3D shape alignment method and 3D shape data processing device

Abstract

To provide a three-dimensional shape positioning method capable of accurately performing positioning between a subject in CT data and the subject in design data without depending on the shape of the subject.SOLUTION: A three-dimensional shape positioning method includes the steps of: acquiring three-dimensional CT data 30 of a subject 90 and at least three positioning members 1, which is acquired by performing X-ray CT imaging of the positioning members 1 together with the subject 90; measuring relative positions between the subject 90 and each one of the positioning members 1; and based on the CT data 30, three-dimensional design data 31 of the subject 90, and relative position information 32, performing positioning between the subject 90 in the CT data 30 and the subject 90 in the design data 31.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional shape alignment method and a three-dimensional shape data processing device, and in particular to a three-dimensional shape alignment method and a three-dimensional shape data processing device that aligns a subject in CT data acquired by X-ray CT imaging with a subject in three-dimensional design data. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a three-dimensional shape registration method for aligning a subject in CT data acquired by X-ray CT imaging with a subject in three-dimensional design data (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-8360 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the CT data acquired by performing X-ray CT imaging may have high accuracy of the surface of the object, but the accuracy of individual points may not be high. In other words, depending on the shape of the object, the CT data may include parts where the accuracy of the shape is reduced. Therefore, there is a problem in that it may be difficult to accurately align the object in the CT data with the object in the design data due to the shape of the object.

[0005] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a three-dimensional shape alignment method and a three-dimensional shape data processing device that are capable of accurately aligning a subject in CT data with a subject in design data, regardless of the shape of the subject. [Means for solving the problem]

[0006] In order to achieve the above object, a method for aligning a three-dimensional shape according to a first aspect of the present invention includes the steps of: acquiring three-dimensional CT data of the subject and the positioning members, the three-dimensional CT data being acquired by X-ray CT imaging of at least three positioning members together with the subject; measuring the relative positions of the subject and each of the positioning members; Acquired CT data Position information of the positioning member and, Based on measured relative position information 3D design data of the subject and the position information of the positioning member in and a step of aligning the object in the CT data with the object in the design data.

[0007] A three-dimensional shape data processing device according to a second aspect of the present invention includes a data acquisition unit that acquires three-dimensional CT data of a subject and positioning members, the three-dimensional CT data being acquired by X-ray CT imaging of at least three positioning members together with a subject; Measured subject and place a relative position information acquisition unit that acquires information on the relative positions of the positioning members; acquired CT data Position information of the positioning member and, Based on measured relative position information 3D design data of the subject and the position information of the positioning member in and a registration unit that aligns the object in the CT data with the object in the design data. [Effects of the Invention]

[0008] In the three-dimensional shape alignment method according to the first aspect and the three-dimensional shape data processing device according to the second aspect, alignment between the object in the CT data and the object in the design data is performed based on the CT data, the three-dimensional design data of the object, and information on the relative positions of the object and each of the positioning members. This makes it possible to obtain position information of the positioning members in the design data based on the design data and the information on the relative positions. Therefore, the CT data toWhen aligning the object in the CT data with the object in the design data, the object in each data can be aligned by aligning the positioning member in the CT data with the positioning member in the design data. Therefore, for example, by using a positioning member having a shape that allows the shape to be accurately acquired in the CT data, the object in the CT data can be aligned with the object in the design data without depending on the shape of the object. As a result, the position of the object in the CT data can be aligned with the object in the design data with high accuracy without depending on the shape of the object. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a three-dimensional shape data processing system including a three-dimensional shape data processing device according to this embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of an X-ray CT imaging device. [Figure 3] FIG. 1 is a diagram showing an example of a subject; [Figure 4] FIG. 2 is a functional block diagram for explaining functions of a processor of the three-dimensional shape data processing device. [Figure 5] FIG. 2 is a flowchart for explaining the processing operation of the three-dimensional shape data processing device according to the present embodiment. [Figure 6] FIG. 10 is a flowchart for explaining details of a process for placing a positioning member relative to a subject. [Figure 7] FIG. 10 is a diagram illustrating a subject on which a positioning member is arranged. [Figure 8] FIG. 10 is a diagram for explaining the arrangement of three positioning members. [Figure 9] 10A and 10B are diagrams for explaining the arrangement of at least two of the positioning members. [Figure 10] FIG. 10 is a flowchart for explaining details of a process for measuring a relative position. [Figure 11] FIG. 10 is a diagram for explaining details of a process for measuring a relative position. [Figure 12] FIG. 10 is a flowchart illustrating details of a process for acquiring first location information. [Figure 13] FIG. 10 is a diagram for explaining details of a process for acquiring first location information. [Figure 14] FIG. 10 is a flowchart illustrating details of a process for acquiring second location information. [Figure 15] FIG. 10 is a diagram for explaining details of a process for acquiring second location information. [Figure 16] FIG. 10 is a flowchart for explaining details of alignment processing by an alignment unit. [Figure 17] 10A and 10B are diagrams for explaining details of alignment processing by an alignment unit. [Figure 18] 10A and 10B are diagrams for explaining a method for fixing a positioning member according to a first modified example. [Figure 19] 10A and 10B are diagrams illustrating a method for fixing a positioning member according to a second modified example. [Figure 20] 10A and 10B are diagrams for explaining the arrangement of a positioning member relative to a subject according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0011] A three-dimensional shape data processing system including a three-dimensional shape data processing device 100 according to this embodiment will be described with reference to FIGS.

[0012] (Outline of the 3D shape data processing system) The three-dimensional shape data processing system includes a three-dimensional shape data processing device 100, an X-ray CT imaging device 200, and a three-dimensional coordinate measuring device 300. The three-dimensional shape data processing system aligns an object 90 in the CT data 30 (see FIG. 3 ) with the object 90 in the design data 31, using CT data 30 generated by the X-ray CT imaging device 200, relative position information 32 acquired by the three-dimensional coordinate measuring device 300, and design data 31 stored in the three-dimensional shape data processing device 100.

[0013] (3D shape data processing device) The three-dimensional shape data processing device 100 shown in FIG. 1 is a device that processes three-dimensional data of an object 90. Specifically, the three-dimensional shape data processing device 100 performs a process of aligning the position of the object 90 in three-dimensional CT data 30 obtained by CT imaging of the object 90 using an X-ray CT imaging device 200 with the position of the object 90 in three-dimensional design data 31. That is, the three-dimensional shape data processing device 100 according to this embodiment aligns the position of the object 90 in the CT data 30 with the position of the object 90 in the design data 31, thereby inspecting whether the object 90 has been manufactured according to the design data 31. The design data 31 is design data created to manufacture the object 90. The design data 31 may be, for example, three-dimensional CAD (Computer Aided Design) data.

[0014] The three-dimensional shape data processing device 100 is a so-called personal computer, and includes a processor 10 and a storage unit 20. A display unit 111 and an input unit 112 are also connected to the three-dimensional shape data processing device 100. The display unit 111 is, for example, a liquid crystal display device. The display unit 111 may also be an electroluminescence display device, a projector, or a head-mounted display. The input unit 112 is, for example, an input device including a mouse and a keyboard. The input unit 112 may also be a touch panel.

[0015] The processor 10 is configured by a CPU (Central Processing Unit), an FPGA (Field-Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), etc. The processor 10 executes a predetermined program 21, thereby performing arithmetic processing as the three-dimensional shape data processing device 100.

[0016] The storage unit 20 includes a nonvolatile storage device. The nonvolatile storage device is, for example, a hard disk drive, a solid state drive, or the like. The storage unit 20 stores various programs 21 executed by the processor 10. The storage unit 20 also stores three-dimensional design data 31 of the subject 90.

[0017] Here, the CT data 30 can convert the internal structure of the object 90 into three-dimensional data. Although the surface data of the object 90 can be obtained with high accuracy, the accuracy may decrease at individual points. That is, when aligning the CT data 30 with individual points, the object 90 in the CT data 30 and the object 90 in the design data 31 may be inaccurate. place It can be difficult to achieve accurate alignment.

[0018] Therefore, in this embodiment, X-ray CT imaging is performed with a positioning member 1 (see FIG. 7) placed relative to the subject 90, thereby obtaining CT data 30 of the subject 90 and the positioning member 1. Furthermore, the relative position of the positioning member 1 placed on the subject 90 with respect to the subject 90 is measured by a three-dimensional coordinate measuring device 300. The three-dimensional shape data processing device 100 aligns the subject 90 in the CT data 30 with the subject 90 in the design data 31, based on the CT data 30 generated by the X-ray CT imaging device 200, the design data 31, and information 32 on the relative position measured by the three-dimensional coordinate measuring device 300.

[0019] The three-dimensional coordinate measuring device 300 includes a contact-type measuring device that performs measurement by bringing a probe 310 (see FIG. 11) into contact with a measurement target such as the object 90, and a non-contact-type measuring device that performs measurement by irradiating the measurement target with laser light or the like. In this embodiment, the three-dimensional coordinate measuring device 300 is a contact-type measuring device. That is, the three-dimensional coordinate measuring device 330 is a device that acquires position coordinates of multiple positions where the probe 310 is in contact and combines these position coordinates to acquire information about the three-dimensional shape of the object 90. The probe 310 is a contactor that is brought into contact with the object 90.

[0020] <X-ray CT imaging device> As shown in FIG. 2, the X-ray CT imaging apparatus 200 includes an X-ray source 210, an X-ray detector 220, a control unit 230, an image processing unit 240, and a rotation mechanism 250.

[0021] The X-ray source 210 is configured to irradiate the subject 90 with X-rays. Specifically, the X-ray source 210 is configured to generate X-rays by causing electrons, which are generated by applying a high voltage to an electrode, to collide with a target. The X-ray source 210 is, for example, an X-ray generating device including an X-ray tube and a power supply.

[0022] The X-ray detector 220 is configured to detect X-rays emitted from the X-ray source 210. The X-ray detector 220 is also configured to convert the detected X-rays into an electrical signal (image signal). The X-ray detector 220 includes a light receiving unit that receives X-rays and a conversion unit that converts the received X-rays into an image signal. The X-ray detector 220 is, for example, an FPD (Flat Panel Detector). The X-ray detector 220 is configured with a plurality of conversion elements (not shown) and pixel electrodes (not shown) arranged on the plurality of conversion elements. The image signal of the X-ray detector 220 is sent to the image processing unit 240.

[0023] The control unit 230 is configured to control the X-ray source 210 and the rotation mechanism 250. The control unit 230 includes a processor configured with a CPU, RAM, ROM, and the like.

[0024] The image processing unit 240 is configured to control the X-ray detector 220. The image processing unit 240 is also configured to acquire X-ray image data based on X-rays detected by the X-ray detector 220. The image processing unit 240 is also configured to generate CT data 30 based on a plurality of X-ray image data acquired by capturing an image of the subject 90 while rotating it around the axis 40 using the rotation mechanism 250. The image processing unit 240 includes a processor such as a CPU, GPU, FPGA, or ASIC. The image processing unit 240 is configured in software as a functional block realized by the processor executing various programs. The image processing unit 240 may also be configured in hardware by providing a dedicated processor (processing circuit) in the X-ray CT imaging device 200.

[0025] The rotation mechanism 250 is configured to rotate the subject 90 around the axis 40. The rotation mechanism 250 includes a mounting section on which the subject 90 is mounted, a rotating section that rotates the mounting section, and a driving section that applies a driving force to the rotating section. The rotating section includes, for example, a pulley for transmitting the driving force from the driving section. The driving section also includes, for example, a motor.

[0026] (subject) 3 is a diagram showing an example of a subject 90. The subject 90 includes a resin product made of a resin material, a metal product made of a metal material, and the like. The manufacturing method of the subject 90 is not important. In this embodiment, the subject 90 is made of, for example, aluminum.

[0027] 3, for convenience, an example of a single component in which rectangular parallelepipeds 90a and 90b are integrally formed is shown as the subject 90. A circular hole 91b is provided in a first surface 91a of the subject 90. Furthermore, a circular hole 91d is provided in a second surface 91c of the subject 90, which is a surface different from the first surface 91a.

[0028] (positioning member) The positioning member 1 has an isotropic shape. Specifically, the positioning member 1 has an isotropic shape, which is a spherical shape. The positioning member 1 is formed of a material having the same or similar X-ray transmittance as the subject 90. The positioning member 1 includes, for example, a ceramic sphere. The isotropic shape means that the shape of the positioning member 1 has no directionality. In other words, even when the positioning member 1 is rotated by the rotation mechanism 250 during X-ray CT imaging using the X-ray CT imaging device 200, there is little difference in the path length of the X-rays passing through the positioning member 1 at each rotation angle.

[0029] (Detailed configuration of the 3D shape data processing device) FIG. 4 is a block diagram showing an outline of each component used by the three-dimensional shape data processing device 100 to align the object 90 in the CT data 30 with the object 90 in the design data 31. As shown in FIG.

[0030] The processor 10 of the three-dimensional shape data processing device 100 includes, as functional blocks, a data acquisition unit 11, a relative position information acquisition unit 12, a position alignment unit 13, a first position information acquisition unit 14, and a second position information acquisition unit 15. In other words, the processor 10 functions as the data acquisition unit 11, the relative position information acquisition unit 12, the position alignment unit 13, the first position information acquisition unit 14, and the second position information acquisition unit 15 by executing a program 21 stored in the storage unit 20.

[0031] The data acquisition unit 11 has a function of acquiring three-dimensional CT data 30 of the subject 90 and the positioning members 1, which is acquired by performing X-ray CT imaging of at least three positioning members 1 (see FIG. 7) together with the subject 90 (see FIG. 3). The data acquisition unit 11 acquires the CT data 30 transmitted from the X-ray CT imaging device 200 via a network. If the CT data 30 is stored in the storage unit 20, the data acquisition unit 11 may read the CT data 30 from the storage unit 20. Alternatively, the data acquisition unit 11 may acquire the design data 31 by reading the design data 31 stored in the storage unit 20 (see FIG. 1). The data acquisition unit 11 outputs the acquired CT data 30 to the first position information acquisition unit 14. Alternatively, the data acquisition unit 11 outputs the acquired design data 31 to the second position information acquisition unit 15.

[0032] The relative position information acquisition unit 12 acquires information 32 about the relative position between the subject 90 and each of the positioning members 1. Specifically, the relative position information acquisition unit 12 acquires information 32 about the relative position measured by the three-dimensional coordinate measuring device 300. The relative position information 32 is information about the relative position between the subject 90 and each of the positioning members 1. In this embodiment, the relative position information 32 includes position information 32a (see FIG. 11) about the reference position 3 set on the subject 90 and position information 32b (see FIG. 11) about each of the positioning members 1. The relative position information acquisition unit 12 acquires the relative position information 32 transmitted from the three-dimensional coordinate measuring device 300 via a network. Note that if the relative position information 32 is stored in the storage unit 20, the relative position information acquisition unit 12 may read the relative position information 32 from the storage unit 20. The relative position information acquisition unit 12 outputs the acquired relative position information 32 to the second position information acquisition unit 15.

[0033] The first position information acquisition unit 14 acquires position information of the positioning member 1 (see FIG. 7) in the CT data 30. Specifically, the first position information acquisition unit 14 acquires first position information 33, which is position information of the center point 2 (see FIG. 8) of the positioning member 1 in the CT data 30. The first position information acquisition unit 14 outputs the acquired first position information 33 to the alignment unit 13.

[0034] The second position information acquisition unit 15 acquires position information of the positioning member 1 in the design data 31 based on the design data 31 and the relative position information 32. Specifically, the second position information acquisition unit 15 acquires second position information 34, which is position information of the center point 2 (see FIG. 8 ) of the positioning member 1 in the design data 31. The second position information acquisition unit 15 outputs the acquired second position information 34 to the alignment unit 13.

[0035] The alignment unit 13 aligns the object 90 in the CT data 30 with the object 90 in the design data 31 based on three-dimensional design data 31 of the object 90 and relative position information 32. In this embodiment, the alignment unit 13 aligns the object 90 in the CT data 30 with the object 90 in the design data 31 based on first position information 33 and second position information 34. Details of the configuration by which the alignment unit 13 aligns the object 90 in the CT data 30 with the object 90 in the design data 31 will be described later.

[0036] (3D shape alignment method) Next, a three-dimensional shape alignment method of this embodiment will be described with reference to Fig. 5. The three-dimensional shape alignment method of this embodiment is a method for aligning the object 90 in the CT data 30 with the object 90 in the design data 31. The three-dimensional shape alignment method can be executed by a three-dimensional shape data processing device 100 (processor 10).

[0037] The method for aligning three-dimensional shapes according to this embodiment includes at least the following steps. (1) A step of acquiring three-dimensional CT data 30 of the object 90 and the positioning members 1 by performing X-ray CT imaging of at least three positioning members 1 together with the object 90. (2) Step of measuring the relative positions of the object 90 and each of the positioning members 1 (3) A step of aligning the object 90 in the CT data 30 with the object 90 in the design data 31 based on the CT data 30, the three-dimensional design data 31 of the object 90, and the relative position information 32.

[0038] Step (1) of acquiring CT data 30 is executed by data acquisition unit 11. Step (1) of acquiring CT data 30 is executed after X-ray CT imaging is performed by X-ray CT imaging device 200. Step (2) of measuring the relative position is executed by three-dimensional coordinate measuring device 300. Step (3) of aligning object 90 in CT data 30 with object 90 in design data 31 is executed by alignment unit 13. The three-dimensional shape alignment method of this embodiment further includes a process of acquiring first position information 33 by first position information acquisition unit 14 and a process of acquiring second position information 34 by second position information acquisition unit 15.

[0039] Moreover, the method for aligning a three-dimensional shape of this embodiment further includes the steps of placing the positioning member 1 relative to the subject 90 and fixing the positioning member 1.

[0040] Next, the flow of processing by the three-dimensional shape data processing device 100 will be described in detail with reference to FIGS.

[0041] <Arrangement of positioning members> In step S1, the positioning member 1 is placed relative to the subject 90. Details of the placement of the positioning member 1 relative to the subject 90 will be described with reference to FIGS.

[0042] 6, at least three positioning members 1 are placed on the subject 90. In this embodiment, three positioning members 1, namely, positioning member 1a to positioning member 1c, are placed on the subject 90.

[0043] In step S1b, each of the positioning members 1 is fixed to the subject 90. In the present embodiment, each of the positioning members 1 is fixed to the subject 90 in a state of being in contact with the subject 90. Thereby, at least until both the X-ray CT imaging and the measurement of the relative positions are completed, the relative positions of each of the positioning members 1 do not change. As a method of fixing the positioning member 1 to the subject 90, there are fixing with an adhesive, screwing, etc., but any method may be used as long as the positioning member 1 can be fixed to the subject 90.

[0044] As shown in FIG. 7, at least two of the positioning members 1 are arranged on different surfaces of the subject 90. In the example shown in FIG. 7, the positioning member 1a is arranged on the second surface 91c of the subject 90, and the positioning member 1c is arranged on the first surface 91a of the subject 90. Also, in the example shown in FIG. 7, the positioning member 1b is provided on a rectangular parallelepiped 90b that contacts the second surface 91c.

[0045] Also, as shown in FIG. 8, each of the positioning members 1 is arranged at a position such that when the central positions of each are connected by a straight line 4 (straight lines 4a, 4b, 4c), a plane 50 is formed by the straight line 4 (straight lines 4a, 4b, 4c). Note that the straight line 4a is a straight line connecting the center point 2a of the positioning member 1a and the center point 2b of the positioning member 1b. Also, the straight line 4b is a straight line connecting the center point 2b of the positioning member 1b and the center point 2c of the positioning member 1c. Also, the straight line 4c is a straight line connecting the center point 2c of the positioning member 1c and the center point 2a of the positioning member 1a.

[0046] Also, as shown in FIG. 9, at least one of the positioning members 1 is arranged at a position close to one end 91e in the longitudinal direction of the subject 90 among one end 91e in the longitudinal direction of the subject 90 and the longitudinal center 92, and at least one other is arranged at a position close to the other end 91f in the longitudinal direction of the subject 90 among the other end 91f in the longitudinal direction of the subject 90 and the longitudinal center 92. Note that in FIG. 9, the longitudinal center 92 of the subject 90 is illustratively shown using a dashed line.

[0047] <X-ray CT imaging> 5, the X-ray CT imaging device 200 performs X-ray CT imaging of the subject 90. This generates three-dimensional CT data 30 of the subject 90. The generated CT data 30 is transmitted to the three-dimensional shape data processing device 100.

[0048] <Relative position measurement> 5, the three-dimensional coordinate measuring device 300 measures the relative positions of the object 90 and the positioning member 1 arranged on the object 90. Details of the measurement of the relative positions by the three-dimensional coordinate measuring device 300 will be described with reference to FIGS.

[0049] As shown in FIG. 10, the process of acquiring relative position information 32 by the three-dimensional coordinate measuring device 300 includes step S3a of acquiring position information 32a of the reference position 3 and step S3b of acquiring position information 32b of the positioning member 1.

[0050] In step S3a, the three-dimensional coordinate measuring device 300 acquires the position information 32a of the reference position 3.

[0051] In step S3b, the three-dimensional coordinate measuring device 300 brings the probe 310 into contact with each of the positioning members 1, thereby acquiring position information 32b of each of the positioning members 1.

[0052] As shown in FIG. 11 , in this embodiment, the three-dimensional coordinate measuring device 300 measures the relative positions of the object 90 and the positioning member 1 by bringing a probe 310 into contact with each of the object 90 and the positioning member 1. The reference position 3 is the center position of a circular hole 91b formed in the surface (first surface 91a) of the object 90, the center position being located on the same plane as the surface (first surface 91a). In this embodiment, the three-dimensional coordinate measuring device 300 acquires position information of the first surface 91a by bringing the probe 310 into contact with a predetermined position on the first surface 91a of the object 90. The three-dimensional coordinate measuring device 300 acquires position information of the first surface 91a by, for example, bringing the probe 310 into contact with each of six contact positions 311 set on the first surface 91a. Similarly, position information of a second surface 91c (top surface) of the object 90 is acquired.

[0053] Furthermore, the three-dimensional coordinate measuring device 300 acquires position information of the circular hole 91b by bringing the probe 310 into contact with the inner circumferential surface of the circular hole 91b. Specifically, the three-dimensional coordinate measuring device 300 acquires position information of the circular hole 91b by bringing the probe 310 into contact with each of the contact positions 312 set on the inner circumferential surface of the circular hole 91b. The three-dimensional coordinate measuring device 300 then acquires position information 32a of the reference position 3 based on the position information of the first surface 91a, the position information of the second surface 91c, and the position information of the circular hole 91b. The three-dimensional coordinate measuring device 300 acquires coordinate values ​​and directions (X0, Y0, Z0) as the position information 32a of the reference position 3. In this embodiment, the relative position information 32 is position information in a first coordinate system defined by the position information 32a of the reference position 3.

[0054] Specifically, the three-dimensional coordinate measuring device 300 acquires position information of the center point 2 of the positioning member 1 (see FIG. 8). In this embodiment, the three-dimensional coordinate measuring device 300 acquires position information of the center point 2a of the positioning member 1a, position information of the center point 2b of the positioning member 1b, and position information of the center point 2c of the positioning member 1c. Specifically, the three-dimensional coordinate measuring device 300 acquires the coordinate values ​​(X1, Y1, Z1) of the center point 2a of the positioning member 1a as position information 32b of the positioning member 1a. Furthermore, the three-dimensional coordinate measuring device 300 acquires the coordinate values ​​(X2, Y2, Z2) of the center point 2b of the positioning member 1b as position information 32b of the positioning member 1b. Furthermore, the three-dimensional coordinate measuring device 300 acquires the coordinate values ​​(X3, Y3, Z3) of the center point 2c of the positioning member 1c as position information 32b of the positioning member 1c.

[0055] The position information 32a of the reference position 3 and the position information 32b of the positioning member 1 acquired by the three-dimensional coordinate measuring device 300 are transmitted to the three-dimensional shape data processing device 100. The position information 32a of the reference position 3 and the position information 32b of the positioning member 1 may be stored in the storage unit 20 included in the three-dimensional shape data processing device 100.

[0056] <CT data acquisition> In step S4 of FIG. 5, the data acquisition unit 11 (see FIG. 3) performs the process of acquiring the CT data 30 (step (1) above). The data acquisition unit 11 acquires the CT data 30 by receiving the CT data 30 transmitted from the X-ray CT imaging device 200 via a network or the like. The data acquisition unit 11 also stores the acquired CT data 30 in the storage unit 20. Note that if the CT data 30 is previously stored in the storage unit 20, the process of step S4 is omitted.

[0057] <First location information acquisition> After that, in step S5, the first location information acquisition unit 14 executes a process of acquiring the first location information 33. The process of acquiring the first location information 33 will be described in detail with reference to Figs.

[0058] 12, step S5 of acquiring first position information 33 includes step S5a of acquiring the shape of the positioning member 1 from the CT data 30, and step S5b of acquiring position information of the center point 2 of the positioning member 1 in the CT data 30. Note that the first position information 33 is position information of each center point 2 of the positioning member 1 in the CT data 30.

[0059] In step S5a, the first position information acquisition unit 14 acquires the shape of the positioning member 1 in the CT data 30. In this embodiment, the first position information acquisition unit 14 identifies the shape of the positioning member 1. There is no restriction on the method by which the first position information acquisition unit 14 identifies the shape of the positioning member 1. The CT data 30 is data indicating the three-dimensional shape of the subject 90 in a second coordinate system defined by the P axis, the Q axis, and the R axis.

[0060] In step S5b, the first position information acquisition unit 14 acquires position information of the positioning member 1 in the second coordinate system. The first position information acquisition unit 14 acquires first position information 33, which is position information of the positioning member 1 in the CT data 30, based on the isotropic shape of the positioning member 1 in the CT data 30. More specifically, the first position information acquisition unit 14 acquires the first position information 33 based on position information of the surface 1d of the spherical positioning member 1 in the CT data 30.

[0061] The first position information acquisition unit 14 acquires, as the center point 2 of the positioning member 1, a point equidistant from each point on the surface 1d of the positioning member 1 whose position was identified in step S5a. Here, the position information of each point on the surface 1d of the positioning member 1 in the CT data 30 can be acquired from the CT data 30 as coordinate values ​​in the second coordinate system. Furthermore, the positioning member 1 has an isotropic spherical shape. Therefore, the first position information acquisition unit 14 can accurately acquire the position information (first position information 33) of the center point 2 of the positioning member 1 in the second coordinate system. Furthermore, the first position information acquisition unit 14 may acquire the position information of the first position information 33 of the positioning member 1 by another known method.

[0062] 13, the first position information acquisition unit 14 acquires the position coordinates (P1, Q1, R1) of the center point 2a in the second coordinate system as the first position information 33 of the positioning member 1a. The first position information acquisition unit 14 also acquires the position coordinates (P2, Q2, R2) of the center point 2b in the second coordinate system as the first position information 33 of the positioning member 1b. The first position information acquisition unit 14 also acquires the position coordinates (P3, Q3, R3) of the center point 2c in the second coordinate system as the first position information 33 of the positioning member 1c.

[0063] The first location information acquisition unit 14 outputs the acquired first location information 33 to the storage unit 20. That is, the first location information 33 is stored in the storage unit 20.

[0064] Obtaining relative position information 5, the relative position information acquisition unit 12 acquires the relative position information 32. Specifically, the relative position information acquisition unit 12 receives the relative position information 32 transmitted from the three-dimensional coordinate measuring device 300. The relative position information acquisition unit 12 outputs the received relative position information 32 to the storage unit 20. That is, the relative position information 32 is stored in the storage unit 20.

[0065] <Acquisition of second location information> Next, in step S7, the second position information acquisition unit 15 executes a process of acquiring the second position information 34. The process of acquiring the second position information 34 will be described in detail with reference to Fig. 14 and Fig. 15. The second position information 34 is position information of each center point 2 (see Fig. 8) of the positioning member 1 in the design data 31.

[0066] As shown in Figure 14, step S7 of acquiring second position information 34 includes step S7a of reading design data 31, step S7b of reading relative position information 32, and step S7c of acquiring position information of the positioning member 1 in the design data 31 based on the design data 31 and the relative position information 32.

[0067] In step S7a, the second position information acquiring unit 15 reads the design data 31 from the storage unit 20.

[0068] In step S7b, the second position information acquisition unit 15 reads the relative position information 32 from the storage unit 20.

[0069] In step S7c, the second position information acquiring unit 15 acquires the position information of each of the positioning members 1 based on the relative position information 32 and the design data 31.

[0070] 15, the second position information acquisition unit 15 acquires second position information 34, which is position information of the positioning member 1 in the design data 31, based on the actual measurement value of the position information 32a of the reference position 3 and the position information 32a of the reference position 3 in the design data 31. The design data 31 is data that indicates the three-dimensional shape of the subject 90 in a third coordinate system defined by the L axis, the M axis, and the N axis. In the example shown in FIG. 15, the positioning members 1a to 1c are illustrated with dashed lines for convenience, but the design data 31 does not include the positioning members 1a to 1c.

[0071] Here, the design data 31 does not include position information of the positioning member 1. On the other hand, the design data 31 includes position information of the reference position 3. Therefore, the second position information acquisition unit 15 can acquire the position coordinates (L0, M0, N0) of the reference position 3 in the design data 31 (third coordinate system) based on the design data 31.

[0072] The second position information acquisition unit 15 aligns the position coordinates (X0, Y0, Z0) of the reference position 3 in the first coordinate system with the position coordinates (L0, M0, N0) of the reference position 3 in the third coordinate system to acquire position information of the positioning member 1 in the design data 31. Specifically, the second position information acquisition unit 15 aligns the position coordinates (X0, Y0, Z0) of the reference position 3 in the first coordinate system with the position coordinates (L0, M0, N0) of the reference position 3 in the third coordinate system, and then acquires the position coordinates of each positioning member 1 in the third coordinate system based on the relationship between the position coordinates (X0, Y0, Z0) in the first coordinate system, which are actual measurement values ​​of the position information 32a of the reference position 3, and the position coordinates (X1, Y1, Z1), (X2, Y2, Z2), and (X3, Y3, Z3) of each positioning member 1. That is, the second position information acquisition unit 15 acquires the position coordinates of each positioning member 1 in the design data 31 by converting the position coordinates (X1, Y1, Z1), (X2, Y2, Z2), (X3, Y3, Z3) of each positioning member 1 into position coordinates in the third coordinate system.

[0073] Specifically, the second position information acquisition unit 15 acquires the distance in each axial direction from the reference position 3 to the positioning member 1a in the first coordinate system based on the position coordinates (X0, Y0, Z0) of the reference position 3 in the first coordinate system and the position coordinates (X1, Y1, Z1) of the positioning member 1a. That is, the second position information acquisition unit 15 acquires the distance in the X-axis direction from the reference position 3 to the positioning member 1a by subtracting the X-coordinate (X0) of the reference position 3 from the X-coordinate (X1) of the positioning member 1a. Similarly, the second position information acquisition unit 15 acquires the distance in the Y-axis direction and the distance in the Z-axis direction from the reference position 3 to the positioning member 1a by subtracting the Y-coordinate (Y1 - Y0) and the Z-coordinate (Z1 - Z0).

[0074] The second position information acquisition unit 15 converts the position coordinates (L1, M1, N1) of the positioning member 1a into position coordinates (L1, M1, N1) of the positioning member 1a by adding the distances in each axial direction of the positioning member 1a from the reference position 3 in the first coordinate system to the position coordinates (L0, M0, N0) of the reference position 3 in the third coordinate system. That is, the second position information acquisition unit 15 acquires the position coordinates (L1, M1, N1) of the positioning member 1a in the third coordinate system by adding (X1-X0, Y1-Y0, Z1-Z0) to the position coordinates (L0, M0, N0) of the reference position 3 in the third coordinate system.

[0075] The second position information acquisition unit 15 similarly acquires the position coordinates (X2, Y2, Z2) of the positioning member 1b in the first coordinate system and the position coordinates (L2, M2, N2) of the positioning member 1b in the third coordinate system. Furthermore, the second position information acquisition unit 15 similarly acquires the position coordinates (X3, Y3, Z3) of the positioning member 1b in the first coordinate system and the position coordinates (L3, M3, N3) of the positioning member 1c in the third coordinate system.

[0076] This allows the second position information acquisition unit 15 to acquire second position information 34, which is the position coordinates of each of the positioning members 1 in the third coordinate system. The second position information acquisition unit 15 outputs the acquired second position information 34 to the storage unit 20. That is, the second position information 34 is stored in the storage unit 20.

[0077] <Subject positioning> In step S8 of FIG. 5, the alignment unit 13 performs alignment processing between the object 90 in the CT data 30 and the object 90 in the design data 31. Reason( The above step (3) is executed. Details of the process in which the alignment unit 13 aligns the object 90 in the CT data 30 with the object 90 in the design data 31 will be described with reference to Figs.

[0078] As shown in FIG. 16, step S8 of aligning the subject 90 in the CT data 30 with the subject 90 in the design data 31 includes step S8a of reading first position information 33, step S8b of reading second position information 34, and step S8c of aligning the subject 90 in the CT data 30 with the subject 90 in the design data 31 based on the first position information 33 and the second position information 34.

[0079] In step S8a, the first location information acquisition unit 14 reads the first location information 33 from the storage unit 20.

[0080] In step S8b, the first location information acquisition unit 14 reads the second location information 34 from the storage unit 20. Note that either the process of step S8a or the process of step S8b may be executed first.

[0081] In step S8c, the alignment unit 13 aligns the object 90 in the CT data 30 with the object 90 in the design data 31 based on the first position information 33 and the second position information .

[0082] Specifically, as shown in FIG. 17, the alignment unit 13 aligns the position of the subject 90 in the CT data 30 with the position of the subject 90 in the design data 31 by aligning the position in each piece of first position information 33 with the position in each piece of second position information 34 corresponding to the first position information 33.

[0083] That is, the alignment unit 13 aligns the position coordinates (P1, Q1, R1) of the center point 2a in the CT data 30 with the position coordinates (L1, M1, N1) of the center point 2a in the design data 31. Furthermore, the alignment unit 13 aligns the position coordinates (P2, Q2, R2) of the center point 2b in the CT data 30 with the position coordinates (L2, M2, N2) of the center point 2b in the design data 31. Furthermore, the alignment unit 13 aligns the position coordinates (P3, Q3, R3) of the center point 2c in the CT data 30 with the position coordinates (L3, M3, N3) of the center point 2c in the design data 31. In this way, the alignment unit 13 aligns the position and posture of the object 90 in the CT data 30 with those of the object 90 in the design data 31.

[0084] That is, in this embodiment, the alignment unit 13 acquires a transformation matrix by aligning each center point 2, and aligns the object 90 in the CT data 30 with the object 90 in the design data 31 by converting the coordinates of each point of the object 90 in the CT data 30 based on the acquired transformation matrix. Note that the alignment unit 13 may be configured to align the object 90 in the CT data 30 with the object 90 in the design data 31 by converting each point of the design data 31 based on the acquired transformation matrix.

[0085] This completes the method for aligning three-dimensional shapes performed by the three-dimensional shape data processing apparatus 100 of this embodiment.

[0086] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0087] In this embodiment, as described above, the method for aligning three-dimensional shapes includes the steps of acquiring three-dimensional CT data 30 of the subject 90 and the positioning members 1 obtained by X-ray CT imaging of at least three positioning members 1 together with the subject 90, measuring the relative position between the subject 90 and each of the positioning members 1, and aligning the subject 90 in the CT data 30 with the subject 90 in the design data 31 based on the CT data 30, three-dimensional design data 31 of the subject 90, and relative position information 32.

[0088] This makes it possible to acquire position information of the positioning member 1 in the design data 31 based on the design data 31 and the relative position information 32. Therefore, when aligning the subject 90 in the CT data 30 with the subject 90 in the design data 31, the position of the positioning member 1 in the CT data 30 is aligned with the positioning member 1 in the design data 31, thereby enabling alignment of the subject 90 in each piece of data. Therefore, for example, by using a positioning member 1 having a shape that allows the shape to be accurately acquired in the CT data 30, it is possible to align the subject 90 in the CT data 30 with the subject 90 in the design data 31 without depending on the shape of the subject 90. As a result, it is possible to accurately align the position of the subject 90 in the CT data 30 with the position of the subject 90 in the design data 31 without depending on the shape of the subject 90.

[0089] Furthermore, in this embodiment, as described above, the three-dimensional shape data processing device 100 includes a data acquisition unit 11 that acquires three-dimensional CT data 30 of the subject 90 and the positioning members 1 obtained by X-ray CT imaging of at least three positioning members 1 together with the subject 90, a relative position information acquisition unit 12 that acquires information 32 on the relative position between the subject 90 and each of the positioning members 1, and an alignment unit 13 that aligns the subject 90 in the CT data 30 with the subject 90 in the design data 31 based on the CT data 30, three-dimensional design data 31 of the subject 90, and the relative position information 32.

[0090] This makes it possible to provide a three-dimensional shape data processing device 100 that can accurately align the subject 90 in the CT data 30 with the subject 90 in the design data 31, similar to the above-mentioned three-dimensional shape alignment method, without depending on the shape of the subject 90.

[0091] Furthermore, in the above embodiment, the following additional effects can be obtained by configuring as follows.

[0092] That is, in this embodiment, as described above, the positioning member 1 has an isotropic shape, and the method further includes a step of acquiring first position information 33, which is position information of the positioning member 1 in the CT data 30, based on the isotropic shape of the positioning member 1 in the CT data 30. Here, when acquiring the CT data 30, if the positioning member 1 has an isotropic shape, the difference in the path length of X-rays passing through the positioning member 1 for each imaging angle when imaging while rotating the positioning member 1 is reduced. If the difference in the path length of X-rays for each imaging angle is small, the difference in the detected intensity of X-rays due to the path length of X-rays for each imaging angle is reduced. In other words, it is possible to suppress a decrease in the accuracy of the shape of the positioning member 1 due to the difference in detected intensity of X-rays caused by the difference in path length. Therefore, with the above configuration, the shape of the positioning member 1 is isotropic, and therefore the shape of the positioning member 1 in the CT data 30 can be acquired with high accuracy. As a result, the first position information 33 obtained based on the shape of the positioning member 1 can be obtained with high accuracy, thereby improving the accuracy of alignment between the subject 90 in the CT data 30 and the subject 90 in the design data 31.

[0093] Furthermore, in this embodiment, as described above, the positioning member 1 has a spherical shape as an isotropic shape, and in the step of acquiring the first position information 33, the first position information 33 is acquired based on position information of the surface 1d of the spherical positioning member 1 in the CT data 30. Here, when acquiring the CT data 30 of the positioning member 1 having a spherical shape, there is no difference in the path length of the X-rays depending on the imaging angle. Therefore, the shape of the positioning member 1 can be acquired more accurately in the CT data 30. Therefore, by acquiring the first position information 33 based on position information of the surface 1d of the positioning member 1 having a spherical shape as described above, the accuracy of the first position information 33 can be further improved. As a result, the accuracy of alignment between the object 90 in the CT data 30 and the object 90 in the design data 31 can be further improved.

[0094] Furthermore, in this embodiment, as described above, the relative position information 32 includes position information 32a of the reference position 3 set for the subject 90 and position information 32b of each of the positioning members 1. The method further includes a step of acquiring second position information 34, which is position information of the positioning member 1 in the design data 31, based on the actual measurement value of the position information 32a of the reference position 3 and the position information 32a of the reference position 3 in the design data 31. In the alignment step, the subject 90 in the CT data 30 is aligned with the subject 90 in the design data 31 based on the first position information 33 and the second position information 34. Here, the CT data 30 and the design data 31 are data in different coordinate systems. However, the relative positions of each of the positioning members 1 in the first position information 33 and the relative positions of each of the positioning members 1 in the second position information 34 are equal to each other. Therefore, the first position information 33 and the second position information 34 can be used to align the subject 90 in the CT data 30, which are data having different coordinate systems, with the subject 90 in the design data 31. Therefore, with the above configuration, by acquiring the first position information 33 and the second position information 34, the subject 90 in the CT data 30 can be easily aligned with the subject 90 in the design data 31.

[0095] Furthermore, in this embodiment, as described above, in the step of performing alignment, the position in each piece of first position information 33 is aligned with the position in each piece of second position information 34 corresponding to the first position information 33, thereby aligning the position of the subject 90 in the CT data 30 with the position of the subject 90 in the design data 31. As a result, at least three positioning members 1 are positioned, and therefore, using the first position information 33 and each piece of second position information 34 corresponding to the first position information 33, not only the positions of the subject 90 in the CT data 30 and the subject 90 in the design data 31 but also the postures of the subject 90 in the CT data 30 and the subject 90 in the design data 31 can be aligned.

[0096] Furthermore, in this embodiment, as described above, the first position information 33 is position information of the center point 2 of each of the positioning members 1 in the CT data 30, and the second position information 34 is position information of the center point 2 of each of the positioning members 1 in the design data 31. As a result, unlike a configuration in which position information of an arbitrary point in the positioning member 1 is acquired as the first position information 33 and the second position information 34, position information of the center point 2 of the positioning member 1, which is a unique point, is acquired, so that the position information of each of the positioning members 1 can be acquired easily and accurately.

[0097] Furthermore, in this embodiment, as described above, in the step of measuring the relative position, the relative position is measured by bringing the probe 310 into contact with each of the subject 90 and the positioning member 1. This makes it possible to accurately obtain information 32 about the relative position between each of the subject 90 and the positioning member 1 by the contact-type three-dimensional coordinate measuring device 300, which obtains position information about the subject 90 by contacting the probe 310.

[0098] Furthermore, in this embodiment, as described above, the reference position 3 is the center position of the circular hole 91b provided in the surface (first surface 91a) of the object 90, which is located on the same plane as the surface (first surface 91a). As a result, of the centers of the circular hole 91b that can be obtained with high accuracy by the three-dimensional coordinate measuring device 300, the center that is located on the same plane as the surface (first surface 91a) of the object 90 is obtained as the reference position 3, so that the position of the positioning member 1 can be obtained with high accuracy in the design data 31. As a result, the accuracy of alignment between the object 90 in the CT data 30 and the object 90 in the design data 31 can be improved.

[0099] In this embodiment, as described above, each of the positioning members 1 has its center position on a straight line. 4 When connecting (lines 4a, 4b, and 4c), the line 4The positioning members 1 are arranged at a position where a plane 50 is formed by the lines 4a, 4b, and 4c. This differs from an arrangement in which the positioning members 1 are arranged in a straight line, and when aligning the position of the subject 90 in the CT data 30 with the position of the subject 90 in the design data 31 based on the positioning members 1, it is possible to align not only the position of the subject 90 but also the posture of the subject 90. As a result, it is possible to easily align the position and posture of the subject 90 in the CT data 30 with the position and posture of the subject 90 in the design data 31.

[0100] Furthermore, as described above, this embodiment further includes a step of arranging at least one of the positioning members 1 at a position close to one of the longitudinal end 91e and the longitudinal center 92 of the subject 90, and arranging at least one of the positioning members 1 at a position close to the other of the longitudinal end 91f and the longitudinal center 92. Unlike the subject 90, position information on the center points 2 of the positioning members 1 can be obtained with high accuracy. Therefore, the plane 50 formed by connecting the center points 2 of the positioning members 1 with the straight lines 4 can also be obtained with high accuracy. In other words, by performing alignment based on the position information of the center points 2 obtained with high accuracy, it is possible to accurately align each point included in the plane 50. Therefore, with the above configuration, the distance between at least two of the positioning members 1 can be increased compared to a configuration in which at least two of the positioning members 1 are disposed at a position closer to one end 91e or closer to the other end 91f of the longitudinal center 92 of the subject 90. Therefore, the size (area) of the plane 50 formed by connecting the center positions (center points 2) of the positioning members 1 with the straight line 4 can be easily increased. As a result, the area of ​​the plane 50 that can be obtained with high accuracy can be easily increased, and the accuracy of alignment by the positioning members 1 can be easily improved accordingly.

[0101] Furthermore, in this embodiment, as described above, in the step of arranging the positioning members 1, at least two positioning members 1 are arranged on different surfaces of the subject 90. This allows the distance between at least two of the positioning members 1 to be increased compared to a configuration in which at least two positioning members 1 are arranged on the same surface of the subject 90. Therefore, the size (area) of the plane 50 formed by connecting the center positions (center points 2) of the positioning members 1 with the straight line 4 can be more easily increased. As a result, the area of ​​the plane 50 that can be obtained with high accuracy can be more easily increased, and the accuracy of alignment by the positioning members 1 can be more easily improved accordingly.

[0102] Furthermore, in this embodiment, as described above, the positioning member 1 is formed of a material having the same or similar X-ray transmittance as the subject 90. Here, if the X-ray transmittance of the positioning member 1 is greater than that of the subject 90, the pixel value of the positioning member 1 in the CT data 30 will be greater than the pixel value of the subject 90. In this case, artifacts may occur due to the large pixel value of the positioning member 1 in the CT data 30. If artifacts occur, it may be difficult to grasp the shape of the subject 90 in the CT data 30. Therefore, by using the positioning member 1 formed of a material having the same or similar X-ray transmittance as the subject 90, as described above, it is possible to suppress the occurrence of artifacts in the CT data 30. As a result, it is possible to suppress the difficulty in grasping the shape of the subject 90 in the CT data 30 due to artifacts.

[0103] Furthermore, as described above, this embodiment further includes a step of fixing each of the positioning members 1 to the subject 90 while in contact with the subject 90. As a result, since the positioning members 1 are fixed to the subject 90 while in contact with the subject 90, it is possible to prevent the relative positions of the positioning members 1 from changing when the CT data 30 and the relative position information 32 are acquired.

[0104] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0105] For example, in the above embodiment, an example of a configuration in which the positioning member 1 is fixed to the subject 90 while in contact with the subject 90 has been shown, but the present invention is not limited to this. For example, as in a first modified example shown in FIG. 18, the positioning member 1 may be fixed to the subject 90 via a jig 5. Specifically, each of the positioning members 1 may be fixed to the subject 90 via a fixing jig 5. In this case, in the process of step S1b in which the positioning member 1 is fixed to the subject 90 in the above embodiment, the jig 5 to which the positioning member 1 is fixed may be fixed to the subject 90. This makes it possible to, for example, fix the positioning member 1 of Even when it is difficult to fix the positioning member 1 in contact with the subject 90, the positioning member 1 can be fixed to the subject 90 via the jig 5. As a result, it is possible to increase the degree of freedom in selecting the positioning member 1, thereby improving convenience for the operator. Note that the jig 5 is preferably made of a highly rigid material so that the relative position between the subject 90 and the positioning member 1 does not change when X-ray CT imaging is performed. The jig 5 is preferably made of, for example, a resin material or a metal material.

[0106] 19, at least three positioning members 1 may be provided on the inner circumferential surface of a box-shaped jig 5a, and the object 90 may be fixed inside the box-shaped jig 5a, thereby fixing the positioning members 1 and the object 90. As shown in the second modification, if the jig 5a has a box-like shape, it is difficult for the probe 310 of the three-dimensional coordinate measuring device 300 to come into contact with the positioning members 1. Therefore, if the jig 5a has a box-like shape, the relative position information 32 may be acquired using a non-contact three-dimensional coordinate measuring device. Alternatively, the positioning members 1 may be fixed to the object 90 using a jig (not shown) that has a frame-like shape instead of a box-like shape. In this case, since the jig has a frame-like shape, the relative position information 32 can be acquired using a contact three-dimensional coordinate measuring device 300.

[0107] Furthermore, in the above embodiment, an example of a configuration in which the alignment unit 13 aligns the object 90, which is a single part, has been described. However, the present invention is not limited to this. For example, as in a third modified example shown in FIG. 20 , the alignment unit 13 may be configured to align the object 90, which is a combination of a first part 90c and a second part 90d. When the object 90 is composed of multiple parts, i.e., the first part 90c and the second part 90d, as in the third modified example, in step S4 of acquiring CT data 30, the CT data 30 may be acquired with at least three positioning members 1 disposed for each part (the first part 90c, the second part 90d). Thus, at least three positioning members 1 are provided for each of the first part 90c and the second part 90d. By using the positioning members 1 to align the object 90 in the CT data 30 with the object 90 in the design data 31, not only the manufacturing accuracy of each of the first part 90c and the second part 90d but also the assembly accuracy can be verified.

[0108] In the above embodiment, the positioning member 1 has an isotropic shape that is spherical, but the present invention is not limited to this. For example, the positioning member 1 may have an isotropic shape that is cubic. Furthermore, the positioning member 1 may have an isotropic shape that is formed by providing a concave spherical surface on a cube or rectangular parallelepiped.

[0109] Furthermore, in the above embodiment, an example of a configuration in which the positioning member 1 has an isotropic shape has been described, but the present invention is not limited to this. For example, the positioning member 1 does not have to have an isotropic shape. However, if the positioning member 1 does not have an isotropic shape, the difference in the path length through which X-rays pass increases depending on the imaging angle during X-ray CT imaging, making it difficult to accurately obtain the shape of the positioning member 1. In this case, it becomes difficult to accurately obtain position information (first position information 33) of the positioning member 1 in the CT data 30. As a result, the accuracy of alignment between the subject 90 in the CT data 30 and the subject 90 in the design data 31 decreases. Therefore, it is preferable that the positioning member 1 have an isotropic shape.

[0110] In the above embodiment, the first position information 33 is the center point 2 of the positioning member 1 in the CT data 30, and the second position information 34 is the center point 2 of the positioning member 1 in the design data 31. However, the present invention is not limited to this. For example, the first position information 33 may be the position information of a point other than the center point 2 of the positioning member 1 in the CT data 30. Furthermore, the second position information 34 may be the position information of a point other than the center point 2 of the positioning member 1 in the design data 31. However, if the first position information 33 is the position information of a point other than the center point 2 of the positioning member 1 in the CT data 30, and the second position information 34 is the position information of a point other than the center point 2 of the positioning member 1 in the design data 31, alignment using the first position information 33 and the second position information 34 becomes complicated. Therefore, it is preferable that the first position information 33 is the center point 2 of the positioning member 1 in the CT data 30, and the second position information 34 is the center point 2 of the positioning member 1 in the design data 31.

[0111] In the above embodiment, an example has been shown in which a contact-type three-dimensional coordinate measuring device 300 is used to acquire relative position information 32, but the present invention is not limited to this. For example, a non-contact-type three-dimensional coordinate measuring device may be used to acquire relative position information 32. As long as it is possible to acquire relative position information 32 with high accuracy, the device and method for acquiring relative position information 32 are not important.

[0112] In the above embodiment, at least one of the positioning members 1 is disposed at a position closer to one of the longitudinal end 91e and the longitudinal center 92 of the object 90, and at least one of the positioning members 1 is disposed at a position closer to the other of the longitudinal end 91f and the longitudinal center 92, but the present invention is not limited to this. For example, the positioning member 1 may be disposed at a position closer to the longitudinal center 92 of the object 90. However, when the positioning member 1 is disposed at a position closer to the longitudinal center 92 of the object 90, the size (area) of the plane 50 becomes smaller. In this case, the accuracy of alignment between the object 90 in the CT data 30 and the object 90 in the design data 31 decreases. Therefore, it is preferable to position at least one of the positioning members 1 at a position close to one of the longitudinal end portions 91e of the subject 90 and the longitudinal center 92, and to position at least one of the other positioning members 1 at a position close to the other of the longitudinal end portions 91f and the longitudinal center 92.

[0113] Furthermore, in the above embodiment, an example of a configuration in which at least two of the positioning members 1 are arranged on different surfaces (first surface 91a and second surface 91c) of the subject 90 has been shown, but the present invention is not limited to this. For example, at least two of the positioning members 1 may be arranged on the same surface of the subject 90. In this case, it is preferable to arrange at least two of the positioning members 1 at positions as far apart as possible so as not to reduce the size (area) of the plane 50.

[0114] Furthermore, in the above embodiment, an example was shown in which the positioning member 1 is made of a material having the same or similar X-ray transmittance as the subject 90, but the present invention is not limited to this. For example, the positioning member 1 may be made of a material having a lower X-ray transmittance than the subject 90. However, if the X-ray transmittance of the positioning member 1 is lower than the X-ray transmittance of the subject 90, artifacts may occur near the positioning member 1 in the CT data 30. In this case, it may be difficult to grasp the shape of the subject 90 in the CT data 30. Therefore, it is preferable that the positioning member 1 be made of a material having the same or similar X-ray transmittance as the subject 90.

[0115] In the above embodiment, the three-dimensional shape data processing device 100 is a so-called personal computer, and is configured separately from the X-ray CT imaging device 200. However, the present invention is not limited to this. For example, the control unit 230 of the X-ray CT imaging device 200 may be configured to execute the three-dimensional shape alignment method in the above embodiment.

[0116] In the above embodiment, an example was shown in which a single processor 10 executes all data processing (processing as the data acquisition unit 11, relative position information acquisition unit 12, alignment unit 13, first position information acquisition unit 14, and second position information acquisition unit 15), but the present invention is not limited to this. All processing in the three-dimensional shape alignment method does not have to be executed by the three-dimensional shape data processing device 100. That is, the processing of step S1 in the above embodiment may be executed manually. Also, part of step S2 of performing X-ray CT imaging and part of step S3 of measuring the relative position may include steps involving manual intervention. Also, the processing of aligning the object 90 in the CT data 30 with the object 90 in the design data 31 may be shared and executed by multiple processors. Each processing step may be executed by a separate processor. The multiple processors may be provided in separate computers. That is, the three-dimensional shape data processing device 100 may be configured with multiple computers that perform data processing.

[0117] [Aspect] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0118] (Item 1) acquiring three-dimensional CT data of the object and the positioning members by performing X-ray CT imaging of at least three positioning members together with the object; measuring a relative position between the object and each of the positioning members; and aligning the object in the CT data with the object in the design data based on the CT data, three-dimensional design data of the object, and information on the relative position.

[0119] (Item 2) the positioning member has an isotropic shape; Item 1. A three-dimensional shape alignment method, further comprising a step of acquiring first position information, which is position information of the positioning member in the CT data, based on the isotropic shape of the positioning member in the CT data.

[0120] (Item 3) the positioning member has a spherical shape as the isotropic shape, 3. The method for aligning a three-dimensional shape according to item 2, wherein in the step of acquiring the first position information, the first position information is acquired based on position information of the surface of the spherical positioning member in the CT data.

[0121] (Item 4) the information on the relative positions includes position information of a reference position set on the subject and position information of each of the positioning members; acquiring second position information, which is position information of the positioning member in the design data, based on an actual measurement value of position information of the reference position and the position information of the reference position in the design data; 4. The method for aligning a three-dimensional shape according to item 2 or 3, wherein in the step of performing alignment, alignment is performed between the subject in the CT data and the subject in the design data based on the first position information and the second position information.

[0122] (Item 5) 5. The method for aligning a three-dimensional shape according to item 4, wherein in the step of performing alignment, the object in the CT data is aligned with the object in the design data by aligning a position in each piece of first position information with a position in each piece of second position information corresponding to the first position information.

[0123] (Item 6) the first position information is position information of a center point of each of the positioning members in the CT data, 6. The method for aligning a three-dimensional shape according to item 4 or 5, wherein the second position information is position information of the center point of each of the positioning members in the design data.

[0124] (Item 7) 7. The method for aligning a three-dimensional shape according to item 6, wherein in the step of measuring the relative position, the measurement of the relative position is performed by bringing a probe into contact with each of the object and the positioning member.

[0125] (Item 8) 8. The method for aligning a three-dimensional shape according to any one of items 4 to 7, wherein the reference position is a center position of a circular hole provided on the surface of the subject, the center position being located on the same plane as the surface.

[0126] (Item 9) 9. The method for aligning a three-dimensional shape according to any one of items 1 to 8, wherein each of the positioning members is disposed at a position such that when a line is drawn between the center positions of the positioning members, a plane is formed by the line.

[0127] (Item 10) Item 10. The method for aligning a three-dimensional shape according to Item 9, further comprising the step of: arranging at least one of the positioning members at a position close to one of the longitudinal end portions of the subject and the longitudinal center, and arranging at least one of the other positioning members at a position close to the other of the longitudinal end portions and the longitudinal center.

[0128] (Item 11) Item 11. The method for aligning a three-dimensional shape according to Item 10, wherein in the step of arranging the positioning members, at least two of the positioning members are arranged on different surfaces of the subject.

[0129] (Item 12) 12. The method for aligning a three-dimensional shape according to any one of items 1 to 11, wherein the positioning member is made of a material having the same or similar X-ray transmittance as the subject.

[0130] (Item 13) 13. The method for aligning a three-dimensional shape according to any one of items 1 to 12, further comprising the step of fixing each of the positioning members to the subject while in contact with the subject.

[0131] (Item 14) Each of the positioning members is fixed by a fixture. Ingredients 14. The method for aligning a three-dimensional shape according to any one of items 1 to 13, further comprising the step of fixing the object to the object via a lens.

[0132] (Item 15) 15. The method for aligning a three-dimensional shape according to any one of items 1 to 14, wherein, in the step of acquiring the CT data, if the subject is composed of a plurality of parts, the CT data is acquired in a state where at least three of the positioning members are arranged for each part.

[0133] (Item 16) a data acquisition unit that acquires three-dimensional CT data of the subject and the positioning members, the three-dimensional CT data being acquired by performing X-ray CT imaging of at least three positioning members together with the subject; a relative position information acquisition unit that acquires information about the relative positions between the subject and each of the positioning members; a positioning unit that aligns the object in the CT data with the object in the design data based on the CT data, three-dimensional design data of the object, and information on the relative position. [Explanation of symbols]

[0134] 1, 1a, 1b, 1c Positioning members 2, 2a, 2b, 2c Center point of positioning member 3 Reference position 4, 4a, 4b, 4c Straight lines (lines connecting the center positions of the positioning members) 5, 5a Jig 11 Data Acquisition Section 12 Relative position information acquisition unit 13 Alignment section 14 1st location information acquisition unit 15 Second location information acquisition unit 30 CT data 31 Design Data 32 Relative position information 32a Location information of reference position 32b Position information of positioning member 33 1st location information 34 Second location information 50 plane (plane formed by connecting the center positions of each positioning member with a straight line) 90 Subject 90c, 90d multiple parts 91a Surface of the subject 91b Circular hole on the surface of the subject 91e One end of the subject in the longitudinal direction 91f The other longitudinal end of the subject 92 Longitudinal center of subject 100 3D shape data processing device 300 3D coordinate measuring device 310 Probe

Claims

1. acquiring three-dimensional CT data of the subject and the positioning members by performing X-ray CT imaging of at least three positioning members together with the subject; measuring a relative position between the object and each of the positioning members; and aligning the subject in the CT data with the subject in the design data using position information of the positioning member in the acquired CT data and position information of the positioning member in three-dimensional design data of the subject that is based on information of the measured relative position.

2. the positioning member has an isotropic shape, The method for aligning a three-dimensional shape according to claim 1 , further comprising the step of acquiring first position information, which is position information of the positioning member in the CT data, based on the isotropic shape of the positioning member in the CT data.

3. The positioning member has a spherical shape as the isotropic shape, 3. The method for aligning a three-dimensional shape according to claim 2, wherein in the step of acquiring the first position information, the first position information is acquired based on position information of a surface of the spherical positioning member in the CT data.

4. the information on the relative positions includes position information of a reference position set on the subject and position information of each of the positioning members; acquiring second position information, which is position information of the positioning member in the design data, based on an actual measurement value of position information of the reference position and the position information of the reference position in the design data; 4. The method for aligning a three-dimensional shape according to claim 2 or 3, wherein in the step of performing alignment, alignment is performed between the subject in the CT data and the subject in the design data based on the first position information and the second position information.

5. 5. The method for aligning a three-dimensional shape according to claim 4, wherein in the step of performing alignment, alignment between the subject in the CT data and the subject in the design data is performed by matching a position in each of the first positional information with a position in each of the second positional information corresponding to the first positional information.

6. the first position information is position information of a center point of each of the positioning members in the CT data; The method for aligning a three-dimensional shape according to claim 4 , wherein the second position information is position information of a center point of each of the positioning members in the design data.

7. 7. The method for aligning a three-dimensional shape according to claim 6, wherein in the step of measuring the relative position, the measurement of the relative position is performed by contacting a probe with each of the subject and the positioning member.

8. The method for aligning a three-dimensional shape according to any one of claims 4 to 7, wherein the reference position is a center position of a circular hole provided in the surface of the subject, the center position being located on the same plane as the surface.

9. The method for aligning a three-dimensional shape according to any one of claims 1 to 8, wherein each of the positioning members is disposed at a position such that, when a straight line is drawn through the respective center positions of the positioning members, a plane is formed by the straight line.

10. 10. The method for aligning a three-dimensional shape according to claim 9, further comprising the step of: positioning at least one of the positioning members at a position between one end of the subject in the longitudinal direction and the center of the longitudinal direction, and positioning at least one of the positioning members at a position between the other end of the subject in the longitudinal direction and the center of the longitudinal direction, and closer to the other end of the subject in the longitudinal direction.

11. The method for aligning a three-dimensional shape according to claim 10 , wherein in the step of arranging the positioning members, at least two of the positioning members are arranged on different surfaces of the subject.

12. 12. The method for aligning a three-dimensional shape according to claim 1, wherein the positioning member is made of a material having an X-ray transmittance that is the same as or similar to that of the subject.

13. The method for aligning a three-dimensional shape according to any one of claims 1 to 12, further comprising the step of fixing each of the positioning members to the subject while in contact with the subject.

14. The method for aligning a three-dimensional shape according to any one of claims 1 to 13, further comprising the step of fixing each of the positioning members to the subject via a fixing jig.

15. The method for aligning a three-dimensional shape according to any one of claims 1 to 14, wherein, in the step of acquiring the CT data, when the subject is composed of a plurality of parts, the CT data is acquired with at least three of the positioning members arranged for each part.

16. a data acquisition unit that acquires three-dimensional CT data of the subject and the positioning members by performing X-ray CT imaging of at least three positioning members together with the subject; a relative position information acquisition unit that acquires information on the measured relative positions between the subject and each of the positioning members; a positioning unit that aligns the subject in the CT data with the subject in the design data using position information of the positioning member in the acquired CT data and position information of the positioning member in three-dimensional design data of the subject based on information on the measured relative position.

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