WO2016020966A1

WO2016020966A1 - Detection method, shape measurement method, shape measurement device, structure production method, structure production system, and shape measurement program

Info

Publication number: WO2016020966A1
Application number: PCT/JP2014/070460
Authority: WO
Inventors: 鈴木　康夫
Original assignee: 株式会社ニコン
Priority date: 2014-08-04
Filing date: 2014-08-04
Publication date: 2016-02-11

Abstract

[Problem] To accurately detect measurement error and accurately measure the three-dimensional shape of an object to be measured. [Solution] A detection method for detecting the displacement of a measurement instrument for measuring the shape of an object to be measured relative to the object to be measured wherein: the measurement instrument photographs a first reference image of the object to be measured and a second reference image of the object to be measured; at the same time as or after the photographing of the first reference image and before the photographing of the second reference image, the measurement instrument photographs an image of the object to be measured having structured light for shape measurement projected thereon by the measurement instrument; a feature area is detected from both the first reference image and second reference image; and relative displacement between the object to be measured and the measurement instrument is detected on the basis of the feature area in the first reference image and the feature area in the second reference image.

Description

Detection method, shape measuring method, shape measuring device, structure manufacturing method, structure manufacturing system, and shape measuring program

The present invention relates to a detection method, a shape measuring method, a shape measuring device, a structure manufacturing method, a structure manufacturing system, and a shape measuring program.

The phase shift method is known as a method for measuring the three-dimensional shape of the measurement object. A shape measuring apparatus using the phase shift method includes a projection unit, an imaging unit, and a control unit. This projection unit projects a striped pattern light having a sinusoidal light intensity distribution (hereinafter referred to as structured light) onto a measurement object. At this time, the phase of the stripe of structured light (in other words, the sine wave that is the intensity distribution of the structured light) is shifted four times, for example, by π / 2 over one period (2π), and the phase of the stripe is 0, π / 2. , Π, and 3π / 2 are projected. The imaging unit images the object from different angles with respect to the projection unit, and the projection unit, the measurement object, and the imaging unit are arranged so as to have a triangulation positional relationship. When the four types of structured light having different phases are projected onto the measurement object, the imaging unit images the measurement object and acquires four images. The control unit applies data relating to the signal intensity of each pixel in the four images captured by the imaging unit to a predetermined arithmetic expression, and obtains the phase value of the fringes at each pixel according to the surface shape of the measurement target. And a calculating part calculates the three-dimensional coordinate data of a measuring object from the phase value of the fringe in each pixel using the principle of triangulation. An apparatus using this phase shift method is disclosed in Patent Document 1, for example.

US Pat. No. 5,450,204

However, in the shape measuring apparatus described above, a plurality of types of structured light are projected onto the measurement object, and the measurement object and the shape measurement apparatus are relatively moved during a series of operations in which each measurement object is imaged. There is a possibility of moving and blurring. In this case, the accuracy of the calculated three-dimensional coordinate data is lowered.

In view of the circumstances as described above, it is an object of the present invention to accurately detect a relative shake between a measurement object and a shape measuring device and accurately measure the three-dimensional shape of the measurement object.

According to the first aspect of the present invention, in the detection method for detecting the relative shake between the measuring instrument that measures the shape of the measuring object and the measuring object, the first reference image of the measuring object is used as the measuring instrument. , Taking a second reference image of the measurement object with a measuring machine, simultaneously with or after taking the first reference image, and before taking the second reference image Taking an image of the measuring object obtained by projecting the structured light for shape measurement from the measuring machine to the measuring object, detecting a feature region from the first reference image, and a second reference image Detecting a feature region from the detection region, detecting a relative shake between the measurement object and the measuring device based on the feature region in the first reference image and the feature region in the second reference image; A detection method is provided.

According to the second aspect of the present invention, the measuring object is obtained by capturing an image of the measuring object obtained by projecting the structural light for shape measurement from the measuring instrument onto the measuring object, and the detection method of the first aspect. A shape measurement method is provided that includes detecting a relative shake between an object and a measuring device, and calculating a shape of the measurement object based on an image and the shake of the measurement object. .

According to the third aspect of the present invention, there is provided a shape measuring apparatus for measuring the shape of the measurement object, the projection unit projecting at least the structural light for shape measurement onto the measurement object, and the image of the measurement object. An imaging unit that captures the image and a first reference image of the measurement object are imaged by the imaging unit, and a second reference image of the measurement object is imaged by the imaging unit, and at the same time as or imaging of the first reference image Control that causes the imaging unit to capture an image of the measurement object on which the structured light is projected by projecting the structural light for shape measurement from the projection unit onto the measurement object later and before the imaging of the second reference image And a feature region from the first reference image, a feature region from the second reference image, and a feature region in the first reference image and a feature region in the second reference image, Detects relative shake between the measurement object and the measuring machine, and based on the image and shake of the measurement object Shape measuring apparatus and a calculator for calculating the shape of the measuring object is provided.

According to the fourth aspect of the present invention, the design apparatus for producing the design information related to the shape of the structure, the molding apparatus for producing the structure based on the design information, and the third for measuring the shape of the produced structure. There is provided a structure manufacturing system including a shape measuring apparatus according to an aspect, and an inspection apparatus that compares design information with shape information related to the shape of the structure obtained by the shape measuring apparatus.

According to the fifth aspect of the present invention, the design information relating to the shape of the structure is produced, the structure is produced based on the design information, and the shape of the produced structure is measured. There is provided a structure manufacturing method including a shape measuring method, and comparing shape information related to the shape of the structure obtained by the shape measuring method with design information.

According to the sixth aspect of the present invention, the computer included in the shape measuring apparatus that measures the shape of the measurement object by capturing an image of the measurement object obtained by projecting the structured light for shape measurement onto the measurement object is measured by the computer. The process of capturing the first reference image of the object, the process of capturing the second reference image of the measurement object, the imaging of the first reference image, or simultaneously with or after the imaging of the second reference image Prior to imaging, processing for capturing an image of a measurement object obtained by projecting structured light for shape measurement onto the measurement object, processing for detecting a feature region from the first reference image, and from the second reference image A process for detecting a feature region, a process for detecting a relative shake between the measurement object and the shape measuring device based on the feature region in the first reference image and the feature region in the second reference image; Processing to calculate the shape of the measurement object based on the image and blur of the measurement object; Shape measuring program for causing the execution is provided.

According to the aspect of the present invention, it is possible to accurately detect the relative shake between the measurement object and the shape measuring device, and to accurately measure the three-dimensional shape of the measurement object.

It is a figure which shows an example of the shape measuring apparatus which concerns on 1st Embodiment. It is a block diagram which shows an example of a detailed structure of the shape measuring apparatus shown in FIG. It is a figure which shows intensity distribution of structured light and reference light in a projection area | region. It is a figure which shows the relationship between a projection area | region and an imaging area. It is a figure which shows the state by which the fringe pattern of each phase was projected on the plane without a measuring object. It is a figure which shows typically about blurring. It is a flowchart explaining an example of a detection method and a shape measuring method, explaining operation | movement of a shape measuring apparatus. It is a figure which shows typically the image imaged in the detection method which concerns on 1st Embodiment along process order. It is a figure which shows typically about the correction method. It is a figure which shows intensity distribution of a space code pattern. It is a figure which shows typically the image imaged in the detection method which concerns on 2nd Embodiment along process order. It is a figure which shows typically the image imaged in the detection method which concerns on a modification along process order. It is a figure which shows typically the image imaged in the detection method which concerns on a modification along process order. It is a figure which shows an example of the shape measuring apparatus which concerns on a modification. It is a block diagram which shows an example of embodiment of a structure manufacturing system. It is a flowchart which shows an example of embodiment of a structure manufacturing method.

<First Embodiment>
FIG. 1 is a diagram illustrating an example of a shape measuring apparatus according to the first embodiment. In FIG. 1, the right direction of the drawing is the X1 axis, a certain direction orthogonal to the X1 axis is the Y1 axis, and a direction orthogonal to the X1 axis and the Y1 axis is the Z1 axis. The shape measuring device 1 is a device that measures the three-dimensional shape of the measuring object 2 using the phase shift method. As shown in FIG. 1, the shape measuring apparatus 1 includes a projection unit 10, an imaging unit 50, an arithmetic processing unit 60, a display device 70, and a housing 80. The shape measuring device 1 is configured to be housed in a case 80 in which the projection unit 10, the imaging unit 50, the arithmetic processing unit 60, and the display device 70 can be carried.

The projection unit 10 generates projection light 100 along the first direction D1 (X1 axis direction in FIG. 1). Then, the projection unit 10 scans the generated projection light 100 along the second direction D2 (the Y1 axis direction in FIG. 1) different from the first direction, so that the structured light 101 is applied to the projection region 200. And the reference beam 102 is projected. The structured light 101 of the first embodiment is structured light used in the phase shift method. In addition, the reference light 102 of the first embodiment is used to detect a feature region on the measurement object 2 in order to detect a relative shake between the measurement object 2 and the shape measurement apparatus 1. Light. Details of the structured light 101, the reference light 102, the projection region 200, and the feature region will be described later (see FIGS. 3 and 4).

As shown in FIG. 1, the projection unit 10 includes a light generation unit 20, a projection optical system 30, and a scanning unit 40. The light generation unit 20 generates the projection light 100. The projection optical system 30 projects the projection light 100 generated by the light generation unit 20. The projection light 100 emitted from the projection optical system 30 is projected toward the measurement object 2 or the vicinity of the measurement object 2 via the scanning unit 40. In addition, the measuring object 2 has one corner | angular part 2a, for example. The scanning unit 40 scans the projection light 100 in the second direction D2 (Y1 axis direction in FIG. 1).

The imaging unit 50 is arranged at a position different from the position of the projection unit 10. The imaging unit 50 images the measurement object 2 onto which the projection light 100 is projected from a direction different from the direction in which the projection unit 10 projects. For example, the imaging unit 50 captures an image of the measurement object 2 onto which the structured light 101 is projected (hereinafter referred to as “measurement image”). Further, for example, the imaging unit 50 captures an image of the measurement object 2 onto which the reference light 102 is projected (hereinafter referred to as “reference image”).

The imaging unit 50 includes a light receiving optical system 51 and an imaging device 52. The light receiving optical system 51 is an optical system that causes the imaging device 52 to form an image of a region including a portion on which the projection light 100 is projected on the surface of the measurement object 2. For the light receiving optical system 51, for example, a plurality of lenses are used. The imaging device 52 generates image data of the measurement object 2 based on the image formed by the light receiving optical system 51 and stores the generated image data.

The arithmetic processing unit 60 controls the generation of the projection light 100 by the light generation unit 20. In addition, the arithmetic processing unit 60 controls the scanning unit 40 and the imaging unit 50 so that the scanning of the projection light 100 by the scanning unit 40 and the imaging of the measurement object 2 by the imaging unit 50 are synchronized. Further, the arithmetic processing unit 60 calculates the three-dimensional shape of the measurement object 2 based on the luminance data (signal intensity) of each pixel in the image data captured by the imaging unit 50.

Next, detailed configurations of the projection unit 10, the imaging unit 50, and the arithmetic processing unit 60 included in the shape measuring apparatus 1 will be described with reference to FIG. FIG. 2 is a block diagram showing an example of a detailed configuration of the shape measuring apparatus 1 shown in FIG. When a three-axis coordinate system is set as shown in FIG. 1, in FIG. 2, the right direction of the paper surface is the X1 axis, the upward direction of the paper surface is the Z1 axis, and the direction from the back of the paper surface to the front is the Y1 axis. Become. As shown in FIG. 2, the projection unit 10 includes a laser controller 21, a laser diode (light source) 22, a projection optical system 30, and a scanning unit 40. The light generation unit 20 illustrated in FIG. 1 includes a laser controller 21 and a laser diode 22.

The laser controller 21 controls the irradiation of the laser light by the laser diode 22 based on the command signal from the control unit 62. The laser diode 22 is a light source that emits laser light based on a control signal from the laser controller 21. The laser diode 22 includes, for example, a red laser diode that emits red light, a green laser diode that emits green light, and a blue laser diode that emits blue light.

The projection optical system 30 projects the projection light 100 as described above. The projection optical system 30 includes one or a plurality of transmission optical elements or reflection optical elements.

The scanning unit 40 reflects the projection light 100 emitted from the projection optical system 30 by using, for example, a reflection optical element such as a mirror, and changes the reflection angle thereof to change the projection light 100 in the second direction D2 ( Scan in the Y1 axis direction in FIG. As an example of the reflective optical element constituting the scanning unit 40, a MEMS (Micro Electro Mechanical Systems) mirror that changes the reflection angle of the projection light 100 by resonating the mirror with static electricity is used. The second direction D2 is a direction on the measurement object 2 different from the first direction D1 (X1 axis direction in FIG. 2). For example, the first direction D1 and the second direction D2 are orthogonal to each other.

As shown in FIG. 1, the MEMS mirror vibrates in the direction S (see FIG. 1) with the vibration center AX in the paper as an axis, and reflects the projection light 100 at a predetermined reflection angle and changes its reflection angle. The scanning width in the second direction D2 by the MEMS mirror (that is, the length in the second direction D2 in the projection region 200) is determined by the amplitude in the vibration direction S of the MEMS mirror. Further, the speed at which the projection light 100 is scanned in the second direction D2 by the MEMS mirror is determined by the angular speed (that is, the resonance frequency) of the MEMS mirror. Further, by vibrating the MEMS mirror, the projection light 100 can be scanned back and forth. The start position of scanning with the projection light 100 is arbitrary. For example, in addition to starting the scanning of the projection light 100 from the end of the projection area 200, the scanning may be started from approximately the center of the projection area 200.

FIG. 3A is a diagram showing the intensity distribution of the structured light 101 in the projection region 200. FIG. 3B is a diagram illustrating the intensity distribution of the reference light 102 in the projection region 200. When a three-axis coordinate system as shown in FIG. 1 is set, in FIGS. 3A and 3B, the right direction of the paper surface is the X1 axis, and the downward direction of the paper surface is the Y1 axis. The direction toward is the Z1 axis.

As shown in FIGS. 3A and 3B, the projection light 100 is slit-like light having a predetermined length in the first direction D1. The projection light 100 is scanned over a predetermined distance in the second direction D2, thereby forming a rectangular projection region 200. The projection area 200 is an area onto which the structured light 101 and the reference light 102 are projected, and is an area defined by the first direction D1 and the second direction D2. The projection area 200 includes part or all of the measurement object 2.

The structured light 101 shown in FIG. 3A is pattern light having a periodic light intensity distribution along the second direction D2. In the first embodiment, a stripe pattern P having a sinusoidal periodic light intensity distribution along the second direction D2 is used as an example of the structured light 101. The fringe pattern P is formed, for example, by setting the wavelength of the projection light 100 to a predetermined wavelength (eg, about 680 nm) and scanning in the second direction D2 while periodically changing the light intensity of the projection light 100. The stripe pattern P has a light and dark pattern in which a bright part (white part in FIG. 3A) and a dark part (black part in FIG. 3B) change along the second direction D2. The fringe pattern P is also expressed as a shading pattern in which a dark portion (black portion in FIG. 3A) and a thin portion (white portion in FIG. 3A) gradually change. Further, since the stripe pattern P is a lattice pattern, it is also expressed as a lattice pattern. Further, the second direction D2 is also referred to as a light / dark direction, a light / dark direction, or a lattice direction.

On the other hand, in the present embodiment, the reference light 102 shown in FIG. 3B has a uniform light intensity (or light and dark, light and shade) in the first direction D1 and the second direction D2. In the first embodiment, a uniform pattern Q formed of white light including red light, green light, and blue light is used as an example of the reference light 102. The uniform pattern Q is formed, for example, by using the projection light 100 as white light and scanning in the second direction D2 while keeping the light intensity constant.

Subsequently, as shown in FIG. 2, the imaging unit 50 includes a light receiving optical system 51, a CCD camera 52a, and an image memory 52b. The imaging device 52 includes a CCD camera 52a and an image memory 52b. As described above, the light receiving optical system 51 forms an image of a region including a portion on which the projection light 100 is projected on the surface of the measurement object 2 on the light receiving surface of the CCD camera 52a. The CCD camera 52a is a camera using a charge-coupled device.

The image data generated by the CCD camera 52a is composed of signal intensity data for each pixel. For example, the image data is composed of signal intensity data of 512 × 512 = 262144 pixels. The image memory 52b stores image data generated by the CCD camera 52a.

FIG. 4 is a diagram showing the relationship between the projection area and the imaging area. A region where the imaging unit 50 images the measurement object 2 (hereinafter referred to as an imaging region) will be briefly described with reference to FIG. When a three-axis coordinate system is set as shown in FIG. 1, in FIG. 4, the right direction of the paper is the X1 axis, the downward direction of the paper is the Y1 axis, and the direction from the back of the paper to the front is the Z1 axis. Become.

As shown in FIG. 4, the imaging region 210 indicates a region of the measurement object 2 that is imaged by the imaging unit 50. The imaging area 210 is within the area of the projection area 200 and is narrower than the projection area 200. However, it is sufficient that the imaging region 210 does not protrude beyond at least the projection region 200. For example, the imaging area 210 may be the same area as the projection area 200. Note that the imaging area 210 may be an area larger than the projection area 200.

When the projection area 200 is larger than the imaging area 210, the projection light 100 starts scanning from the outside of the imaging area 210 (that is, outside the imaging field) and from within the imaging area 210 (that is, within the imaging field). Either the case where scanning is started or the case where scanning starts.

Subsequently, as shown in FIG. 2, the calculation processing unit 60 includes an operation unit 61, a control unit 62, a setting information storage unit 63, a capture memory 64, a calculation unit 65, an image storage unit 66, and a display control unit 67. Have.
The operation unit 61 outputs an operation signal corresponding to a user operation to the control unit 62. The operation unit 61 is, for example, a button or switch operated by the user. Further, for example, a touch panel is formed on the display device 70. This touch panel is also used as the operation unit 61.

The control unit 62 includes a first control unit 62a and a second control unit 62b. The first control unit 62a controls the scanning unit 40 and the imaging unit 50. The second controller 62b controls the light generator 20. The control unit 62 executes the following control according to the program stored in the setting information storage unit 63.

The first control unit 62a outputs a command signal to the scanning unit 40 and the CCD camera 52a, and controls the imaging of the measurement object 2 by the CCD camera 52a to be synchronized with the scanning of the fringe pattern P by the scanning unit 40. In addition, the first control unit 62a performs control so as to synchronize imaging of one frame by the CCD camera 52a and scanning of the stripe pattern P a plurality of times.

The second control unit 62b can emit desired laser light combining red light, blue light, and green light from the laser diode 22 by outputting a command signal to the laser controller 21. The second control unit 62 b can adjust the light intensity of the laser light emitted from the laser diode 22 by outputting a command signal to the laser controller 21. When projecting the fringe pattern P onto the measurement object 2, the control unit 62 (the first control unit 62a and the second control unit 62b) controls the laser controller 21 and the scanning unit 40, for example, to synchronize control with a predetermined wavelength. The projection light 100 is scanned in the second direction D2 while periodically changing the light intensity of the projection light 100. Further, when the control unit 62 (the first control unit 62a and the second control unit 62b) projects the uniform pattern Q onto the measurement object 2, for example, by synchronously controlling the laser controller 21 and the scanning unit 40, The projection light 100 is scanned in the second direction D2 while keeping the light intensity of the white projection light 100 constant.

The frequency of the MEMS mirror constituting the scanning unit 40 is set to, for example, 500 Hz (the oscillation cycle of the MEMS mirror is 2 ms for reciprocation). The shutter speed of the CCD camera 52a (exposure time of the CCD camera 52a) is set to 40 ms, for example. Accordingly, while the CCD camera 52a captures one image, the scanning unit 40 scans the projection light 100 in the projection region 200 40 times (20 reciprocating scans). The first control unit 62a performs control so that the projection light 100 is reciprocated 20 times, for example, by the scanning unit 40 during imaging of one frame by the CCD camera 52a. However, it is possible to arbitrarily set how many reciprocating scans of the projection light 100 are performed when the CCD camera 52a captures one frame. For example, by adjusting the shutter speed of the CCD camera 52a and the frequency of the MEMS mirror, the number of scans of the projection light 100 captured by one frame imaging is adjusted.

The setting information storage unit 63 stores a program for causing the control unit 62 to execute control. In addition, the setting information storage unit 63 stores a program for causing the calculation unit 65 to perform shake detection processing and a program for executing calculation processing of a three-dimensional shape. The setting information storage unit 63 stores a program for causing the display control unit 67 to execute display control. The setting information storage unit 63 also stores calibration information used when calculating the actual coordinate value of the measurement object 2 from the fringe phase of the fringe pattern P in the calculation process of the calculation unit 65. As the calibration information, information related to the focal length of the imaging unit 50, information related to the position on the imaging surface of the imaging device 52 where the optical axes of the imaging unit 50 intersect, and information related to distortion of the lens included in the imaging unit 50, etc. Etc. are included. In addition, the setting information storage unit 63 sets the phase of the fringe pattern P for each pixel based on information (eg, luminance) of the image captured by the imaging unit 50 (CCD camera 52a) in the calculation process of the calculation unit 65. A phase calculation program, data, and the like for obtaining are stored.

The capture memory 64 captures and stores the image data stored in the image memory 52b. The capture memory 64 stores a measurement image of the measurement object 2 imaged by projecting the fringe pattern P, a reference image of the measurement object 2 imaged by projecting the uniform pattern Q, and the like. The capture memory 64 is provided with a plurality of storage areas. The image data of the measurement image and the image data of the reference image are stored in different storage areas, for example.

The calculation unit 65 executes a predetermined calculation according to the program and calibration information stored in the setting information storage unit 63. For example, relative blur between the measurement object 2 and the shape measuring device 1 is detected from the image data of the reference image stored in the capture memory 64. This blur is change information regarding at least one of a relative position change and a posture change between the measurement object 2 and the shape measuring apparatus 1. Here, the position change and the posture change are for the X1 direction, the Y1 direction, and the direction around the Z1 axis (hereinafter referred to as “θZ1 direction”). Further, the calculation unit 65 calculates the three-dimensional shape data (three-dimensional shape coordinate data) of the measurement object 2 from the image data of the measurement image stored in the capture memory 64. In the calculation of the three-dimensional shape data, the calculation unit 65 can perform calculation based on the measurement image and the shake.

The calculation unit 65 detects a feature area (refer to FIG. 8 described later) in the reference image. The feature region is a region that is included in the reference image of the measurement object 2, for example, and can be identified by the change in luminance with respect to other regions. In this case, the change in luminance is based on a change in the shape of the measurement object 2, a change in the light reflectance of the surface of the measurement object 2, and the like. The feature region includes a plurality of regions arranged with a predetermined distance in the reference image, and includes, for example, three regions. In the present embodiment, a case will be described as an example where the reference image is set so that the region corresponding to the corner 2a of the measurement object 2 and its periphery is set as the feature region. The feature region in this case includes three unit regions corresponding to the three straight lines gathered at the corner 2a (see FIG. 8).

The image storage unit 66 stores the three-dimensional shape data of the measurement object 2 calculated by the calculation unit 65. The display control unit 67 executes display control of a three-dimensional image according to a program stored in the setting information storage unit 63. That is, the display control unit 67 reads the three-dimensional shape data stored in the image storage unit 66 in accordance with the operation of the operation unit 61 by the user or automatically. And the display control part 67 performs control which displays the image of the three-dimensional shape of the measuring object 2 on the display screen of the display apparatus 70 based on the read-out three-dimensional shape data.

The display device 70 is a device that displays a three-dimensional image of the measurement object 2. As the display device 70, for example, a liquid crystal display device or an organic EL display device is used. In FIG. 1, the display device 70 is omitted.

Further, the control unit 62, the calculation unit 65, and the display control unit 67 are configured by a calculation processing device such as a CPU (Central Processing Unit). That is, the arithmetic processing unit performs processing executed by the control unit 62 in accordance with a program stored in the setting information storage unit 63. In addition, the arithmetic processing unit performs processing executed by the arithmetic unit 65 in accordance with a program stored in the setting information storage unit 63. Further, the arithmetic processing unit performs processing executed by the display control unit 67 in accordance with a program stored in the setting information storage unit 63. This program includes a shape measurement program.

The shape program includes, for an arithmetic processing unit (control unit 62), processing for capturing a first reference image of the measurement object 2, processing for capturing a second reference image of the measurement object 2, and A process of imaging a measurement image of the measurement object 2 obtained by projecting the fringe pattern P onto the measurement object 2 simultaneously with or after the imaging of the first reference image and before the imaging of the second reference image; Is executed. In addition, the shape program detects a feature region (described later) from the first reference image and detects the feature region (described later) from the second reference image with respect to the arithmetic processing unit (arithmetic unit 65). And a process for detecting a relative shake between the measurement object 2 and the shape measuring device 1 based on the feature region in the first reference image and the feature region in the second reference image. Based on the shake and the measurement image of the measurement object 2, a process for calculating the shape of the measurement object 2 is executed.

Next, the principle of the phase shift method will be described.
The phase shift method is based on the principle of triangulation, and a fringe image (the fringe pattern P is projected by shifting the fringe phase of the fringe pattern P having a sinusoidal light intensity distribution projected onto the measurement object 2. This is a method of measuring the shape three-dimensionally by analyzing the measured image of the measured object 2). In the present embodiment, the fringe pattern P is four types of fringe patterns P obtained by shifting the fringe phase by π / 2 along the second direction D2. Here, the phase of the fringe pattern P can be rephrased as a phase of a sine wave that is a light intensity distribution of the fringe pattern P. That is, four types of fringe patterns P are generated by shifting a sine wave, which is a light intensity distribution, by π / 2 along the second direction D2.

Hereinafter, for example, the reference stripe pattern P is a first stripe pattern (first phase light) P1, and the phase of the first stripe pattern P1 is zero. The stripe pattern P obtained by shifting the phase of the first stripe pattern P1 by π / 2 is defined as the second stripe pattern (second phase light) P2, and the stripe pattern obtained by shifting the phase of the first stripe pattern P1 by π. Let P be the third stripe pattern (third phase light) P3, and let the stripe pattern P obtained by shifting the phase of the first stripe pattern P1 by 3π / 2 be the fourth stripe pattern (fourth phase light) P4.

FIGS. 5A to 5D are views showing a state in which the first fringe pattern P1 to the fourth fringe pattern P4 are projected on a plane without the measuring object 2, and the imaging region 210 in the projection region 200 is shown in FIG. It is an image. 5A shows the first stripe pattern P1, FIG. 5B shows the second stripe pattern P2, FIG. 5C shows the third stripe pattern P3, and FIG. 5D shows the fourth stripe pattern P4.

In the phase shift method, the first fringe pattern P1 to the fourth fringe pattern P4 as shown in FIGS. 5A to 5D are projected from the projection unit 10 onto the measurement object 2 and are different from the projection unit 10. The measurement object 2 is imaged by the imaging unit 50 arranged at an angle. At this time, the projection unit 10, the measurement object 2, and the imaging unit 50 are arranged so as to have a triangulation positional relationship.

The imaging unit 50 captures four measurement images by imaging the measurement object 2 in a state where the first stripe pattern P1 to the fourth stripe pattern P4 are projected onto the measurement object 2, respectively. Then, the arithmetic processing unit 60 applies the data on the signal strengths of the four measurement images captured by the imaging unit 50 to the following (Equation 1), and the fringes in each pixel according to the surface shape of the measurement object 2 are calculated. A phase value φ is obtained.

φ (u, v) = tan ⁻¹ {(I4 (u, v) −I2 (u, v)) / (I1 (u, v) −I3 (u, v))} (Expression 1)
However, (u, v) indicates the position coordinates of the pixel. I1 is the signal intensity of the measurement image captured when the first fringe pattern P1 is projected. Similarly, I2 is the second stripe pattern P2, I3 is the third stripe pattern P3, and I4 is the signal intensity of the measurement image when the fourth stripe pattern P4 is projected.

Thus, the phase of the signal intensity that changes sinusoidally for each pixel of the image can be obtained. A line (equal phase line) obtained by connecting points having the same phase φ (u, v) represents the shape of a cross section obtained by cutting an object along a certain plane in the same manner as the cutting line in the optical cutting method. Therefore, a three-dimensional shape (height information at each point of the image) is obtained by the principle of triangulation based on this phase φ (u, v).

As shown in FIGS. 5A to 5D, every time the phase of the stripe pattern P shifts to 0, π / 2, π, 3π / 2, the position of the stripe (the stripe It is confirmed that the bright portions and the dark portions of the stripes are shifted by the phase difference. As described above, by shifting the phase of the fringe pattern P, the bright and dark portions of the fringe are projected in the second direction D2 on the imaging region 210 in accordance with the phase. The

As shown in FIGS. 5A to 5D, for example, in the second stripe pattern P2, the second direction D2 is equal to the first stripe pattern P1 by the distance corresponding to the position of the stripe corresponding to the phase π / 2. It is shifted to. Further, in the third stripe pattern P3, the position of the stripe is shifted in the second direction D2 by a distance corresponding to the phase π with respect to the first stripe pattern P1. Similarly, in the fourth stripe pattern P4, the position of the stripe is shifted in the second direction D2 by a distance corresponding to the phase 3π / 2 with respect to the first stripe pattern P1. For this reason, on the imaging region 210, the position of the stripe is projected from the first stripe pattern P1 to the fourth stripe pattern P4 in the second direction D2 at equal intervals.

5A to 5D show the image of the stripe pattern P projected on the plane, the shape of the image of the stripe pattern P does not change. When the measuring object 2 is present, the fringe pattern P is projected on the surface of the measuring object 2, so that the image of the fringe pattern P in the second direction D2 (see FIG. 3 in the Y1-axis direction).

Here, the shape measuring apparatus 1 is handled with the user holding the casing 80, for example. When the user picks up an image of the measurement object 2 that is stationary while holding the housing 80, the shape measuring device 1 projects the first stripe pattern P1 to the fourth stripe pattern P4 onto the measurement object 2, and A measurement image of the measurement object 2 is captured for each of the stripe patterns. During this series of operations, there is a possibility that a relative positional change (blurring) may occur between the measuring object 2 and the shape measuring apparatus 1 due to, for example, camera shake of the user.

FIG. 6 is a diagram for explaining the relative shake between the measurement object 2 and the shape measuring apparatus 1. In FIG. 6, for convenience of explanation, the surface 2 f of the measurement object 2 is displayed as a curved surface, but the same explanation can be made when it is a flat surface.
In the case where relative shake occurs between the measuring object 2 and the shape measuring apparatus 1, the measuring object 2 is not displaced and only the shape measuring apparatus 1 is displaced, and only the measuring object 2 is displaced and the shape measuring apparatus is displaced. The case where 1 is not displaced can be treated as the same value. Therefore, hereinafter, in explaining the relative shake between the measuring object 2 and the shape measuring apparatus 1, it is assumed that only the measuring object 2 is displaced and the shape measuring apparatus 1 is not displaced for convenience.

For example, when a measurement image is captured with the first stripe pattern P1 projected (hereinafter referred to as “first timing”), and when a measurement image is captured with the second stripe pattern P2 projected, for example ( Hereinafter, when a relative shake between the measurement object 2 and the shape measuring device 1 occurs between the “second timing” and the shape measuring device 1 (projection unit 10 and The surface 2f of the measuring object 2 is displaced with respect to the imaging unit 50).

In this case, in an arbitrary pixel (u1, v1) of the imaging unit 50 (CCD camera 52a), a position on the surface 2f that is imaged at the first timing (hereinafter, a first position L1) due to the displacement of the surface 2f. And a position on the surface 2f (hereinafter, the second position L2) imaged at the second timing is different. In other words, the position where the first stripe pattern P1 is projected at the first timing and the position where the second stripe pattern P2 is projected at the second timing are different on the surface 2f. Accordingly, at the second timing with respect to the first timing, the second fringe pattern P2 is projected at a position on the surface 2f to be projected when the shape measuring apparatus 1 and the measurement object 2 are not relatively displaced. Instead, the projection position is displaced. That is, with the displacement between the first position L1 and the second position L2 on the surface 2f, the phase of the projected fringe pattern P is projected at the first timing with the first fringe pattern P1 and the second timing. In addition to the phase difference (π / 2) with the second stripe pattern P2, the phase changes (hereinafter, the amount of phase change is referred to as δ1).

Due to this phase change, the signal intensity (I2 (u1, v1)) of the pixel (u1, v1) in the measurement image captured at the second timing is relative to the shape measuring apparatus 1 and the measurement object 2. If it is not displaced, the value deviates from the value that should be obtained. For this reason, the fringe phase value (φ (u1, v1)) in each pixel is a value deviated from the value to be obtained when the shape measuring apparatus 1 and the measurement object 2 are not relatively displaced. . Therefore, the measurement accuracy of the three-dimensional shape of the measurement object 2 obtained based on the phase value is lowered.

On the other hand, the shape measuring apparatus 1 according to the first embodiment accurately detects a relative shake between the measurement object 2 and the shape measuring apparatus 1 and corrects the shake, thereby correcting the side wisdom object. 2 three-dimensional shape is accurately measured. Hereinafter, an example of a shake detection method by the shape measuring apparatus 1 and an example of a shape measurement method using this detection method will be described.

In the detection method according to the present embodiment, the imaging unit 50 captures a measurement image of the measurement target 2 obtained by projecting the stripe pattern P for shape measurement from the projection unit 10 onto the measurement target 2, and the measurement target 2 Detecting relative shake with the shape measuring apparatus 1. Moreover, the shape measuring method according to the present embodiment includes calculating the shape of the measuring object 2 based on the measurement image of the measuring object 2 and the above-described blur. In the following description, the imaging unit 50 of the shape measuring apparatus 1 is calibrated in advance and the internal parameters are known. This calibration is so-called camera calibration, and is included in information related to the focal length of the imaging unit 50, information related to the position on the imaging surface of the imaging device 52 where the optical axes of the imaging unit 50 intersect, and the imaging unit 50. Information related to distortion of lenses and the like is used as an internal parameter.

FIG. 7 is a flowchart illustrating an example of the detection method and the shape measurement method according to the first embodiment. Further, FIG. 8 is a diagram schematically showing images captured in the detection method in the order of processing.

When the shutter operation is performed by the user while the power of the shape measuring apparatus 1 is turned on, the control unit 62 receives a signal indicating that the shutter operation has been performed from the operation unit 61. When the shutter operation by the user is not performed, the standby state is set. Further, when the shutter operation is performed, the distance from the measurement object 2 may be measured and the projection optical system 30 and the imaging lens 51 may be focused.

When the shutter operation is performed, the control unit 62 outputs a command signal to the light generation unit 20 and the scanning unit 40 to project the first fringe pattern P1 having the phase 0 onto the measurement object 2. In addition, the control unit 62 outputs a command signal to the imaging unit 50 to capture a measurement image of the measurement object 2 on which the first fringe pattern P1 is projected (step S01).

The control unit 62 controls the operations of the light generation unit 20 and the scanning unit 40 so that the light generation of the projection light 100 by the light generation unit 20 (laser controller 21) and the scanning by the scanning unit 40 are synchronized. Regarding the light generation control by the light generation unit 20, the control unit 62 adjusts the light intensity of the projection light 100 having a predetermined wavelength so as to periodically change in a sinusoidal shape. Regarding control of scanning by the scanning unit 40, the control unit 62 causes the projection light 100 to scan in the second direction D2 at a predetermined speed. As a result, the first stripe pattern P1 in which the light intensity (or light and dark, light and shade) periodically changes in a sine wave shape in the second direction D2 is projected onto the projection region 200. Accordingly, the first fringe pattern P1 is projected onto the measurement object 2 arranged in the projection region 200. Note that the number of scans of the projection light 100 is arbitrarily set.

Further, based on the command signal from the control unit 62, the CCD camera 52a images the surface of the measurement object 2 on which the first stripe pattern P1 is projected. As shown in FIG. 8, the first measurement image M1 of the measurement object 2 on which the first stripe pattern P1 is projected is acquired by this imaging. Then, the CCD camera 52a generates image data of the first measurement image M1. The image data of the first measurement image M1 is temporarily stored in the image memory 52b and then stored in a storage area provided in the capture memory 64.

Note that, as the first measurement image M1 in FIG. 8, for convenience of explanation, an image in a state where the first stripe pattern P1 projected on the plane is captured as it is is shown. Actually, since the first fringe pattern P1 is projected on the surface of the measurement object 2, an image in which the first fringe pattern P1 is deformed according to the shape of the measurement object 2 is obtained. The same applies to a second measurement image M2 to a fourth measurement image M4 described later.

Next, the control unit 62 outputs a command signal to the light generation unit 20 and the scanning unit 40 to project the uniform pattern Q (see FIG. 3B) on the measurement object 2. In addition, the control unit 62 outputs a command signal to the imaging unit 50 to capture a reference image of the measurement object 2 on which the uniform pattern Q is projected (step S02).

The control unit 62 controls the operations of the light generation unit 20 and the scanning unit 40 so that the light generation of the projection light 100 by the light generation unit 20 (laser controller 21) and the scanning by the scanning unit 40 are synchronized. Regarding the light generation control by the light generation unit 20, the control unit 62 sets the projection light 100 to white light. In addition, the control unit 62 adjusts so that the light intensity of the projection light 100 is constant. Regarding control of scanning by the scanning unit 40, the control unit 62 causes the projection light 100 to scan in the second direction D2 at a predetermined speed. Thereby, the uniform pattern Q adjusted so that the light intensity (or light and dark, light and shade) is uniform in the second direction D2 is projected onto the projection region 200. Therefore, the uniform pattern Q is projected onto the measurement object 2 arranged in the projection area 200. Note that the number of scans of the projection light 100 is arbitrarily set.

Further, based on a command signal from the control unit 62, the CCD camera 52a images the surface of the measurement object 2 on which the uniform pattern Q is projected. By this imaging, a first reference image (first reference image) R1 of the measurement object 2 onto which the uniform pattern Q is projected is acquired. The CCD camera 52a generates image data of the first reference image R01. The image data of the first reference image R01 is once stored in the image memory 52b and then stored in a storage area provided in the capture memory 64.

Next, the control unit 62 outputs a command signal to the light generation unit 20 and the scanning unit 40 to project the second fringe pattern P2 having a phase of π / 2 onto the measurement object 2. In addition, the control unit 62 outputs a command signal to the imaging unit 50 to capture a measurement image of the measurement object 2 on which the second stripe pattern P2 is projected (step S03). Thereby, as shown in FIG. 8, the 2nd measurement image M2 of the measuring object 2 in which the 2nd striped pattern P2 was projected is acquired. Thereafter, image data of the second measurement image M <b> 2 is generated by the CCD camera 52 a, and this image data is stored in the capture memory 64.

Next, the control unit 62 outputs a command signal to the light generation unit 20 and the scanning unit 40 to project the uniform pattern Q onto the measurement object 2. In addition, the control unit 62 outputs a command signal to the imaging unit 50 to capture a reference image of the measurement object 2 on which the uniform pattern Q is projected (step S04). Thereby, as shown in FIG. 8, the 2nd reference image (2nd reference image) R2 of the measuring object 2 in which the uniform pattern Q was projected is acquired. Thereafter, image data of the second reference image R02 is generated by the CCD camera 52a, and this image data is stored in the capture memory 64.

Hereinafter, the control unit 62 alternately projects the stripe pattern P and the uniform pattern Q on the measurement object 2 in the order of the third stripe pattern P3, the uniform pattern Q, the fourth stripe pattern P4, and the uniform pattern Q, The measurement object 2 on which the stripe pattern P or the uniform pattern Q is projected is imaged (steps S05 to S08). Accordingly, as shown in FIG. 8, the third measurement image M3 of the measurement object 2 on which the third stripe pattern P3 is projected, the third reference image R03 of the measurement object 2 on which the uniform pattern Q is projected, A fourth measurement image M4 of the measurement object 2 onto which the four-stripe pattern P4 is projected and a fourth reference image R04 of the measurement object 2 onto which the uniform pattern Q is projected are obtained. Thereafter, image data of each image is generated by the CCD camera 52 a, and this image data is stored in the capture memory 64.

Next, the calculation unit 65 detects a feature region in the first reference image R01 to the fourth reference image R04 (step S09). In the present embodiment, the computing unit 65 detects the feature region C corresponding to the corner 2a of the measurement object 2 and its periphery from the first reference image R01 to the fourth reference image R04. In the feature region C, three unit regions Ca to Cc corresponding to each of the three straight lines gathering at the corner 2a are provided. For convenience of explanation, only the feature region C is displayed as the first reference image R01 to the fourth reference image R04 in FIG. Actually, an image displaying the entire surface of the measuring object 2 is obtained.

Next, the calculation unit 65 detects a relative shake between the measurement object 2 and the shape measuring apparatus 1 (step S10). In step S10, the calculation unit 65 first calculates the three-dimensional shape of the measurement object 2 using the first measurement image M1 to the fourth measurement image M4. In this case, the calculation unit 65 obtains the initial phase distribution φ (u, v) of each pixel on the assumption that there is no shake due to camera shake or the like (the phase change amount δ1 is 0). Then, the calculation unit 65 performs a phase connection process on the obtained initial phase distribution φ (u, v). Thus, a continuous phase distribution φ ′ (u, v) is obtained. Then, the calculation unit 65 obtains the coordinate data (x ′, y ′, z ′) of the three-dimensional shape of the measuring object 2 from the obtained phase distribution φ ′ (u, v) using the principle of triangulation. calculate. The coordinate data of the three-dimensional shape calculated in this way is calculated in step 10 as having no relative shake between the measuring object 2 and the shape measuring device 1 (the phase change amount δ1 is 0). However, there is a possibility that the above-mentioned blur actually occurs (the amount of phase change δ1 is not 0). Therefore, the calculated coordinate data of the three-dimensional shape is a rough value that may be different from the value of the actual three-dimensional shape.

Next, the calculation unit 65 associates the calculated coordinate data of the rough three-dimensional shape of the measurement object 2 with the two-dimensional coordinates of the feature regions C of the first reference image R01 to the fourth reference image R04. The rotation and translation from the shape measuring device 1 to the surface 2f are calculated. The calculation method of rotation and translation in this case includes academic papers (eg, V. Lepetit et al. “EPnP: An Accurate O (n) Solution to the PnP Problem”, International Journal Of Computer Vision, vol. 81, p 155-166, 2009.) and publicly known publications can be used.

First, the calculation unit 65 performs rotation R1 and translation from the shape measuring device 1 to the surface 2f at the first timing based on the correspondence between the coordinate data of the rough three-dimensional shape and the two-dimensional coordinates of the feature region C of the first reference image R01. t1 is calculated. Next, the calculation unit 65 rotates from the shape measuring apparatus 1 to the surface 2f at the second timing based on the correspondence between the coordinate data of the rough three-dimensional shape and the two-dimensional coordinates of the feature region C of the second reference image R02, for example. R2 and translation t2 are calculated.

Next, the arithmetic unit 65 obtains the rotation Ra and the translation ta of the feature region C by the following [Equation 1] using the obtained R1, t1, R2, and t2. The rotations R1, R2, and Ra are represented by determinants, and the translations t1, t2, and ta are represented by vectors. The rotation Ra and the translation ta are first change information about the shake that occurs between the first measurement image M1 and the second measurement image M2.

In addition, the calculation unit 65 captures the third measurement image M3 from the shape measurement apparatus 1 (third) based on the correspondence between the rough three-dimensional shape coordinate data and the two-dimensional coordinates of the feature region C of the third reference image R03. The rotation R3 and translation t3 to the surface 2f at (timing) are calculated. Next, the computing unit 65 obtains the rotation Rb and translation tb of the feature region C by the following [Equation 2] using the obtained R3, t3 and the above R2, t2. The rotation Rb and the translation tb are second change information about the shake that occurs between the second measurement image M2 and the third measurement image M3.

Further, the calculation unit 65 captures the fourth measurement image M4 from the shape measurement device 1 (fourth) based on the correspondence between the rough three-dimensional shape coordinate data and the two-dimensional coordinates of the feature region C of the fourth reference image R04. Rotation R4 and translation t4 to the surface 2f at (timing) are calculated. Next, the arithmetic unit 65 obtains the rotation Rc and the translation tc of the feature region C by the following [Equation 3] using the obtained R4 and t4 and the above R3 and t3. The rotation Rc and the translation tc are the third change information about the shake that occurs between the third measurement image M3 and the fourth measurement image M4.

Thus, by the detection method according to the present embodiment, blur (first change information) between the first measurement image M1 and the second measurement image M2, and between the second measurement image M2 and the third measurement image M3. A shake (second change information) and a shake (third change information) between the third measurement image M3 and the fourth measurement image M4 are detected.

After detecting the shake by the detection method, the calculation unit 65 calculates the shape of the measurement object 2 based on the shake detection result and the first measurement image M1 to the fourth measurement image M4 (step S11). . In step S11, the arithmetic unit 65 causes the blur between the first measurement image M1 and the second measurement image M2, the blur between the second measurement image M2 and the third measurement image M3, and the third measurement image M3. And the fourth measurement image M4 are corrected.

Here, in the case of a shake due to a hand shake or the like of the user, it can be assumed that the distance between the first position L1 and the second position L2 shown in FIG. 6 is very small. For this reason, in the 1st position L1 and the 2nd position L2, the change of the light reflectivity in the surface 2f can be disregarded. As shown in FIG. 6, when the surface 2f moves, the distance from the imaging position to the imaging unit 50 changes, and the incident angle and reflection angle of the fringe pattern P at this imaging position change. Due to this influence, the intensity of the reflected light of the stripe pattern P reflected at the imaging position and reaching the imaging unit 50 changes. However, in the case of camera shake or the like, the distance between the first position L1 and the second position L2 is very small, so the change in the distance from the imaging position to the imaging unit 50 and the fringe pattern at the imaging position. The influence of changes in the incident angle and reflection angle of P can be ignored. Therefore, the change in the light intensity of the fringe pattern P projected to the first position L1 and the second position L2 can be regarded as being only due to the change in the phase of the fringe pattern P projected from the projection unit 10. Therefore, in this embodiment, for each pixel, the amount of change in the phase of the fringe pattern P (for example, the amount of change δ1) is obtained, and the initial phase distribution φ (u, v) taking this amount of change into consideration is obtained. Can be corrected.

Hereinafter, a case where the phase change amount δ1 is obtained for an arbitrary pixel (u1, v1) of the imaging unit 50 (CCD camera 52a) will be described as an example. Specifically, the calculating unit 65 first converts the position of the surface 2f at the first timing by converting the position of the surface 2f at the first timing based on the first change information (rotation R, translation t) obtained as described above. Calculate the position. The position of the surface 2f at the first timing is calculated based on rough three-dimensional coordinate data.

Next, the calculation unit 65 obtains the position coordinates of the first position L1 and the second position L2. In this case, the calculation unit 65 obtains, for example, the coordinates of the intersection of the light beam back-projected from any one pixel (u1, v1) of the imaging unit 50 and the surface 2f at the first timing as the position coordinate of the first position L1. Further, the calculation unit 65 obtains the coordinates of the intersection of the light ray back projected from the pixel (u1, v1) and the surface 2f at the second timing as the position coordinate of the second position L2.

Next, the calculation unit 65 obtains a phase change amount δ1 when the structured light 101 is projected from the projection unit 10 to the first position L1 and the second position L2. FIGS. 9A and 9B are diagrams for explaining the principle of obtaining the phase change amount δ1. FIG. 9A is a diagram showing the intensity distribution of the fringe pattern P projected on the first position L1. FIG. 9B is a diagram illustrating the intensity distribution of the fringe pattern P projected on the first position and the second position L2.

First, as shown in FIG. 9A, the first fringe pattern P1 is projected onto the measurement object 2 at the first timing. At this time, a portion corresponding to the phase φ _L1 of the fringe pattern P (the phase of one dark portion is set to 0) is projected onto the first position L1. Further, in one pixel for imaging the first position L1 of CCD cameras 52a, luminance image of which corresponds to the light intensity of the phase phi _L1 stripe pattern P is captured.

Further, as shown in FIG. 9B, at the second timing, the second fringe pattern P2 having a phase larger by π than the first fringe pattern P1 is projected onto the measurement object 2. For this reason, when there is no camera shake or the like, a portion corresponding to a phase (φ _L1 + π / 2) obtained by adding π / 2 to the phase φ _L1 in the stripe pattern P is projected at the first position L1. The In this case, an image having a luminance corresponding to the light intensity at the phase (φ _L1 + π / 2) in the stripe pattern P is captured by the one pixel of the CCD camera 52a.

On the other hand, when camera shake or the like occurs, the imaging position of the pixel of the imaging unit 50 is the second position L2. Here, when the position in the Y1 direction of the second position L2 is changed with respect to the first position L1, as shown in FIG. 9B, the position of the second position L2 is a fringe pattern P (second pattern). In the fringe pattern P2), the first position L1 is shifted in the Y1 direction (eg, + Y1 direction). For this reason, the phase φ _L2 of the second position L2 is a value different from the phase (φ _L1 + π / 2) of the first position L1. In this case, in the pixels of the imaging unit 50, the luminance image of which corresponds to the light intensity of the phase phi _L2 of the fringe pattern P is captured.

Since the fringe pattern P has a periodic light intensity distribution in a sine wave shape in the Y1 direction, the portion corresponding to the phase (φ _L1 + π / 2) of the first position L1 and the phase φ of the second position L2 _The light intensity is different from the portion corresponding to _L2 . For this reason, the brightness at the first position L1 and the image at the second position L2 captured by the one pixel of the CCD camera 52a at the second timing are different from each other.

In the present embodiment, the change in the light intensity of the fringe pattern P projected to the first position L1 and the second position L2 can be regarded as being only due to the change in the phase of the fringe pattern P projected from the projection unit 10. . For this reason, it is assumed that the difference in luminance between the image at the first position L1 and the image at the second position L2 captured by the one pixel at the second timing is caused only by the change in the phase of the fringe pattern P. Can do.

Therefore, the calculation unit 65 obtains the phase φ _L2 of the fringe pattern P projected on the second position L2 based on the luminance of the image captured by the pixel. Then, the calculation unit 65 determines how much the obtained phase φ _L2 is deviated from the phase (φ _L1 + π / 2) of the fringe pattern P projected on the first position L1 as a phase change amount δ1. calculate.

In addition, the calculating unit 65 uses the same method as described above, and the phase change amount δ2 caused by the shake between the second stripe pattern P2 projected at the second timing and the third stripe pattern P3 projected at the third timing. (Change in phase different from phase difference (π / 2)) and blurring between the third stripe pattern P3 projected at the third timing and the fourth stripe pattern P4 projected at the fourth timing A phase change amount δ3 (a phase change different from the phase difference (π / 2)) is calculated.

Next, the calculation unit 65 corresponds to the fourth timing with the initial phase of the fringe pattern P corresponding to the second timing being (π / 2 + δ1), the initial phase of the fringe pattern P corresponding to the third timing being (π + δ1 + δ2). Assuming that the initial phase of the fringe pattern P is (3π / 2 + δ1 + δ2 + δ3), an initial phase distribution φ (u1, v1) is obtained, and phase connection processing is performed. Then, the calculation unit 65 calculates three-dimensional coordinate data (x1, y1, z1) from the obtained phase distribution φ ′ (u1, v1) using the principle of triangulation. The calculation unit 65 performs the above calculation for each pixel to calculate the coordinate data (x, y, z) of the three-dimensional shape of the measurement object 2. ¥. The calculation unit 65 performs the above correction again or repeatedly using the coordinate data (x, y, z) calculated in this way as the rough coordinate data of the three-dimensional shape. Also good. As a result, the accuracy of the position of the surface 2f at the first timing is increased, and therefore, more accurate detection is possible.

The calculation unit 65 stores the calculated coordinate data of the three-dimensional shape of the measurement object 2 in the image storage unit 66. The display control unit 67 reads the coordinate data of the three-dimensional shape stored in the image storage unit 66 according to the operation of the operation unit 61 by the user or automatically. The display control unit 67 displays the three-dimensional shape of the measurement object 2 on the display screen of the display device 70 based on the read coordinate data of the three-dimensional shape. The three-dimensional shape is displayed as a point group that is a set of points in the three-dimensional space. This point cloud data can be output from the shape measuring apparatus 1.

The display device 70 may display not only the three-dimensional shape of the measurement object 2 but also a fringe image captured by the imaging unit 50. That is, the display control unit 67 may cause the display device 70 to display the fringe image captured by the imaging unit 50 based on the image data stored in the capture memory 64. According to such a configuration, the user can confirm whether or not the measurement object 2 has been accurately imaged at the imaging site based on the fringe image captured by the imaging unit 50.

Further, the display device 70 may be configured to display at least one of the image captured by the imaging unit 50 and the three-dimensional shape calculated by the calculation unit 65. In this case, at least one of the image picked up by the image pickup unit 50 and the three-dimensional shape calculated by the calculation unit 65 is displayed on an external display device connected to the shape measuring device 1 wirelessly or by wire. But you can.

As described above, according to the first embodiment, in the detection method for detecting the relative shake between the shape measuring apparatus 1 that measures the shape of the measuring object 2 and the measuring object 2, The first reference image R01 and the second reference image are captured, the first measurement image M1 of the measurement object is captured after the first reference image R01 and before the second reference image R02, The feature region C is detected from the first reference image R01, the feature region C is detected from the second reference image R02, and the relative blur between the measurement object 2 and the shape measuring device 1 is based on these feature regions C. Therefore, the relative shake between the measurement object 2 and the shape measuring device 1 can be detected with high accuracy.

Second Embodiment
Next, a second embodiment will be described. In the present embodiment, when the first reference image R01 to the fourth reference image R04 are imaged, light having a rectangular wave intensity distribution as a spatial code (hereinafter referred to as “spatial code pattern”) is used as the reference light. ) Will be described as an example. FIGS. 10A to 10D are diagrams showing the intensity distribution of the spatial code pattern projected onto the measurement object 2, for example.

As shown in FIGS. 10A to 10D, the spatial code pattern QA is a striped pattern light having a rectangular intensity distribution in the second direction D2. In the spatial code pattern QA, bright portions (white portions in FIG. 10) and dark portions (black portions in FIG. 10) appear alternately. In the present embodiment, description will be made using spatial code patterns QA1 to QA4 having four types of rectangular light intensity distributions with different frequencies in the second direction D2. In other words, the spatial code pattern is, for example, a lattice pattern in which white and black are combined.

In the first embodiment, an image obtained by shifting the phase of the fringe pattern P is acquired, and the three-dimensional shape of the measurement object 2 is obtained by performing phase connection. In this method, when the surface shape of the measuring object 2 changes smoothly, the three-dimensional shape of the measuring object 2 can be obtained accurately. Here, for the following description, the fringes of the fringe pattern P are shown as a pattern with one period of the sine wave in the sinusoidal intensity distribution of the fringe pattern P as a unit. That is, the fringe pattern P includes a fringe having a phase of 0 to 2π and a fringe having a phase of 2π to 4π with a phase reference of 0, which is projected on one end of the projection region 200, (m−1) It includes fringes with a phase range of π to 2mπ (where m is an integer).

Based on the triangulation principle as in the first embodiment, for example, there is a convex step on the surface of the measurement object 2, and the elevation (Y1 coordinate in FIG. 1) changes from the lower surface to the upper surface of the step. Is larger than the altitude difference corresponding to the period (that is, 2π) of the fringe pattern P in the area on the measurement object 2 corresponding to the area of any adjacent pixel of the imaging device 52 (that is, fringe). If any stripe of the pattern P is displaced in the D1 direction for one period or more), which phase range of the stripe of the stripe pattern P, which is a periodic sine wave, is projected on the upper surface of the step. It cannot be confirmed (for example, it is not known whether a fringe having a phase of 0 to 2π is projected or a fringe having a phase of 2π to 4π is projected). That is, there is a possibility that the absolute phase value corresponding to the stripe projected on the step cannot be obtained only by the phase shift method.

In order to avoid this problem, there is a method using a combination of the spatial code method and the phase shift method. For example, US Pat. No. 6,075,605 describes a method of using such a phase shift method in combination with the spatial code method. In the case of this method, in addition to the sinusoidal stripe pattern P, a plurality of types of rectangular shapes are formed in the same area as the area where the fringe pattern P having a sinusoidal intensity distribution is projected onto the measurement object by the phase shift method. Each of the phase ranges of (m−1) π to 2mπ (where m is an integer) in the fringe pattern P projected onto the measurement object 2 by individually projecting and imaging each spatial code pattern having an intensity distribution The stripes can be identified.

In the example shown in FIG. 10, in the spatial code pattern QA1 in (a), eight white lines and eight black lines are alternately arranged. In the spatial code pattern QA2 in (b), four white lines and four black lines are alternately arranged. In the spatial code pattern QA3 in (c), two white lines and two black lines are alternately arranged. In the spatial code pattern QA4 in (d), the left half is white and the right half is black.

FIG. 11 is a diagram schematically illustrating images captured in the detection method according to the second embodiment in the order of processing.
As shown in FIG. 11, in this case, after capturing the first measurement image M1, the control unit 62 outputs an instruction signal to the projection unit 10 to project the spatial code pattern QA1. In addition, the control unit 62 outputs an instruction signal to the imaging unit 50, and images the measurement object 2 on which the spatial code pattern QA1 is projected. Thereby, the first reference image RA1 is acquired. Similarly, the control unit 62 projects the spatial code patterns QA2 to QA4 and images the measurement object 2 on which the spatial code patterns QA2 to QA4 are projected. Thereby, the second reference image RA2 to the fourth reference image RA4 are acquired.

Next, the calculation unit 65 detects a feature region in the first reference image RA1 to the fourth reference image RA4. In the present embodiment, the calculation unit 65 sets a part of an image captured in a bright part of the spatial code patterns QA1 to QA4 as a feature region. In the present embodiment, the first feature area CA1 displayed in common in the bright portions of the spatial code patterns QA1 and QA2, and the second feature region CA2 displayed in common in the bright portions of the spatial code patterns QA2 to QA4 Is a feature region. For convenience of explanation, only the feature areas CA1 to CA2 are displayed as the first reference image RA1 to the fourth reference image RA4 in FIG. Actually, a part of the measuring object 2 corresponding to the bright part of the spatial code patterns QA1 to QA4 is displayed.

Next, the calculation unit 65 detects a relative shake between the first measurement image M1 and the second measurement image M2. For example, the calculation unit 65 obtains rough three-dimensional coordinate data as in the first embodiment, and calculates the three-dimensional shape and the feature region CA1 of the first reference image RA1 and the feature region CA1 of the second reference image RA2. According to the correspondence with the two-dimensional coordinates, rotation and translation from the shape measuring device 1 to the surface 2f of the measurement object 2 are obtained. Then, the computing unit 65 calculates the rotation and translation of the feature area CA1 between the first reference image RA1 and the first reference image RA2 from the obtained rotation and translation, as the first measurement image M1 and the second measurement image M2. As information on relative shake between In practice, the shake is caused by the movement of the shape measuring apparatus 1. Similarly, the calculation unit 65 performs rotation and translation of the feature area CA2 between the second reference image RA2 and the third reference image RA3, relative to each other between the second measurement image M2 and the third measurement image M3. It asks for information about blurring. In addition, the arithmetic unit 65 rotates and translates the feature area CA2 between the third reference image RA3 and the fourth reference image RA4, and the relative blur between the third measurement image M3 and the fourth measurement image M4. As information about. Thus, the feature region is not limited to a common part in all reference images. Thereafter, the calculation unit 65 calculates the shape of the measurement object 2 based on the shake detection result and the first measurement image M1 to the fourth measurement image M4. In this case, the arithmetic unit 65 obtains the phase variations δ, δ2, and δ3 of the fringe pattern P for each pixel as in the first embodiment, and the initial phase distribution in consideration of the variations δ, δ2, and δ3. The blur is corrected by obtaining φ (u, v).

In this case, the arithmetic unit 65 may associate the spatial code patterns QA1 to QA4 with each stripe pattern P. In this case, the spatial code patterns QA1 to QA4 serve as structured light and reference light. As a result, the respective fringes (m−1) π to 2mπ (where m is an integer) of the sinusoidal fringe pattern P are identified in the respective regions within the projection region assigned with the spatial code. .

As described above, according to the second embodiment, when the first reference image R01 to the fourth reference image R04 are imaged, the spatial code patterns QA1 to QA4 are projected as the reference light, so that the measurement object 2 and The relative shake with the shape measuring apparatus 1 can be detected with high accuracy. Moreover, according to 2nd Embodiment, since the shape of the measurement target object 2 is calculated by correct | amending a measurement image based on the detected blur, the three-dimensional shape of a measurement target object can be measured accurately. Further, when the three-dimensional shape of the measurement object 2 is measured by combining the phase shift method and the spatial code method, the spatial code patterns QA1 to QA4 can be used as the reference light, thereby reducing the overall imaging time. can do.

Also, in the second embodiment, by projecting a code with a coarser pattern than a code with a finer pattern than the spatial code patterns QA1 to QA4 later, it is possible to easily detect the feature region as the imaging time elapses. In some cases, camera shake due to the user is likely to occur as the imaging time elapses. In such a case, measurement errors can be detected with high accuracy.

<Modification>
Next, a modification of the above embodiment will be described.
For example, in the first embodiment described above, an example in which the first reference image R01 to the fourth reference image R04 are captured after capturing the first measurement image M1 to the fourth measurement image M4 has been described as an example. However, the present invention is not limited to this. For example, as shown in FIG. 12, the first reference image RB1 of the measurement object 2 projected with the uniform pattern Q before imaging the first measurement image M1 of the measurement object 2 projected with the first stripe pattern P1. Then, after imaging the first measurement image M1 to the fourth measurement image M4, the second reference image RB2 of the measurement object 2 onto which the uniform pattern Q is projected may be imaged. In this case, the calculation unit 65 detects the feature region CB in the first reference image RB1 and the second reference image RB, and based on these feature regions CB, the measurement object 2 and the shape measuring device are obtained by the same method as described above. Detect relative shake between 1 and 1. In this case, since the time required for the projection of the uniform pattern Q and the imaging of the reference image is reduced as compared with the first embodiment, the overall imaging time can be reduced.

In the second embodiment, the case where the first measurement image M1 to the fourth measurement image M4 and the first reference image RA1 to the fourth measurement image RA4 are alternately captured has been described as an example. It is not limited to. For example, as shown in FIG. 13, the reference image may be continuously captured between the first measurement image M1 to the fourth measurement image M4. In FIG. 13, reference images RC1 and RC2 of the measurement object 2 onto which the spatial code pattern QA1 is projected are shown as continuously captured reference images. However, the present invention is not limited to this. For example, after capturing a reference image of the measurement object 2 onto which the spatial code pattern is projected, a reference image of the measurement object 2 onto which the uniform pattern Q is projected may be captured.

Moreover, in the said embodiment, although the measurement object 2 which projected the structured light and the measurement object 2 which projected the reference light were mentioned as an example and demonstrated, the structure imaged by the same imaging part 50 was demonstrated as an example. It is not limited. For example, as illustrated in FIG. 14, the shape measuring device 201 may include a second imaging unit 150 in addition to the imaging unit 50.

In this case, one of the imaging unit 50 and the second imaging unit 150 is used for imaging the measurement object 2 on which structured light is projected, and the other is used for imaging the measurement object 2 on which reference light is projected. Can be used.

In the shape measuring apparatus 201, the projection unit 10 scans in the second direction D2 while changing the light intensity periodically, for example, by setting the wavelength of the projection light 100D to a predetermined wavelength (eg, about 680 nm), The structured light is projected onto the measurement object 2. In the second imaging unit 150, a filter 153 that blocks light having a wavelength corresponding to the predetermined wavelength and transmits light having another wavelength is disposed between the light receiving optical system 151 and the imaging device 152. Thereby, when projecting structured light onto the measuring object 2, the imaging unit 50 can capture a measurement image of the measuring object 2 onto which the structured light is projected. In the second imaging unit 150, the structured light is blocked by the filter 153. Further, the second imaging unit 150 can acquire an image of the measurement object 2 by natural light as a reference image without projecting the reference light from the projection unit 10.

As described above, the measurement object 2 on which the structured light is projected and the measurement object 2 on which the reference light is projected are imaged by separate imaging units (the imaging unit 50 and the second imaging unit 150), thereby measuring the measurement object. It becomes possible to acquire the measurement image and the reference image of the object 2 at the same time. Thereby, the imaging time can be shortened.

In the above embodiment, the case where the shake is corrected after the shake is detected has been described as an example. However, the present invention is not limited to this. For example, the calculation unit 65 may determine whether or not to perform subsequent correction and measurement of the three-dimensional shape according to the degree of shake after detecting the shake. In this case, when the degree of blur exceeds a preset threshold value, it is possible to make a negative determination for subsequent correction and measurement of the three-dimensional shape. Moreover, when it is determined as NO, the calculation unit 65 may output a predetermined signal and warn the user. Then, the user who has received the warning may measure the shape of the measurement object again.

In the first embodiment, the first change information, the second change information, and the third change information are detected by using the first reference image R01 to the fourth reference image R04, respectively. However, the present invention is not limited to this. For example, at least two of the first change information, the second change information, and the third change information may be detected, and one other change information may be detected based on this. Thereby, shortening of processing time can be aimed at.

In the above-described embodiment, the case where the region corresponding to the corner 2a of the measurement object 2 and the periphery thereof is set as the feature region has been described as an example. However, the present invention is not limited to this. For example, as long as it is a part common to a plurality of reference images, another part may be used as the feature region. In addition, the configuration including three unit regions has been described as an example of the feature region. However, the configuration is not limited to this, and for example, a configuration including two or one unit region may be used. It may be configured to include two or more unit regions.

Further, the present invention is not limited to the case where the feature region is set in advance, and for example, the calculation unit 65 may automatically detect the feature region. As an example, after a plurality of reference images are captured, the calculation unit 65 may obtain a pattern that is commonly included in the plurality of reference images by a pattern matching method or the like. In this case, a closed shape such as an L-shaped part or a cross-shaped part can be selected as the pattern. In addition, a mark (for example, a circular seal or a QR code mark) arranged around the measurement object 2 or around it may be used as a feature region for the overlapping process described later. The positions and shapes of such marks are set in advance. Therefore, when the mark is used as the feature region, the feature region is set in advance. Moreover, in the said embodiment, although the case where the characteristic area | region was an area | region on the image of the measuring object 2 was mentioned as an example, it demonstrated as an example, but it is not limited to this. For example, a part of the measurement object 2 can be used as a feature region.

<Structure manufacturing system and structure manufacturing method>
FIG. 15 is a block diagram illustrating an example of an embodiment of a structure manufacturing system. The structure manufacturing system SYS illustrated in FIG. 15 includes the shape measuring device 1 (or the shape measuring device 201), the design device 710, the molding device 720, the control device (inspection device) 730, and the repair device 740. .

The design device 710 creates design information related to the shape of the structure. Then, the design device 710 transmits the produced design information to the molding device 720 and the control device 730. Here, the design information is information indicating the coordinates of each position of the structure. Further, the measurement object is a structure.

The forming apparatus 720 forms a structure based on the design information transmitted from the design apparatus 710. The molding process of the molding apparatus 720 includes casting, forging, cutting, or the like. The shape measuring devices 1 and 201 measure the three-dimensional shape of the structure (measurement object 2) produced by the forming device 720, that is, the coordinates of the structure. Then, the shape measuring devices 1, 201 transmit information indicating the measured coordinates (hereinafter referred to as shape information) to the control device 730.

The control device 730 includes a coordinate storage unit 731 and an inspection unit 732. The coordinate storage unit 731 stores design information transmitted from the design device 710. The inspection unit 732 reads design information from the coordinate storage unit 731. Further, the inspection unit 732 compares the design information read from the coordinate storage unit 731 with the shape information transmitted from the shape measuring devices 1 and 201. And the test | inspection part 732 test | inspects whether the structure was shape | molded according to design information based on the comparison result.

Further, the inspection unit 732 determines whether or not the structure molded by the molding device 720 is a non-defective product. Whether or not the structure is a non-defective product is determined based on, for example, whether or not the error between the design information and the shape information is within a predetermined threshold range. If the structure is not molded according to the design information, the inspection unit 732 determines whether the structure can be repaired according to the design information. If it is determined that it can be repaired, the inspection unit 732 calculates a defective portion and a repair amount based on the comparison result. Then, the inspection unit 732 transmits information indicating a defective portion (hereinafter referred to as defective portion information) and information indicating a repair amount (hereinafter referred to as repair amount information) to the repair device 740.

The repair device 740 processes the defective portion of the structure based on the defective portion information and the repair amount information transmitted from the control device 730.

FIG. 16 is a flowchart showing processing by the structure manufacturing system SYS, and shows an example of an embodiment of a structure manufacturing method. As shown in FIG. 16, the design device 710 creates design information related to the shape of the structure (step S31). The design device 710 transmits the produced design information to the molding device 720 and the control device 730. The control device 730 receives the design information transmitted from the design device 710. Then, the control device 730 stores the received design information in the coordinate storage unit 731.

Next, the molding apparatus 720 molds the structure based on the design information created by the design apparatus 710 (step S32). Then, the shape measuring devices 1 and 201 measure the three-dimensional shape of the structure formed by the forming device 720 (step S33). Thereafter, the shape measuring devices 1 and 201 transmit shape information that is a measurement result of the structure to the control device 730. Next, the inspection unit 732 compares the shape information transmitted from the shape measuring apparatuses 1 and 201 with the design information stored in the coordinate storage unit 731, and whether the structure has been molded according to the design information. Whether or not is checked (step S34).

Next, the inspection unit 732 determines whether or not the structure is a good product (step S35). If it is determined that the structure is a non-defective product (step S35: YES), the process by the structure manufacturing system SYS is terminated. On the other hand, when the inspection unit 732 determines that the structure is not a non-defective product (step S35: NO), the inspection unit 732 determines whether the structure can be repaired (step S36).

If the inspection unit 732 determines that the structure can be repaired (step S36: YES), the inspection unit 732 calculates the defective portion of the structure and the repair amount based on the comparison result of step S34. Then, the inspection unit 732 transmits the defective part information and the repair amount information to the repair device 740. The repair device 740 performs repair (rework) of the structure based on the defective part information and the repair amount information (step S37). Then, the process proceeds to step S33. That is, the process after step S33 is performed again with respect to the structure which the repair apparatus 740 performed repair. On the other hand, when the inspection unit 732 determines that the structure can be repaired (step S36: NO), the process by the structure manufacturing system SYS is terminated.

As described above, in the structure manufacturing system SYS and the structure manufacturing method, based on the measurement result of the structure by the shape measuring apparatuses 1 and 201, the inspection unit 732 determines whether the structure is manufactured according to the design information. judge. Accordingly, it can be accurately determined whether or not the structure manufactured by the molding apparatus 720 is a non-defective product, and the determination time can be shortened. Further, in the structure manufacturing system SYS described above, when the inspection unit 732 determines that the structure is not a non-defective product, the structure can be repaired immediately.

In the structure manufacturing system SYS and the structure manufacturing method described above, the molding device 720 may execute the processing again instead of the repair device 740 executing the processing.

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above-described embodiment without departing from the spirit of the present invention. In addition, one or more of the requirements described in the above embodiments may be omitted. Such modifications, improvements, and omitted forms are also included in the technical scope of the present invention. In addition, the configurations of the above-described embodiments and modifications can be applied in appropriate combinations. In addition, as long as it is permitted by law, the disclosure of all published publications and US patents related to the X-ray apparatus and the like cited in the above embodiments and modifications are incorporated herein by reference.

For example, in each of the above-described embodiments and modifications, the first direction D1 and the second direction D2 are orthogonal to each other, but are orthogonal if the first direction D1 and the second direction D2 are different directions. You don't have to. For example, the second direction D2 may be set to an angle of 60 degrees or 80 degrees with respect to the first direction D1.

Further, in each of the above-described embodiments and modifications, each drawing shows one or more optical elements, but unless the number to be used is specified, it is used as long as the same optical performance is exhibited. The number of optical elements to be performed is arbitrary.

In each of the above-described embodiments and modifications, the light for generating the structured light 101 and the reference light 102 by the light generation unit 20 and the like is light having a wavelength in the visible light region, light having a wavelength in the infrared region, and an ultraviolet region. Any of the light having a wavelength of may be used. By using light having a wavelength in the visible light region, the user can recognize the projection region 200. By using a red wavelength in the visible light region, damage to the measurement object 2 can be reduced.

Further, in each of the above-described embodiments and modifications, the scanning unit 40 uses an optical element that reflects structured light, but is not limited thereto. For example, a diffractive optical element, a refractive optical element, parallel flat glass, or the like may be used. The structured light may be scanned by vibrating a refractive optical element such as a lens with respect to the optical axis. As this refractive optical element, a part of the optical elements of the projection optical system 30 may be used.

In each of the above-described embodiments and modifications, the CCD camera 52a is used as the imaging unit 50, but the present invention is not limited to this. For example, an image sensor such as a CMOS image sensor (CMOS: Complementary Metal Oxide Semiconductor) may be used instead of the CCD camera.

Further, in each of the above-described embodiments and modifications, the 4-bucket method is used in which the phase of the fringe pattern P used in the phase shift method is shifted four times during one period, but is not limited thereto. For example, a 5-bucket method in which one period 2π of the phase of the fringe pattern P is divided into 5 or a 6-bucket method in which the period is also divided into 6 may be used.

In each of the above-described embodiments and modifications, the phase shift method is used, but the three-dimensional shape of the measurement object 2 is measured using only the spatial code method described in the second embodiment. But you can.

In the second embodiment described above, the fringe pattern P is imaged before the spatial code pattern QA is imaged, but this may be reversed.

In each of the above-described embodiments and modifications, the stripe pattern P and the spatial code pattern QA are expressed in white and black. However, the present invention is not limited to this, and either one or both of them may be monochromatic. For example, the stripe pattern P and the spatial code pattern QA may be generated in white and red.

Further, in each of the above-described embodiments and modifications, the blur between the first measurement image M1 and the second measurement image M2 and the second measurement image when the first measurement image M1 to the fourth measurement image M4 are projected. Although the blur between M2 and the 3rd measurement image M3 and the blur between the 3rd measurement image M3 and the 4th measurement image M4 were detected, it is not limited to this. For example, when the first reference image R01 to the fourth reference image R04 are projected, the blur between the first reference image R01 and the second reference image R02, and between the second reference image R02 and the third reference image R03. It is also possible to detect blurring and blurring between the third reference image R03 and the fourth reference image R04.

Further, in the above-described embodiment and modification, the projection unit 10, the imaging unit 50, the arithmetic processing unit 60, and the display device 70 have been described as an example of a configuration housed in a portable case 80. It is not limited to this. For example, the arithmetic device 60 and the display device 70 do not have to be arranged in the housing 80 and may be installed outside the housing 80. In this case, as the arithmetic device 60 and the display device 70, for example, a personal computer (including a notebook type and a desktop type) can be used.

Note that all functions of the arithmetic processing unit 60 may not be housed in a portable case, and some functions of the arithmetic processing unit 60 (the arithmetic unit, the image storage unit, the display control unit, and the setting information storage) May be provided to an external computer. Further, the present invention is not limited to the portable shape measuring devices 1 and 201. For example, a measuring machine in which a multi-joint arm is provided with a three-dimensional measuring unit or a stage on which a measuring object 2 is placed is three-dimensionally displayed. The present invention can also be applied to a stationary shape measuring apparatus such as a measuring machine in which the measuring unit is configured to be movable.

Even in this case, it is not necessary to synchronize the reciprocating vibration of the MEMS mirror and the light intensity emitted from the laser diode as in the above-described embodiment, and complicated and sophisticated synchronization control is not necessary. When carrying the shape measuring device housed in a portable case that can carry the projection unit 10, the imaging unit 50, the arithmetic processing unit 60, and the display device 70, the external measurement environment (temperature, humidity, atmospheric pressure, etc.) changes in particular. Although it becomes easy, even if the external environment changes, the shape of the measurement object 2 can be measured with high accuracy.

Moreover, in each above-mentioned embodiment and modification, when the measurement target object 2 does not fit in the imaging visual field of the imaging part 50, each different position of the measurement target object 2 is measured, and each measurement result is connected. The three-dimensional shape of the entire measurement object 2 may be measured. When connecting the measurement results, an overlapping process for overlapping a part of the measurement results may be used. This overlapping process is performed by the calculation unit 65.

The overlapping process will be described. First, the first portion of the measurement object 2 is imaged by the imaging unit 50. Next, the imaging unit 50 captures an image of the second part that partially overlaps the first part of the measurement object 2. The calculation unit 65 calculates a three-dimensional shape for each of the first part and the second part. Further, the calculation unit 65 searches for a portion where the first portion and the second portion overlap, and connects the three-dimensional shapes of the first portion and the second portion by overlapping the portions. Note that the calculation unit 65 searches for pixels in a predetermined area that is common coordinate data for the three-dimensional shape of the first portion and the three-dimensional shape of the second portion, and overlaps the first portion and the second portion. Judging.

The three-dimensional shape of the entire measurement object 2 is measured by repeatedly executing such processing until the entire measurement object 2 is imaged. According to this, even when the measuring object 2 is a large object, the three-dimensional shape of the entire measuring object 2 can be easily measured.

Further, a part of the configuration of the shape measuring apparatus 1 may be realized by a computer. For example, the calculation unit processing unit 60 may be realized by a computer. In this case, the computer captures the first reference image of the measurement object 2 according to the shape measurement program stored in the storage unit, the process of capturing the second reference image of the measurement object 2, and the first A process of imaging a measurement image of the measurement object 2 obtained by projecting the fringe pattern P onto the measurement object 2 simultaneously with or after the imaging of the first reference image and before the imaging of the second reference image; Processing for detecting a feature region (described later) from the first reference image, processing for detecting the feature region (described later) from the second reference image, feature region in the first reference image, and second reference image The shape of the measuring object 2 is determined based on the processing for detecting the relative shake between the measuring object 2 and the shape measuring device 1 based on the characteristic area in FIG. Processing to calculate.

Note that the requirements of the above-described embodiments can be combined as appropriate. Some components may not be used. In addition, as long as it is permitted by law, the disclosure of the text is incorporated with the disclosure of all published publications and US patents related to the detection methods, shape measurement methods, shape measurement devices, etc. cited in the above embodiments and modifications. Part.

C, CA: Feature region, D1: First direction, D2: Second direction, SYS: Structure manufacturing system, P: Stripe pattern, Q: Uniform pattern, QA: Spatial code pattern, M1 to M4: First 1 measurement image to 4th measurement image, R01 to R04, RA1 to RA4 ... 1st reference image to 4th reference image, 1 ... shape measuring device (shape measuring device, measuring machine), 2 ... measurement object, 10 ... projection , 20 ... light generation unit, 40 ... scanning unit, 50 ... imaging unit, 60 ... calculation processing unit, 62 ... control unit, 62a ... first control unit, 62b ... second control unit, 65 ... calculation unit, 70 ... Display device, 100: projection light, 101: structured light, 102: reference light

Claims

In a detection method for detecting a relative shake between a measuring machine that measures the shape of a measurement object and the measurement object,
Capturing a first reference image of the measurement object with the measuring instrument;
Capturing a second reference image of the measurement object with the measuring instrument;
The measurement object obtained by projecting the structural light for shape measurement from the measuring instrument onto the measurement object at the same time as or after the imaging of the first reference image and before the imaging of the second reference image. Taking an image of an object with the measuring machine;
Detecting a feature region from the first reference image;
Detecting the feature region from the second reference image;
Detecting relative blur between the measurement object and the measuring device based on the feature region in the first reference image and the feature region in the second reference image;
A detection method comprising:
The detection method according to claim 1, wherein the feature region includes a plurality of regions.
The imaging of the first reference image is performed by projecting first reference light onto the measurement object,
The detection method according to claim 1, wherein the second reference image is captured by projecting second reference light onto the measurement object.
The first reference light and the second reference light are light set so as to include light having a uniform intensity distribution or light having a rectangular wave-like intensity distribution as a spatial code. Item 4. The detection method according to Item 3.
The structure light is light set to include light having a sinusoidal intensity distribution or light having a rectangular wave intensity distribution as a spatial code. The detection method according to.
The detection method according to claim 1, wherein the shake is at least one of a relative position change and a posture change between the measurement object and the measuring device.
Imaging of the image of the measurement object
Projecting first structured light having a predetermined intensity distribution as the structured light to capture a first image of the measurement object;
2. After capturing the first image, projecting second structured light having a different intensity distribution from the first structured light as the structured light to capture a second image of the measurement object. The detection method according to claim 6.
The imaging of the first reference image is performed simultaneously with or before the imaging of the first image,
The imaging of the second reference image is performed simultaneously with or before the imaging of the second image,
Capturing a third reference image of the measurement object with the shape measuring device after capturing the second image,
The detection of the blur is at least one of a relative position change and a posture change between the measurement object and the measuring device based on the feature region in the first reference image and the second reference image. Detecting a first change information regarding the relative position change between the measurement object and the measuring device based on the second reference image and the feature region in the third reference image, and The detection method according to claim 7, comprising: detecting second change information related to at least one of posture changes; and detecting the shake based on the first change information and the second change information.
Capturing an image of the measurement object obtained by projecting the structured light for shape measurement from the measurement machine onto the measurement object; and
Detecting a relative shake between the measurement object and the measuring device by the detection method according to any one of claims 1 to 8;
Calculating the shape of the measurement object based on the image of the measurement object and the blur;
A shape measuring method including:
Calculating phase information from an image of the measurement object;
Correcting the calculated phase information based on the blur;
Including
The shape measurement method according to claim 9, wherein the measurement of the shape of the measurement object is performed based on the corrected position information.
A shape measuring device for measuring the shape of a measurement object,
A projection unit that projects at least structured light for shape measurement onto the measurement object;
An imaging unit that captures an image of the measurement object;
The first reference image of the measurement object is imaged by the imaging unit, the second reference image of the measurement object is imaged by the imaging unit, and at the same time or after the imaging of the first reference image. Before the imaging of the second reference image, the imaging unit projects an image of the measurement object obtained by projecting the structured light for shape measurement from the projection unit onto the measurement object. A control unit for imaging
A feature region is detected from the first reference image, the feature region is detected from the second reference image, the feature region in the first reference image, and the feature region in the second reference image; And a calculation unit that detects a relative shake between the measurement object and the measuring device and calculates a shape of the measurement object based on the image of the measurement object and the shake. Shape measuring device.
The shape measuring apparatus according to claim 11, wherein the feature region includes a plurality of regions.
The projection unit can project the first reference light and the second reference light onto the measurement object,
The controller is
Projecting the first reference light onto the object to be measured to capture the first reference image;
The shape measuring apparatus according to claim 11, wherein the second reference light is projected onto the measurement object to capture the second reference image.
The first reference light and the second reference light are light set so as to include light having a uniform intensity distribution or light having a rectangular wave-like intensity distribution as a spatial code. Item 14. The shape measuring apparatus according to Item 13.
The structure light is light set to include light having a sinusoidal intensity distribution or light having a rectangular wave intensity distribution as a spatial code. The shape measuring device described in 1.
The detection method according to any one of claims 11 to 15, wherein the shake is at least one of a relative position change and a posture change between the measurement object and the measuring device.
As the imaging of the image of the measurement object, the control unit,
Projecting a first structured light having a predetermined intensity distribution as the structured light to capture a first image of the measurement object;
17. The second image of the measurement object is captured by projecting second structured light having a different intensity distribution from the first structured light as the structured light after capturing the first image. The shape measuring apparatus as described in any one of them.
The controller is
Imaging the first reference image simultaneously with or before imaging the first image,
Imaging the second reference image simultaneously with or before imaging the second image,
After capturing the second image, the shape measuring device captures a third reference image of the measurement object,
The calculation unit relates to at least one of a relative position change and a posture change between the measurement object and the measuring device based on the feature region in the first reference image and the second reference image. First change information is detected, and based on the feature region in the second reference image and the third reference image, a relative position change and posture change between the measurement object and the measuring machine are detected. The shape measuring apparatus according to claim 17, wherein second change information relating to at least one of them is detected, and the shake is detected based on the first change information and the second change information.
A design device for creating design information on the shape of the structure;
A molding apparatus for producing the structure based on the design information;
The shape measuring device according to any one of claims 11 to 18, which measures the shape of the manufactured structure,
An inspection device for comparing shape information on the shape of the structure obtained by the shape measuring device with the design information;
Structure manufacturing system including.
Creating design information on the shape of the structure;
Producing the structure based on the design information;
The shape measuring method according to claim 9 or 10, wherein the shape of the manufactured structure is measured,
Comparing the shape information on the shape of the structure obtained by the shape measuring method with the design information;
A structure manufacturing method comprising:
A computer included in a shape measuring apparatus that measures the shape of the measurement object by capturing an image of the measurement object obtained by projecting the structured light for shape measurement onto the measurement object,
Processing to capture a first reference image of the measurement object;
Processing to capture a second reference image of the measurement object;
The image of the measurement object obtained by projecting the structural light for shape measurement onto the measurement object at the same time as or after the imaging of the first reference image and before the imaging of the second reference image. Processing to image,
Processing for detecting a feature region from the first reference image;
Processing for detecting the feature region from the second reference image;
A process for detecting a relative shake between the measurement object and the shape measuring device based on the feature region in the first reference image and the feature region in the second reference image;
Processing for calculating the shape of the measurement object based on the image of the measurement object and the blur;
A shape measurement program that executes