit 382 stores therein the FF correction data generated by the FF correction data generating unit 361.
With each of the functional means as described above, it is possible to shape a three-dimensional shaped object with high accuracy. Meanwhile, the above-described software blocks correspond to functional means that are implemented by causing the CPU 201 to execute a program of the present embodiment to cause each piece of hardware to function. Further, all of the functional means described in each of the embodiments may be realized by software, or a part or all of the functional means may be mounted as hardware that provide corresponding functions.
Furthermore, all of the above-described functional means need not always be included in the shaping device 100 as in the configuration as illustrated in
Further, a contraction process of the shaping layer depends on the shape of the shaping layer. Therefore, when the shapes of the upper and lower shaping layers are the same, and if the lower layer is shaped such that the lower layer has a desired shape after contraction, subsequent upper shaping layers can be shaped in desired shapes by applying the same correction algorithm as that of the lower shaping layers. Meanwhile, the same correction algorithm as that of the lower layer need not be applied only when the shapes of the upper and lower shaping layers are the same, but it may be possible to perform correction using the same algorithm as that of the lower shaping layer when the shapes of the shaping layers are similar to each other. For example, if a difference between the shapes of the upper and lower shaping layers is equal to or smaller than a predetermined threshold, it may be possible to assume that the contraction process goes in the same manner, and correct the upper shaping layer by using the same algorithm as that of the lower shaping layer.
In the three-dimensional shaped object illustrated in
As described above, to improve the shaping accuracy of the three-dimensional shaped object, it is preferable to perform correction such that a desired shape can be obtained through a small number of times of deposition. Therefore, in each of embodiments described below, correction based on feedforward control is performed in addition to correction based on feedback control.
A data flow in a first embodiment will be described with reference to
The shaping data generating unit 320 outputs shaping data of each of layers that are generated based on the input shape data of the three-dimensional shaped object. The shaping data generating unit 320 outputs n-th layer shaping data to the FB correction vector output unit 350. Further, the shaped object shape measuring unit 340 outputs (n−1)-th layer measurement data to the FB correction vector output unit 350. The FB correction vector output unit 350 receives, as inputs, the n-th layer shaping data and the (n−1)-th layer measurement data, and outputs an FB correction vector to the correcting unit 370. Furthermore, the shaping data generating unit 320 outputs the n-th layer shaping data to the correcting unit 370. Moreover, the FF correction vector output unit 360 outputs the FF correction vector to the correcting unit 370. The correcting unit 370 receives, as inputs, the FB correction vector, the FF correction vector, and the n-th layer shaping data. The correcting unit 370 corrects the n-th layer shaping data based on the FB correction vector and the FF correction vector. The corrected shaping data is output as n-th corrected shaping data.
Here, in the FB correction vector output unit 350, as illustrated in
The layer conversion processing unit 354 calculates an n-th layer FB correction vector on the basis of the n-th layer shaping data, the (n−1)-th layer shaping data, and the (n−1)-th layer FB correction vector. For example, the layer conversion processing unit 354 is able to calculate the n-th layer FB correction vector by extracting a corresponding point in the shaping data of each of the layers in image processing and interpolating each of the corresponding points from the (n−1)-th layer correction vector. Accordingly, it is possible to shape a shaping layer that has a desired shape after contraction. Meanwhile, the FB correction vector output unit 350 may be configured to output the difference vector to the correction information storage unit 381.
As illustrated in
Further, as illustrated in
The first adding unit 371 calculates the correction vector on the basis of the FB correction vector output from the FB correction vector output unit 350 and the FF correction vector output from the FF correction vector output unit 360. The correction vector is output to the second adding unit 372. The second adding unit 372 corrects the n-th layer shaping data on the basis of the correction vector. Then, the n-th corrected shaping data is output to the shaping unit control unit 330.
Referring back to
In the example of the above-described embodiment, it is explained that the correcting unit 370 corrects the shape of the shaping data, but embodiments are not limited to this example. The correcting unit 370 is able to correct various parameters and algorithms for controlling a shaping process, such as temperature at which a three-dimensional shaped object is shaped, a moving speed of the head 110, or an ejection amount of the shaping material 140, in addition to correction of the shape of the shaping data.
A process performed by the shaping device 100 will be described.
At Step S1004, the shaped object shape measuring unit 340 measures the shape of the shaping layer. Measurement data measured by the shaped object shape measuring unit 340 is output to the FB correction vector output unit 350.
At Step S1005, the FB correction vector output unit 350 outputs the FB correction vector. Specifically, the FB correction vector is calculated by first obtaining a difference between the measurement data and the shaping data of the measured shaping layer, and subsequently obtaining a correction amount. The calculated FB correction vector is output to the correcting unit 370.
At Step S1006, the correcting unit 370 outputs the correction vector. Specifically, the first adding unit 371 of the correcting unit 370 calculates the correction vector on the basis of the FB correction vector and the FF correction vector. The FF correction vector is output by causing the FF correction vector output unit 360 to read the FF correction data from the FF correction data storage unit 382 and multiply the FF correction data by an appropriate FF gain.
At Step S1007, the correction vector calculated at Step S1006 is output from the first adding unit 371 and stored in the correction information storage unit 381.
Thereafter, at Step S1008, the FF correction data output unit 360 outputs the FF correction data. Specifically, the FF correction data generating unit 361 generates the FF correction data. The FF correction data generating unit 361 analyzes the correction vector that is stored in the correction information storage unit 381 at Step S1007, and generates correction data for performing FF correction. The FF correction data generating unit 361 stores the generated FF correction data in the FF correction data storage unit 382. The process of generating the FF correction data at Step S1008 need not always be performed at a timing as indicated in
At Step S1009, the correcting unit 370 corrects the shaping data. Specifically, the second adding unit 372 calculates the corrected shaping data on the basis of the correction vector and the shaping data. The calculated corrected shaping data is output to the shaping unit control unit 330. Then, at Step S1010, the shaping unit control unit 330 controls the shaping unit 206 and shapes a next shaping layer on the basis of the corrected shaping data.
Thereafter, at Step S1011, the shaping device 100 separates the process depending on whether an uppermost shaping layer has been shaped. If the uppermost shaping layer has been shaped (YES), that is, if the three-dimensional shaped object is completed, the process proceeds to Step S1012, and the shaping device 100 terminates the process. If the uppermost shaping layer has not been shaped (NO), that is, if the three-dimensional shaped object is not completed, the process returns to Step S1003, and shaping is performed again. Then, the processes from Step S1003 to S1010 as described above are repeated until the three-dimensional shaped object is completed. Meanwhile, it may be possible to return the process to Step S1001, and start the process again. Further, the correction process may be performed on all of shaping layers from the lowermost layer, or may be performed on upper layers located above an arbitrary shaping layer.
Through the process as described above, the shaping device 100 is able to reduce shaping layers for which shape errors occur and shape a desired three-dimensional shaped object.
In
Further, even when three-dimensional shaped objects with the same shapes are shaped, shape errors are not always the same due to various error causes, and the shape errors may vary as illustrated in
It has been described above that when the shape of the shaping layer is the same as the shape of the shaping layer that has already been shaped, correction is performed using the same correction algorithm. With this configuration, the shaping device 100 is able to cause the shape error to converge to zero through a smaller number of times of deposition, so that it is possible to shape a desired three-dimensional shaped object. In particular, when a plurality of shaping layers with the same shapes are sequentially deposited, it is possible to further reduce the number of times of deposition until convergence by generating the FF correction data on the basis of a correction vector of a shaping layer that has been shaped most recently. Therefore, in the second embodiment, the correction vector and the shaping data are stored in the correction information storage unit 381, and the FF correction data generating unit 361 generates the correction data from the shape of each of shaping layers based on the shaping data.
For example, a case will be described in which an i-th shaping layer to an (i+j)-th shaping layer have the same shapes. In this case, the correction information storage unit 381 acquires shaping data of each of the shaping layers from the shaping data generating unit 320, and stores the shaping data in association with each of sequentially-output correction vectors of the shaping layers. The FF correction data generating unit 361 compares a shape of the i-th layer and a shape of an (i+1)-th layer, and if the shapes are the same, correction data of the (i+1)-th layer is generated based on correction data of the i-th layer.
Thereafter, similarly, when correction data of an (i+2)-th layer is to be generated, the shape of the i-th layer, the shape of the (i+1)-th layer, and a shape of the (i+2)-th layer are compared, and if the shapes are the same, the correction data of the (i+2)-th layer is generated based on the correction data of the (i+1)-th layer.
In this manner, in the second embodiment, the FF correction data generating unit 361 generates the FF correction data on the basis of the correction vector of the shaping layer that has been shaped most recently among shaping layers with the same shapes. Accordingly, the shaping device 100 is able to reduce the number of times of deposition until the shape error converges to zero. Meanwhile, when it is determined whether the shapes are the same by comparing the shaping layers, it may be possible to determine that the shapes are the same if a shape difference is smaller than a threshold.
The FF correction data generating unit 361 may determine whether the shape error has converged on the basis of the number of times that the same correction algorithm is continuously applied. For example, the FF correction data generating unit 361 may determine that the shape error has converged if the number of times that the same correction algorithm is applied exceeds a threshold. If the FF correction data generating unit 361 determines that the shape error has converged, it is possible to generate the FF correction data by performing a statistical process on the correction data of the shaping layers that have the same shapes and that have been shaped in the past, and on the basis of a statistic, such as an average value or a median value. Consequently, it is possible to cope with variation of the shape error, and shape a three-dimensional shaped object with stable quality.
In the third embodiment, as illustrated in
According to the fourth embodiment, the FF correction data generating unit 361 is able to determine whether the FB correction has converged on the basis of a change amount between shaping layers of the FB correction vector. Therefore, the FF correction data generating unit 361 is able to generate the FF correction data on the basis of the correction vector for which the FB correction has converged, so that the shaping device 100 is able to perform appropriate FF correction and shape a desired three-dimensional shaped object.
As described above, according to each of the embodiments of the present invention, it is possible to provide a shaping device, a system, and a method for shaping a desired three-dimensional shaped object.
Each of the functions of each of the embodiments of the present invention as described above may be implemented by a device executable program that is written by C, C++, C#, Java (registered trademark), or the like, and the program of the present embodiment may be distributed by being stored in a device readable recording medium, such as a hard disk device, a compact disk-ROM (CD-ROM), a ROM, a magneto-optical disk (MO), a digital versatile disk (DVD), a flexible disk, an electrically erasable programmable ROM (EEPROM), or an erasable programmable ROM (EEROM), or may be transferred via a network in a format that can be handled by a device.
As described above, according to an embodiment, it is possible to provide a shaping device, a system, and a method for shaping a desired three-dimensional shaped object.
The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, at least one element of different illustrative and exemplary embodiments herein may be combined with each other or substituted for each other within the scope of this disclosure and appended claims. Further, features of components of the embodiments, such as the number, the position, and the shape are not limited the embodiments and thus may be preferably set. It is therefore to be understood that within the scope of the appended claims, the disclosure of the present invention may be practiced otherwise than as specifically described herein.
The method steps, processes, or operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance or clearly identified through the context. It is also to be understood that additional or alternative steps may be employed.
Further, any of the above-described apparatus, devices or units can be implemented as a hardware apparatus, such as a special-purpose circuit or device, or as a hardware/software combination, such as a processor executing a software program.
Further, as described above, any one of the above-described and other methods of the present invention may be embodied in the form of a computer program stored in any kind of storage medium. Examples of storage mediums include, but are not limited to, flexible disk, hard disk, optical discs, magneto-optical discs, magnetic tapes, nonvolatile memory, semiconductor memory, read-only-memory (ROM), etc.
Alternatively, any one of the above-described and other methods of the present invention may be implemented by an application specific integrated circuit (ASIC), a digital signal processor (DSP) or a field programmable gate array (FPGA), prepared by interconnecting an appropriate network of conventional component circuits or by a combination thereof with one or more conventional general purpose microprocessors or signal processors programmed accordingly.
Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), digital signal processor (DSP), field programmable gate array (FPGA) and conventional circuit components arranged to perform the recited functions.
Number | Date | Country | Kind |
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2019-034664 | Feb 2019 | JP | national |