JPH01274007A - Three-dimensional measuring device - Google Patents

Abstract

PURPOSE:To enable measurement of a three-dimensional shape of the whole of an object by single reading of an image, by arranging a mask pattern to be made up of a number of slits cut at random to distinguish the slits. CONSTITUTION:A mask pattern 9 is provided for projecting slit patterns, a pattern projector 10 to project a pattern to an object, a TV camera 11 to read images and a memory 12 to store an image data. Moreover, an image of a slit pattern projected to the object is made to correspond to a pattern 9 and an arithmetic device 13 is provided to measure a three-dimensional distance to the object by trigonometrical survey. Then, a number of slits in the pattern 9 allows measurement of the whole of the object by one image photography and a cut pattern on the slits provides an indicator for to which slit a slit on the image taken corresponds. This enables three dimensional measurement of a distance of the whole of the object by single image photography.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a three-dimensional measuring device that measures the shape of an object by projecting a light pattern. [Prior art] Figure 9 is from "Digital Image Processing Engineering" by Kei Tezuka-1 Tadahiro Kitahashi and Hideo Ogawa, published by Nikkan Kogyo Shimbun, 1985, pp.
190 is a diagram showing a method called a slit light projection method for three-dimensional measurement shown in FIG. FIG. 10 is a block diagram showing the configuration of the three-dimensional measuring device, in which (1) is a mask pattern for the slit pattern to be projected, (2) is a mask pattern drive device for changing the slit position, and (3) is a mask pattern for the slit pattern to be projected. (4) is a pattern projection device that projects the slit pattern onto an object; (4) is a Brevi camera that reads the image of the measurement target onto which the slit pattern is projected; (5) is a storage device that stores image data;
(6) is the slit pattern projected onto the object and the memory device @
(5) This is an arithmetic device that measures the three-dimensional distance of the part of the object that is hit by the slit pattern from the slit image stored in step (5). FIG. 11 is a pattern diagram showing the slit pattern mask pattern (1) of FIG. 10. Next, the operation will be explained. Mask pattern for slit pattern projection (1) t'', mask pattern 1lEKid
Move the device (2) to an appropriate position, and then turn the pattern projection device (
3) Shine a slit-shaped light pattern onto an object. Next, this image is read by a television camera (4) and stored in an image data storage device (5), and an image of the portion illuminated by artificial light is detected by a calculation device (6). Image of detected slit pattern and mask pattern opening used for projection)
The distance from the position of the object to the part of the object that is illuminated by the light is measured by triangulation. The above operation is performed by a mask pattern driving device.

[2] Use mask pattern [1]
By moving the entire object and repeating the process, the distance of the entire object is measured. [Problems to be Solved by the Invention] Since the conventional three-dimensional measuring device f using slit pattern projection is configured as described above, in order to measure the shape of the entire object, it is necessary to sequentially use a mask for projecting the slit pattern. The pattern had to be moved and images taken to measure the entire distance, which required a large number of images and caused problems such as the time it took to measure. This invention was made to solve the above-mentioned 21 problems, and aims to provide a three-dimensional measuring device that can measure the shape of an entire object by simply projecting a pattern twice and photographing an image of the mouth. purpose. [Means for Solving the Problems] The three-dimensional measuring device t according to the present invention uses slit holes. [Operation] Among the mask patterns in this invention, a large number of slits are The cutting pattern on each slit provides an indication of which slit on the mask pattern each slit on the captured image corresponds to, and - [Embodiment] An embodiment of the present invention will be described below with reference to the drawings.
The figure shows an example of a mask pattern for slit pattern projection used in the present invention. In FIG. 1, (7) is a part that generates slit cuts for measurement, and (8) is a cutting pattern randomly placed on each slit (7). FIG. 2 is a block diagram of this embodiment, where (9) is the mask pattern shown in FIG. 1, αq is a butter/projector for projecting the pattern onto an object, and αη is a television for reading the image. A camera (6) is a storage device for storing image data, (t3vi) correlates the image of the slit pattern projected onto the object with the mask pattern (9), and uses triangulation to This is an arithmetic device that measures dimensional distance.The function and operation of this embodiment will be explained.In step 2 of the flowchart shown in Fig. 3, in step (b), a pattern as shown in Fig. 1 is projected onto an object. By projecting the pattern shown in Figure 1, an image consisting of a large number of slits and random cutting patterns on the object is generated. The image of the slit pattern on the object is detected in step αQ, and the image of the cutting pattern on the object is detected in step αQ. In order to measure the three-dimensional distance of the entire object by triangulation using only one image, it is necessary to determine which of the slit images projected onto the object each slit in the mask pattern corresponds to. It is necessary to find out whether they correspond.In the step step, each slit image on this image is correlated with the slit pattern on the mask.In the step step C17)
The three-dimensional distance to the object is calculated from the correspondence obtained in . Next, the correspondence between the slit image and the mask pattern in Stellar Print will be explained. FIG. 4 is a flowchart showing the mapping process in step αη. 1st
When the mask pattern of this embodiment as shown in the figure is used, a slit image with random cuts is generated on the object. FIG. 5 explains this by giving an example. A in Figure 5
is a diagram showing a part of the mask pattern used for projection,
The shape is the part sandwiched between the cutting pattern C on the slit and the cutting pattern C8. In Figure W and Figure 5, B is an example of a slit image produced when a mask pattern, only a portion of which is shown in A, is projected. In the flowchart shown in FIG. 4, in step α9, a segment image having a cutting pattern at both ends is first detected from the slit image, and its end points, that is, the cutting pattern are detected. In the example of B in Figure 5, -gl
*4 r JJm is a segment, C:, C;
There are 21 endpoints. Next, in step (2), correspondence of this segment is searched. Correspondence of segments is performed by taking correspondence between their end points. In FIG. 5, dashed lines indicate locations where end points corresponding to end points C, , C, of segment 2 in mask pattern A may exist. (This S is called an evipolar line) In this example, the segment on mask A! corresponds to segment 21 on image B. In this invention, since the cutting pattern that generates the end points is placed in 27 dams, is there a possibility that false correspondence will occur? It can be lowered. In step 2, it is checked whether there is a segment that matches both end points as a result of the correspondence search for each segment, and in step 2, it is checked whether there is only one such matching segment. If there is only one such corresponding segment, the correspondence is established, the step memorizes this correspondence, and exits 0. If there is one or more such correspondences, then the step ends , examine the correspondence of surrounding segments. This will be explained in full with examples in FIG. 6.A in FIG. 6 shows the slit turn and cutting pattern on the mask pattern, and B shows the pattern on the image. When segments 2 and 2' correspond, the surrounding segments must also correspond. In other words! Segment Aa that is continuous with Aji and Yari on the same slit as
, Ab is! It is on the same slit as! ’ is continuous. a, , corresponding to stone 2 and adjacent to ec
, -gd is 0 corresponding to -136 + -04 adjacent to 2'! Around (-ga + -gb, -13c
p-8d) and! When the surroundings of ' (,!3...432 + IB + 4) have such a correspondence relationship, J and p' are the corresponding ones and steps (c)
, and store this correspondence using stepum. If the peripheral correspondence is still undetermined, stay in the step area and wait until the correspondence progresses. For those for which correspondence at both ends could not be obtained in step ■, in step (to),
Check to see if there is something that corresponds to one side, and if there is something that corresponds, proceed to step (to) and check the peripheral correspondence. If there is no correspondence on both sides at step (to), check whether the correspondence search for all segments has been completed at step 10, and after completing the search for all segments, at step (to) Check whether a corresponding segment exists based on the correspondence relationship. In this way, by associating multiple slits from the correspondence of random cutting patterns placed on the slits, three-dimensional distance measurement of the entire object can be performed by projecting a single turn and taking an image. becomes possible. 2. In the above embodiment, the cutting pattern (8) on the slit in the mask pattern is used, but instead of the cutting pattern (8), a cutting pattern gold amount of a different color from the slit portion (7) is used. Good too. FIG. 7 shows another embodiment using colored cutting patterns. (2) is the slit part, (11) is the cutting pattern part, and the fields and 3υ are made of different colors. Further, in the embodiment described above, it is also possible to use the pattern for distinguishing each slit. [Effects of the Invention] As described above, according to the present invention, the mask pattern for generating the pattern to be projected is configured to consist of a large number of slits with random cuts to distinguish each slit. , it is possible to measure the three-dimensional shape of the entire object by reading the image once, and there is an effect that three-dimensional measurement can be performed at high speed with a small number of images.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a mask pattern for slit pattern projection used in the present invention, FIG. 2 is a block diagram showing a three-dimensional measuring device according to an embodiment of the present invention, and FIGS. FIGS. 7 and 8 are explanatory diagrams showing the operation of the three-dimensional measuring device according to the present invention, respectively, and FIG. FIG. 10 is a block diagram showing the conventional three-dimensional measuring device, and FIG. 11 is an explanatory drawing showing the conventional mask pattern for projecting a slit pattern. In figure 2, (7) &i mislit (8) are the cutting points,
(9) is a mask pattern, QCI is a pattern projector, (
6) is an imager (television camera), and (to) is an arithmetic device. 2. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A pattern projector that projects an optical image of a mask pattern having a plurality of slit patterns cut into segment slits at randomly arranged cutting points onto an object to be measured, and images the projected optical image. With respect to each of the segment slits in the image obtained by capturing the image, the correspondence with each of the segment slits in the mask pattern is determined using the positions of the cutting points at both ends, and the correspondence between the mask pattern and the projection is calculated. A three-dimensional measurement device equipped with an arithmetic device that calculates the three-dimensional distance to an optical image.