JPH0442010A - Three-dimensional shape measuring apparatus - Google Patents

Abstract

PURPOSE:To sense the image of an object in a broad range and to synthesize the slit images readily and accurately by emitting scanning slit light beams which are intersected with stationary light on the object to be measured from both sides with the light emitting axis of a stationary-slit light source as a boundary. CONSTITUTION:Reference slit light which is stationary slit light is emitted on an object 2 from a reference laser 3s. At this time, the image of a reference- light cutting line on the object caused by the reference slit light from the reference laser 3s is picked up with a right CCD camera 5r and a left CCD camera 5l. The image of the picked-up reference-light cutting line is processed as a reference cylinder image 50s of each of images 40r and 40l. An image processor detects the position of the reference slit image 50s on each of the images 40r and 40l. The position data are stored in an image memory.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is capable of non-contact measurement of the shape of a human body in medical care, the three-dimensional measurement of a human body in the apparel industry, the three-dimensional shape of a mold, the flatness of a steel plate, etc. The present invention relates to a three-dimensional shape measuring device.

[Prior art] As a method for non-contact measurement of the three-dimensional shape of the object to be measured as described above, the slit light projection method (light cutting method) is a typical method, as described in the reference document "4th Industrial Image Sensing Technology Symposium Lecture Proceedings'' (title: ``Three-dimensional curved surface shape measurement using image encoder - Macro shape measurement by slit light scanning'', pages 235 to 240) by Kabe et al.

Three-dimensional shape measuring device applying such a slit light projection method 1. Now, as shown in FIG. 5, one slit light beam from a laser 3 (semiconductor laser) serving as a slit light source is irradiated onto the surface of the object 2, and at that time, a light cutting line on the object 2 due to the slit light is is imaged by a CCD camera 5 disposed outside the irradiation optical axis of the slit light, and for example, a slit image 5 shown in the image image 40 after image processing.
The three-dimensional shape of the object 2 is measured from a distortion of 0. Such a three-dimensional shape measuring device 1a
Here, the laser 3 is rotated in the direction of the arrow m in the figure by the drive of a scanner (not shown) connected to the laser 3, and the predetermined irradiation angle θ is changed at equal pitches to scan the entire surface of the object 2. It is designed to scan.

As mentioned above, when measuring the three-dimensional shape of the object 2 in a non-contact manner, when measuring a wide range of objects, it is necessary to measure using multiple, for example, CCD cameras, and obtain the information obtained from each CCD camera. 3 each from the slit light image
Techniques for finding dimensional shapes and synthesizing the three-dimensional shapes are also being developed.

[Problem to be solved by the invention]

The above three-dimensional shape measuring device 1. Here, the entire object 2 is measured by rotating one slit light source and changing the irradiation angle θ. However, as the shape of the object 2 becomes more complex and its irregularities become larger, discontinuities or shadows in the projected light cutting line appear on the surface of the object 2. In addition, if a certain surface of the object 2 is parallel or approximately parallel to the slit light irradiation direction, or if the surface shape of the object 2 changes rapidly, it may occur at the end of the imaging range of the CCD camera 5. When the image is captured, the pitch width of the slit image 50 projected from the region increases, resulting in poor in-plane resolution. Therefore, the range of the properly obtained slit image was narrow.

On the other hand, according to the method described above in which images are taken using a plurality of CCD cameras and the slit images taken by the respective CCD cameras are combined, due to errors such as the distances between the respective CCD cameras, the slit images cannot be combined. It is conceivable that the slit images obtained by adjacent CCD cameras overlap, or that gaps are created between the slit images. Furthermore, in the past, there was no standard for compositing such slit images. Therefore, it has been difficult to combine the slit images with high accuracy.

Therefore, an object of the present invention is to be able to image a target object over a wide range by obtaining a plurality of appropriate slit images without overlapping or gaps between the slit images, and to synthesize the slit images. The object of the present invention is to provide a three-dimensional shape measuring device that can easily and accurately measure the shape of a three-dimensional shape.

[Means to solve the problem]

In order to achieve the above object, the main means adopted by the present invention is to irradiate a measurement object with slit light from a slit light source, and to irradiate a projected slit image of the measurement object. A three-dimensional shape in which a series of operations for imaging using an imaging means arranged off the optical axis is performed at each scanning position of a light source that scans the slit light at a predetermined angle or interval at an equal pitch. In the measuring device, there is a stationary slit light source that irradiates the object to be measured with stationary slit light, and a scanning slit light that intersects the stationary slit light from one side and the other side of the irradiation optical axis of the stationary slit light source. The first beam that irradiates the object to be measured.
and a second scanning slit light irradiation means, first and second imaging means for capturing a projected image by each of the slit lights from one side and the other side of the irradiation optical axis of the stationary slit light source, and the one side and the other side. The present invention is a three-dimensional shape measuring device comprising an image synthesizing means for synthesizing each projection image by the scanning slit light taken from the side with reference to the intersection with the projection image by the stationary slit light.

[Effect]

According to the three-dimensional shape measuring device according to the present invention, the stationary slit light source irradiates the object to be measured with stationary slit light in order to use it as a reference during image synthesis, which will be described later. The first and second slit light irradiation means irradiate the object to be measured with scanning slit light that intersects with the stationary slit light from one side and the other side of the irradiation optical axis of the stationary slit light source. , to the projected slit image,
For example, there are fewer breaks and shadows, resulting in a more appropriate slit image. Furthermore, since the first and second imaging means capture the slit image by each of the slit lights from one side and the other side of the irradiation optical axis of the stationary slit light source, the pinch width of the slit image does not widen. . Furthermore, since the image synthesizing means synthesizes each slit image by the scanning slit light taken from the one side and the other side using the intersection with the slit image by the stationary slit beam as a reference, it is extremely easy to synthesize the slit images. Moreover, it can be performed with high precision.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here,
FIG. 1 is a block diagram showing a three-dimensional shape measuring device according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view showing how the three-dimensional shape measuring device is used to measure the three-dimensional shape of an object. Figure 3(a) shows the right CC of the same three-dimensional shape measuring device.
A state explanatory diagram showing the reference slit image taken by the D camera, Fig. 3 (bl is the left C of the three-dimensional shape measuring device)
A state explanatory diagram showing a reference slit image taken by the OD camera; FIG. 4(a) is a state explanatory diagram showing a right scanning slit image taken by the right CCD camera;
Figure (b) is a state explanatory diagram showing a left scanning slit image taken by the left CCD camera.

Note that the following examples are merely examples embodying the present invention, and are not intended to limit the technical scope of the present invention.

As shown in FIGS. 1 and 2, the three-dimensional shape measuring device 1 according to the present embodiment includes a cylindrical lens that irradiates invisible slit light (infrared laser light) that is stationary slit light toward an object 2. 3. A reference laser including a semiconductor laser (not shown) with a and the reference leather 3. The above-mentioned reference laser 3. a right laser 3r and a left laser 3I that irradiate the object 2 with scanning slit light that intersects with the stationary slit light; and the right laser 3r.
and the right laser 3r and the left laser 3! along the upper surface of the object 2 at right angles to the optical axis of the invisible slit of the left laser 3I and in the horizontal direction. a scanner 6 that scans at an equal pitch, a scanner controller 7 that controls equal pinch scanning by the scanner 6, and the reference laser 38.
Right laser 3r, left laser 3! and a scanner 6 via a serial interface 7.
Work 5tation (hereinafter referred to as EWS) and
Above the object 2, the reference laser 3. The right CCD camera is placed at the left and right positions from the irradiation optical axis5. and left side CCD camera 5I
And the right CCD camera 5r and the left CCD camera 5!
Reference slit image 504. Right scanning slit image 50° Left scanning slit image 50! The right scanning slit image 50 . stored in the cough image memory 9 is stored in the image memory 9 as image data. and left scanning slit image 50! Each image data related to the above reference slit image 5
0. and an image processor 8 which synthesizes the image based on the intersection with the EWS 10 and transfers the synthesized image to the EWS 10.

Reference laser 3. are arranged above the object 2 in the vertical direction, and the reference laser 3 .
The right laser 3r and the left laser 3.
is in place.

In the figure, a laser controller 11 controls each of the above-mentioned lasers 3.3, . 3/
control. The DMA interface 1 is a general-purpose interface that forwards data directly between the image processor 8 and the EWS 10 without the intervention of their respective central processing units. The image monitors 20r and 201 are connected to the right CCD camera 5. and each scanning slit image 50r, 50 captured by the left CCD camera 5I.
This is an image monitor for displaying each of i in real time.

Therefore, when measuring the surface shape of the object 2 using the three-dimensional shape measuring device 1 configured as described above, first the reference laser 3. The reference slit light, which is a stationary slit light, is irradiated onto the object 2 from.

At this time, the reference laser 3. The reference light cutting line 30° on the object 2 due to the reference slit tip is the above-mentioned right side C.
The image is captured by the CD camera 5r and the left CCD camera 57. The imaged reference light section line 30. is shown in Figure 3 (a
) and the image 40140! by the image processor 8, as shown in FIG. Reference cylinder image 50 of
．． The image is then processed. The image processor 8 then outputs the reference slit image 50.0 and each image 40.0 to the reference slit image 50.0.
,40! The position above is detected and this position data is stored in the image memory 9.

Next, the right laser 3. and left laser 3. is activated, scanning slit light is irradiated onto the object 2 from each, and the right light cut* a projected by each scanning slit light is
o r and left light cutting line 30! are the above-mentioned right CCD camera 5r and left CCD camera 5! The image is taken by At this time, the right scanning slit image 50r and the left scanning slit image 507 captured by each of the cameras 5.degree. 5I are shown in image images 40r and 40 (in FIG. The image processor 8 receives a right scanning slit image 50r (
In order to read the position on the image 40r of FIG. 4(a), the previously captured reference slit image 50. (
The right side up to the position shown by the broken line in the figure is traced along the right scanning slit image 50r, and the reference slit image 5
0. No tracking further to the right, while the left COD camera 5
．． Left scanning slit image captured by (Figure 4 (b)
) is the reference slit image 50. Image 4 is on the left side of
tracked for position reading at 0z and the reference slit image 50. It is not tracked further to the right, so the reference slit image 50. The right scanning slit image 50 detected on the left and right with . and left scanning slit image 50
The position data of t is stored in the image memory 9, respectively.

Such a series of scanning slint image reading scans are performed at equal pitches over the entire surface of the object 2 in a predetermined scanning direction (indicated by arrow M in the figure) by driving the scanner 6. Here, the right laser 31 and the left laser 3 are set to scan integrally with their respective irradiation optical axes substantially coincident, but the right laser 3r and the left laser 3I are set individually. Each slit image 50□ stored in the image memory 9 may be scanned by
, 50r, and 50t are converted into corresponding three-dimensional coordinate values by the image processor 8 using the well-known three-dimensional equation applied in the slit light projection method described above. In this way, each position data of the right scanning slit image 50r and the left scanning slit image 507 converted into three-dimensional coordinates is used for compositing the left and right images, and is converted into three-dimensional coordinates on a plane cut by the reference light cutting line 30°. The above will match.

In addition, the above reference laser 3! The reference slit light irradiated from the slit is always irradiated in a stationary state. Therefore, at the light cutting line on the object 2 that overlaps with the scanning slit light beams from the scanning lasers 3r and 3I, the brightness is approximately doubled, but the Halley shift of the slit image due to this is caused by the image processor 8 as appropriate. Since the center-of-gravity method using threshold processing is adopted, it is possible to prevent these problems.

As described above, the three-dimensional shape measuring device 1 according to the present embodiment
5. irradiates the object 2 with scanning slit light from the left and right sides of the object 2, and two CCD cameras 5. ．． 5. Since the image is captured on multiple channels, the imaging range where the slit image is captured as an appropriate slit image with fewer interruptions and shadows is wider than before, and the pitch width of the slit image does not become extremely wide. Also, reference laser 3. are each of the above CCD cameras 5. , S, is used as a reference slit light source when composing the slit images taken by , S, so that the compositing of the left and right three-dimensional image data becomes extremely easy and accurate. This makes it possible to prevent overlapping or omission of the three-dimensional image data as much as possible when composing the three-dimensional image data.

Further, in this embodiment, the scanning slit light is set to intersect the reference slit light at a right angle, but the scanning slit light may intersect the reference slit light at an angle other than the right angle.

In this example, the first and second scanning slit light irradiation means used slit light made of a laser beam with excellent straightness, but the invention is not limited to this. Any suitable light source may be used.

〔Effect of the invention〕

As described above, the present invention irradiates an object to be measured with slit light from a slit light source, and uses an imaging means disposed outside the irradiation optical axis to capture a projected image of the object to be measured. In a three-dimensional shape measuring device, a series of operations for imaging the object to be measured are performed at each scanning position of a light source that scans the slit light at a predetermined angle or interval at an equal pitch. a stationary slit light source that irradiates the object, and first and second scans that irradiate the object to be measured with scanning slit light that intersects the stationary slit light from one side and the other side of the irradiation optical axis of the stationary slit light source. slit light irradiation means; first and second imaging means for capturing projection images by each of the slit lights from one side and the other side of the irradiation optical axis of the stationary slit light source;
Three-dimensional shape measurement characterized by comprising an image synthesizing means for synthesizing each projection image by the scanning slit light taken from the one side and the other side with reference to the intersection with the projection image by the stationary slit light. Since it is a device, it is possible to obtain a plurality of appropriate slit images without overlapping or gaps between the slit images.

Thereby, it becomes possible to image the target object over a wide range. Further, since the stationary slit light clarifies the range of the plurality of slit images of the object, the plurality of slit images can be synthesized extremely easily and with high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a three-dimensional shape measuring device according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view showing how the three-dimensional shape measuring device is used to measure the three-dimensional shape of an object. Figure 3(a) shows the right CC of the same three-dimensional shape measuring device.
A state explanatory diagram showing the reference Surin) N image taken by the D camera, Figure 3 Φ) is the left CC of the same three-dimensional shape measuring device.
A state explanatory diagram showing a reference slit image taken by the D camera, FIG. 4(a) is a state explanatory diagram showing a right scanning slit image taken by the right CCD camera, and FIG. 4(b) is a state explanatory diagram showing the right scanning slit image taken by the right CCD camera. FIG. 5 is a state explanatory diagram showing a left scanning slit image captured by a camera, and FIG. 5 is an a#! It is a state explanatory diagram when A is seen from the side. [Explanation of symbols] 1.11... Three-dimensional shape measuring device 2... Target object 3... Laser 3,...
Right laser 3I...Left laser 3,...Reference laser 5...CCD camera 5,...Right CC
D camera 5! ...Left side CCD camera 6...Scanner 8...Image processor Applicant: Kobelcono Stem Co., Ltd. Kobe Steel, Ltd.

Claims (1)

[Claims] (1) The series of operations described above includes irradiating a measurement object with slit light from a slit light source and capturing a projected slit image of the measurement object using an imaging means disposed outside the irradiation optical axis. In a three-dimensional shape measuring device that performs scanning at each scanning position of a light source that scans the slit light at a predetermined angle or at regular intervals, a stationary slit light source that irradiates the measurement object with stationary slit light; First and second scanning slit lights that irradiate the object to be measured with scanning slit light that intersects the stationary slit light from one side and the other side of the irradiation optical axis of the stationary slit light source.
scanning slit light irradiation means; first and second imaging means for capturing images projected by the respective slit lights from one side and the other side of the irradiation optical axis of the stationary slit light source; and imaging from the one side and the other side. A three-dimensional shape measuring device comprising: image synthesis means for synthesizing each projection image formed by the scanning slit light with reference to the intersection with the projection image formed by the stationary slit light.