KR102134590B1 - Method of extracting difference between 3d model of measurement object and 3d scan data of the same - Google Patents

Abstract

An embodiment of the present invention provides a method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object. In the method of extracting the error between the 3D model of the measurement object and the 3D scan data of the measurement object, first, a jig fitting to the 3D model of the measurement object is manufactured by 3D printing. Thereafter, 3D scan data is generated by 3D scanning the jig and the measurement object while the jig is provided with the measurement object manufactured according to the 3D model. Using the shape data of the jig included in the 3D scan data, a reference is derived so that a reference for comparing an error between the 3D model of the measurement object and the 3D scan data is located outside the measurement object. Next, an error between the 3D model of the measurement object and the 3D scan data is extracted using the reference.

Description

How to extract the error between the 3D model of the measurement object and the 3D scan data of the measurement object {METHOD OF EXTRACTING DIFFERENCE BETWEEN 3D MODEL OF MEASUREMENT OBJECT AND 3D SCAN DATA OF THE SAME}

The present invention relates to a method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object, and more particularly, a jig fitting to the 3D model of the measurement object is produced by 3D printing, and the measurement object and the jig The present invention relates to a method of extracting an error between a 3D model of a measurement object that scans together and 3D scan data of a measurement object.

In general, a 3D scanner can acquire a myriad of point cloud data in a single measurement in a non-contact method, and can easily implement a 3D shape of a specific product using the obtained point cloud data. There are more and more users who design a product in CAD and output it to a 3D printer directly from CAD data, or to output it to a 3D printer using 3D scan data obtained by scanning a product with a 3D scanner. In designing and measuring a product, it is important to accurately design a product to check whether the CAD design data and 3D scan data are matched, and to accurately extract the differences. In the case of scanning by attaching a mark directly to a measurement object such as a small subsidiary material without using a jig, a part that cannot be measured occurs excessively, and between the measurement result (e.g. scan data) and the CAD model (CAD design data). Because the comparison criteria are not clear, it is difficult to accurately evaluate the measurement results. For example, when a measurement standard is placed inside a measurement object during 3D scanning, the error between the scanned object and the CAD model changes according to the location of the measurement reference, causing problems in measurement.

The technical problem to be achieved by the present invention is a method of extracting an error between the 3D model of the measurement object and the 3D scan data of the measurement object by manufacturing a jig that allows the measurement standard to be located outside the measurement object during 3D scanning through 3D printing. Is to provide.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems that are not mentioned can be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object. In the method of extracting the error between the 3D model of the measurement object and the 3D scan data of the measurement object, first, a jig fitting to the 3D model of the measurement object is manufactured by 3D printing. Thereafter, 3D scan data is generated by 3D scanning the jig and the measurement object while the jig is provided with the measurement object manufactured according to the 3D model. Using the shape data of the jig included in the 3D scan data, a reference is derived so that a reference for comparing an error between the 3D model of the measurement object and the 3D scan data is located outside the measurement object. Next, an error between the 3D model of the measurement object and the 3D scan data is extracted using the reference.

In an embodiment of the present invention, in the process of deriving the reference, from the shape data of the jig included in the 3D scan data, the top surface of the jig, a first side surface in contact with the top surface, the top surface and the first Based on the second side facing the side, at least one of a reference point, a reference line, and a reference plane may be extracted as the reference.

In an embodiment of the present invention, the reference point is a first crossing line crossing the top surface of the jig and the first side, a second crossing line crossing the top surface and the second side, and the first side and the A third crossing line crossing the second side surface may be extracted, and a point at which the first to third crossing lines meet each other may be extracted as the reference point.

In an embodiment of the present invention, the reference point is a top line from the top of the jig, a first side line from the first side, and a second side line from the second side, and the top line, the first side A point at which the line and the second side line intersect each other may be extracted as the reference point.

In an embodiment of the present invention, in the process of manufacturing the jig by 3D printing, first, a jig model fitting to the 3D model of the measurement object generated using CAD may be generated. Thereafter, the jig may be formed by 3D printing according to the jig model. A surfacer may be applied to the formed jig, and a mark for measurement may be attached to the jig to which the surfacer is applied.

In an embodiment of the present invention, in the process of extracting the error, the error of the jig may be extracted by comparing the jig model with shape data of the jig included in the 3D scan data using the reference. An error between the 3D model of the measurement object and the data of the measurement object included in the 3D scan data may be extracted based on the error of the jig.

In an embodiment of the present invention, the jig model may be generated using CAD, similar to the measurement object, and the jig may be formed by 3D printing using the jig model generated by CAD.

In an embodiment of the present invention, the jig has a hexahedral shape, and the mark may be attached to the top and side surfaces of the jig.

According to an embodiment of the present invention, when 3D scanning with a measurement object using a jig made by a 3D printer, the measurement reference is located outside the measurement object, and the measurement reference can be conveniently and clearly set, so that the scan data of the measurement object It is possible to accurately evaluate the error between the and the model to be measured.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a flowchart of an error extraction method according to an embodiment of the present invention.
FIG. 2 is a diagram explaining comparison with a 3D model of a measurement object after measurement without using a jig.
3(a) is a diagram illustrating an example of a jig model fitted to a model of a measurement object.
3(b) is a diagram for explaining the attachment of marks to an example of a jig manufactured by 3D printing.
4 is a diagram illustrating an example of a process of 3D scanning a jig and a measurement object.
5 is a diagram illustrating an example of a process of comparing 3D scan data and a model of a measurement object.
6A and 6B are diagrams illustrating an example of a process of comparing 3D scan data and a model of a measurement object.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and therefore is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, bonded)" with another part, it is not only "directly connected", but also "indirectly connected" with another member in the middle. "Including the case. In addition, when a part "includes" a certain component, it means that other components may be further provided, rather than excluding other components unless specifically stated to the contrary.

The terms used in the present specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart of an error extraction method according to an embodiment of the present invention.

In this embodiment, in order to extract an error between the 3D model of the measurement object and the 3D scan data of the measurement object 100, first, a jig 200 (refer to FIG. 3) that is fitted to the 3D model of the measurement object is Produced by 3D printing. Next, 3D scan data is generated by 3D scanning the jig 200 and the measurement target 100 with the measurement object 100 manufactured according to the 3D model on the jig 200. Next, using the shape data of the jig 200 included in the 3D scan data, the reference is made so that the reference for comparing the error between the 3D model of the measurement object and the 3D scan data is located outside the measurement object 100. It can be derived (S70). Using the derived criteria, an error between the 3D model of the measurement object and the 3D scan data is extracted. Hereinafter, each process of FIG. 1 will be described in detail with reference to FIGS. 2 to 6.

2 is a diagram illustrating comparison with a 3D model of a measurement object after measurement without using the jig 200.

In FIG. 2, the small subsidiary material to which the mark 230 is attached is simply placed on the support 5 without using the jig 200. When the scan is executed in this state, it is difficult to accurately determine the comparison standard between the measurement result (3D scan data) and the 3D model of the measurement target. As a result, it becomes difficult to compare and evaluate the degree of correspondence between the 3D scan data and the 3D model to be measured (e.g., a CAD model), and excessively occur in the small subsidiary material that is the target 100 that is not evaluated for measurement. I can.

3(a) is a diagram illustrating an example of a jig model fitted to a 3D model of a measurement object.

In order to extract an error between the 3D model of the measurement object and the 3D scan data of the measurement object 100, first, a jig 200 fitting to the 3D model of the measurement object is manufactured by 3D printing. To this end, a 3D model of the object to be measured is created using CAD (S10), a jig model that is fitted with the 3D model of the object to be measured 100 is created (S20), and then a jig 200 is performed by 3D printing along the jig model. Can be formed (S30). In generating a 3D model of the measurement object (S10), a 3D model of the measurement object may be designed in CAD (S10). Alternatively, 3D scan data of the measurement object 100 is generated by 3D scanning the measurement object 100, which may be a small subsidiary material, and the 3D scan data of the measurement object 100 thus generated is used to use the CAD model of the measurement object ( It is also possible to form a 3D model of the measurement object. CAD can also be used to create jig models. The jig 200 is formed by 3D printing according to the jig model using CAD. That is, for the jig 200, a CAD model, a 3D scan to be described later, and 3D printing using a CAD model are performed. Here, a process of 3D scanning with a CAD model and a jig 200, which will be described later, is also scheduled for the small subsidiary material, which is the measurement target 100, so if you consider manufacturing the measurement target 100 by 3D printing, the jig ( 200), it can be seen that the basis for evaluating the error of the measurement object is prepared.

3(b) is a diagram for explaining the attachment of the mark 230 to an example of the jig 200 manufactured by 3D printing.

As a pretreatment for the measurement, the surfacer 210 may be applied to the jig 200 formed as described above (S40), and the mark 230 may be attached to the jig 200 to which the surfacer 210 is applied (S50). ). It is preferable that the jig 200 has a simple shape and is convenient for use as a reference for measurement to be described later, and may have a hexahedral shape as illustrated in FIG. 3(b), and shown in FIG. 3(a). As shown, a part to which the measurement object 100 is to be fitted may also be formed. In this embodiment, the mark 230 is a top surface 201 of the jig 200, and a first side surface 202 in contact with the top surface 201, a second side surface in contact with the top surface 201 and the first side surface 202 A mark 230 for 3D scanning may be attached to the entire hexahedron such as (203). Of course, in addition to this, the mark 230 may be attached to the measurement object 100 as well.

4 is a diagram illustrating a process of 3D scanning the jig 200 and the measurement object 100.

Thereafter, 3D scan data may be generated by 3D scanning the jig 200 and the measurement target 100 with the measurement object 100 manufactured according to the 3D model on the jig 200 (S60). . The scanning method shown in FIG. 4 is only an example, and various 3D scanners 310 such as an optical scanner and a contact scanner may be applied. In FIG. 4, in order to photograph the entire shape of the jig 200 and the measurement object 100, the jig 200 and the measurement object 100 fitted to the jig 200 are placed on a rotating table, and rotated in the vertical and horizontal directions. You can shoot. The 3D scan data of the jig 200 and the measurement object 100 fitted to the jig 200 is generated by the 3D scan, and the 3D scan data can be post-processed.

By setting the standard for comparing the error between the 3D model of the measurement object and the 3D scan data, in comparing the scanned measurement object 100 and the CAD model (CDA data), the inside of the measurement object 100 during 3D scanning When the measurement reference is placed, the error between the scanned object and the CAD model changes according to the location of the measurement reference. For example, as described in FIG. 2, when the measurement object 100 is scanned without using the jig 200, the reference point 240 of the comparison is used as the measurement object 100 for comparison with the CAD object. ) In itself, that is, when placed inside the measurement object 100, it may be difficult to clearly determine which point inside the measurement object 100 corresponds to where in the CAD model, and for this reason, the scanned object according to the location of the measurement reference And the error between the CAD model changes. Alternatively, even if the jig 200 is used to scan the measurement object 100 together with the jig 200, the above-described problem occurs when the measurement reference is placed inside the measurement object 100. In addition, when trying to set a standard for comparison outside of the measurement object 100, considering its clarity, consistency, and ease of execution, how to set or generate the standard may be a problem.

5 is a diagram illustrating an example of a process of deriving a reference point 240.

In this embodiment, by using the shape data of the jig 200 included in the 3D scan data, the reference for comparing the error between the 3D model of the measurement object and the 3D scan data is located outside the measurement object 100, The standard is derived (S70). To this end, from the shape data of the jig 200 included in the 3D scan data, the first side surface 202 and the top surface 201 and the first side surface 201 in contact with the top surface 201 and the top surface 201 of the jig 200 Based on the second side surface 203 in contact with 202, at least one of the reference point 240, the reference line, and the reference plane may be extracted as a reference. In this embodiment, as described above, the jig 200 may have a simple shape by having a hexahedral shape, and the mark 230 is attached to the upper surface 201 and the side surface of the jig 200 so that it is three-dimensional for comparison. The foundation is laid.

As an example of reference extraction, the first cross line 241 where the top surface 201 and the first side surface 202 of the jig 200 cross, and the second crossing line where the top surface 201 and the second side surface 203 cross A line 243 and a third crossing line 245 where the first side 202 and the second side 203 intersect are extracted, and the point at which the first to third crossing lines 245 meet each other is a reference point ( 240). In this case, the reference point 240 is located outside the measurement object 100, the shape of the jig 200 is simple, as described above, and the mark 230 for measurement is located on various surfaces of the jig 200. Because it is formed, it is easy to handle and can provide a clear and consistent basis for comparison.

Alternatively, one of the first crossing line 241, the second crossing line 243, and the third crossing line 245 may be used as a reference line, or the upper surface 201 and the side surface may be used as a reference plane. That is, when creating a common spatial coordinate system between the three-scan data and the CAD model using software for image or data analysis and registration, one or more of the first to third intersection lines 241, 243, and 245 are used as the reference line of the coordinate system. You could also use it.

As another example of the reference extraction, the top line 251 is extracted from the top surface 201 of the jig 200, and the first side line 253 and the second side line 203 are extracted from the first side surface 202. 2 The side line 255 is extracted, and a point where the top line 251, the first side line 253, and the second side line 255 intersect each other may be extracted as the reference point 240. Specifically, the upper surface line 251 may form a plurality of virtual diagonal lines included in the upper surface 201 as illustrated in FIG. 5, and one of the upper surface lines 251 may be selected. Similarly, one of the plurality of diagonal lines included in the first side surface 202 is selected as the first side line 253, and one of the plurality of diagonal lines included in the second side surface 203 is selected to form the second side line ( 255). The top line 251, the first side line 253, and the second side line 255 can be moved in parallel in a three-dimensional space to extract one point that intersects each other, and this intersection is referred to as the reference point 240. You can choose.

6(a) and 6(b) are diagrams illustrating an example of a process of comparing 3D scan data and a model of the measurement target 100.

As described above, an error between the 3D model of the measurement object and the 3D scan data is extracted using the derived criteria. To this end, first, an error of the jig 200 may be extracted using a reference (S80), and an error of a measurement object may be extracted using the jig error (S90). For example, using software for analysis or registration, first, 3D scan data is loaded (for example, see FIG. 6(a)), and as described in FIG. 5, a reference for comparison may be generated. Thereafter, as shown in Fig. 6(b), the CAD data (3D model of the measurement target) of the measurement target 100 is matched on the 3D scan data for which the standard is set by matching, etc. I can. In this case, the 3D scan data of the jig 200, which is the basis of the reference setting, and the jig model designed or created for the actual work of the jig 200 (e.g., CAD data of the jig 200) are first compared, and the jig ( 200) You can extract your own errors. Thereafter, as described above, the 3D scan data of the measurement target 100 included in the 3D scan data and the 3D model (CAD data) of the measurement target are compared using the above criteria, and an error of the measurement target may be obtained. That is, it can be used to extract an error of a measurement object by using the jig error. In other words, it can be used to accurately check the error of the system using a jig that is easy to set the standard, and to obtain or correct the error between the 3D model of the measurement target (eg, CAD data) and the scan data of the measurement target .

As described above, according to an embodiment of the present invention, the jig 200 and the measurement object 100 are modeled, the jig 200 is actually made by 3D printing, and the jig 200 is 3D scanned together with the measurement object 100, and the jig error is By extracting, it is possible to accurately check and evaluate the error of the measurement object. Accordingly, when the measurement object 100 is manufactured, especially when it is manufactured by 3D printing, the error is already accurately known, so that it is possible to manufacture and measure with improved precision. have.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

230: mark
100: measurement target
200: jig
210: surfacer
310: 3D scanner
240: reference point
241: first crossing line
243: second intersection line
245: third intersection line
251: top line
253: first side line
255: second side line
201: top
202: first side
203: second side

Claims (8)

In a method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object performed by an information processing device,
Manufacturing a jig fitting to the 3D model of the measurement object by 3D printing;
Generating 3D scan data by 3D scanning the jig and the measurement object while having the measurement object manufactured according to the 3D model on the jig;
Deriving a reference so that a reference for comparing an error between the 3D model of the measurement object and the 3D scan data is located outside the measurement object using shape data of the jig included in the 3D scan data; And,
Using the reference, including the step of extracting an error between the 3D model of the measurement object and the 3D scan data,
The step of manufacturing the jig by 3D printing,
Generating a jig model fitting to the 3D model of the measurement object generated using CAD;
Forming the jig by 3D printing according to the jig model;
Applying a surfacer to the formed jig; And
Attaching a gauge point for measurement to the jig on which the surfacer is applied to the upper surface of the jig;
Attaching a mark to a first side of the jig to which the mark is attached to the upper surface;
A method for extracting an error between the 3D model of the measurement object and 3D scan data of the measurement object, comprising the step of attaching a mark on a second side of the jig with the mark on the upper surface in contact with the upper surface of the jig.
The method of claim 1,
The step of deriving the criteria,
From the shape data of the jig included in the 3D scan data, based on the top surface of the jig, a first side in contact with the top surface, and a second side in contact with the top surface and the first side, among a reference point, a reference line, and a reference plane A method of extracting an error between the 3D model of the measurement object and 3D scan data of the measurement object, wherein at least one is extracted as the reference.
The method of claim 2,
The reference point is a first crossing line crossing the top surface of the jig and the first side surface, a second crossing line crossing the top surface and the second side surface, and a third crossing line crossing the first side surface and the second side surface. A method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object, comprising extracting an intersection line and extracting a point at which the first to third intersection lines converge as the reference point.
The method of claim 2,
The reference point extracts a top line from the top surface of the jig, a first side line from the first side, and a second side line from the second side, and the top line, the first side line and the second side line are A method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object, wherein points intersecting each other are extracted as the reference point.
delete The method of claim 1,
The step of extracting the error
Comparing the jig model and shape data of the jig included in the 3D scan data using the reference to extract a jig error; And
Extracting an error between the 3D model of the measurement object and the data of the measurement object included in the 3D scan data based on the error of the jig; comprising: a 3D model of the measurement object and a 3D measurement object A method of extracting errors between scan data.
The method of claim 1,
The jig model is created using CAD, similar to the measurement object,
A method of extracting an error between a 3D model of a measurement object and 3D scan data of a measurement object, characterized in that the jig is formed by 3D printing using the jig model generated by CAD.
The method of claim 1,
The jig has a hexahedral shape, and the marks are on the top and side surfaces of the jig.
A method of extracting an error between the 3D model of the measurement object and 3D scan data of the measurement object, characterized in that attached thereto.

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