JP7022661B2 - Shape measuring device and shape measuring method - Google Patents

Description

The present invention relates to a shape measuring device and a shape measuring method for measuring the shape of an object in a non-contact manner.

As a technique for measuring the three-dimensional shape of a three-dimensional object such as a metal part, a resin part, or a rubber part in a non-contact manner, a technique using light is often used. As an example, Patent Document 1 describes a shape measuring method for obtaining three-dimensional spatial coordinates of an object by a physical grid type shadow moire method. In this shape measuring method, a grid plate having a grid pattern is arranged in the vicinity of the object, and illumination light emitted from a light source such as a halogen lamp irradiates the object through the grid plate. As a result, a grid pattern is projected on the surface of the object. Further, the moire fringes generated by the grid pattern and the grid pattern are imaged by an image pickup unit such as a camera, and the three-dimensional spatial coordinates of the object are obtained from the image pickup result.

Japanese Unexamined Patent Publication No. 4-147001

According to the shape measurement technology using the shadow moiré method described above, or the shape measurement technology that combines the shadow moiré method with phase shift, the shape of an object is measured by optimizing the grid pitch of the grid pattern and the resolution of the image pickup unit. Can be done well. However, these shape measurement techniques are not always universal, and have a problem that accurate shape measurement is difficult for an object having a relatively large step portion such as a stepped gear.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a shape measuring device and a shape measuring method capable of accurately measuring the shape of an object even when the object has a step portion. And.

One aspect of the present invention is a shape measuring device that measures the shape of an object in a non-contact manner, and includes a pattern image that is arranged apart from the object in a first direction and is set based on a spatial coding method. A projection unit that emits pattern light in the first wavelength band toward an object and an illumination light in a second wavelength band that is arranged apart from the object in the first direction and is different from the first wavelength band are emitted toward the object. It is arranged between the light source unit and the object, the light source unit, and the projection unit in the first direction, and transmits all the light in the first wavelength band and shields a part of the light in the second wavelength band. A lattice plate that forms a lattice pattern and an object that can be imaged through the lattice plate are provided, and an object on which a pattern image is projected by irradiation with pattern light is imaged to acquire a pattern projection image, and irradiation with illumination light is performed. An image pickup unit that acquires a moire fringe image generated by superimposing an image of an object and an image of a grid pattern by imaging an object on which a grid pattern corresponding to the grid pattern is projected, and a moire fringe image captured by the image pickup unit. It is characterized by including a control unit that obtains three-dimensional spatial coordinates of an object based on a pattern projection image.

Further, another aspect of the present invention is a shape measuring method for measuring the shape of an object in a non-contact manner, in which a pattern light in a first wavelength band including a pattern image set based on a spatial coding method is applied to the surface of the object. The first shape measurement step of irradiating the object to project the pattern image and acquiring the pattern projection image by imaging the object on which the pattern image is projected, and the grid of the illumination light in the second wavelength band different from the first wavelength band. A second shape that illuminates the surface of an object through a pattern to project a lattice pattern, and also captures the object on which the lattice pattern is projected to acquire a moire fringe image generated by superimposing the image of the object and the image of the lattice pattern. It is characterized by including a measurement step and a coordinate determination step of obtaining three-dimensional spatial coordinates of an object based on a moire fringe image and a pattern projection image.

In the shape measurement of an object based on a moire fringe image (shadow moire method), it was difficult to measure the surface of an object with high accuracy in which a portion (that is, a step portion) where the surface of the object fluctuates greatly in the first direction exists. .. On the other hand, by combining the shadow moiré method with the spatial coding method based on the pattern image, the three-dimensional spatial coordinates of the object can be satisfactorily obtained.

As described above, since the three-dimensional spatial coordinates of the object are obtained by combining the shadow moire method and the spatial coding method, not only the object having no step portion but also the object having the step portion is the object. The shape of the object can be measured accurately.

It is a figure which shows the 1st Embodiment of the shape measuring apparatus of an object which concerns on this invention. It is a figure which shows typically the internal structure of the measuring head equipped in the shape measuring apparatus of FIG. It is a graph which shows the transmittance characteristic of a grid pattern. It is a flowchart which shows the shape measurement operation by the shape measuring apparatus shown in FIG. It is a figure which shows the shape measurement operation by simulation. It is a figure which shows the 2nd Embodiment of the shape measuring apparatus of an object which concerns on this invention. It is a figure which shows typically an example of the appearance inspection apparatus equipped with the 3rd Embodiment of the shape measuring apparatus which concerns on this invention. It is a figure which shows the 4th Embodiment of the shape measuring apparatus of an object which concerns on this invention.

FIG. 1 is a diagram showing a first embodiment of an object shape measuring device according to the present invention. This shape measuring device 1A is a device that measures the shape of an object W in a state where an object W having a relatively large step portion Wa such as a stepped gear is stationary. For the following description, the XYZ axis is set as shown in FIG. Here, the XY plane is a horizontal plane, and the Z axis coincides with the vertical axis. Further, the positive direction on the Z axis is a vertically upward direction.

The shape measuring device 1A has a holding unit 2 that holds the object W to be measured in a stationary state. A columnar member 3 is erected from the holding portion 2 in the vertical direction Z, and the measuring head 4 is vertically attached to the upper end portion of the columnar member 3 in the Z direction and is attached to the intermediate portion of the columnar member 3. The grid plate 5 is attached so as to be able to move up and down in the Z direction. The measuring head 4 and the grid plate 5 are connected to the elevating part 6. Then, by operating the elevating unit 6 in response to an elevating command from the control unit 10 that controls the entire device, the measuring head 4 and the grid plate 5 are moved according to the dimensions of the object W in the vertical direction Z, that is, the object height. It moves up and down integrally, and the grid plate 5 is positioned directly above the object W. Further, after the positioning of the grid plate 5 is completed, the first shape measurement step and the second shape measurement step are executed by the projector, the light source unit, and the image pickup unit built in the measurement head 4, respectively. The first shape measuring step and the second shape measuring step correspond to an example of the "first shape measuring process" and the "second shape measuring process" of the present invention, respectively.

FIG. 2 is a diagram schematically showing the internal structure of the measuring head. The projector 7, the light source unit 8, and the image pickup unit 9 built in the measurement head 4 are all arranged apart from the object W in the (+ Z) direction, and face the surface of the object W with the grid plate 5 interposed therebetween. There is. Of these, the projector 7 emits the pattern light L1 in the first wavelength band λ1 including the pattern image set based on the spatial coding method toward the object W. As shown in the column (a) of FIG. 2, the pattern light L1 irradiates the object W through the lattice plate 5 in the first shape measuring step. In the present embodiment, a gray code is used as the pattern image, and the projector 7 corresponds to an example of the "projection unit" of the present invention.

Further, the light source unit 8 has three light sources 81 to 83 arranged in a row while being separated from each other by a predetermined interval in the X direction. The light sources 81 to 83 are point light sources composed of LEDs (Light Emitting Diodes), LDs (Laser Diodes), and the like, and all of them are capable of emitting illumination light L2 in the second wavelength band λ2 (≠ λ1). For example, the first wavelength band λ1 and the second wavelength band λ2 can be defined as a “red wavelength band” and a “blue wavelength band”, respectively.

The light sources 81 to 83 can be independently turned on and off in response to a lighting command from the control unit 10. Then, in the second shape measurement step, as shown in the column (b) of FIG. 2, the light source 81 located at the uppermost stream in the X direction is turned on for a certain period of time. That is, the light source 81 is turned off after the illumination light L2 is applied to the object W through the grid plate 5. Following this, the light sources 82 and 83 are turned on in this order for a certain period of time in the same manner as the light source 81, and then turned off.

In this way, the pattern light L1 and the illumination light L2 having different wavelength bands are incident on the lattice plate 5, but in the present embodiment, the entire pattern light L1 is projected onto the object W in the first shape measurement step, while the second pattern light L1 is projected onto the object W. 2 In the shape measurement step, it is necessary to project a lattice image onto the surface of the object W using the illumination light L2 in the second wavelength band. Therefore, in the present embodiment, the lattice plate 5 is configured as follows.

As shown in FIGS. 1 and 2, the lattice plate 5 is provided on the main surface of the flat plate base material 51 and the flat plate base material 51 on the (+ Z) direction side at a predetermined pitch so as to be separated from each other and has a sinusoidal grid pattern. It has a plurality of pattern members 52 constituting (reference numeral G in FIG. 5). The flat plate base material 51 is made of a glass plate, a plastic plate, or the like, and has the first optical property of transmitting light in the first wavelength band λ1 and the second wavelength band λ2. On the other hand, each pattern member 52 is manufactured by patterning a dielectric film or the like, and as shown in FIG. 3, it transmits light in the first wavelength band λ1 while blocking light in the second wavelength band λ2. It has a second optical characteristic. The vertical axis and the horizontal axis in FIG. 3 indicate "transmittance" and "wavelength", respectively.

The lattice plate 5 configured in this way is irradiated with the pattern light L1 in the first wavelength band λ1, and the pattern light L1 passes through the lattice plate 5 as it is and is irradiated to the object W. As a result, the Gray code is projected on the surface of the object W, and the shape of the object W can be measured by a conventionally known spatial coding method (first shape measuring step). On the other hand, when the illumination light L2 in the second wavelength band λ2 is irradiated to the lattice plate 5, the light irradiated to the pattern member 52 in the illumination light L2 is shielded by the pattern member 52, and the rest is transmitted through the flat plate base material 51. Then, the object W is irradiated. Therefore, a grid image corresponding to the sinusoidal grid pattern (reference numeral G in FIG. 5) is projected on the surface of the object W. In this way, the grid plate 5 functions as a grid that does not transmit only to the specific second wavelength band λ2.

The image pickup unit 9 has a monochrome image pickup element 91 that acquires a monochrome image, and an image pickup lens 92 that forms an image of an object W on the image pickup surface 911 (see FIG. 5) of the monochrome image pickup element 91. Therefore, as shown in the column (a) of FIG. 2, when the projector 7 emits the pattern light L1 toward the object W in response to the projection command from the control unit 10 with the light sources 81 to 83 turned off, As described above, the Gray code is projected on the surface of the object W, and the monochrome image pickup element 91 takes an image of the object W. The image captured in this way is an example of the "pattern projection image" of the present invention, and the image data is transferred from the monochrome image sensor 91 to the control unit 10, and the shape of the object W can be measured by the spatial coding method. (First shape measurement step).

On the other hand, when the light sources 81 to 83 are sequentially turned on while the projection by the projector 7 is restricted, the grid image is projected on the surface of the object W as described above. Since the image pickup unit 9 captures the object W on which the grid image is projected through the grid plate 5, the image captured by the monochrome image sensor 91 is a sine with the image of the object W on which the grid image is projected. A moire fringe image generated by superimposing images of a wave grid pattern is included. This image data is transferred from the monochrome image sensor 91 to the control unit 10, and the shape of the object W can be measured by the shadow moire method (second shape measurement step). Further, in this embodiment, in order to execute the shadow moiré method with phase shift as described in detail later, the light sources 81 to 83 are sequentially made to emit light at different timings to move the lattice pattern on the surface of the object W. ing. Then, the grid pattern moving in this way is imaged by the image pickup unit 9.

The control unit 10 has a computer composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. Then, the control unit 10 controls the operation of each unit of the device as described above to image the surface of the object W on which the gray code is projected to acquire a pattern projection image (first shape measurement step), and the light source 81. Acquiring a moire fringe image (second shape measurement step) while moving the lattice pattern on the surface of the object W in the arrangement direction of the light sources 81 to 83 in accordance with the lighting switching of the objects W to 83 is continuously executed. Further, the control unit 10 determines the three-dimensional spatial coordinates of the object W based on the image thus obtained (= pattern projection image + moire fringe image) (coordinate determination step). The execution of such a first shape measuring step, a second shape measuring step, and a coordinate determination step will be described with reference to FIGS. 4 and 5.

FIG. 4 is a flowchart showing a shape measuring operation by the shape measuring device shown in FIG. Further, FIG. 5 is a diagram simulating the shape measurement operation. In the shape measuring device 1A, when the object W to be measured is held by the holding portion 2, the first shape measuring step (step S1), the second shape measuring step (step S2), and the coordinate determination step (step S3) are performed. Execute in this order.

In the first shape measurement step, the projector 7 emits the pattern light L1 of the first wavelength band λ1 including the Gray code toward the object W with the light sources 81 to 83 turned off, and the object is emitted through the lattice plate 5. Irradiate W. As a result, the Gray code is projected onto the surface of the object W (step S1-1). At this time, since the pattern light L1 is light having a wavelength band λ1, the object W passes through the grid plate 5 as it is as shown in the column (a) of FIG. 5 without being affected by the sinusoidal grid pattern G. The surface is irradiated.

Then, a well-known spatial coding method, for example, a journal of the Institute of Electronics, Information and Communication Engineers, March 1985, Vol. J68-D No. The three-dimensional coordinates (X, Y, Z) of the point P of the object W are measured by the spatial coding method described on pages 369 to 371 of 3. That is, in the pattern light L1, a plurality of projected lights are irradiated toward the object W with a certain spread, and the pattern light L1 is assigned to a fine fan-shaped region (in the column (a) of the figure, one of them). It is divided into (shown with dots), and each space thus formed is coded, that is, a projected light code is given to each space (step S1-2). Then, with respect to the X and Y coordinates of the point P of the object W, the direction of the point P as seen from the image pickup unit 9 obtained from the coordinates C (x, y) on the image pickup surface 911 of the projected monochrome image sensor 91. That is, the angle θ with respect to the vertical direction Z is calculated (step S1-3). Further, a fan-shaped region is specified from the light / dark pattern (projected light code) of the Gray code of the coordinates C (x, y), and the irradiation direction of the projected light in the fan-shaped region to the point P, that is, the angle ψ with respect to the vertical direction Z. Is calculated (step S1-4). Further, the Z-axis coordinates of the point P in the vertical direction Z are calculated by the principle of triangulation (step S1-5), and the X and Y coordinates of the point P are calculated (step S1-6). The three-dimensional position of the point P calculated in this way, that is, the three-dimensional coordinates P (X, Y, Z) is stored in the memory of the control unit 10. In this embodiment, the origin of the three-dimensional coordinates is set to the principal point O of the imaging lens 92.

When the shape measurement of the object W by the space coding method, that is, the first shape measurement step (step S1) is completed in this way, the shadow moire method accompanied by a phase shift, for example, the method described in Patent Document 1, is a tertiary of the point P of the object W. The original coordinates (X, Y, Z) are measured (second shape measuring step: step S2). That is, while the emission of the pattern light L1 from the projector 7 is stopped, the light source 81 is turned on as shown in the column (b) of FIG. 5, and the illumination light L2 in the second wavelength band λ2 is emitted toward the object W. Then, a grid image corresponding to the sinusoidal grid pattern G is projected on the surface of the object W (step S2-1). Then, the monochrome image sensor 91 images the object W on which the grid pattern is projected via the grid plate 5. This means that the imaging of the object W is repeated while the timing of the light emission of the light sources is different until it is confirmed in step S2-2 that the imaging of the object W is completed for all the light sources 81 to 83. More specifically, the light source 82 is turned on after the light source 81 is turned off, and the object W on which the grid pattern is projected is imaged through the grid plate 5 in the same manner as when the light source 81 is turned on. Further, following the extinguishing of the light source 82, the light source 83 is turned on, and the object W on which the lattice pattern is projected is imaged through the lattice plate 5 in the same manner as when the light sources 81 and 82 are turned on.

Then, when it is confirmed that the imaging of the object W is completed for all the light sources 81 to 83 (“YES” in step S2-2), the monochrome image pickup element 91 with respect to the point P (X, Y, Z) of the object W. The phase value φ (x, y) is calculated from the coordinates C (x, y) on the image pickup surface 911 (step S2-3). In the column (b), the origin is the intersection of the grid surface of the sinusoidal grid pattern G and the optical axis OA of the imaging unit 9.

Here, the phase value φ (x, y) is within one pitch of the pattern member 52 in which the shape of the object W to be measured is continuously changing or the step portion Wa constitutes the sinusoidal grid pattern G. In the case of, 2π can be simply added, but when there is a step of 1 pitch or more, the phase jump corresponds to a multiple of 2π, that is, the fringe order n (x, y). Need to be asked.

Therefore, in the present embodiment, the coordinate determination step (step S3) is executed. In this coordinate determination step, the fringe order n (x, y) is determined based on the three-dimensional coordinates (X, Y, Z) of the point P obtained in the first shape measurement step (step S1) (step S3-1). ). Then, the unwrapping process is performed by the fringe order n (x, y), and the three-dimensional coordinates (X, Y, Z) calculated by the unwrapping process are set as the three-dimensional position of the point P (step S3-2).

As described above, according to the present embodiment, the following effects can be obtained. For an object W in which the shape of the object W is continuously changing or an object W in which a step portion Wa exists but is within one pitch of the pattern member 52, the object W is highly accurate by combining the shadow moiré method with the phase shift. The shape of W can be measured. Here, if a step portion Wa exceeding one pitch exists in the object W, phase wrap (skipping) occurs, but in the present embodiment, the unwrapping process is executed based on the position information obtained by the spatial coding method. There is. Therefore, the shape measurement can be performed with high accuracy not only for the object W having no step portion Wa but also for the object W having the step portion Wa.

Further, in order to measure the shape of the object W using only the second shape measuring step, the shape is measured by replacing it with a grid plate 5 having a grid pitch (pitch of adjacent pattern members 52) that matches the step portion Wa. Need to be done. On the other hand, in the present embodiment, the shape of the object W can be measured with high accuracy without changing the grid plate 5 by combining the spatial coding method based on the pattern image as described above.

FIG. 6 is a diagram showing a second embodiment of the object shape measuring device according to the present invention. The major difference between the shape measuring device 1B according to the second embodiment is that the shape of the object W is conveyed in the horizontal direction X by circulating the conveyor 22 by the conveyor driving unit 21. The point where the measurement is performed and the point where the phase shift is performed by the movement of the object W instead of performing the phase shift by switching the light sources 81 to 83 in the second shape measurement step, and the other configurations are basically the first. 1 It is the same as the embodiment. Also in this second embodiment, since the shadow moiré method accompanied by the phase shift and the spatial coding method are combined, the shape measurement of the object W can be performed with high accuracy regardless of the presence or absence of the step portion Wa. In the present embodiment, the conveyor 22 corresponds to an example of the "moving portion" of the present invention.

Further, the shape measuring device 1B configured in this way may be incorporated into a so-called visual inspection device that checks whether the object W has a defect such as a scratch as shown in FIG. 7, for example. As an example of the visual inspection apparatus, there is, for example, the one described in Japanese Patent Application Laid-Open No. 2017-227621. In this visual inspection device, in order to inspect the presence or absence of defects in a metal product (corresponding to an example of the "object" of the present invention) manufactured by forging or casting, the appearance inspection of the metal product is performed and the shape of the metal product is inspected. Extract the defect area containing the defect. Therefore, for example, as shown in FIG. 7, in the appearance inspection device 100, the appearance inspection unit 120 and the shape measurement unit 130 convey the object (metal product) W in a predetermined direction by a transfer mechanism 110 such as a conveyor, and the defect is caused by the shape measurement unit 130. It may be configured to measure the shape of the region. Hereinafter, the configuration and operation of the visual inspection apparatus 100 will be described with reference to FIG. 7.

FIG. 7 is a diagram schematically showing an example of an appearance inspection device equipped with a third embodiment of the shape measuring device according to the present invention. In the visual inspection device 100, the object W to be visually inspected is conveyed in the horizontal direction by the conveying mechanism 110. Further, the appearance inspection unit 120 and the shape measurement unit 130 are arranged side by side along the transport path of the object W. The visual inspection unit 120 is arranged on the upstream side (left-hand side in the figure) of the shape measuring unit 130 in the transport direction of the object W.

In the visual inspection unit 120, the image pickup camera 121 is arranged vertically above the transport mechanism 110. Further, two lighting fixtures 122 and 123 are arranged so as to sandwich the image pickup camera 121 diagonally above the transport mechanism 110. In the visual inspection apparatus 100, the data of the reference image acquired by imaging the object W previously determined to be a non-defective product by the image pickup camera 121 is stored. Then, when the object W to be inspected is conveyed to the appearance inspection unit 120 by the conveying mechanism 110, the object W is imaged by the image pickup camera 121, and the captured image and the reference image are compared to determine the presence or absence of a defect. do.

On the other hand, the shape measuring unit 130 is provided on the downstream side of the visual inspection unit 120 in the transport direction X of the object W. Similar to the above embodiment, the shape measuring unit 130 is provided with two sets of shape measuring units 131 for measuring the shape of the object W by the measuring head 4 and the grid plate 5 diagonally above the transport mechanism 110. A robot arm (not shown) is connected to each shape measuring unit 131, and the shape is measured by each shape measuring unit 131 in an arbitrary posture with respect to the object W conveyed from the visual inspection unit 120 by the conveying mechanism 110. Is feasible. Each shape measuring unit 131 is in a state where the posture is controlled so as to face the defect region found by the visual inspection unit 120, and the first shape measuring step, the second shape measuring step, and the coordinate determination are performed as in the above embodiment. The process is executed, the shape of the defect region is measured in detail, and the measurement result is output.

As described above, according to the visual inspection apparatus 100 shown in FIG. 7, it is possible to find a defect region existing on the surface of the object W and perform detailed shape measurement thereof, so that the inspection of the object W can be performed with high accuracy. It can be carried out. In the visual inspection device 100 shown in FIG. 7, the object W is conveyed to the shape measuring unit 130 by the transport mechanism 110 in the same posture as when it was inspected by the visual inspection unit 120, but the visual inspection unit 120 and the shape measurement are performed. An inversion mechanism (not shown) that adjusts the posture of the object W with the unit 130, for example, inverting the object W may be provided, whereby the range that can be measured by the shape measuring unit 130 can be expanded.

The present invention is not limited to the above-described embodiment, and various modifications can be made other than those described above as long as the present invention is not deviated from the gist thereof. For example, in the present embodiment, the first shape measurement step (step S1) and the second shape measurement step (step S2) are executed in this order using the monochrome image sensor 91, but these orders are reversed. May be good. Further, the first shape measurement step (step S1) and the second shape measurement step (step S2) may be performed at the same time by using a color image sensor such as a color CCD or a color CMOS instead of the monochrome image sensor 91. In this case, the time required for shape measurement can be shortened.

Further, in order to simultaneously perform the first shape measurement step (step S1) and the second shape measurement step (step S2), instead of the monochrome image sensor 91, the two monochrome image sensors 93, as shown in FIG. 94 and a color separation element 95 such as a dichroic mirror may be provided (fourth embodiment).

FIG. 8 is a diagram showing a fourth embodiment of the object shape measuring device according to the present invention. In this fourth embodiment, when the first shape measurement step (step S1) and the second shape measurement step (step S2) are performed at the same time, the light in the first wavelength band λ1 and the light in the second wavelength band λ2 are used. Although it is incident on the image pickup unit 9, in the present embodiment, the color separation element 95 is arranged on the emission side of the image pickup lens 92. The color separation element 95 reflects the light of the first wavelength band λ1 and guides it to the first monochrome image pickup element 93, and at the same time, transmits the light of the second wavelength band λ2 as it is and guides it to the second monochrome image pickup element 94. .. Therefore, the first monochrome image pickup element 93 receives the light in the first wavelength band and receives the light in the first wavelength band in the first shape measurement step (step S1), and the second monochrome image pickup element 94 receives the light in the second wavelength band to measure the second shape. The step (step S2) can be executed at the same time, and the time required for shape measurement can be shortened.

Further, in the above embodiment, in order to execute the second shape measurement step (step S2), a point light source is used as the three light sources 81 to 83, but a line light source may be used. Further, the number of light sources is not limited to "3", and may be 4 or more.

Further, in the second shape measurement step (step S2), the phase shift is also used, and the combined use of the phase shift is suitable for improving the accuracy of the shape measurement, but the space is one of the technical features of the present invention. It is not an essential configuration for the combination with the coding method, but an arbitrary configuration.

The present invention can be applied to all shape measuring techniques for measuring the shape of an object in a non-contact manner.

1A, 1B ... Shape measuring device 5 ... Lattice plate 7 ... Projector (projection unit)
8 ... Light source unit 9 ... Imaging unit 10 ... Control unit 22 ... Conveyor (moving unit)
51 ... Flat plate substrate 52 ... Pattern member 81-83 ... Light source 91 ... Monochrome image sensor 93 ... First monochrome image sensor 94 ... Second monochrome image sensor 95 ... Color separation element 131 ... Shape measurement unit (shape measurement device)
G ... Sine and cosine grid pattern L1 ... Pattern light L2 ... Illumination light λ1 ... First wavelength band λ2 ... Second wavelength band W ... Object Wa ... Step portion X ... Horizontal direction (second direction)
Z ... Vertical direction (first direction)

Claims (8)

A shape measuring device that measures the shape of an object in a non-contact manner.
A projection unit that is arranged apart from the object in the first direction and emits pattern light in the first wavelength band including a pattern image set based on the spatial coding method toward the object.
A light source unit that is arranged apart from the object in the first direction and emits illumination light in a second wavelength band different from the first wavelength band toward the object.
Arranged between the object and the light source unit and the projection unit in the first direction, all the light in the first wavelength band is transmitted, and a part of the light in the second wavelength band is shielded. And the lattice plate that forms the lattice pattern,
The object is provided so as to be able to image through the lattice plate, and the object on which the pattern image is projected by irradiation with the pattern light is imaged to obtain a pattern projection image, and the lattice pattern is obtained by irradiation with the illumination light. An imaging unit that acquires a moire fringe image generated by superimposing an image of the object and an image of the lattice pattern by imaging the object on which the lattice pattern corresponding to the above is projected.
A shape measuring device including a control unit for obtaining three-dimensional spatial coordinates of the object based on the moire fringe image captured by the image pickup unit and the pattern projection image. The shape measuring device according to claim 1.
The grid plate is
A flat plate substrate having the first optical property of transmitting light in the first wavelength band and the second wavelength band,
It has a second optical property of transmitting light in the first wavelength band while blocking light in the second wavelength band, and is provided on one main surface of the flat plate substrate so as to be separated from each other. A shape measuring device having a plurality of pattern members constituting a pattern. The shape measuring device according to claim 1 or 2.
The image pickup unit captures the object with a monochrome image sensor that acquires a monochrome image, and the image pickup unit captures the object.
The control unit emits the pattern light and the illumination light individually, and executes a first shape measurement process for acquiring the pattern projection image by the image pickup unit in response to the emission of the pattern light, and the illumination. A shape measuring device that executes a second shape measuring process for acquiring a moire fringe image by the imaging unit in response to light emission. The shape measuring device according to claim 1 or 2.
The image pickup unit captures the object with a color image sensor that acquires a color image, and the image pickup unit captures the object.
The control unit simultaneously emits the pattern light and the illumination light, and the first shape measurement process for acquiring the pattern projection image by the image pickup unit and the second shape measurement for acquiring the moire fringe image by the image pickup unit. A shape measuring device that performs processing at the same time. The shape measuring device according to claim 1 or 2.
The image pickup unit has a color separation element that separates incident light into light in the first wavelength band and light in the second wavelength band, and light in the first wavelength band separated by the color separation element. It has a first monochrome image pickup element that receives light and captures the object, and a second monochrome image pickup element that receives light in the second wavelength band separated by the color separation element and captures the object.
The control unit simultaneously emits the pattern light and the illumination light, and acquires the pattern projection image by the first monochrome image sensor, and the moire fringe image by the second monochrome image sensor. A shape measuring device that simultaneously executes the second shape measuring process. The shape measuring device according to any one of claims 3 to 5.
In the light source unit, three or more light sources that emit illumination light are arranged in a row so as to be separated from each other.
The control unit
In the second shape measurement process, by causing the three or more light sources to emit light at different timings, the lattice pattern is moved on the surface of the object to change the phase.
Shape measurement that acquires the position information of the object based on the pattern projection image captured by the image pickup unit, unwraps the phase based on the position information, and determines the three-dimensional spatial coordinates of the object. Device. The shape measuring device according to any one of claims 3 to 5.
Further provided with a moving portion for moving the object in a second direction different from the first direction.
The control unit
In the second shape measurement process, the lattice pattern is moved on the surface of the object by the movement of the object in the second direction to change the phase.
Shape measurement that acquires the position information of the object based on the pattern projection image captured by the image pickup unit, unwraps the phase based on the position information, and determines the three-dimensional spatial coordinates of the object. Device. It is a shape measurement method that measures the shape of an object in a non-contact manner.
The surface of the object is irradiated with the pattern light of the first wavelength band including the pattern image set based on the spatial coding method to project the pattern image, and the object on which the pattern image is projected is imaged. The first shape measurement process to acquire the pattern projection image and
The surface of the object is irradiated with illumination light in a second wavelength band different from the first wavelength band to project a grid pattern, and the object on which the grid pattern is projected is imaged to capture the object. The second shape measuring step of acquiring a moire fringe image generated by superimposing the image of the above and the image of the lattice pattern, and
A shape measuring method comprising: a coordinate determination step of obtaining three-dimensional spatial coordinates of the object based on the moire fringe image and the pattern projection image.

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