JP2021143841A - Three-dimensional shape measuring device - Google Patents

Abstract

To provide a three-dimensional shape measuring device with which it is possible to suppress the occurrence of a region that constitutes a shade while suppressing the measurement time from becoming extended.SOLUTION: This three-dimensional shape measuring device comprises: projection means for projecting a plurality of patterns mutually different in phase to a measurement object; movement means for moving the projection means; photographing means for photographing the measurement object with each of the plurality of patterns projected thereto; a storage unit for storing a correspondence relation between the height of the measurement object and the phase acquired from the photographed image of the measurement object in cases when the projection means exists at a first position; measurement means for processing the image acquired by the photographing means and thereby measuring the three-dimensional shape of the measurement object; and update means which, when the projection means is moved to a second position by the movement means, updates the correspondence relation in accordance with a physical relationship between the first position and the second position.SELECTED DRAWING: Figure 4

Description

The present invention relates to a three-dimensional shape measuring device.

Conventionally, as a technique for measuring the three-dimensional shape of an object using an image, a pattern having periodicity is projected on the measurement target from a projection means such as a projector, and the measurement target in the state where the pattern is projected is photographed by a camera or the like. A phase shift method is known in which an image is taken by means and the three-dimensional shape of the object to be measured is obtained by using the relationship between the distortion of the pattern in the photographed two-dimensional image and the height of the object to be measured. Specifically, the three-dimensional shape of the measurement target is measured by analyzing the distortion of the pattern that occurs depending on the shape (unevenness, etc.) of the surface of the measurement target in the captured image.

In the above method, there is a problem that the pattern is blocked and a shadow is generated due to the shape of the surface of the measurement target, and therefore the three-dimensional shape may not be measured. In response to such a problem, Patent Document 1 proposes a technique of arranging a plurality of projection means so as to project patterns from different directions on a measurement target to reduce a shadowed area. Patent Document 2 proposes a technique for suppressing the formation of a shadow region by moving the projection means.

JP-A-2018-077251 JP-A-2018-081048

However, in the method of arranging a plurality of projection means, it is necessary to arrange a large number of projection means in order to sufficiently reduce the shadow area, which may increase the size of the entire measuring device and increase the cost. There is. Further, in the method of moving the projection means, the relationship between the distortion of the pattern in the two-dimensional image to be captured and the height of the measurement target is calibrated. Since the calibration takes several minutes to several tens of minutes, the measurement time of the three-dimensional shape may increase.

One aspect of the disclosed technique is to provide a three-dimensional shape measuring device capable of suppressing the occurrence of a shadow region while suppressing a long measurement time.

One aspect of the disclosed technique is illustrated by the following three-dimensional shape measuring device. In this three-dimensional shape measuring device, a projection means for projecting a plurality of patterns having different phases to a measurement target, a moving means for moving the projection means, and the measurement target on which each of the plurality of patterns is projected. A storage unit that stores the correspondence between the height of the measurement target and the phase acquired from the imaging of the measurement target when the projection means is present at the first position, and the shooting means. When the measuring means for measuring the three-dimensional shape of the measurement target and the projection means are moved to the second position by the moving means by processing the image acquired by the above, the first position and the second position. An update means for updating the correspondence relationship according to the positional relationship of the positions is provided.

With such a configuration, even if a shadow region is generated by projecting the pattern from a predetermined position, the projection means is moved so that the pattern is projected on the shadow region. It is possible to take a picture of the measurement target with the pattern projected on it. Therefore, the moving means may move the projection means to a position where the photographing means can shoot a pattern in which the measuring means can measure the three-dimensional shape of the measurement target. ..

In the conventional technique, when the projection means is moved, the angle at which the pattern is projected on the inspection target changes, so that the correspondence relationship stored in the storage unit is acquired again (initial calibration). In the disclosed technique, since the correspondence can be updated according to the positional relationship between the first position and the second position of the projection means, it is not necessary to perform the initial calibration even if the projection means is moved. Therefore, the disclosed technique can suppress a long measurement time due to the initial calibration.

Here, the moving means may rotate the projection means on a circumference centered on the measurement target. Then, in such a case, the updating means makes an angle formed by a first line segment connecting the first position and the center of the circumference and a second line segment connecting the second position to the center. The correspondence may be updated accordingly.

Further, according to the disclosed technique, the three-dimensional shape measuring device may have a plurality of the image projection means. With such a configuration, a plurality of patterns can be projected onto the measurement target at the same time, and the three-dimensional shape of the measurement target can be measured more efficiently.

Further, the moving means is a cylindrical rotation mechanism having a hollow portion that opens in the axial direction, and is arranged so that the opening is located above the measurement target, and the photographing means is placed on the measurement target. The measurement target may be photographed from a direction perpendicular to the measurement object through the opening of the rotation mechanism. With such a configuration, it is possible to photograph the measurement target from directly above while reducing the size of the entire device.

This three-dimensional shape measuring device can suppress the occurrence of a shadow region while suppressing a long measurement time.

FIG. 1 is a schematic view showing a hardware configuration of a three-dimensional shape measuring device according to an embodiment. FIG. 2 is a schematic view illustrating the arrangement relationship between the photographing means, the projection means, and the moving means of the three-dimensional shape measuring device according to the embodiment and the measurement target. FIG. 3 is a schematic view illustrating the internal structure of the moving means in the embodiment. FIG. 4 is a diagram illustrating a functional block of the three-dimensional shape measuring device according to the embodiment. FIG. 5 is a diagram showing an example of a target member used in initial parameter generation in the embodiment. FIG. 6 is a flowchart illustrating the flow of the three-dimensional shape measurement process in the embodiment. FIG. 7 is a flowchart illustrating the flow of the initial parameter generation process in the embodiment. FIG. 8 is a diagram schematically showing a trajectory of the projector. FIG. 9 is a flowchart illustrating the flow of the parameter update process in the embodiment. FIG. 10 is a flowchart illustrating the flow of the initial phase information update process in the embodiment. FIG. 11 is a flowchart illustrating the flow of the parameter coefficient update process in the embodiment. FIG. 12 is a diagram showing an example of the configuration of a three-dimensional shape measuring device including two projectors. It is a figure which illustrates the defective region which occurs when the information shown by a two-dimensional numerical array is rotated.

<Embodiment>
Hereinafter, embodiments will be described with reference to the drawings. The configurations of the embodiments shown below are examples, and the disclosed technology is not limited to the configurations of the embodiments.

(Configuration of 3D shape measuring device)
First, a configuration example of the three-dimensional shape measuring device 1 according to the embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic view showing a hardware configuration of a three-dimensional shape measuring device according to an embodiment. FIG. 2 is a schematic view illustrating the arrangement relationship between the photographing means, the projection means, and the moving means of the three-dimensional shape measuring device according to the embodiment and the measurement target. FIG. 3 is a schematic view illustrating the internal structure of the moving means in the embodiment.

As illustrated in FIG. 1, the three-dimensional shape measuring device 1 according to the embodiment includes a projector 10, a camera 11, a control device 12 (for example, a computer), and a moving mechanism 13.

The projector 10 is a means for projecting a pattern onto a measurement target. Here, the pattern is, for example, a striped pattern in which the change in brightness shows periodicity, and the phase can be changed in time. Since the process of measuring the three-dimensional shape of the measurement target by this pattern is known, detailed description thereof will be omitted. The number of projectors 10 may be one or two or more as in the embodiment. The projector 10 is an example of a “projection means”.

The camera 11 is a means for photographing a measurement target in a state where a pattern is projected and outputting a digital image. The camera 11 has, for example, an optical system and an image sensor. When measuring the three-dimensional shape, the camera 11 captures a plurality of images while changing the phase of the pattern projected from the projector 10. The camera 11 is an example of "shooting means".

As shown in FIGS. 2 and 3, in the embodiment, the camera 11 is housed in the hollow portion of the hollow cylindrical rotating mechanism 131 which is a part of the moving mechanism 13, and is also a part of the moving mechanism 13. The object O to be measured is photographed through a circular opening provided in the center of a reference plate 132. That is, in the embodiment, the measurement object O is arranged so as to be located directly below the camera 11 at the time of measurement. The measurement object O is, for example, a printed circuit board on which electronic components are mounted. In this specification, an image taken by a photographing means is referred to as an "observed image". The measurement target O is an example of a “measurement target”.

The control device 12 controls the projector 10, the camera 11, and the moving mechanism 13 described later, processes the image captured from the camera 11, measures the three-dimensional shape, and the like. The control device 12 includes a CPU (processor), a memory, a non-volatile storage device (for example, a hard disk or a flash memory), an input device (for example, a keyboard, a mouse, a touch panel, etc.), and a display device (for example, a liquid crystal display). Including computer. The function of the control device 12, which will be described later, can be realized by loading the program stored in the non-volatile storage device into the memory and executing the program by the CPU. However, all or part of the functions of the control device 12 may be replaced with dedicated hardware. Further, the functions of the control device 12 may be realized by the collaboration of a plurality of computers by utilizing the technologies of distributed computing and cloud computing.

The moving mechanism 13 is a means for moving the projector 10 relative to the measurement object O. As illustrated in FIGS. 2 and 3, the moving mechanism 13 in the embodiment has a hollow cylindrical rotating mechanism 131 driven by a motor (not shown) and is assembled to the rotating mechanism 131 to support the projector 10. The reference plate 132 and the reference plate 132 are provided. The rotating mechanism 131 includes a housing 131a and a rotating body 131b. The upper portion of the housing 131a is fixed to the frame 15 of the three-dimensional shape measuring device 1. The moving mechanism 13 is an example of a “moving means”.

The rotation mechanism 131 is configured such that the rotating body 131b rotates within a range of 2π (radians) about a rotation axis extending in the Z-axis direction by transmitting the rotation of the motor by, for example, a gear. When the rotating body 131b rotates, the reference plate 132 assembled to the rotating mechanism 131 also rotates, and the projector 10 locked to the reference plate 132 is a circle centered on the rotation axis of the cylindrical rotating mechanism 131. It will rotate around the circumference. That is, when the measurement object O is arranged coaxially with the rotation axis of the rotation mechanism 131, the projector 10 rotates around the measurement object O on a plane defined by the XY axes.

(Function of control device 12)
Subsequently, the function of the control device 12 will be described with reference to FIG. The control device 12 includes an image acquisition unit 20, a three-dimensional shape measurement unit 21, a projection means position control unit 22, a shadow area determination unit 23, an initial parameter generation unit 24, an orbit center acquisition unit 25, a parameter update unit 26, and a parameter storage unit. Has 27.

The image acquisition unit 20 captures a plurality of observation images used for three-dimensional shape measurement from the camera 11. The image acquisition unit 20 acquires, for example, four images in which the phases of the patterns projected on the measurement object O differ by π / 4 (radians).

The three-dimensional shape measuring unit 21 calculates the three-dimensional shape of the measurement object O based on the acquired plurality of observed images. In the embodiment, the phase angle of 1 pixel representing the position of one point on the surface of the measurement object O between the four acquired images is calculated. The three-dimensional shape measuring unit 21 calculates the height of the one point using the calculated phase angle and the parameters stored in the parameter storage unit 27. The three-dimensional shape measuring unit 21 measures the three-dimensional shape of the measurement object O from the observed image by executing such a process for all pixels. The three-dimensional shape measuring unit 21 is an example of a “measuring means”.

The projection means position control unit 22 outputs a signal for controlling the moving mechanism 13 so as to move the projection means to the position based on the input projection means position information. For example, when arbitrary projection means position information is input via an input device, the projection means position control unit 22 outputs a signal for driving the rotation mechanism 131 so as to move the projector 10 to the position. The projection means position information may be an absolute value with a specific position as a reference point, or may be a value indicating a relative position with respect to the position of the projector 10 at the time of inputting the position information. ..

The shadow area determination unit 23 determines whether or not there is a shadow area in which the pattern is not projected in the observation image acquired by the image acquisition unit 20. The criteria for determination are not particularly limited. For example, a predetermined threshold value is set as a reference for the brightness value of the observed image, and if there is a portion where the brightness value of the observed image is lower than the threshold value, it is used as a shadow. It may be determined that it is an area. Further, when the projected pattern is compared with the pattern of the observed image and a missing portion of the pattern can be detected in the observed image, it may be determined that a shadow region exists.

The initial parameter generation unit 24 has a correspondence relationship (initial phase information) between each pixel of the imaging and the phase angle when the pattern is projected from the projector 10 onto the target member whose height is known in advance. ) Is generated. FIG. 5 is a diagram showing an example of a target member used in initial parameter generation in the embodiment. FIG. 5A is a plan view of the target member 100. FIG. 5B is a side view of the target member 100. As can be understood with reference to FIG. 5, the target member 100 is provided with regions R1, R2, R3, R4, and R5 having different heights from each other. Each of the regions R1, R2, R3, R4, and R5 has an area corresponding to the entire shooting range of the camera 11. The height of each region of the target member 100 is, for example, region R1> region R2> region R3> region R4> region R5. In the present specification, the height of each region of the target member 100, based on the imaging table 14, _{X 1} the height of the region R1, the height _{X 2} region R2, the height of the region R3 _X 3, the height of the region R4 _{X 4,} the height of the region R5 assumed to be _{X 5.}

The initial parameter generation unit 24 generates initial phase information, for example, based on an image taken of the region R5. Further, the initial parameter generation unit 24 generates an approximate expression for calculating the height based on the phase angle. The initial parameter generation unit 24 stores the generated parameters including the initial phase information and the approximate expression in the parameter storage unit 27.

Returning to FIG. 4, the orbit center acquisition unit 25 acquires the center position of the locus in which the projector 10 moves, based on the locus in which the projector 10 moves. As for the center position, for example, the track center acquisition unit 25 indicated by coordinates stores the acquired center position in the parameter storage unit 27. In the present embodiment, the projector 10 rotates around the rotation axis of the cylindrical rotation mechanism 131. Therefore, when the center of the trajectory of the projector 10 is known in advance, the trajectory center acquisition unit 25 may be omitted by storing the center position in the non-volatile storage unit.

When the parameter update unit 26 detects the movement of the projector 10, the parameter update unit 26 updates the parameters stored in the parameter storage unit 27. Details of updating the parameters will be described later. The parameter update unit 26 is an example of the “update means”.

The parameter storage unit 27 stores the parameters generated by the initial parameter generation unit 24. The parameter storage unit 27 is, for example, a non-volatile storage device. The parameter storage unit 27 is an example of a “storage unit”.

(Flow of 3D shape measurement processing)
FIG. 6 is a flowchart illustrating the flow of the three-dimensional shape measurement process in the embodiment. Hereinafter, the flow of the three-dimensional shape measurement process in the embodiment will be described with reference to FIG.

In S1, the initial parameter generation unit 24 generates initial parameters. The initial parameter generation unit 24 stores the generated initial parameters in the parameter storage unit 27. The process of S1 is executed, for example, when the three-dimensional shape measuring device 1 is installed. Details of the process of generating the initial parameters will be described later with reference to FIG. 7.

In S2, the image acquisition unit 20 acquires four images in which the phases of the patterns projected from the projector 10 on the measurement object O differ by π / 2 (radians). The three-dimensional shape measurement unit 21 calculates the phase of each pixel of the observation image based on the plurality of observation images acquired by the image acquisition unit 20.

The parameter update unit 26 determines whether or not the projector 10 has moved. If the projector 10 has moved (YES in S3), the process proceeds to S6. If the projector 10 is not moving (NO in S3), the process proceeds to S4.

In S4, the three-dimensional shape measuring unit 21 calculates the phase difference between the phase calculated from the observed image and the initial phase for each pixel.

In S5, the three-dimensional shape measuring unit 21 calculates the height of the observed image at each pixel based on the phase difference calculated in S4 by using the approximate expression stored in the parameter storage unit 27.

In S6, the parameter updating unit 26 that has detected the movement of the projector 10 updates the initial phase information and the approximate expression stored in the parameter storage unit 27. The position of the projector 10 after the movement is an example of the “second position”. Details of the processing of S6 will be described later with reference to FIG.

(Flow of initial parameter generation process)
FIG. 7 is a flowchart illustrating the flow of the initial parameter generation process in the embodiment. The process illustrated in FIG. 7 corresponds to the process in S1 of FIG. Hereinafter, the flow of the initial parameter generation process by the initial parameter generation unit 24 will be described with reference to FIG. 7.

In S11, the orbit center acquisition unit 25 causes the projector 10 to project light at the initial position, + π / 2 (radian) from the initial position, and −π / 2 (radian) from the initial position. Let the camera 11 take a picture. When the image is taken in this way, as illustrated by the “x” mark in FIG. 8, patterns are generated in which light is projected at different positions at each position of the projector 10. The orbit center acquisition unit 25 determines the equation of the straight line L1 connecting the pattern at the + π / 2 (radian) position and the pattern at the −π / 2 (radian) position based on the image taken by the camera 11. Subsequently, the track center acquisition unit 25 determines the equation of the perpendicular line L2 to the straight line L1 from the pattern at the position of 0. The orbit center acquisition unit 25 acquires the position of the center P of the circular orbit of the projector 10 by calculating the intersection of the straight line L1 and the perpendicular line L2. The orbit center acquisition unit 25 stores the acquired position of the center P in the parameter storage unit 27.

In S12, in the initial parameter generation unit 24, with the projector 10 arranged at the initial position, the phase of the projected pattern is π / 2 for each of the regions R1, R2, R3, R4, and R5 of the target member 100. (Radian) Acquires four different images. The initial position is an example of the "first position".

In S13, the initial parameter generation unit 24 generates the correspondence between each pixel of the image captured by the camera 11 and the phase angle based on the image captured in the region R5. In the present specification, the correspondence generated based on the image obtained by capturing the region R5 is referred to as initial phase information. The initial phase information can be shown as a two-dimensional numerical array in which phase values are arranged for each pixel.

In S14, the initial parameter generation unit 24 generates the correspondence between each pixel and the phase angle for each of the regions R1, R2, R3, and R4. The initial parameter generation unit 24 generates a correspondence between the relative height with the region R5 and the phase angle for each pixel based on the initial phase information generated in S13 and the correspondence between each pixel and the phase angle. do.

For example, the initial parameter generation unit 24 calculates the following phase angle difference φ for each pixel. The region R4, the difference in height between the region R5 is X ₄ -X _5, the phase angle difference between the region R5 is calculated to be the phi _1. The initial parameter generating unit 24, the region R3, the difference in height between the region R5 is X ₃ -X _5, the phase angle difference between the region R5 is calculated that the phi _2. The initial parameter generating unit 24, the region R2, the difference in height between the region R5 is X ₂ -X _5, calculates the phase angle difference between the region R5 is phi _3. The initial parameter generating unit 24, the region R1, the difference in height between the region R5 is X ₁ -X _5, the phase angle difference is calculated to be a phi _4.

The initial parameter generation unit 24 calculates an approximate expression showing the correspondence between the height and the phase angle from the relationship between the height and the phase angle φ thus acquired. The approximate expression can be shown, for example, in the form of the following expression (1), and the expression (1) corresponding to each pixel is generated.

In equation (1), z is the desired height. Further, in the equation (1), the coefficients a, b, c, and d are real number constants determined by each pixel. In the present specification, the information indicating the coefficients a, b, c, and d of the approximate expression for each pixel is also referred to as a parameter coefficient. The parameter coefficients are a two-dimensional numerical array in which the value of the coefficient a is arranged for each pixel, a two-dimensional numerical array in which the value of the coefficient b is arranged for each pixel, and a two-dimensional numerical value in which the value of the coefficient c is arranged for each pixel. It can be shown as an array and a two-dimensional numerical array in which the value of the coefficient d is arranged for each pixel.

In the formula (1), a number from 1 to 4 is entered in "d" of _{φ d.} For example, _{if it is "φ 1} ", it is the phase difference between the region R5 and the region R4 of the pixel for which the height z is to be calculated. The approximate expression exemplified in the above equation (1) is a cubic expression, but the approximate expression may be a fourth-order or higher-order formula or a second-order or lower-order formula.

(Flow of parameter update process)
FIG. 9 is a flowchart illustrating the flow of the parameter update process in the embodiment. The process illustrated in FIG. 9 corresponds to the process in S6 of FIG. Hereinafter, the flow of the parameter update process will be described with reference to FIG.

In S61, the parameter updating unit 26 updates the initial phase information stored in the parameter storage unit 27 according to the positional relationship between the position before the movement and the position after the movement of the projector 10. Details of the processing of S61 will be described later with reference to FIG.

In S62, the parameter updating unit 26 updates according to the parameter coefficient stored in the parameter storage unit 27 and the positional relationship between the position before the movement and the position after the movement of the projector 10. Details of the processing of S62 will be described later with reference to FIG.

(Flow of initial phase information update process)
FIG. 10 is a flowchart illustrating the flow of the initial phase information update process in the embodiment. The process illustrated in FIG. 10 corresponds to the process in S61 in FIG. Hereinafter, the flow of the initial phase information update process will be described with reference to FIG.

In S611, the parameter update unit 26 unwraps (phase connection) the initial phase information stored in the parameter storage unit 27. The initial phase information is shown in the range where the phase of each pixel is from 0 (radians) to 2π (radians). When the phase of each pixel changes in the range from 0 to 2π in this way, the phase does not change continuously so that the value next to 2π becomes 0. Therefore, it becomes difficult to process S612 that approximates the initial phase information represented by the two-dimensional numerical array with a curved surface. Unwrap causes the phase in the initial phase information to change continuously,
Approximation on a curved surface becomes easy.

In S612, the parameter update unit 26 approximates the initial phase information unwrapped in S611 with a curved surface. The parameter update unit 26 can perform approximation by a curved surface with a quadratic expression, for example. The approximation of the curved surface is not limited to the quadratic equation, and may be approximated by a cubic or higher-order equation.

In S613, the parameter updating unit 26 acquires the positional relationship (angle) between the position before the movement and the position after the movement of the projector 10 detected in S3 of FIG. The angles indicating the positional relationship between the position before the movement and the position after the movement are, for example, the first line segment connecting the initial position of the projector 10 and the center position stored in the parameter storage unit 27, and the position of the projector 10 after the movement. It may be an angle formed by a second line segment connecting the center position stored in the parameter storage unit 27. The initial phase information approximated by the curved surface in S612 is rotated about the center position stored in the parameter storage unit 27 by the angle at which the projector 10 has moved.

In S614, the parameter update unit 26 wraps the initial phase information rotated in S613. By the processing of S614, the phase of each pixel of the initial phase information is shown in the range of 0 (radian) to 2π (radian).

The parameter update unit 26 can update the initial phase information according to the position of the moved projector 10 by the process of FIG.

(Flow of parameter coefficient update process)
FIG. 11 is a flowchart illustrating the flow of the parameter coefficient update process in the embodiment. The process illustrated in FIG. 11 corresponds to the process in S62 of FIG. Hereinafter, the flow of the parameter coefficient update process will be described with reference to FIG.

In S621, the parameter update unit 26 approximates a two-dimensional numerical array for each of the coefficients a, b, c, and d with a curved surface. The parameter update unit 26 can perform approximation by a curved surface by, for example, a quadratic expression, as in the process of S612 in FIG. The approximation of the curved surface is not limited to the quadratic equation, and may be approximated by a cubic or higher-order equation.

In S622, the parameter updating unit 26 rotates the two-dimensional numerical array of the parameter coefficients approximated by the curved surface in S621 by the moved angle of the projector 10 around the center position stored in the parameter storage unit 27.

The parameter update unit 26 can update the parameter coefficient according to the position of the moved projector 10 by the process of FIG.

<Action and effect of the embodiment>
In the embodiment, when the projector 10 moves, the initial phase information and the parameter coefficient are updated according to the positional relationship between the position before the movement and the position after the movement of the projector 10. Therefore, even when the projector 10 is moved, it is not necessary to perform the initial calibration of the initial phase information and the parameter coefficient. Therefore, the three-dimensional shape measuring device 1 according to the embodiment can save the time for initial calibration even if the projector 10 is moved, and can suppress the lengthening of the measuring time.

In the embodiment, when the initial phase information and the parameter coefficient are rotated according to the positional relationship between the position before the movement and the position after the movement of the projector 10, the rotation is executed after approximating with a curved surface. When the initial phase information and the parameter coefficients shown in the two-dimensional numerical array are rotated as the two-dimensional numerical array, a defective region U1 in which the information is missing occurs, as illustrated in FIG. In the present embodiment, it is possible to suppress the occurrence of such a defective region U1 by executing rotation after approximating with a curved surface.

Further, the three-dimensional shape measuring device 1 according to the embodiment moves the projector 10 by updating the initial phase information and the parameter coefficient according to the positional relationship between the position before the movement of the projector 10 and the position after the movement. Can also measure the shape of the object O to be measured with high accuracy.

With the configuration of the three-dimensional shape measuring device 1 according to the above embodiment, one projector 10 can generate a pattern for the measurement object O from any position on the circumference centered on the measurement object O. It becomes possible to project. Therefore, highly accurate three-dimensional shape measurement can be performed without arranging a large number of projection means, and it is possible to suppress an increase in size and cost of the apparatus.

<Modification example>
In the three-dimensional shape measuring device 1 according to the embodiment, only one projector 10 is arranged, but it is not always necessary to do so, and two or more projection means may be provided. For example, as illustrated in FIG. 12, two projectors 10a and 10b may be arranged at opposite positions of the reference plate 132, and the pattern may be projected onto the measurement object O at the same time. In this case, the drive (rotation) angle of the rotation mechanism 131 can be 2π (radians).

When a pattern is projected by a plurality of projection means, a shadow region is less likely to be generated on the measurement object O, so that the measurement efficiency can be improved. Further, when the projection means is moved, the rotation angle of the moving means can be reduced, and the time for moving can be shortened. Therefore, any number of projection means can be arranged in consideration of the balance between the efficiency of measurement and the cost reduction.

When the shadow area exists in the observation image, the shadow area determination unit 23 inputs the position information to the projection means position control unit 22 to move the projector 10 so that the shadow disappears from the observation image. May be good. The position information to be input may be rotated by a predetermined angle from the current position of the projector 10. When the shadow area determination unit 23 moves the projector 10, the parameter update process illustrated in S6 of FIG. 6 may be executed according to the positional relationship between the position before the movement and the position after the movement of the projector 10. ..

<Others>
The above-described embodiment is merely an exemplary description, and the disclosed technique is not limited to the above-mentioned specific embodiment. The disclosed technology can be variously modified within the scope of its technical idea. For example, in the above embodiment, the moving mechanism 13 has a configuration of a motor, a cylindrical rotating mechanism driven by the rotation of the motor, and a reference plate, but the configuration is not necessarily limited to such a configuration. For example, as the motor, a linear motor may be used in addition to the rotary motor. Further, other means (for example, an actuator using pneumatic pressure or hydraulic pressure) may be used instead of the motor. Further, the rotation mechanism does not have to be cylindrical, and may have a configuration that does not use a reference plate.

Further, the movement of the projector 10 is also rotationally moved on the plane defined by the XY axes in the above embodiment, but it is not limited to this, and for example, it is rotated on the plane defined by the ZX axis. It may be a moving one, or it may be a combination of these. Further, the method of movement is not limited to rotational movement, and may move in a curved shape other than a straight line or an arc.

The embodiments and modifications disclosed above can be combined with each other.

1 ... 3D shape measuring device 10 ... Projector 11 ... Camera 12 ... Control device 13 ... Moving mechanism 14 ... Shooting table 15 ... Frame 20 ... Image acquisition unit 21・ ・ ・ Three-dimensional measurement unit 22 ・ ・ ・ Projection means position control unit 23 ・ ・ ・ Shadow area determination unit 24 ・ ・ ・ Initial parameter generation unit 25 ・ ・ ・ Orbit center acquisition unit 26 ・ ・ ・ Parameter update unit 27 ・ ・・ Parameter storage unit O ・ ・ ・ Measurement target

Claims (5)

A projection means that projects multiple patterns with different phases to the measurement target,
A moving means for moving the projection means and
An imaging means for photographing the measurement target on which the plurality of patterns are projected, and an imaging means.
A storage unit that stores the correspondence between the height of the measurement target and the phase acquired from the imaging of the measurement target when the projection means is present at the first position.
A measuring means for measuring the three-dimensional shape of the measurement target by processing the image acquired by the photographing means, and a measuring means for measuring the three-dimensional shape of the measurement target.
When the projection means is moved to the second position by the moving means, the projection means includes an updating means for updating the correspondence relationship according to the positional relationship between the first position and the second position.
Three-dimensional shape measuring device. The moving means rotates and moves the projection means on a circumference centered on the measurement target.
The updating means establishes the corresponding relationship according to the angle formed by the first line segment connecting the first position and the center of the circumference and the second line segment connecting the second position to the center. Update,
The three-dimensional shape measuring device according to claim 1. The moving means moves the projection means to a position where the photographing means can shoot a pattern in which the measuring means can measure the three-dimensional shape of the measurement target.
The three-dimensional shape measuring device according to claim 1 or 2. A plurality of the projection means are provided.
The three-dimensional shape measuring device according to any one of claims 1 to 3. The moving means is a cylindrical rotating mechanism having a hollow portion that opens in the axial direction, and is arranged so that the opening is located above the measurement target.
The photographing means photographs the measurement object from a direction perpendicular to the measurement object through the opening of the rotation mechanism.
The three-dimensional shape measuring device according to any one of claims 1 to 4.

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