JP3922784B2 - 3D shape measuring device - Google Patents

Description

[0001]
[Technology to which the invention belongs]Field]
  The present invention relates to an apparatus for measuring a three-dimensional shape of a moving measuring object using a phase shift method, and is particularly suitable for an application for measuring a three-dimensional shape of a plate-like object such as an exterior material with high accuracy. is there.
[0002]
[Prior art]
  In the field of industrial products, when quantitatively evaluating a three-dimensional shape, a measurement method involving physical contact may cause scratches or the like due to contact, and may impair the appearance. Moreover, since it is desirable that measurement can be performed in-line during the manufacturing process, not offline or sampling, measurement without contact while moving is required. However, in a non-contact three-dimensional measuring apparatus such as an industrial product, in the light cutting method that is generally used, there is little data that is effective in a captured image for a target object that moves at high speed. Therefore, high-precision measurement cannot be performed. Therefore, in order to realize a measuring device that can measure an object moving at high speed in a non-contact and high-precision manner, an image processing device using a phase shift method that can make all points of the captured image effective data (JP-A-4-98111) has been proposed.
[0003]
  A procedure for measuring a three-dimensional shape by a phase shift method using a general CCD camera will be described with reference to FIG. When the light source 3 and the sine wave pattern filter 5 are combined to illuminate the measurement object 1 with illumination having a light intensity distribution in a sine wave pattern, and a point on the measurement object 1 is observed by the CCD camera 6, the CCD screen The intensity I of the upper point p (x, y) is given by
[0004]
  I = e + f · cosφ
  e: DC optical noise
  f: Contrast of sine wave
  φ: Phase given by the unevenness of the object
  The phase is changed to φ + 0, φ + π / 2, φ + π, and φ + 3π / 2 by moving the sine wave pattern, and images having intensity distributions I0, I1, I2, and I3 corresponding thereto are taken in to obtain the phase.
[0005]
  α = tan^-1{(I3-I1) / (I0-I2)}
  Using this phase, the three-dimensional coordinates (X, Y, Z) of the point P on the measurement object are given by the following equation.
  X = −sx
  Y = b + s (−c−y cos φ)
  Z = a + s (−d + ysinφ)
  s = (− b cos θ) / u
  θ = tan^-1(Lα / a)
  u = (− c−y cos φ) cos θ + (− d + y sin φ) sin θ
  φ = tan^-1(B / a)
  c = am
  d = bm
  l: pitch of the sine wave pattern projected on the reference plane
  m: Camera magnification
  The three-dimensional shape for the measurement object is measured from these equations.
[0006]
[Problems to be solved by the invention]
  As described above, the conventional apparatus using the phase shift method is only an apparatus that measures the height by moving the sine wave pattern, and there is no apparatus that moves and measures the object. Also, when the object is moving, unlike the case where the object is fixed, the moving object can create a blind spot due to a change in the incident angle, which has not occurred with conventional illumination, and the accuracy is reduced. There is. An object of the present invention is to propose a three-dimensional shape measuring apparatus capable of solving such problems, and to simplify the operation of three-dimensional shape measurement by the phase shift method.
[0007]
[Means for Solving the Problems]
  According to the present invention, in order to solve the above problem, as shown in FIGS. 1 and 2, in an apparatus for measuring a three-dimensional shape of a moving measuring object 1,
    Illuminating means (light source 3, lens 4, filter 5) for irradiating the measuring object 1 from above with substantially parallel light having a sine wave pattern-like light intensity distribution with a predetermined period in the moving direction of the measuring object 1;
    Imaging means for imaging the measurement object 1 (camera 6, lens 7, frame grabber 8);
    An image memory 9 for storing an image captured every time the measurement object 1 moves a distance corresponding to at least four phases (preferably phases 0, π / 2, π, 3π / 2);
    And an arithmetic means 10 for obtaining a height from an image in the image memory 9 by a phase shift method.
  Here, in order to adapt the period of the sine wave pattern and the moving speed of the measuring object 1, the distance corresponding to the phase π / 2 of the sine wave pattern is measured from the imaged light intensity distribution of the sine wave pattern. It is preferable to automatically set the moving speed of the measuring object 1 so that the measured distance is moved between a plurality of or one imaging interval. Alternatively, the moving speed of the measurement object is actually measured, and the period of the sine wave pattern may be set by an illuminating unit including a liquid crystal projector so as to match the moving speed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
  Example 1
  Hereinafter, the present invention will be described with reference to examples. FIG. 1 is a diagram showing an example of an apparatus for carrying out the present invention. The measurement object 1 is an exterior material and is moved in the direction indicated by the arrow G by the conveyor 2. A light source 3 and a lens 4 create parallel light, and a lighting unit formed by arranging a filter 5 having a sine wave pattern shade in front of the light source 3 makes the light and dark sine wave from right above the exterior material 1 as a measurement object. A pattern that changes to is projected. By displacing the optical axes of the camera 6 and the lens 7, the deformation of the projection pattern caused by the unevenness of the surface of the exterior material is observed by the imaging means arranged in an oblique direction so that the surface of the exterior material 1 as a measurement object is focused. The optical system is configured so that it can. The conveyor 2 moves by a distance L corresponding to the phase π / 2 of the sinusoidal light intensity distribution, and the camera 6 takes an image every time the conveyor 2 moves the distance L. FIG. 2 is a block diagram of the image processing system. The image from the camera 6 is input to the frame grabber 8, quantized, and transferred to the image memory 9. The image transferred to the image memory 9 is phase-calculated by the processing device 10 using the phase shift method, and the height is measured.
[0009]
  By using such a configuration, it is not necessary to make corrections due to changes in the incident angle of illumination at each point on the object surface due to movement, and it is possible to eliminate portions that are not illuminated, and the captured image Image processing using all points as data becomes possible, and the shape of the moving target object can be accurately measured three-dimensionally.
[0010]
  FIG. 3 shows a sine wave pattern projected by the apparatus of the present embodiment. The light and dark directions of the sine wave pattern are the same as the moving direction of the exterior material 1. FIG. 4 shows the images captured by the camera 6 of the present apparatus and captured at the movement distances 0, L, 2L, and 3L stored in the image memory 9, that is, the phase of the sine wave-shaped light intensity distribution is 0, π / 2, It is an image taken with a shift of π, 3π / 2.
[0011]
  (Example 2)
  The operation of Embodiment 2 of the present invention is shown in FIG. The configuration of the apparatus is the same as that shown in FIGS. FIG. 5 shows the timing of the imaging operation by the camera. In the figure, A is the exposure timing at which the electronic shutter of the CCD camera (that is, the electronic switch between the photoelectric conversion unit and the charge storage unit) opens, and B is the CCD camera. This is the timing of charge reading from the charge storage unit to the charge transfer unit (ie, the charge coupled device). Here, when the exposure interval is T and the moving distance of the measurement object corresponding to the phase π / 2 of the sinusoidal light intensity distribution is L, in this embodiment, the conveyor speed V = L / T continuously. The measurement object is moved, and the four pieces of image data shown in FIG. 4 are captured in a time of 4 frames (= 4T). Since this imaging is in synchronization with the conveyor speed, images whose phases are shifted by 0, π / 2, π, and 3π / 2 can be continuously captured in the image memory at the imaging interval T of the camera.
[0012]
  In this embodiment, an image whose phase is shifted by 0, π / 2, π, 3π / 2 can be captured in real time with respect to a continuously moving measuring object, so that shape measurement can be performed in the exterior material manufacturing process. In this case, it is possible to realize an inline compatible device instead of offline.
[0013]
  (Example 3)
  FIG. 6 shows an apparatus according to Embodiment 3 of the present invention. In this embodiment, the amount of movement of the conveyor 2 is monitored by the encoder 11, and the encoder 11 determines the timing of exposure to the camera 6 every time the measuring object 1 moves a distance L corresponding to the phase π / 2. Give a trigger. FIG. 7 shows the operation of this embodiment. In the figure, A shows the timing of exposure in response to the trigger from the encoder 11. In the operation of the second embodiment illustrated in FIG. 5, the exposure interval T is constant, but in the third embodiment, the exposure interval is determined according to the trigger signal interval supplied from the encoder 11. As a result, even if the speed of the conveyor 2 is not set accurately, it is possible to reliably capture images whose phases are shifted by 0, π / 2, π, 3π / 2 in the image memory. As described above, in this embodiment, the moving distance L can be accurately detected by using the encoder 11 that monitors the moving amount of the conveyor 2, and high-precision measurement is possible.
[0014]
  (Example 4)
  The operation of the fourth embodiment of the present invention is shown in FIG. The configuration of the apparatus is the same as that shown in FIGS. In the fourth embodiment, when the speed of the conveyor is slow and the measurement object is continuously moving at V = L / nT (n = 2, 3, 4,...), Every n times the imaging interval T of the camera. Extracting the image to be captured, that is, extracting only the images shifted by phase 0, π / 2, π, 3π / 2 from the plurality of images and thinning out the other images, the speed of the conveyor and the imaging The interval is adjusted.
[0015]
  In general, the production line speed in a factory is often determined in advance. In addition, the imaging interval of the camera is generally 1/30 second and is determined in advance. Therefore, the sine wave pattern must be set for the speed of the conveyor. As in the second embodiment, when V = L / T, if the conveyor speed V is slow, one cycle (= 4L) of the sine wave pattern is shortened, but on the CCD screen due to the pixel resolution of the CCD camera. In this case, the reflected light cannot be separated for each pixel and cannot be regarded as a sine wave distribution. Further, when the conveyor speed V is high, one cycle (= 4L) of the sine wave pattern becomes long, but it may not be possible to create a sine wave pattern within one field of view of the CCD camera.
[0016]
  In order to solve this problem, in this embodiment, when the speed of the conveyor is low, an image shifted in phase 0, π / 2, π, 3π / 2 is extracted from a plurality of images, and the conveyor The period of the sine wave pattern can be set regardless of the speed.
[0017]
  (Example 5)
  The operation of the fifth embodiment of the present invention is shown in FIG. The configuration of the apparatus is the same as that shown in FIGS. However, the light source is a strobe light source, and a trigger for determining the light emission timing is given by an encoder (see FIG. 6) that monitors the amount of movement of the conveyor. In FIG. 9, A shows the light emission of the strobe light source in response to the trigger from the encoder and the exposure timing of the CCD camera. B is the charge reading timing of the CCD camera. In this embodiment, only the image data read immediately after the flash emission is used. That is, as in Example 4, when the conveyor speed is slow and the measurement object is continuously moving at V = L / nT (n = 2, 3, 4,...), The measurement object is phase π / 2. Each time the distance L corresponding to is moved, a trigger signal is given to the strobe light source by the encoder, and an image whose phase is shifted by 0, π / 2, π, 3π / 2 is captured at the timing when the light source is emitted.
[0018]
  Next, a description will be given of an embodiment in which, when the conveyor speed is high, an image having a phase shifted by 0, π / 2, π, 3π / 2 in real time is fetched into a memory using a plurality of cameras or a plurality of illumination means. .
[0019]
  (Example 6)
  FIG. 10 shows an apparatus according to Embodiment 6 of the present invention. In the present embodiment, two cameras 6a and 6b are arranged at an interval L in the moving direction of the measurement object 1, and the measurement object 1 moving on the conveyor 2 is simultaneously imaged by these cameras 6a and 6b. The images are sequentially transferred to the image memory in the order of the cameras 6a and 6b.
[0020]
  FIG. 11 shows the operation of this embodiment. Images corresponding to phases 0 and π are continuously captured by the camera 6a, and images corresponding to phases π / 2 and 3π / 2 are continuously captured by the camera 6b. The image obtained by the first imaging is an image of phase 0 for the camera 6a and an image after movement of phase π / 2 for the camera 6b. Actually, the cameras 6a and 6b image the measurement object 1 at the same time, but the camera 6b is shifted by a distance L corresponding to the phase π / 2 with respect to the camera 6a. It will be the same as when the image was taken. The images obtained by the second imaging are images after movement by phase π for the camera 6a, and images after movement by phase 3π / 2 for the camera 6b. That is, the measurement object 1 moves by a distance (= 2L) corresponding to the phase π between the first imaging and the second imaging. Therefore, according to the present embodiment, if the imaging interval of the cameras 6a and 6b is T, the conveyor speed can be increased to V = 2L / T, and the image capture can be completed in 2T time. .
[0021]
  (Example 7)
  FIG. 12 shows an apparatus according to Embodiment 7 of the present invention. In the present embodiment, two cameras 6a and 6b are arranged in a direction perpendicular to the moving direction of the measurement object 1, and the synchronization signals of the cameras 6a and 6b are shifted by a half time (= T / 2) of the imaging interval T. Then, every time the measuring object 1 moving on the conveyor 2 moves by a distance L corresponding to the phase π / 2, the images are alternately captured, and the captured images are sequentially transferred to the image memory in the order of the cameras 6a and 6b. To do.
[0022]
  FIG. 13 shows the operation of this embodiment. The image corresponding to the phases 0 and π is the camera 6a, and the image corresponding to the phases π / 2 and 3π / 2 is the camera 6b, every time T / 2. Images are taken alternately and continuously. The image obtained by the first imaging is an image of phase 0 by the camera 6a, and the image obtained by the second imaging is an image after moving by phase π / 2 by the camera 6b. The image obtained by the third imaging is an image after movement by phase π by the camera 6a, and the image obtained by the fourth imaging is an image after movement by phase 3π / 2 by the camera 6b. During each imaging, the measuring object 1 moves a distance L corresponding to the phase π / 2. Therefore, also in this embodiment, the conveyor speed can be increased to V = 2 L / T, and the image capture can be completed in 2T time.
[0023]
  FIG. 14 shows the timing of the imaging operation by the cameras 6a and 6b of the present embodiment. In FIG. 14, A is an exposure for opening an electronic shutter (that is, an electronic switch between the photoelectric conversion unit and the charge storage unit) of the CCD camera. Timing B is the timing of charge reading from the charge storage section of the CCD camera to the charge transfer section (ie, the CCD section). As is apparent from this time chart, in this embodiment, all operations of the cameras 6a and 6b are shifted by a time of T / 2.
[0024]
  (Example 8)
  FIG. 15 shows the timing of the imaging operation according to the eighth embodiment of the present invention. The configuration of the apparatus is the same as in FIG. 12, and the images captured by the cameras 6a and 6b are the same as in FIG. In this embodiment, only the exposure timings of the cameras 6a and 6b are shifted by T / 2, and the other operations are synchronized. That is, the CCD camera captures the image at the moment when the electronic shutter is opened in the imaging interval T in the charge storage unit, and this image is read in accordance with the synchronization signal. Therefore, the image data of the cameras 6a and 6b Even if the reading timing is the same, the same operation as in the seventh embodiment can be realized if the exposure timing when the electronic shutter opens is shifted by T / 2.
[0025]
  In Examples 7 and 8, since the images of the cameras 6a and 6b are shifted by the optical axis interval of the cameras, only the images of the portions corresponding to the two cameras are used. Further, when the same field of view is imaged by tilting the cameras 6a and 6b, it is necessary to correct the image with respect to the tilt.
[0026]
  Example 9
  FIG. 16 shows an apparatus according to Embodiment 9 of the present invention. In this embodiment, the light source 3 for irradiating three-color light made by combining high-intensity LEDs of red, green, and blue, and three color filters 5R that allow only specific light of red, green, and blue to pass therethrough. , 5G, 5B are provided. In addition, a color camera 6c is used as the imaging means. FIG. 17 is a view of the arrangement of the three color filters as viewed from directly above. The phase of the sine wave pattern formed by the shades of red, green, and blue is shifted by π / 2. If the phase of the sine wave pattern formed by the shades of red is 0, the sine wave formed by the shades of green The phase of the wave pattern is delayed by π / 2, and the phase of the sine wave pattern formed by blue shading is further delayed by π / 2. Therefore, when the measurement object 1 moving on the conveyor 2 is imaged by the color camera 6c, the R, G, and B component images have phases of π / in the order of red, green, and blue as shown in FIG. The image is shifted by 2 and the phase 0 image (R component image), the image after shifting by phase π / 2 (G component image), and the image after shifting by phase π (B component image) are captured simultaneously. Will be the same. Then, after the measuring object 1 has moved a distance (= 3L) corresponding to the phase 3π / 2, if the R component image is captured again, the phase is shifted by 0, π / 2, π, 3π / 2 in real time. Images can be captured in memory. If the imaging interval by the color camera 6c is T, the speed of the conveyor 2 can be increased to V = 3L / T. In this embodiment, the light source 3 does not have to be an LED, and may be any light source that can irradiate light including three primary color components as a point light source substantially at the focal position of the lens. For example, a laser light source may be used.
[0027]
  (Example 10)
  FIG. 19 shows an apparatus according to Embodiment 10 of the present invention. In the present embodiment, a light source 3 that sequentially irradiates three colors of light by combining red, green, and blue high-intensity LEDs is provided, and a single gray filter is used as the filter 5 of the sine wave pattern. Further, a color camera 6c is used as the image pickup means. The measurement object 1 moving on the conveyor 2 is caused to emit red, green, and blue light sources 3 sequentially at an interval T / 3, picked up by a color camera 6c, and picked up images of the R, G, and B components. The images are transferred to the image memory one after another in the order of red, green, and blue.
[0028]
  First, when the red light source emits light, an image having a phase 0 (R component image) is captured as shown in FIG. 20. Next, when the green light source emits light after a lapse of T / 3, An image after shifting by π / 2 (image of the G component) is picked up, and further, when a blue light source emits light after a lapse of T / 3, an image after shifting by phase π (image of the B component) is picked up. The While the red, green, and blue light sources emit light sequentially, the electronic shutter of the color camera 6c is open, and charge accumulation of R, G, and B components is performed only when the strobe light source 3 emits light. As shown in FIG. 21, when the sequential light emission of the red, green, and blue light sources is completed, the image data is read out. Thereafter, the red light source emits light again after a lapse of T / 3 from the light emission of the blue light source, and an image (R component image) after a phase shift of 3π / 2 is taken.
[0029]
  Also in the present embodiment, as in the ninth embodiment, the speed of the conveyor can be increased to V = 3 L / T. Further, the light source may not be an LED, and any light source capable of sequentially irradiating three primary color lights as a point light source substantially at the focal position of the lens may be used. For example, a laser light source may be used.
[0030]
  (Example 11)
  FIG. 22 shows an apparatus according to Embodiment 11 of the present invention. In this embodiment, four cameras 6a, 6b, 6c, and 6d with red, green, blue, and infrared color filters are arranged at intervals L in the moving direction of the measurement object 1, and red, green, blue, A gray filter 5 having a sine wave pattern is arranged in front of a light source 3 that simultaneously emits four-color light produced by combining infrared high-intensity LEDs. In this embodiment, as shown in FIG. 23, an image corresponding to phase 0 is a red component image, an image corresponding to π / 2 is a green component image, an image corresponding to π is a blue component image, and 3π / 2. The image to be captured is captured as an infrared component image, and four images for calculating the phase can be captured at a time. However, the light source 3 does not have to be an LED, and any light source can be used as long as it can irradiate four-color light at the same focal point of the lens. For example, a laser light source may be used.
[0031]
  (Example 12)
  FIG. 24 shows an apparatus according to Embodiment 12 of the present invention. In this embodiment, the illumination means is arranged in both the front and rear directions of the moving direction of the measurement object 1, and the imaging means is arranged in the direction directly above the measurement object 1. In the three-dimensional shape measurement for a measuring object having a relatively deep groove shape such as an exterior material, the blind spot of the imaging unit and the blind spot of the illumination unit are problematic. That is, the light from the illumination means may not reach the deep part of the groove, or the field of view by the imaging means may not reach the deep part of the groove. Therefore, in this embodiment, the camera 6 as the image pickup means is arranged directly above the measurement object 1 so that it can be observed up to a deep part of the groove, and the illumination means is also arranged in the moving direction of the measurement object 1. It was arranged in both the front and rear directions so that it could illuminate the deep part of the groove. The pair of light sources 3a and 3b emit light alternately, and the light from each of the light sources 3a and 3b is converted into parallel light having different incident angles by the lenses 4a and 4b, and the light and darkness is changed into a sine wave pattern by the filters 5a and 5b. Projected onto the measurement object 1. The phase of the sinusoidal pattern projected onto the measurement object 1 is shifted by π / 4. This is to make the phase of the image captured by one of the light sources 3a and the image captured after the other light source 3b emits light later.
[0032]
  FIG. 25 shows an image captured by the camera 6 of this embodiment. First, the light source 3a emits light and a phase 0 image is captured. Next, the light source 3b emits light. At this time, as shown in FIG. 26, since the measurement object 1 is moved by a distance corresponding to the phase π / 4, the sine wave pattern irradiated by the light source 3b is Irradiation is performed by shifting the distance corresponding to the phase π / 4 compared to the sine wave pattern irradiated by the light source 3a. As a result, a phase 0 image is captured even when the light source 3b emits light. By synthesizing images captured when the light sources 3a and 3b emit light, an image having a phase 0 without a blind spot is captured. Next, the light source 3a emits light and an image of phase π / 2 is captured. At this time, the measurement object 1 moves by a distance corresponding to the phase π / 2 with respect to the previous light emission of the light source 3a. Yes. Next, the light source 3b emits light and an image having a phase of π / 2 is picked up. At this time, as described above, the measurement object 1 moves by a distance corresponding to the phase π / 4 as compared to when the light source 3a emits light. is doing. By synthesizing images captured when the light sources 3a and 3b emit light, an image having a phase π / 2 without a blind spot is captured. In the same manner, an image having a phase π and an image having a phase 3π / 2 without a blind spot are taken.
[0033]
  (Example 13)
  FIG. 27 shows an apparatus according to Embodiment 13 of the present invention. In this embodiment, red and blue light sources 3R and 3B are used in place of the light sources 3a and 3b of the twelfth embodiment, and a color camera 6c is used as an image pickup means. Further, the two sine wave patterns by the light sources 3R and 3B projected onto the measurement object 1 have the same phase, and the red and blue light sources 3R and 3B are continuously irradiated. The measurement object 1 moving on the conveyor 2 is imaged by the color camera 6c, and, as shown in FIG. 28, the R component image and the B component image are synthesized, so that the phase 0, π / 2 without a blind spot is obtained. , Π, 3π / 2 images are taken into the memory.
[0034]
  (Example 14)
  FIG. 29 shows an apparatus according to Embodiment 14 of the present invention. In this embodiment, two cameras 6 a and 6 b are arranged as imaging means in both the front and rear directions of the movement direction of the measurement object 1, and the illumination means is arranged in the direction directly above the measurement object 1. The two cameras 6a and 6b simultaneously capture images, and as shown in FIG. 30, the images of the cameras 6a and 6b are synthesized to obtain one image. Other configurations and operations are the same as those in the first embodiment.
[0035]
  (Example 15)
  FIG. 31 shows an apparatus according to Embodiment 15 of the present invention. In the present embodiment, it is possible to rotate the illumination means and the imaging means so as not to cause a blind spot. As described above, in the three-dimensional shape measurement for the measurement object having a relatively deep groove shape (vertical joint, horizontal joint, etc.) such as an exterior material, the blind spot of the camera and the blind spot of illumination become a problem. When a blind spot is generated when the direction of the joint coincides with the direction of illumination as shown in FIG. 32 (a), the filter 5 and the camera 6 are rotated, and a measurement without a blind spot as shown in FIG. 32 (b) is possible. It is what.
[0036]
  (Example 16)
  FIG. 33 shows the operation of the sixteenth embodiment of the present invention. In this embodiment, the measurement accuracy is improved by obtaining and correcting the change in the light intensity accompanying the change in the incident angle. In the measurement by the phase shift method, it is necessary to compare the intensities at the same point. Therefore, the change in the light intensity caused by the change in the incident angle to the camera with the movement of the measurement object affects the measurement accuracy. In order to solve this problem, in this embodiment, the change in the light intensity with respect to various incident angles θ1 to θ4 as shown in the figure is obtained in advance, and the incident angle is set before comparing the light intensity at the same point. Accordingly, the light intensity is corrected.
[0037]
  (Example 17)
  FIG. 34 shows the operation of the embodiment 17 of the present invention. In the present embodiment, a telecentric optical system is configured by using the camera 6 and the lens 7 so that the incident angle to the camera 6 can always be kept constant. Thereby, the change in the incident angle to the camera 6 is eliminated, the difference between the actual position and the imaging position is eliminated, and the measurement accuracy is improved.
[0038]
  (Example 18)
  FIG. 35 shows an apparatus according to Embodiment 18 of the present invention. In this embodiment, a distance L corresponding to π / 2 is obtained from a light intensity distribution in a sine wave pattern from an image on the conveyor 2 to be imaged (see FIG. 37), and the conveyor speed V = L / T is automatically set. It is to set. By this method, the conveyor control is simplified, and the shape of the moving measurement object can be accurately measured three-dimensionally.
[0039]
  (Example 19)
  FIG. 36 shows an apparatus according to Embodiment 19 of the present invention. In the figure, a filter 5 is composed of a liquid crystal element, and constitutes a liquid crystal projector together with a light source 3 and a lens 4. FIG. 37 shows a sine wave pattern projected on the reference plane by the liquid crystal projector and the distribution of the irradiation intensity thereof. In this embodiment, the conveyor speed V is actually measured, the period 4VT of the light intensity distribution in the sine wave pattern is obtained from the image on the conveyor to be imaged, and the gray image of the sine wave pattern is automatically set on the liquid crystal projector. By this method, the shape of the moving measurement object can be accurately measured three-dimensionally according to the conveyor speed.
[0040]
  (Example 20)
  FIG. 38 shows a cross-sectional shape of an exterior material to be subjected to shape measurement in Example 20 of the present invention. Many plate-like objects such as exterior materials are warped and conveyed on a conveyor. Therefore, in the present embodiment, as shown in FIG. 39, after the height calculation by the phase shift method, a low pass filter is applied to the whole to calculate only the shape of the warp, and by removing this height component, The actual shape of the exterior material is detected. Moreover, in the target object which has a specific design like an exterior material, it can be used also for the measurement of the design.
[0041]
  (Example 21)
  FIG. 40 shows a cross-sectional shape of an exterior material to be subjected to shape measurement in Example 21 of the present invention, and FIG. 41 shows a cross-sectional shape of the main part thereof. In the present embodiment, as shown in FIG. 42, after the height calculation by the phase shift method, first, the joint base where the height is the lowest is obtained, then the joint position is obtained from the height from the joint base, Find the width.
[0042]
【The invention's effect】
  According to the invention of claim 1, the speed of the measurement object is automatically set from the period of the sine wave pattern, and according to the invention of claim 2, the sine wave pattern is automatically set from the moving speed. Thus, the operation of three-dimensional shape measurement by the phase shift method can be simplified.
  According to the first or second aspect of the invention, the three-dimensional shape of the moving measuring object can be accurately measured by the phase shift method without causing a blind spot portion due to illumination..
[Brief description of the drawings]
[Figure 1]Example 1It is a perspective view which shows the whole structure of this apparatus.
[Figure 2]Example 1It is a schematic block diagram of the image processing part of the apparatus.
[Fig. 3]Example 1It is explanatory drawing which shows the sine wave pattern projected by the apparatus of.
[Fig. 4]Example 1It is explanatory drawing which shows the image taken in into the image memory of the apparatus.
[Figure 5]Example 2It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
[Fig. 6]Example 3It is a perspective view which shows the whole structure of this apparatus.
[Fig. 7]Example 3It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
[Fig. 8]Example 4It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
FIG. 9Example 5It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
FIG. 10Example 6It is a perspective view which shows the whole structure of this apparatus.
FIG. 11Example 6It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG.Example 7It is a perspective view which shows the whole structure of this apparatus.
FIG. 13Example 7It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 14Example 7It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
FIG. 15Example 8It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
FIG. 16Example 9It is a perspective view which shows the whole structure of this apparatus.
FIG. 17Example 9It is explanatory drawing which shows arrangement | positioning of the color filter used for this apparatus.
FIG. 18Example 9It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 19Example 10It is a perspective view which shows the whole structure of this apparatus.
FIG. 20Example 10It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 21Example 10It is explanatory drawing which shows the timing of the imaging operation by the apparatus of.
FIG. 22Example 11It is a perspective view which shows the whole structure of this apparatus.
FIG. 23Example 11It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 24Example 12It is a perspective view which shows the whole structure of this apparatus.
FIG. 25Example 12It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 26Example 12It is a perspective view for operation | movement description of this apparatus.
FIG. 27Example 13It is a perspective view which shows the whole structure of this apparatus.
FIG. 28Example 13It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 29Example 14It is a perspective view which shows the whole structure of this apparatus.
FIG. 30Example 14It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 31Example 15It is a perspective view which shows the whole structure of this apparatus.
FIG. 32Example 15It is explanatory drawing which shows the imaging operation by the apparatus of.
FIG. 33Example 16It is operation | movement explanatory drawing of this apparatus.
FIG. 34Example 17It is operation | movement explanatory drawing of this apparatus.
FIG. 35Example 18It is a perspective view which shows the whole structure of this apparatus.
FIG. 36Example 19It is a perspective view which shows the whole structure of this apparatus.
FIG. 37Example 19It is explanatory drawing which shows the distribution of the sine wave pattern and its irradiation intensity which are projected on a reference plane by the apparatus of FIG.
FIG. 38Example 20It is sectional drawing of the exterior material used as shape measurement object.
FIG. 39Example 20It is a flowchart which shows the operation | movement of.
FIG. 40Example 21It is sectional drawing of the exterior material used as shape measurement object.
41 is an enlarged cross-sectional view of a main part of FIG. 40. FIG.
FIG. 42Example 21It is a flowchart which shows the operation | movement of.
FIG. 43 is a perspective view for explaining the principle of a conventional example.
[Explanation of sign]
  1 Measurement object
  2 Conveyor
  3 Light source
  4 Lens
  5 Filter
  6 Camera
  7 Lens
  8 frame grabber
  9 Image memory
10 Image processing device

Claims (2)

In an apparatus for measuring the three-dimensional shape of a moving measuring object,
Illuminating means for irradiating the measurement object from above with substantially parallel light having a sine wave pattern-like light intensity distribution with a predetermined period in the moving direction of the measurement object;
Imaging means for imaging the measurement object;
Means for measuring a distance corresponding to the phase π / 2 minutes of the sine wave pattern from the imaged sine wave pattern-like light intensity distribution;
Means for automatically setting the moving speed of the measurement object so as to move the measured distance during a plurality of or one imaging interval;
An image memory for storing an image captured each time the measurement object moves a distance corresponding to at least four phases;
A three-dimensional shape measuring apparatus comprising: an arithmetic means for obtaining a height from an image in an image memory by a phase shift method. In an apparatus for measuring the three-dimensional shape of a moving measuring object,
Means for measuring the moving speed of the measurement object;
From a liquid crystal projector that irradiates the measurement object from above with a substantially parallel light having a sine wave pattern-like light intensity distribution with a predetermined period set to match the measured movement speed in the movement direction of the measurement object Lighting means,
Imaging means for imaging the measurement object;
An image memory for storing an image captured each time the measurement object moves a distance corresponding to at least four phases;
A three-dimensional shape measuring apparatus comprising: an arithmetic means for obtaining a height from an image in an image memory by a phase shift method.

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