JPH07280518A - Object measurement device - Google Patents

Abstract

PURPOSE:To measure at high speed a three-dimensional position of an edge part from an image of an object obtained by the external lighting by measuring a three-dimensional position of a real edge part of an object and an edge part of a pattern having difference of density drawn on a structural face of the object. CONSTITUTION:An image of an object that is illuminated by a natural light or an external light is inputted to an optical edge-detection section 240 via a variable focal length lens 220. A focal length control section 230 controls a focal of the lens 220 so as to take a certain focal length for measuring the object, then a value of the focal length at that time is stored in a focal length- storing register 250 as depth information. The detection section 240 detects a part in true focus having great difference of density from an optical image focused by the lens 220 as an edge part and a two-dimensional detection section 260 detects the coordinates of the plane position thereof so that the coordinates together with the focal length stored in the register 250 are outputted. The above operations are repeated with respect to various focal lengths, thereby measuring the position and shape of the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object measuring device,
In particular, the present invention relates to an object measuring device that measures three-dimensional information about an object from a scene.

More specifically, the three-dimensional shape of an object is acquired from a scene in which one object is photographed. Further, when there are a plurality of objects in the scene, the three-dimensional positional relationship of those objects such as left, right, up and down, front and back is acquired. For measuring the three-dimensional information of such an object, for example, in the case of a single object, mock-up shape measurement in the design process, grasp of mounting positions of parts in the manufacturing process, shape measurement of the product in the inspection process, It is necessary for grasping the mounting position of parts in the manufacturing process and removing defective products by measuring the shape of the product in the inspection process.

When a plurality of objects are present in a scene, recognition of obstacles, signs, etc. seen ahead in an autonomous vehicle can be mentioned. Further, the work robot is also required as a visual system for obtaining a part having a required shape from among various kinds of parts.

[0004]

2. Description of the Related Art Conventionally, for obtaining three-dimensional information of an object, a method using a sensor, a method using stereo vision, a method using monocular vision, a method using active light measurement, etc. have been proposed.

The method using a sensor is to emit a laser beam or the like and measure the intensity of the reflected light with the sensor to measure the distance to the object, or the emitted light is reflected from the object. There is a range finder that measures the distance by measuring the time to.

Stereo vision is a general method for measuring the three-dimensional shape of an object by detecting corresponding points from both images using two television cameras. This is to know the relative position of each point on the object by the principle of triangulation from the images captured from two TV cameras separated by a certain distance.

The method of using monocular vision for stereo vision has the advantage that it requires only one television camera and can be implemented relatively easily. In order to obtain depth information, a method using shadow information, perspective information, texture information, etc., a method of moving the TV camera with respect to an object and acquiring object information, changing the focal length of the TV camera, There are methods such as obtaining depth information.

A method using monocular vision is one in which a television camera is used.
Since it requires only a table and can be realized relatively easily in terms of method, it is advantageous as compared with other methods, and various studies have been conducted. These studies are roughly divided into (1) a method using electronic processing, (2) a method using active optical measurement, and (3) a method using an optical device dedicated to edge detection.

As an example of (1), there is the method of Anno et al. (Anno, Okada, Yokoyama, Kitagawa: “Stereoscopic measurement using multiple images with continuously changing focal length”, IPSJ 36th. (National convention 5W-8). In this method, first, a plurality of images are captured in the frame memory while changing the focal length of the camera lens. Next, for each image, an edge image is extracted by first-order differentiation or the like by electronic processing,
A frame in which an intensity peak value appears for each edge is detected. Further, the Hough transform is used to extract the linear component to obtain the three-dimensional information of the object.

In the active light measurement of (2), slit light or light having a specific pattern is projected on an object, the light pattern projected on the object is captured by a television camera, and the positional deviation of each point is detected. , To obtain distance information. In this method, the measurement range of the object is limited to the distance that can be irradiated with laser light or the like. However, the three-dimensional information of the object can be accurately obtained by using the method with the monocular vision together.

Examples of active light measurement include the method of Araki et al. (Araki, Shimizu, Noda, Chiba, Tsuda, Ikeya, Sannomiya, Gomi: "High-speed, continuous three-dimensional measurement system",
Image Optics Conference Proceedings, Vol.22 (992) pp.243-
246). In this method, the slit light is radiated to the object and the projected image is captured by one TV camera. At this time, instead of the normal image sensor, a one-dimensional PSD (position detection element) is arranged on the plane to detect each object. The displacement of the slit light at a point is detected at high speed to perform three-dimensional measurement of the object.

As a method using the optical device dedicated to edge detection of (3), for example, there is a method according to Lange et al. (E. Lange, E. Funatsu, K. Hara and K. KYuma: "Direct image processing". Optical Neurochip for “(Optical neur
ochip for direct image processing ")", 1992 IEICE Spring Conference D-83). This method is to detect a portion having a large grayscale difference as an edge portion from an image directly input to the two-dimensional semiconductor optical device.

[0013]

However, in the method using the above-described sensor, since the laser light to be emitted is a spot light, the sensor is two-dimensionally scanned in order to measure an object having a spread. Therefore, it takes a very long time for measurement. Also, in the case of a proximity sensor, the sensor must be sufficiently close to the object,
It is a measurement measurement of an object with small unevenness, and it is difficult to measure an object at a depth because the propagation time of light is short, and the distance information of an object that is some distance away is obtained.

The method using stereo vision requires two TV cameras, it is difficult to detect corresponding points from both images, and it is difficult to know the absolute value of the distance itself. Have.

The method using electronic processing has a problem that a large-capacity frame memory is required to capture a plurality of images and that all the processing is performed by an electronic computer, which requires processing time. Although a large portion is detected as an edge, there is a problem that even if the edge actually exists, it cannot be detected if there is no shade difference due to external illumination.

The method using active light measurement can obtain accurate three-dimensional shape information of an object, but in order to obtain a three-dimensional shape of the entire object, it is necessary to scan the slit light to be irradiated locally. . Further, although the output result of the optical position detecting element is photoelectrically converted and finally processed by the computer, the processing speed cannot be improved for the photoelectric conversion and the processing part in the computer. Further, in contrast to the method using electronic processing, this method cannot detect a pattern with a large difference in shade drawn on the object constituting surface.

The method using the optical device dedicated to edge detection is
The optical device dedicated to the optical edge detection cannot detect only the focused edge portion. Further, similarly to the method by the electronic processing, even if the edge actually exists, it cannot be detected if the difference in gray level does not occur. further,
The current research is in the stage of verifying that an edge image is detected by presenting a two-dimensional optical image such as a slide, and there is no report that the edge portion is directly extracted from the real object.

Thus, in the measurement of three-dimensional information of a real object, it is not limited to the case where a light pattern can be projected onto the object. It is desirable that the edge part in the pattern drawn on the object constituting surface is detected. Furthermore, for an object that is sufficiently close to the extent that a light pattern can be projected, the three-dimensional position of the actual edge portion and the shape and inclination information of the object configuration surface, which cannot be obtained only by the information on the grayscale difference, are obtained without changing the device configuration. It is desirable to be able to measure.

The present invention has been made in view of the above points, and has been achieved by solving the above-mentioned conventional problems and by using only external illumination light without preparing a special illumination light source for an object. It is an object of the present invention to provide an object measuring device capable of measuring three-dimensional position information of an actual edge portion and an edge portion in a pattern having a large shade difference drawn on the surface of the object constituting the object image.

Further, according to the present invention, for an object that is sufficiently close to the extent that a light pattern can be projected, by projecting light patterns of various shapes on the object without changing the device configuration, it is possible to obtain only the information on the grayscale difference. An object of the present invention is to provide an object measuring device capable of measuring the three-dimensional position of an unobtainable real edge portion and the shape and inclination information of the object constituting surface.

A further object of the present invention is to provide an object measuring apparatus capable of performing final high-speed processing and capable of measuring a three-dimensional object which can be realized by compact mounting.

[0022]

FIG. 1 is a principle configuration diagram (1) of the present invention.

The object measuring apparatus of the present invention comprises a focus changing means 120 for continuously changing the focal length and a focus changing means 1.
Optical edge detecting means 130 for extracting a focused edge portion from the optical image formed by 20, and three-dimensional position detecting means 140 for outputting the two-dimensional position coordinates of the edge portion and the focal length at that time. And measures the three-dimensional positions of the real edge portion of the real object and the edge portion in the pattern having a shade difference drawn on the object constituting surface.

FIG. 2 is a principle configuration diagram (No. 2) of the present invention.

The object measuring apparatus according to the present invention is not able to obtain the information only on the gray level difference by adding the light pattern projection means 150 for irradiating the object with the light patterns of various shapes to the above-mentioned configuration of FIG. It is possible to measure the three-dimensional position of the actual edge portion and the shape and inclination of the object constituting surface.

[0026]

According to the present invention, the real edge portion of the real object illuminated by the external illumination light and the edge portion in the shaded pattern on the object constituting surface are extracted from the optical image formed by the focus varying means 120. By removing the blurred edge portion, the focused edge portion can be detected. Further, at each focal length by the three-dimensional position detecting means 140, the actual edge portion of the object in focus, the edge portion of the pattern having a shade on the object constituting surface, and the focus projected on the object constituting surface. The three-dimensional position information of the object can be measured by detecting the two-dimensional position coordinates of the matching light pattern.

Further, according to the present invention, the light pattern projection means 15 is provided.
By adding 0 to the configuration of the above object measuring apparatus, when a light pattern of a certain shape is projected on the object,
Only the specific light pattern projected on the object configuration surface is detected, and 3
The 3D position information is output simultaneously by combining the 3D position and the shape and inclination of the object configuration surface with the object measurement result obtained by external illumination and the object measurement result obtained by projecting light patterns of various shapes. It is possible to

[0028]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 3 shows the system configuration of the first embodiment of the present invention. The object measuring apparatus 200 shown in the figure has a focus variable lens 220 which is a focus varying means 120, a focal length holding register 250, a focal length control section 230, an optical edge detecting section 240 which is an optical edge detecting section 130, and a three-dimensional position detection It is composed of a two-dimensional position detector 260 which is the means 140.

The image of the input object illuminated by natural light or external illumination light is input to the optical edge detector 240 through the variable focus lens 220. Focus variable lens 22
The focal length of 0 is controlled by the focal length control unit 230. The value of the focal length set by the focal length control unit 230 is stored in the focal length holding register 250. The optical edge detection unit 240 detects, as an edge portion, a focused portion having a large grayscale difference from the optical image of the object formed by the variable focus lens 220. The two-dimensional position detection unit 260 detects the plane position coordinates of each point of the edge portion that is in focus, and the focal length holding register 25
It is output together with the focal length stored in 0. For object measurement, the focal length control unit 230 controls the focal point of the variable focus lens 220 so as to take a certain focal length value, and outputs the focal length value at that time as depth information. On the other hand, the optical edge detection unit 240 and the two-dimensional position detection element 260 output two-dimensional coordinate values for the focused edge portion in the image formed at the focal length. By repeating this for various values of the focal length, it is possible to measure the object.

Hereinafter, each part of the object measuring device 200 will be described in detail. Focus variable lens 220 and focus control unit 230
May be, for example, an electric zoom lens. In this embodiment, the variable focus lens 220 is an electric zoom lens, and the focal length control unit 230 controls the rotation amount of the electric zoom lens. The simplest implementation is to move the single lens back and forth. The focal length can be changed by moving the lens back and forth. In this case,
Since the focus variable lens 220 is a lens that can move back and forth, the focal length control unit 230 is a stage that controls the amount of front and back movement of the lens. In the above example, the focal length is changed by a mechanical operation.

There are also methods that do not require mechanical operation. For example, like a Fresnel lens, it is known to play the same role as a lens by drawing a diffraction pattern on a concentric circle.

FIG. 4 shows an example of the configuration of the variable focus lens and the focal length control section of the first embodiment of the present invention. In the figure, the Fresnel lens pattern is a transmissive liquid crystal panel 50.
Displayed at 0. The focal length control unit 230 also serves as a controller that generates a Fresnel lens pattern to be displayed and causes the transmissive liquid crystal panel 500 to display it. The change in the focal length can be realized by changing the shape of the Fresnel lens pattern to be displayed, and does not require mechanical operation. Thereby, the high-speed variable focus lens 220 can be realized. The Fresnel lens pattern is not always displayed on the transmissive liquid crystal panel 5.
However, it is not limited to 00 and can be realized by various spatial light modulators.

The optical edge detector 240 also has various configurations. For example, a method is known in which a grayscale edge portion is detected at high speed from an image by spatial parallel optical digital calculation. For example, SD Goodman et al. “Apply the symbol substitution method to image processing (“ Symbolic substitution appl ”
ication to image processing "), Applied Optics Vo
l.27 p.1708 (1988)) ”, an example thereof is described. There is also a method using a spatial light modulator. For example,
Suzuki et al., "Image edge detection using FLC-SLM", Proceedings of the 53rd Japan Society of Applied Physics 17p-Q-12,1992
There is a method proposed in the year. In this method, the contour line is directly detected from the image by using the characteristic of the spatial light modulator, and further the optical filtering is applied to detect the focused edge portion of the image as a bright edge image.

The focal length holding register 250 may be a register for storing the focal length or a small capacity memory. The two-dimensional position detecting unit 260 is a two-dimensional photodiode array or one-dimensional position detecting elements arranged in a plane.

FIG. 5 shows a specific structure of the object measuring apparatus according to the first embodiment of the present invention. The figure shows an example of an object measuring apparatus in the case of performing edge detection by spatial parallel digital calculation. The object measuring device shown in FIG.
Fresnel lens pattern display controller 21, focal length holding register 22, two-dimensional optical element 30, light source 31, lens array 32, lens 33, polarization beam splitter 34, lens 35, lens array 36, half-wave plate 37, compound lens It comprises a refraction plate array 38, a lens array 39, a lens 40, an optical threshold element 41, a two-dimensional photodiode array 60, optical paths 1 and 5 and signal lines 2, 3, 6 and 7 connecting them.

First, the input object image 10 illuminated by natural light or external illumination light passes through the liquid crystal lens 20 like the optical path 1 and is written and stored in the two-dimensional optical element 30. At this time, in the image to be written, the edge portion where the focal length is matched has a large shade difference, and the edge portion where the focal length is not matched is a blurred edge image with a small shade difference. The liquid crystal lens 20 is the transmissive liquid crystal panel 500 as shown in FIG. 4, and the Fresnel lens pattern display control unit 21 generates a Fresnel lens pattern to be displayed on the liquid crystal lens 20, and the liquid crystal is transmitted via the signal line 2. It is a controller for displaying on the lens 20. On the other hand, the Fresnel lens pattern display control unit 21 stores the value of the focal length at that time in the focal length holding register 22 via the signal line 3.

The two-dimensional optical element 30 is an optical element capable of writing, storing and reading an incoherent light image or a laser light image. Examples of such an optical element include, for example, the document “Bistable spatial light modulator using a strongly conductive liquid crystal (“ Bistable spatial light modulator ”by Fukushima et al.
tor using a ferroelectric liquid-crystal ")”, Opti
The ferroelectric liquid crystal spatial light modulator described in cs Letters Vol.15 p.285 (1990)) can be mentioned. FIG. 6 shows the structure of a ferroelectric liquid crystal spatial light modulator. In the same figure, a ferroelectric liquid crystal spatial light modulator has a conductive film (a-Si: H PC) 304 of hydrogenated amorphous silicon between two glass plates 301 and 301 'coated with transparent electrodes (ITO). , A dielectric mirror (DM) 306, and a ferroelectric liquid crystal 305. The erasing light and the writing light as an input are emitted from the left side of FIG. On the other hand, when the light for changing the straight line is irradiated from the right side, the polarization state of the read light changes according to the light intensity (brightness) of the written optical image. That is, in the bright portion of the written optical image, the polarization state of the read light becomes the light in the polarization state orthogonal to the incident light. On the other hand, in the dark portion of the written optical image, the polarization state of the read light remains the same as the incident light. Therefore, an optical image similar to the written image can be obtained by inserting a polarizing plate on the optical path of the read light so that the light having a polarization state orthogonal to the polarization state of the incident light is inserted. If a polarizing plate that allows light having the same polarization state as that of the above-mentioned state to pass is inserted, an inverted image will be obtained. The liquid crystal used in the spatial light modulator shown in FIG. 6 is not limited to the ferroelectric liquid crystal. Further, a similar spatial light modulator can be realized by using a crystal having an optical birefringence such as BSO or a material having a magneto-optical effect.

In FIG. 5, the linearly polarized light emitted from the light source 31 as shown by the path 4 becomes a plurality of point light sources by the lens array 32. Further, the light passes through the lens 33 and the polarization beam splitter 34 to illuminate the two-dimensional optical element. At this time, the light rays from the light sources at a plurality of points generated by the lens array 32 are written in the two-dimensional element 30 and the image of the object is read out at the same time. The light beam reflected from the two-dimensional optical element 30 has a lens 35 and a lens array 36 as in the optical path 5.
Pass through. Further, the half-wave plate 37 makes the light of the same polarization information as the light source 31. In front of the birefringent plate array 38, the optical image of the optical path 5 is an optical image in which the optical images written in the two-dimensional optical element 30 are multiplexed.

The birefringent plate array 38 shifts the image of each of the multiple-focused optical images in a certain direction by a certain amount so as to detect only an image portion having an edge of a particular shape. Refract as you do.

After passing through the lens array 39 and the lens 40, the birefringent plate array 38 is provided on the optical threshold element 41.
As a result, the images respectively shifted by a certain amount in a certain direction are superimposed to form one image. Optical threshold element 41
Of the superposed images, the light intensity at each point is thresholded and binarized. That is, points having light intensity higher than the threshold value are bright points, and points having light intensity lower than the threshold value are dark points. Such an optical threshold element 41 can be realized by a general spatial light modulator.

In the optical threshold element 41, a point having an intensity equal to or higher than the threshold is in focus at the edge portion,
This is an edge part where the difference in shade is large. The two-dimensional photodiode array 60 outputs the two-dimensional plane position coordinates of a bright point in the image via the signal line 6. As a result, the position coordinates of the focused edge portion at a certain focal length in the three-dimensional position information 70 of the object are measured. on the other hand,
Since the focal length holding register 22 outputs the value of the focal length at this time through the signal line 7, the depth information of the object can be measured among the three-dimensional position information 70 of the object.

Next, another example of the first embodiment will be shown. The present embodiment is a configuration of an object measuring device having another pattern of FIG. 5 of the first embodiment. However, the system configuration shown in FIG. 3 is the same.

FIG. 7 is a block diagram of another object measuring apparatus according to the first embodiment of the present invention. The object measuring device shown in FIG.
Suzuki et al., "Image edge detection using FLC-SLM", Proceedings of the 53rd Japan Society of Applied Physics 17 pQ-12,1992
This is an example when the edge detection method of “year” is used.

The object measuring device shown in FIG.
0, Fresnel lens pattern display controller 21, focal length holding register 22, light contour extraction element 50, light source 51, polarization beam splitter 52, lens 53, polarization beam splitter 54, optical filtering element 55, filter pattern 56, lens 57, The lens 58, the two-dimensional photodiode array 60, the optical paths 1, 5, 9 and the signal lines 2, 3,
It is composed of 6, 7, and 8.

First, the image 10 of the input object illuminated by natural light or external illumination light passes through the liquid crystal lens 20 and is written in the light contour extraction element 50. Here, the configurations and operations of the liquid crystal lens 20, the Fresnel lens pattern display controller 21, and the focal length holding register 22 are the same as those in FIG.

The linearly polarized light emitted from the light source 51 is
The light beam is extracted from the light contour extraction element 50 through the polarization beam splitter 42 like the optical path 4. The light contour extraction element 50 is an optical element similar to the ferroelectric liquid crystal spatial light modulator shown in FIG. 6, but the edge image can be read directly by using the method of Suzuki et al. That is, the polarization direction of the incident light and the rubbing method of the liquid crystal (when the alignment direction when the voltage signal is not applied to the liquid crystal is made coincident, the boundary portion of the grayscale difference is obtained as a contour image, A contour line is extracted, except that an edge portion having a matching focal length appears as a contour having a narrow line width in the contour image. Fourier transform into an optical Fourier transform image on the optical filtering element 55. The optical filtering element 55 is the spatial light modulator of Fig. 6 and is an optical element that performs normal binarization.
The filter pattern 56 is written in the image data through the imaging lens 57. Therefore, on the optical filtering element 55,
The product image of the optical Fourier transform image on the readout side and the written filter pattern is the image after readout. The filtered light image passes through the lens 58 and reaches the two-dimensional photodiode array 60, but the edge image obtained at this time is output brightly (strong in light intensity) only at the focused edge portion. It Therefore, the two-dimensional photodiode array 60 may output the position coordinates of the portion where the bright edge portion exists via the signal line 6. As a result, the position coordinates of the focused edge portion at a certain focal length in the three-dimensional position information 70 of the object are measured. On the other hand, since the focal length holding register 22 outputs the value of the focal length at this time through the signal line 7,
The depth information of the three-dimensional position information 70 of the object is also measured.

FIG. 8 shows the relationship between the measurement object and the measurement result according to the first embodiment of the present invention. The object is a wedge-shaped object, as shown in (a) from the left side of the object, (b) from above the object, and (c) from the left side of the object.
It should be placed so that it looks like the figure. Further, the object measurement direction and the external illumination light direction are assumed to be the directions of the arrows shown in the figure. (D) is a real edge image seen from the measurement direction, but since the object has a spread in the depth direction, the television camera cannot detect it when all the edges are in focus.

Here, the focal length is changed to 1, 2, 3
Edge images that can be detected when the surface is focused are shown in (e), (f), and (g), respectively.

As described above, according to the method of the first embodiment, the focused edge portion is detected at each focal length. However, in this case, the edge portion on the front side cannot be detected because there is no density difference in the external illumination direction in FIG.

[Second Embodiment] Next, a second embodiment of the present invention will be described.

FIG. 9 shows the system configuration of the second embodiment of the present invention. The same components as those in FIG. 3 are designated by the same reference numerals.

First, the entire system of the second embodiment will be described with reference to FIG. The system shown in FIG. 9 has a configuration in which a light pattern projection light source 270, which is the light pattern projection unit 150, is added to the structure shown in FIG.

Here, the object is irradiated with the light pattern emitted from the light pattern projection light source 270. The image of the input object on which the light pattern is projected is input to the optical edge detection unit 280 through the variable focus lens 220. The focal length of the variable focus lens 220 is controlled by the focal length controller 230. The value of the focal length set by the focal length control unit 230 is stored in the focal length holding register 250. The optical edge detection unit 240 uses the variable focus lens 2
A light pattern having a specific shape is detected from the object image input via 20. The detected light pattern is sent to the two-dimensional position detecting element 260. The two-dimensional position detecting element 260 detects the plane position coordinates where the light pattern exists. For object measurement, the focal length control unit 230 controls the focal point of the variable focus lens 220 so as to take a certain focal length value, and also obtains the focal length value at that time. On the other hand, the optical edge detection element 240 and the two-dimensional position detection element 260 detect only the in-focus edge portion, and the two-dimensional position coordinates where the optical pattern exists are recorded together with the focal length stored in the focal length holding register 250. Output. By repeating this for various values of the focal length, it is possible to measure the object.

Focus variable lens 220, focal length control unit 2
30, optical edge detector 240, focal length holding register 2
50, the method of configuring the two-dimensional detection element 260 is the same as that described above.

The specific example of the second embodiment is the same as the configuration described in FIGS. 4 and 5 except for the light pattern projection light source 270, so that in the present embodiment, the first embodiment is used. Description of the same parts as those in the embodiment will be omitted.

FIG. 10 shows the structure of the light pattern projection light source. The light pattern projection light source includes a light source 81, a diffraction grating 82 and a lens 83. The light beam emitted from the light source 81 is diffracted by the diffraction grating 82 as a multicall optical pattern. The light that has passed through the diffraction grating 82 is reflected by the lens 8
3 makes parallel light rays, and a certain-shaped light pattern is two-dimensionally distributed. Various shapes can be considered as the shape of the projected light pattern.

FIG. 11 shows the shape of the light pattern projected on the object. FIG. 4A shows an optical pattern in which slit light of horizontal lines is arranged in the vertical direction at regular intervals. FIG. 2B shows an optical pattern in which a plurality of slit light beams of vertical lines are arranged in the horizontal direction at regular intervals. FIG. 3C is a light pattern in which cross-shaped light patterns are arranged at regular intervals in the vertical and horizontal directions. The shape of the light pattern is not limited to this, but in the case of vertical and horizontal line slit light and a cross-shaped light pattern, it is easy to generate with a diffraction grating, and the projected pattern is vertical and horizontal. Alternatively, since the light pattern is an oblique straight line or a combination thereof, there is an advantage that the light edge detection unit 240 can easily detect the light pattern.

Focus variable lens 22 in the second embodiment.
0, focal length control device 230, two-dimensional position detection unit 260
The configuration of the (element) and the focal length holding register 250 is the same as that of the first embodiment. The optical pattern detection element 280 in FIG. 9 may be the same as that in the first embodiment. However,
The method and magnitude of image shifting in the birefringent array 36 in FIG. 5 needs to be adjusted so that the projected light pattern can be detected. In FIG. 7, the filtering pattern 46 needs to be a pattern that can detect the projected light pattern.

FIG. 12 shows the relationship between the measurement object and the measurement result according to the second embodiment of the present invention. How to place the object is the same as in FIG. As shown in FIG. 12, the projection light source of the light pattern emits light obliquely from above. The shape of the projected light pattern is a light pattern in which a plurality of vertical slit light beams are arranged at regular intervals in the horizontal direction as shown in FIG. In FIG. 12, by changing the focal length,
Light pattern images that can be detected when the surface of No. 3 is in focus are shown in (e), (f), and (g), respectively. Since the light pattern is projected on the object configuration surface, in the case of the object surface tilted in the depth direction, only the light pattern existing in the depth when the object is in focus is detected at each focal length, and the tilt of the object surface is detected. it can. Also, the edge part in front of the object is
In FIG. 8, it was not possible to detect because there is no difference in shade, but in FIG. 12, it can be extracted as the projected light pattern shape change portion. That is, since the projected light pattern is divided into a region detected as horizontal slit light and a region detected as vertical slit light, the edge portion of the boundary can be detected.

In the second embodiment, the three-dimensional position information of the object can be detected as a continuous change in the inclination of the projected light pattern even when there is a curved surface such as a sphere, a cylinder, or a cone. have.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the claims.

[0063]

As described above, the object measuring device of the present invention is
Since photoelectric conversion and electronic processing are not required and only the optical elements and optical components are used until the final position measurement step, high-speed processing is possible and compact mounting is possible.

According to the present invention, without preparing a special illumination light source for an object, there is a large difference in shade drawn on the actual edge portion and the object constituting surface from the object image obtained only by the external illumination light. It is possible to measure the three-dimensional position information of the edge portion in the pattern.

For an object that is sufficiently close to the extent that a light pattern can be projected, without changing the device configuration,
By projecting light patterns of various shapes on the object,
It is possible to measure the three-dimensional position of the real edge portion and the shape and inclination information of the object constituting surface, which cannot be obtained only by the information on the grayscale difference.

Further, it is also possible to combine on the object measuring device the object measurement result obtained by projecting light patterns of various shapes with the object measurement result under external illumination, and output the respective three-dimensional position information at the same time. It is possible to measure the three-dimensional shape of the real edge portion of the real object, as well as the extraction of marks, symbols and the like drawn on the object-constituting surface, and the inclination and shape of the surface on which the marks and symbols are described.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram (1) of the present invention.

FIG. 2 is a principle configuration diagram (2) of the present invention.

FIG. 3 is a system configuration diagram of an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration example of a variable focus lens and a focal length control unit according to an embodiment of the present invention.

FIG. 5 is a configuration diagram of an object measuring device according to a first embodiment of the present invention.

FIG. 6 is a configuration diagram of a ferroelectric liquid crystal spatial light modulator.

FIG. 7 is a configuration diagram of an object measuring device according to a first embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between a measurement object and a measurement result according to the first embodiment of this invention.

FIG. 9 is a system configuration diagram of the first embodiment of the present invention.

FIG. 10 is a configuration diagram of an optical pattern projection light source.

FIG. 11 is a diagram showing a shape of a light pattern projected on an object.

FIG. 12 is a diagram showing a relationship between a measurement object and a measurement result according to the second embodiment of the present invention.

[Explanation of symbols]

 1 Optical path of optical image from input object image 2 Control signal line to liquid crystal lens 3 Signal line 4 Linear incident read light 5 Optical edge detection optical path 6 Signal line 7 Signal line 8 Optical path of read light from optical filtering element 9 Optical Path of Writing Light of Filter Pattern 10 Input Object 20 Liquid Crystal Lens 21 Fresnel Lens Pattern Display Controller 22 Focal Length Holding Register 30 Two-Dimensional Optical Element 31 Light Source 32 Lens Array 33 Lens 34 Change Beam Splitter 36 Lens 37 1/2 Wave Plate 38 birefringent plate array 39 lens array 40 lens 41 optical threshold element 50 optical contour extraction element 51 light source 52 modified beam splitter 53 lens 54 polarization beam splitter 55 optical filtering element 56 filter pattern 57 lens 58 lens 60 two-dimensional photodiode array Ray 70 Three-dimensional position information 81 Light source 82 Diffraction grating 83 Lens 100, 200, 210 Object measuring device 120 Focus changing means 130 Optical edge detecting means 140 Three-dimensional position detecting means 150 Optical pattern projecting means 220 Focus variable lens 230 Focal length control Section 240 optical edge detection section 250 focal length holding register 260 two-dimensional position detection section 270 light pattern projection light source 301 glass 303 transparent electrode 304 photoconductive film 305 ferroelectric liquid crystal 306 dielectric mirror 500 transmissive liquid crystal panel 2301 Fresnel lens pattern display Controller

Claims (5)

[Claims] 1. An object measuring device for measuring a three-dimensional input object from a scene, comprising: focus changing means for forming an image of the three-dimensional input object at various focal lengths; and image formation by the focus changing means. 2 of the optical edge detecting means for detecting the focused edge portion in the optical image and the edge portion detected by the optical edge detecting means.
It has a three-dimensional position detecting means for outputting the three-dimensional coordinates and the focal length at that time, and measures the three-dimensional positions of the actual edge portion of the object and the edge portion in the pattern having the shade difference drawn on the object constituting surface. An object measuring device characterized by the above. 2. The object measuring device according to claim 1, further comprising a light pattern projection means for projecting light patterns of various shapes onto a three-dimensional input object. 3. The focus varying means generates and displays a Fresnel lens pattern which is a concentric diffraction pattern to be displayed on the display means.
The object measuring device described. 4. The object measuring device according to claim 1, wherein the optical edge detecting means detects only an image portion having an edge of a specific shape by spatial parallel digital calculation. 5. The object measuring device according to claim 1, wherein the optical edge detection means uses an optical contour extraction element that directly reads an edge image at a boundary portion of a gray level difference in an optical image.