JPH09196633A - Method and apparatus for measurement of object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a distance with high resolution regardless of the problem of occlusion. SOLUTION: An object 12 to be measured is irradiated with beamlike laser light from a laser oscillator 1. Diffused light which is reflected from the object 12 to be measured is collected on an identical line segment 17 by mirrors 13, 14 and semitransparent mirrors 15, 16. At this time, the diffused light is passed through two optical routes, i.e., a route indicated by a solid line and a route indicated by a broken line, intensity fringes of light are generated on the line segment 17 by the interference of the light which is passed through the two optical routes, and the fringes are detected by a one-dimensional photodetector 18 which is arranged in the position of the line segment 17. Then, when the interval between the fringes or a spatial frequency is measured, the distance Z to the object 12 to be measured is computed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to distance measurement, industrial measurement, and three-dimensional design CAD (Computer Aided Design).
The present invention relates to an object measuring method and device used for the above.

[0002]

[Prior art]

(1) The technology for measuring the distance to an object in a non-contact manner is a basic technology required in various industrial fields. Non-contact measurement methods include methods that use sound, radio waves, light, etc.
The method using light is the best in terms of versatility and reliability. The method of using this light is a method of using triangulation, a method of directly measuring the round-trip time of light, a method of indirectly measuring the round-trip time of light using modulated light, an irradiation light and a reflection, depending on the measurement principle. It can be divided into interferometry that measures the phase difference of light.

(2) By the way, if the distance of a certain point on the surface of the object can be measured, it goes without saying that the three-dimensional shape of the object can be measured by measuring a large number of points on the entire surface of the object. Conventionally, there has been a measuring device using the triangulation method based on this idea. In the method using such a measuring device, the measurement range in the X and Y directions can be arbitrarily set by changing the scanning range, and the measurement resolution in the X and Y directions can be arbitrarily set by changing the scanning speed. By using the parallel movement mechanism for scanning, it is possible to always perform measurement from the same angle, which is advantageous in that there is no change in resolution depending on the angle when measuring in the X and Y directions.

(3) On the other hand, the technology for handling three-dimensional information is an important technology that supports new media such as multimedia and virtual reality. However, while the technology of processing and displaying three-dimensional information has made remarkable progress, the technology in the field of three-dimensional information input has not been sufficiently developed. Furthermore, in these applications, not only simple shape input of a three-dimensional object but also color information is required to be input. On the other hand, recently, a three-dimensional shape measuring device and a TV
(Television) It has been attempted to measure the shape and color of an object simultaneously by linking a camera.

[0005]

[Problems to be Solved by the Invention]

(A) By the way, the above method (1) has various problems. First, the triangulation method is the most balanced method and forms the mainstream of the current measurement method, but the relative resolution relative to the measurement range is coarse, and the resolution itself changes depending on the measurement distance. There is. Further, the triangulation method has a problem called "occlusion" in which measurement is impossible when either one of the optical paths is blocked because the optical paths of the irradiation light and the reflected light are different. Moreover, the problem of resolution and occlusion is in an exclusive relationship, and if the angle formed by the forward and return paths of light is reduced in order to reduce the problem of occlusion, the resolution becomes coarse and the change in resolution depending on the distance also increases. . On the other hand, when improving the resolution performance,
The problem of occlusion is exacerbated because the angle between the forward and return paths of light must be increased. This is a problem rooted in the principle of triangulation and cannot be solved.

On the other hand, other methods that are not based on the principle of triangulation do not have such problems, but, for example, in the time difference measurement method, since the speed of light is extremely high, the time difference is very small and accurate measurement is impossible. In the interferometry, the same fringes appear at constant distances, so that the absolute distance cannot be obtained and only a minute distance (several nm to several μm) can be measured. As for the solution of these shortcomings, future expectations can be expected due to the progress of electronics, but at present, there are many aspects that are inferior to triangulation method and it is used only under special conditions.

(B) The measuring device described in (2) above has the problem described in (a) above when measuring the distance at one point, so that this type of device is also used when a three-dimensional shape is obtained. Had similar shortcomings. Regarding the time required for measurement, since the above-described measurement method requires two-dimensional scanning, for example, even if it takes only one field time (1/60 seconds) of a video signal to measure one point, When 500 points are measured in each of the X and Y directions, it takes about 69 minutes to measure all the points.

Therefore, in order to improve the speed, the distance is measured in parallel in one one-dimensional direction of the X direction or the Y direction at the same time, and the remaining one-dimensional direction is successively measured while scanning. Also, the operation time is 8.3 seconds, and the measurement time can be greatly reduced. There is a triangulation measuring device based on this method, but the method using the triangulation method as a principle of measurement has the problem as described in (a) above in principle.

On the other hand, there is also a measuring method for measuring two-dimensional distance information at once, as represented by the moire method using lattice fringes. Although this method is excellent in terms of measurement time, X
Since the resolution in the direction or the Y direction is limited by the interval of the lattice stripes, the resolution in that direction is very poor. What is directly measured is the inclination of the surface, and distance information is obtained by integrating the measured values. Therefore, there is a problem that measurement cannot be performed if the distance of the measurement surface changes discontinuously.

(C) In the simultaneous shape and color measuring method using the combination of the three-dimensional shape measuring apparatus and the TV camera as described in (3) above, the distance information and the color information can be obtained by simply combining them. Misalignment of measurement points will occur. For example, there is a device that combines a distance measuring device using a slit-shaped laser and a TV camera to set the color near the stripe of the laser light appearing on the measured object as the color of the measurement position, but color information at the distance measurement position itself. not,
Further, there is a problem that the color of the object and the color of the laser light are mixed when the distance in the vicinity is reduced to increase the accuracy.

A device has also been devised in which a distance measuring device and a TV camera are alternately moved in a time division manner. According to this method, it is possible to measure color information without being affected by laser light. However, when the scanning is performed at a constant speed, the measurement time is different and the measurement position also shifts. The problem can be solved by interrupting the scanning only during the color measurement subsequent to the distance measurement, but it is not very mechanically impossible to repeatedly stop and restart the scanning several tens of times per second. The scanning accuracy is also deteriorated.

The present invention has been made in view of the above points, and a first object thereof is to provide an object measuring method and apparatus capable of ignoring the problem of occlusion and capable of measuring distance with high resolution. It is in. A second object is a method and apparatus for measuring a three-dimensional shape of an object by using the distance measuring method, which has extremely small occlusion, excellent resolution even in slope measurement, and strong against optical noise. It is to provide a measuring method and apparatus. The third purpose is to use the distance measuring method,
An object of the present invention is to provide an object measuring method and apparatus capable of measuring distance information and color information at the same time without causing a shift in the measurement position.

[0013]

Detailed Description of the Invention

In order to solve the above problems, the invention according to claim 1 is an object measuring device for measuring a distance to an object to be measured, wherein a beam-shaped laser beam is applied to the object to be measured. Irradiation means for irradiating and the diffused light of the beam-shaped laser light reflected from the measured object have different optical distances from reflection points on the measured object at both ends on the same line segment. Converging means for condensing on the line segment by using two kinds of optical paths and interference fringes generated by interference between reflected lights coming from the two kinds of optical paths are converted into a one-dimensional light and shade stripe pattern. And a measuring means for measuring the distance or the spatial frequency of the stripe pattern and calculating the distance to the object to be measured based on the measured value.

According to a second aspect of the present invention, in an object measuring method for measuring a distance to a measured object, the measured object is irradiated with a beam laser beam, and the beam reflected from the measured object is measured. The diffused light of the circular laser light is condensed on the line segment using two types of optical paths having different optical distances from the reflection points on the object to be measured at both ends on the same line segment. , The interference fringes generated by the interference between the reflected lights coming from the two types of optical paths are converted into a one-dimensional light and shade stripe pattern by a light receiving element, and the interval or spatial frequency of the stripe pattern is measured, and the measured value It is characterized in that the distance to the measured object is obtained based on

According to a third aspect of the present invention, in the first aspect of the invention, there is provided scanning means for scanning the beam-shaped laser light in a two-dimensional direction based on a designated scanning displacement angle or displacement length. Then, the measuring means scans the beam-shaped laser light in a two-dimensional direction within a predetermined range including the object to be measured by changing the displacement angle or displacement length of the scan, and regarding the displacement angle or displacement length of each scan. Calculating three-dimensional position information at the beam irradiation point from the distance information obtained by measuring the distance to the beam irradiation point on the measured object and the displacement angle or displacement length of the scanning at the time of measuring the distance. It is characterized in that the shape of the measured object is obtained.

[0016] According to a fourth aspect of the present invention, in an object measuring device for measuring a three-dimensional shape of an object to be measured, irradiation means for irradiating the object to be measured with vertical (or horizontal) slit-shaped laser light, A horizontal (or vertical) slit that transmits diffused light of the slit-shaped laser light reflected from the measured object and diffused light that has passed through the slit are provided at both ends of a horizontal (or vertical) cross section on the same plane. Condensing means for condensing on the same plane by using two kinds of optical paths having different optical distances from the reflection point on the object to be measured, and lights coming from the two kinds of optical paths. Of the slit-shaped laser light by measuring the interval or the spatial frequency of the two-dimensional light receiving element for converting the interference fringes generated by the interference of the two into a two-dimensional light and shade fringe pattern. It is characterized by having a measuring means for calculating the source location information.

According to a fifth aspect of the invention, in the fourth aspect of the invention, the slit laser beam is horizontally (or vertically) based on a designated scan displacement angle or displacement length.
Scanning means for scanning in the direction, and displacement detecting means for determining a displacement angle or displacement length of the scanning performed by the scanning means, and the measuring means measures the displacement angle or displacement length of the scanning detected by the displacement detecting means. It is characterized in that the three-dimensional position information is calculated by using the three-dimensional position information.

According to a sixth aspect of the present invention, in the object measuring method for measuring a three-dimensional shape of an object to be measured, the object to be measured is irradiated with a vertical (or horizontal) slit-shaped laser beam, and the object to be measured is measured. The diffused light of the slit-shaped laser light reflected from the object is transmitted through a horizontal (or vertical) slit, and the diffused light transmitted through the slit is measured at both ends of a horizontal (or vertical) cross section on the same plane. Interference fringes generated by interference of lights coming from the two types of optical paths, which are condensed on the same plane by using two types of optical paths having different optical distances from the upper reflection point. Is converted into a two-dimensional light and shade stripe pattern by a light receiving element, and the distance of the vertical (or horizontal) portion irradiated with the slit laser light is measured by measuring the interval or spatial frequency of the stripe pattern. 3D of the irradiated portion based on the obtained distance information and the displacement angle or displacement length of the scan when the distance is measured. It is characterized in that position information is calculated to obtain the shape of the measured object.

According to a seventh aspect of the invention, in an object measuring device for measuring the three-dimensional shape and color of an object to be measured,
A first irradiation unit that irradiates the measured object with laser light, a second irradiation unit that irradiates the measured object with white light from which the wavelength component of the laser light has been removed, and an image of the measured object. A first photographing means for photographing the object to be measured through a filter that is geometrically and optically equivalent to the first photographing means and that filters the wavelength component of the laser light; The laser irradiating the object to be measured from the difference between the shape measuring means for measuring the three-dimensional shape of the object to be measured and the two images taken by the first photographing means and the second photographing means. The position of the light on the image is obtained, and the color of the measured object at the position is determined by the second
And a color measuring unit that obtains the pixel value at the same position on the image captured by the image capturing unit.

The invention according to claim 8 is characterized in that, in the invention according to claim 7, the shape measuring means comprises a transmitting means for transmitting only a wavelength component of the laser light. The invention according to claim 9 is an object measuring method for measuring a three-dimensional shape and a color of an object to be measured,
The laser light and the white light from which the wavelength component of the laser light is removed are simultaneously irradiated to the object to be measured, and 3
At the same time as measuring the dimensional shape, a first image obtained by photographing the measured object and a second image obtained by photographing the measured object via a filter that removes the wavelength component of the laser light are taken in, The position on the image of the laser beam applied to the measured object is obtained from the difference between the images, and the color of the measured object at the position is calculated from the pixel value at the same position of the second image. It is characterized in that the three-dimensional shape and the color of the object to be measured are obtained at the same time.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [Principle of Operation] First, the principle of distance measurement according to the present invention will be described. As shown in FIG.
The beam-shaped laser light is applied to the measured object 12. The diffused light reflected from the measured object 12 is condensed on the same line segment 17 by using the mirrors 13, 14 and half mirrors 15, 16. At this time, in FIG. 1, the diffused light is the half mirror 16 → mirror 14 → represented by the solid line.
There are two optical paths, that is, the path of the half mirror 15 and the path of the half mirror 16 → the mirror 13 → the half mirror 15 shown by a broken line.

Here, at both ends of the line segment 17, points A and
At point B, the difference in optical distance from the reflection point of the measured object 12 to points A and B is d ₁ for the solid line route and d ₂ for the broken line route. Then, if the optical paths reaching the same point on the line segment 17 are at different positions on both paths at the passage point of the half mirror 16, the value of d _{1 and} the value of d ₂
Are different. When the wavelength of the laser light with which the line segment 17 is irradiated is λ, the phase of the laser light changes between the ends of the line segment 17 by d ₁ / λ and d ₂ / λ times for each path.

By the way, in coherent light such as laser light, the light intensity doubles in the same phase, but cancels each other in the opposite phase and the light intensity becomes 0.
There are | d ₁ / λ−d ₂ / λ | light intensity stripes on the top. This intensity fringe is located at the position of the line segment 17 in the one-dimensional light receiving element 18
Is detected by placing.

Here, the distance from the laser oscillator 11 to the reflection point on the measured object 12 is Z, the distance from the laser oscillator 11 to the point A is L, the length between _AB is l _AB , and on the half mirror 16. Letting dl _{AB be} the shift of the light passing through the same point on the line segment 17 (that is, the shift between the solid line and the alternate long and short dash line in FIG. 1), the following approximate expression is established within an error range of 10 ⁻³ . │d ₁ / λ-d ₂ / λ│ = (1 / λ) [l _AB dl _AB / Z- {3Ll _AB dl _AB (L + l _AB ) / (2Z ³ )}] (1) Therefore, the interval between stripes Alternatively, the distance Z to the measured object 12 is obtained from the spatial frequency.

According to the measuring method based on the above principle, it is possible to measure the distance with a very high resolution as compared with the triangulation method using the light receiving element with the same resolution. This point will be described in detail below. First, in the triangulation method, as shown in FIG. 2A, the distance is obtained from the position of the peak point captured by the one-dimensional light receiving element. Therefore, when the distance slightly changes from that of FIG. 2A, the detection signal of the one-dimensional light receiving element becomes as shown in FIG. 2B, and therefore, the limit resolution is the same as the position shown in FIG. It comes down to how small a difference from the position shown in (b) can be obtained, and if the resolution of the one-dimensional light receiving element is n, then at most n resolution can be obtained by the triangulation method.

On the other hand, according to the present invention, when the detection signal as shown in FIG. 3A is obtained and the one-dimensional light receiving element 18 having the same resolution as the above is used as the measurable spatial frequency, According to Nyquist's theorem, the range is "0 to n / 2". However, according to the present invention, not only when the frequency is increased by 1 as shown in FIG.
Even when the half frequency is increased as in (c), the waveform changes clearly. Therefore, the limit resolution is higher than 1 frequency and 1
It depends on the grayscale resolution of one pixel of the three-dimensional light receiving element 18.

The detection value at the right end or the left end of the one-dimensional light receiving element 18 returns to the original detection value after passing through the states of "maximum intensity light quantity" and "light quantity 0" each time the spatial frequency changes by "1". For example, if the resolution of the light amount of one pixel of the one-dimensional light receiving element 18 is 256 gradations, the maximum of 5 of one spatial frequency is 5.
It is possible to measure with a resolution of 1/12. Therefore, even if the one-dimensional light receiving element 18 having the same resolution as above is used, 512
X (n / 2) = 256n, which is 256 times the resolution of the triangulation method.

This very high resolution has the following advantages. For example, the problem of occlusion can be solved by making the angle between the irradiation light and the reflected light with respect to the measured object 12 extremely small. As described above, if the angle formed by these lights is made very small, the resolution is significantly deteriorated, but the original resolution is very high as described above, so the influence on the measurement accuracy can be ignored. In addition, the problem that the triangulation method "changes resolution depending on distance" has little influence on measurement accuracy because the resolution is sufficiently high. Further, although most of the conventional measurement methods including the triangulation method have a problem that the resolution is lowered when measuring the slope, the high resolution as in the present invention is also effective in such a case.

Further, the above method is also excellent in terms of resistance to optical noise. For example, as shown in FIG. 4A, since the distance is obtained from the position of the peak point a of the light receiving element in the triangulation method, the peak point a as shown in FIG.
If the optical noise b of more than the amount of light is mixed, this will be erroneously detected as a peak point. On the other hand, since the method of the present invention measures the distance between the stripes or the spatial frequency, even if there is the same level of optical noise as in FIG. 4B as shown in FIG. If the detection information is converted into a spatial frequency expression by Fourier transform or the like as in the above), the noise component is diffused and the peak point c can be clearly detected. In addition to the above, the present invention is excellent in that it can be sufficiently realized by the present technology, because it does not require an optical component in which a component is required to have a special precision or shape.

[First Embodiment] FIG. 6A is a view showing the arrangement of a distance measuring apparatus according to this embodiment. In this figure, reference numeral 40 is a measuring unit, 41 is a laser oscillator that emits a beam of light, and 42 is an object to be measured. Reference numeral 43 denotes an optical element, which has two bases of the trapezoidal columnar prisms having the same bottom shape and different heights, which are half-mirrored by applying a chrome coat or the like to the bottoms of the two trapezoidal columnar prisms. It is a pasting. This optical element 4
By making the heights of the two trapezoidal prisms that form part 3 different, the difference in the optical distance from the reflection points at both ends of the CCD 47 (line segment 17 in FIG. 1) becomes different.
Focusing of diffused light using different types of optical paths is achieved. Further, 44 and 45 are reflecting surfaces, 46 is a half mirror surface, 4
7 is a CCD which is a one-dimensional light receiving element, 48 is a calculator, 4
Reference numeral 9 denotes an optical element 43, a CCD 47, etc., and a laser oscillator 41.
Is a housing that fixes the light and blocks external light.

Next, the operation of the distance measuring device having the above structure will be described. The laser light emitted from the laser oscillator 41 hits the measured object 42 and is reflected as diffused light in all directions from the irradiation point. When a part of this reflected light enters the optical element 43, it is divided into two by the half mirror surface 46 into the reflected light shown by the broken line in FIG. 6 and the transmitted light shown by the solid line in FIG. The transmitted light is reflected by the reflecting surface 44, the reflected light is reflected by the reflecting surface 45, and then is combined into one light by the half mirror surface 46, and thereafter, the CCD 47 is irradiated with the combined light. That is, the half mirror surface 46 of the optical element 43 corresponds to the half mirror 15 and the half mirror 16 in FIG. 1, the reflecting surface 45 corresponds to the mirror 13, and the reflecting surface 44 corresponds to the mirror 14.

Next, the CCD 47 converts the interference fringes produced by the interference of the laser beams coming from both optical paths into a one-dimensional gray image and sends it to the computer 48. The calculator 48 calculates the distance Z or the spatial frequency of the interference fringes and calculates the distance Z to the object 42 to be measured by the equation (1). In addition, the optical system used in the present embodiment, "diffused light of the laser light reflected from the measured object is condensed on the same line segment, and the difference in the optical distance from the reflection point at both ends of the line segment. However, the optical system is not limited to the one described above as long as the optical system satisfies one of the two types of optical paths.

[Second Embodiment] 3 described in the present embodiment
The three-dimensional shape measuring apparatus scans the beam-shaped laser light in a two-dimensional direction to measure the distance of the beam irradiation point on the measured object by the distance measuring apparatus of the first embodiment, and obtains the obtained distance information and the measured distance information. Three-dimensional position information of the measured point is obtained from the scan displacement angle or displacement length. Then, the three-dimensional shape of the object to be measured is obtained by successively obtaining the three-dimensional position information while successively updating the displacement angle or displacement length of scanning.

FIG. 7 is a view showing the arrangement of the three-dimensional shape measuring apparatus according to this embodiment. The same parts as those in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted. In this figure, 52 is an object to be measured, 53 is an X-direction rotator,
54 is a Y direction rotator, 55 is an X direction displacement angle detector, 5
6 is a Y-direction displacement angle detector, and 57 is a calculator.

Next, the operation of the three-dimensional shape measuring apparatus having the above structure will be described. First, the computer 57 instructs the X-direction rotator 53 and the Y-direction rotator 54 about the orientation of the measuring unit 40. Then, the X-direction rotator 53 and the Y-direction rotator 54
Controls the orientation of the measuring unit 40 according to this command. On the other hand, the X-direction displacement angle detector 55 and the Y-direction displacement angle detector 56 detect the accurate displacement angles Θ _X and Θ _Y of the measuring unit 40 and send them to the computer 57.

Next, the measuring unit 40 performs the same operation as that described in the first embodiment, obtains the distance Z, and sends it to the computer 57. Next, the position coordinates of the measurement point with the laser oscillation portion of the laser oscillator 41 as the origin are P _X , P _Y ,
When P _Z is set, the calculator 57 calculates these values as P _X = Zsin Θ _X (2) P _Y = Zsin Θ _Y (3) P _Z = _Z cos Θ _X · cos Θ _Y (4) Find the position coordinates of.

After completion of the calculation, the computer 57 performs scanning by slightly changing the direction of the measuring section 40 by the X-direction rotator 53 or the Y-direction rotator 54, and measures at different positions of the measured object 52. . In this way, the scanning and the measurement are repeated until the surface of the object to be measured 52 is measured with sufficient density, and the 3 of the object to be measured 52 is measured.
Find the dimensional shape.

In the present embodiment, the measuring unit 40 is rotated about the laser oscillation unit of the laser oscillator 41 in the apparatus, but the rotation center position can be set arbitrarily by changing the position coordinate calculation formula. Can be set to. Further, a mechanism for moving the measuring unit 40 in parallel in the XY directions may be provided to move the measuring unit 40 in parallel. By doing so, the obtained distance information Z becomes P _{z as} it is, and P _x and P _y correspond to the displacement amounts of the moving mechanism in the X and Y directions. Further, if the X-direction rotator 53 and the Y-direction rotator 54 have sufficient mechanical accuracy that does not affect the measurement accuracy,
X-direction displacement angle detector 55 and Y-direction displacement angle detector 56
May be omitted and the command value of the computer 57 may be used as the displacement amount as it is.

As described above, the advantages of the distance measuring method shown in the first embodiment are reflected as they are in the three-dimensional shape measuring apparatus according to this embodiment. Therefore, the three-dimensional shape measuring method using the conventional triangulation principle is used. It has the following advantages over the measuring device. Excellent in resolution Extremely low occlusion Degradation in resolution that occurs when measuring slopes is not a problem Strong against optical noise contained in measurement light

[Third Embodiment] First, the principle of three-dimensional shape measurement used in this embodiment and a fourth embodiment described later will be described. As shown in FIG. 8, the slit laser oscillator 61 vertically irradiates the measured object 62 with the slit laser light. The diffused light of the laser light reflected by the measured object 62 passes through the horizontal slit 63 and then enters the half mirror 64. The transmitted light shown by the solid line in the figure is the mirror 6
The reflected light reflected by the mirror 6 and shown by the broken line in FIG.
After being reflected by, the light is condensed by the half mirror 65 and irradiated onto the light receiving element 68.

At this time, if the positional relationship among the half mirror 64, the half mirror 65, the mirror 66, and the mirror 67 is the same as that in FIG. 1, an interference fringe is formed on the light receiving element 68 by the same operation as in the first embodiment. Occurs. Focusing on the reflection point C on the measured object 62, the diffused light of the laser light reflected from the reflection point C passes through the horizontal slit 63, and therefore reaches only the horizontal line C ′ on the light receiving element 68. On the other hand, focusing on the reflection point D, since the diffused light of the laser light reflected from the reflection point D also passes through the horizontal slit 63, the light receiving element 6
On 8 only the horizon D'is reached.

That is, the interference fringes generated on a certain horizontal line on the light receiving element 68 represent the distance of a certain reflection point of the measured object 62, and the interval or the spatial frequency of the interference fringes is independently calculated for each horizontal line. If the distance is calculated, the distance of the vertical line portion on the measured object 62 on which the slit light hits is obtained in parallel. Therefore, if the measurement is repeated while scanning the vertical line portion on the measured object 62 in the horizontal direction, the measured object 62
Can be obtained. In the above description, even if the terms "horizontal" and "vertical" are interchanged, the same is true.

Next, the structure of the three-dimensional shape measuring apparatus according to the present embodiment will be explained. FIG. 9 is a diagram showing the configuration of the device. In this figure, 71 is a laser oscillator that emits slit-shaped light in the vertical direction, 72 is an object to be measured, 73 is a horizontal slit, 74 and 75 are half mirrors, and 76 and 77.
Is a plane mirror, 78 is a CCD which is a two-dimensional light receiving element,
Reference numeral 79 is a calculator, 80 is a horizontal rotator, 81 is a horizontal displacement angle detector, and 82 is a housing that also serves as a light shield.

Here, the distance difference from the measured point at both ends of the CCD 78 must be different between the solid line route and the broken line route shown in FIG. In this embodiment, the half mirror 74, the half mirror 75, and the plane mirror 77 are arranged in parallel to each other and at the positions corresponding to the three vertices of the rectangle, and only the plane mirror 76 is oriented in the same direction as these mirrors. This condition is satisfied by arranging at a position shifted from the remaining one vertex.

Since the position of the plane mirror 76 is displaced as described above, the optical path length of the solid line and the optical path length of the broken line in the figure are slightly different, and therefore light coming from the same measurement point is also on the CCD 78. Then, the height shifts slightly. However, since the displacement of the plane mirror 76 is extremely small compared to the length between the measured object 72 and the slit 73, this difference can usually be ignored. Further, even if the vertical resolution of the CCD 78 is extremely high and this difference cannot be ignored, if a cylindrical lens focusing on the slit 73 is inserted between the slit 73 and the half mirror 74 to make parallel light only in the vertical direction, the deviation will occur. Disappear.

Next, the operation of the three-dimensional shape measuring apparatus having the above structure will be described. First, the computer 79 instructs the horizontal rotator 80 to orient the measuring unit 40, and the horizontal rotator 8
0 controls the orientation of the measuring unit 40 according to this command. On the other hand, the horizontal displacement angle detector 81 detects the accurate displacement angle Θ _X of the measuring section 40 and sends it to the computer 79.

Next, the slit-shaped laser light emitted from the laser oscillator 71 hits the measured object 72 and is reflected as diffused light in all directions from the irradiation line portion. This reflected light passes through the slit of the slit 73 and reaches the half mirror 74,
The half mirror 74 divides the light into two, a reflected light shown by a broken line and a transmitted light shown by a solid line. Then, the transmitted light is reflected by the plane mirror 76, the reflected light is reflected by the plane mirror 77, and then is combined into one light by the half mirror 75 to form C.
The CD78 is irradiated.

Next, the CCD 78 converts the interference fringes generated by the light of the solid line part and the light of the broken line part into a two-dimensional gray image and sends it to the computer 79. The calculator 79 calculates the distance Z by obtaining the stripe interval or the spatial frequency for each horizontal line. Next, when the position coordinates of the reflection point with the laser oscillation portion of the laser oscillator 71 as the origin are P _X , P _Y , and P _Z , the computer 79 determines the distance Z, the displacement angle Θ _X , and the horizontal line with the CCD 78. Angle Θ _Y formed by the plane including the slit 73 and the horizontal plane
From these, these three position coordinates are obtained by the following equations. P _X = Z sin θ _X (5) P _Y = _Z sin θ _Y (6) P _Z = _Z cos θ _X · cos θ _Y (7)

By performing this processing for all the horizontal lines on the CCD 78, three-dimensional position information with respect to the laser light irradiation portion in the measured object 72 is obtained. After the calculation is completed, the calculator 79 causes the horizontal rotator 80 to slightly change the direction of the measuring unit 40, and measures the different positions of the measured object 72. In this way, by repeating the scanning and the measurement until the surface of the measured object 72 is measured with a sufficient density, the measured object 72 is measured.
The three-dimensional shape of is calculated.

If the horizontal rotator 80 has sufficient mechanical accuracy that does not affect the measurement accuracy, the horizontal displacement angle detector 81 is omitted and the horizontal rotator 8 is omitted.
The command value to 0 may be used as the displacement amount as it is. Further, in the present embodiment, the laser oscillating unit is rotated by the horizontal rotator 80 as the center of rotation, but the center of rotation may be arbitrary by changing the calculation formula of the position coordinates.

Further, instead of the horizontal rotator 80, a moving mechanism for moving in parallel in the horizontal direction may be provided to move the measuring section 40 and the like in parallel. In this case, than the distance calculated information Z, calculates the displacement amount _{... (8) P Y = ZsinΘ} Y ... (9) P Z = ZcosΘ Y ... 3 -dimensional position information as (10) of P _X = movement mechanism. The above-described one is an example of an optical system, and an optical system that satisfies the conditions of the present embodiment is not limited to this.

As described above, if the three-dimensional shape measuring apparatus of this embodiment is used, the one-dimensional direction is measured in parallel at the same time, so the measurement time is sufficiently short. Also, the first
Since the advantages of the distance measuring method described in the embodiment are reflected as they are, they have the following advantages over the conventional three-dimensional shape measuring apparatus using the principle of triangulation. Excellent resolution Highly low occlusion Resolution degradation that occurs when measuring slopes is not a problem Strong against noise contained in measurement light

On the other hand, the resolution in the parallel measurement direction is determined by the resolution of the light receiving element, although the measurement time is inferior to the method for measuring the two-dimensional distance information at one time, which is represented by the moire method using the lattice fringes. Therefore, it is excellent in the following points. The resolution is much higher than that of lattice fringes. The resolution in the scanning direction is even higher, and the resolution and measurement range can be set arbitrarily. Since distance information is directly measured, it is possible to measure even on a measurement surface where the distance changes discontinuously.

[Fourth Embodiment] First, the operating principle of the object measuring apparatus according to the present embodiment will be explained. In the present embodiment, the object to be measured is irradiated with the laser light and the white light from which only the wavelength component of the laser light has been removed. Then, the three-dimensional shape of the measured object is determined by the measuring device described in the above embodiment, and at the same time, the measured object is photographed by the first photographing means and the second photographing means. At this time, the first photographing means and the second photographing means are designed to perform geometrically equivalent photographing, and the same image can be obtained unless laser light is irradiated.

On the other hand, when the laser light is irradiated, the first photographing means passes through a filter which removes only the wavelength component of the laser light when the spotted or linear laser light hit portion appears in the image. The second image capturing means can obtain the same image as when the laser light is not emitted. Therefore, the irradiation position of the laser beam in the image is obtained by taking the difference between the image obtained by the first photographing means and the image obtained by the second photographing means. The three-dimensional shape and color of the measured object can be obtained at the same time by setting the color of the object at the position as the pixel value at the same position of the image by the second photographing means.

Next, the structure of the object measuring apparatus according to the present embodiment will be explained. FIG. 10 shows the configuration of the device. In this figure, reference numeral 70 includes a measuring device for irradiating the object to be measured with beam-shaped or slit-shaped laser light to measure a three-dimensional shape, including the method of the second embodiment or the third embodiment, and 83 is a normal measuring device. It is a white irradiation light source such as a fluorescent lamp, an incandescent lamp, and a halogen lamp. Further, 84 and 85 are filters for removing only the wavelength component of the laser light, for example, if the laser light is infrared, a hot mirror that allows only visible light to pass,
If the laser light has a certain wavelength in the visible light, it is a multilayer dielectric thin film mirror or the like that reflects only that wavelength.

Further, reference numeral 86 is a filter which transmits only the wavelength component of the laser light, for example, a cold mirror if the laser light is infrared light, or a multilayer dielectric thin film filter if the laser light has a certain wavelength within the visible light. The filter 86 is provided in the reflected light input section of the measuring device 70 when the measuring device 70 is affected by light having a wavelength other than the laser light. Therefore, when the measuring device 70 is not affected by light other than the wavelength of the laser light, the filter 86 can be omitted.

Reference numerals 87 and 88 denote color photographing devices such as TV cameras, and the color photographing device 87 and the color photographing device 88 have the same or simple geometrical optical conditions such as an angle of view, a photographing position, and a photographing magnification. It must be configured so that processing can be equivalent. In this embodiment, an optical system using the half mirror 90 satisfies this condition. Using this optical system, the color photographing device 87 and the color photographing device 88 can photograph exactly the same image except that the left and right are reversed,
By reversing the left and right of the image on one side, "a geometrically-optically equivalent photographing means" can be easily realized. In addition, 89
Is a calculator, 90 is a half mirror, and 92 is an object to be measured.

Next, the operation of the object measuring device having the above configuration will be described. The white light emitted by the white irradiation light source 83 is applied to the measured object 92 after removing only the wavelength component of the laser light through the filter 84. And the measuring device 70
Measures the three-dimensional shape of the measured object 92 irradiated with white light. On the other hand, at the same time as the measurement by the measuring device 70, the object to be measured 9 is measured by the color photographing device 87 and the color photographing device 88.
Shoot 2nd magnitude at the same time.

Since the filter 85 is provided in front of the image input section of the color photographing device 88, the image after the laser light is removed as shown in FIG. 11, that is, the image is illuminated with white light. The same image G ₁ as when the measured object 92 is captured is obtained. On the other hand, the color photographing device 87 obtains an image G _{2 of the} measured object irradiated with white light and laser light. Therefore, by obtaining the difference between the image G ₁ and the horizontally inverted image G ₃ of the image G ₂ , the image G ₄ of the irradiation position on the image of the laser light at the time of measuring the distance of the measuring device 70 is accurately obtained.

Next, by reading the pixel value of the same pixel coordinates as the obtained irradiation position from the image G ₁ , the color of the measured object 92 at the irradiation position can be accurately obtained. The computer 89 measures the three-dimensional shape and color information of the measured object 92 at the same time and without deviation by repeating the scanning / measuring of the measuring device 70 and performing the color reading operation in synchronization therewith.

The above-mentioned taking optical system is merely an example of the present invention, and is not limited to the one described above. As described above, according to the object measuring device of this embodiment, since the color information of the position exactly the same as the laser light irradiation position is obtained, the measurement position does not shift. Further, since the distance information measurement and the color information measurement are performed at the same time, the measurement position does not shift due to the measurement time shift despite the use of the scanning unit.

[0063]

As described above, according to the invention of claim 1 or 2, the object to be measured is irradiated with the beam-shaped laser light, and the reflected diffused light is reflected by using two kinds of optical paths. Since it converges on a line segment and converts the interference fringes generated by the interference of the reflected light from these optical paths into a one-dimensional light and shade fringe pattern, the distance between the fringe patterns or the spatial frequency is measured to obtain the distance. As compared with the conventional method using the light receiving element having the same resolution, it is possible to obtain an effect that the distance measurement can be performed with extremely high resolution. Also, from this, it is possible to solve the problem of occlusion by making the angle between the irradiation light and the reflected light extremely small, there is no problem that the resolution deteriorates even when measuring slopes, and it is also excellent in terms of resistance to optical noise. Further, it is possible to obtain the effect that the current technology can be sufficiently realized without the need for special precision and shape of optical parts.

According to the third aspect of the invention, distance information obtained by scanning the beam-shaped laser light in the two-dimensional direction and measuring the distance to the beam irradiation point on the object to be measured and the scanning displacement. Since the shape of the measured object is obtained by calculating the three-dimensional position information of the beam irradiation point from the angle or displacement length, the resolution is excellent, and the occlusion is extremely small.
The resolution degradation that occurs during slope measurement does not pose a problem, and the effect of being strong against optical noise contained in the measurement light is obtained.

According to the invention of claim 4 or 6, the object to be measured is irradiated with vertical (horizontal) slit laser light, and the reflected diffused light is transmitted through the horizontal slit.
By condensing light using different types of optical paths, converting interference fringes generated by interference of light from these optical paths into a two-dimensional light and shade stripe pattern, and measuring the interval or spatial frequency of the stripe pattern. Since the three-dimensional position information is calculated and the shape of the object to be measured is obtained by repeating the measurement while scanning the slit-shaped laser light horizontally (vertically), the one-dimensional directions can be measured in parallel and the measurement time can be shortened. The effect that it can be made sufficiently short is obtained. Further, as in claim 1 or 2, the resolution is excellent, the occlusion is extremely small,
The degradation of resolution that occurs during slope measurement does not pose a problem, and it is also effective against noise contained in the measurement light. Furthermore, even when compared with a method such as the moire method which measures two-dimensional distance information at one time by utilizing lattice fringes, the resolution is much higher than that of lattice fringes, the resolution in the scanning direction is even higher, and the resolution and measurement range can be arbitrarily set. It also has the advantage that it can be set and that it can measure even on a measurement surface where the distance changes discontinuously.

According to the invention of claim 5, the displacement detecting means detects the displacement angle or displacement length of the scanning performed by the scanning means based on the designated displacement angle or displacement length of the scanning,
Since the three-dimensional position information is calculated based on this detected value,
Even if the mechanical accuracy of the scanning means is not sufficient, it is possible to obtain the effect that the measurement can be performed without affecting the measurement accuracy.

According to the invention described in claim 7 or 9, when the laser light and the white light from which the wavelength component of the laser light is removed are simultaneously irradiated to the object to be measured, the three-dimensional shape of the object to be measured is measured. At the same time, the position of the laser light on the image is obtained from the difference between the first image and the second image, and the color of the measured object at this position is calculated from the pixel value at the same position of the second image. Since the three-dimensional shape and color of the measured object are obtained at the same time,
The color at the exact same position as the irradiation position of the laser light is required, and the effect that there is no deviation of the measurement position is obtained. Further, even if the shape measuring unit is configured to obtain the shape of the measured object by scanning, there is an effect that the deviation of the measurement position due to the deviation of the measurement time does not occur.

According to the eighth aspect of the invention, since the shape measuring means includes means for transmitting only the wavelength component of the laser light, the shape measuring means is affected by light having a wavelength other than the laser light. Even with the configuration, the effect that the influence on the measurement due to this can be eliminated can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of a distance measuring method according to the present invention.

2A and 2B are light intensity distribution charts of a one-dimensional light receiving unit in the triangulation method, where FIG. 2A shows a certain distance, and FIG. 2B shows a slight distance from the distance shown in FIG. It is a figure about the case where is changed.

FIG. 3 is a light intensity distribution chart of the one-dimensional light receiving portion in the present invention, where FIG. 3A shows a case of a detection signal having two frequencies, and FIG. 3B shows a case where the frequency is increased by one frequency from FIG. 3A. The same figure, (c), is when the half frequency is increased from the same figure (a).

4A and 4B are distribution diagrams of light intensity of a one-dimensional light receiving unit by a triangulation method, in which FIG. 4A shows the case where optical noise is not mixed, and FIG. 4B shows the optical noise b mixed. Time.

5A is a light intensity distribution diagram of the one-dimensional light receiving unit according to the present invention when optical noise is mixed, and FIG. 5B is a diagram when detection information is converted into a spatial frequency representation. Is.

6A is a diagram showing a configuration of an apparatus according to a first embodiment of the present invention, and FIG. 6B is a perspective view of an optical element 43.

FIG. 7 is a diagram showing the structure of an apparatus according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating the operating principle of the device according to the third embodiment of the present invention.

FIG. 9 is a diagram showing the configuration of an apparatus according to a third embodiment of the present invention.

FIG. 10 is a diagram showing the structure of an apparatus according to a fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating a captured image and its processing process in the same embodiment.

[Explanation of symbols]

11, 41, 61, 71, 94 ... Laser oscillator, 12,
42, 52, 62, 72, 92 ... Object to be measured, 13, 1
4, 66, 67 ... Mirror, 15, 16, 64, 65, 7
4, 75, 90 ... Half mirror, 18 ... One-dimensional light receiving element, 43 ... Optical element, 44, 45 ... Reflecting surface, 46 ... Half mirror surface, 47, 78 ... CCD, 48, 57, 79,
89 ... Calculator, 53 ... X-direction rotator, 54 ... Y-direction rotator, 55 ... X-direction displacement angle detector, 56 ... Y-direction displacement angle detector, 63 ... Horizontal slit, 68 ... Light receiving element, 73
... Slits, 76, 77 ... Planar mirrors, 80 ... Horizontal rotator, 81 ... Horizontal displacement angle detector, 83 ... White illumination light source, 84, 85, 86 ... Filter, 87, 88 ... Color imaging device

Claims (9)

[Claims] 1. An object measuring device for measuring a distance to an object to be measured, comprising: irradiation means for irradiating the object to be measured with a beam laser beam; and diffusion of the beam laser beam reflected from the object to be measured. Condensing means for condensing light on the line segment using two kinds of optical paths having different optical distances from the reflection points on the object to be measured at both ends on the same line segment, A one-dimensional light receiving element for converting an interference fringe generated by interference between reflected lights coming from the two types of optical paths into a one-dimensional light and shade fringe pattern, and measuring an interval or a spatial frequency of the fringe pattern and performing the measurement. An object measuring device, comprising: a measuring unit that calculates a distance to the measured object based on a value. 2. An object measuring method for measuring a distance to an object to be measured, wherein the object to be measured is irradiated with beam laser light, and diffused light of the beam laser light reflected from the object to be measured is The light is condensed on the line segment by using two types of optical paths having different optical distances from the reflection points on the measured object at both ends on the same line segment. The interference fringes generated by the interference of the arriving reflected light are converted into a one-dimensional light and shade fringe pattern by a light receiving element, the interval or the spatial frequency of the fringe pattern is measured, and the measured object is based on the measured value. An object measuring method characterized in that the distance to is obtained. 3. A scanning unit that scans the beam-shaped laser light in a two-dimensional direction based on a designated displacement angle or displacement length of the scan, wherein the measuring unit measures the displacement angle or displacement length of the scan. The beam-shaped laser light is changed and scanned in a two-dimensional direction within a predetermined range including the object to be measured, and the distance to the beam irradiation point on the object to be measured is measured for the displacement angle or displacement length of each scan. 3. The shape of the measured object is obtained by calculating three-dimensional position information at the beam irradiation point from the distance information obtained as a result and the displacement angle or displacement length of the scan at the time of measuring the distance. The object measuring device described. 4. An object measuring device for measuring a three-dimensional shape of an object to be measured, comprising: irradiation means for irradiating the object to be measured with vertical (or horizontal) slit laser light; and the object reflected by the object to be measured. A horizontal (or vertical) slit that transmits diffused light of the slit-shaped laser light, and diffused light that has passed through the slit are reflected from the reflection points on the measured object at both ends of a horizontal (or vertical) cross section on the same plane. Light condensing means for condensing on the same plane by using two types of optical paths having different optical distances, and interference fringes generated by interference between lights coming from the two types of optical paths. A two-dimensional light receiving element for converting into a two-dimensional light and shade stripe pattern, and a meter for calculating three-dimensional position information of the slit laser light irradiation portion by measuring an interval or a spatial frequency of the stripe pattern. Object measuring apparatus characterized by having means. 5. A scanning unit for scanning the slit laser beam in a horizontal (or vertical) direction based on a designated displacement angle or displacement length of the scanning, and a displacement angle or displacement length of the scanning performed by the scanning unit. 5. The object according to claim 4, further comprising a displacement detecting unit that obtains the three-dimensional position information, wherein the measuring unit calculates the three-dimensional position information using a displacement angle or a displacement length of scanning detected by the displacement detecting unit. Measuring device. 6. An object measuring method for measuring a three-dimensional shape of a measured object, comprising irradiating the measured object with vertical (or horizontal) slit-shaped laser light, and reflecting the slit-shaped object with the slit shape. The diffused light of the laser light is transmitted through a horizontal (or vertical) slit, and the diffused light transmitted through the slit is optically reflected from a reflection point on the measured object at both ends of a horizontal (or vertical) cross section on the same plane. Two types of optical paths having different distances are used to condense on the same plane, and interference fringes generated by the interference of lights coming from the two types of optical paths are two-dimensionally shaded by a light receiving element. The stripe pattern is converted into a striped pattern, and the distance or the spatial frequency of the striped pattern is measured to simultaneously measure the distance of the vertical (or horizontal) portion irradiated with the slit laser light. The measurement is repeated while scanning the laser beam horizontally (or vertically), and the three-dimensional position information of the irradiated portion is calculated from the obtained distance information and the displacement angle or displacement length of the scan at the time of the distance measurement. An object measuring method, characterized in that the shape of the measured object is obtained. 7. An object measuring device for measuring a three-dimensional shape and a color of an object to be measured, comprising: first irradiating means for irradiating the object to be measured with laser light; and wavelength components of the laser light to the object to be measured. Second irradiating means for irradiating the white light from which is removed, first photographic means for photographic the object to be measured, geometrically-optically equivalent to the first photographic means, and a wavelength component of the laser light. Second photographing means for photographing the measured object through a filter for removing the object, shape measuring means for measuring the three-dimensional shape of the measured object, the first photographing means and the second photographing means The position on the image of the laser beam applied to the object to be measured is obtained from the difference between the two images captured by the second image capturing means to capture the color of the object to be measured at the position. Pixel value at the same position on the captured image An object measuring apparatus, comprising: 8. The object measuring device according to claim 7, wherein the shape measuring unit includes a transmitting unit that transmits only the wavelength component of the laser light. 9. An object measuring method for measuring a three-dimensional shape and a color of an object to be measured, wherein the object to be measured is simultaneously irradiated with laser light and white light from which a wavelength component of the laser light is removed, At the same time as measuring the three-dimensional shape of the measurement object, a first image obtained by photographing the measurement object and a second image obtained by photographing the measurement object via a filter that removes the wavelength component of the laser light are displayed. The position of the laser beam irradiated on the object to be measured on the image is obtained from the difference between the two images, and the color of the object to be measured at the position is determined by the pixel at the same position in the second image. An object measuring method characterized in that a three-dimensional shape and a color of the measured object are calculated at the same time by calculating from a value.