JPH02162247A - Automatic surface-shape measuring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to measure the size, shape and area of the flaw of an object to be measured automatically and highly accurately at a high speed by processing the image of a digital image signal from an A/D converting part. CONSTITUTION:The base part of a specimen 1 such as a round rod test piece is mounted on a chuck part 2a of a rotary jig 2. The specimen is positioned and attached with respect to an image sensing part 3. The rotary jig 2 can be rotated and moved up and down and right and left by a moving means 2b. The moving motion is controlled with a control part 6, and moving instructions can be issued from an image processing part 7. The image of the specimen 1 which is attached to the rotary jig 2 is picked up with the image sensing part 3, and the analog image information is obtained. The analog image signal is supplied to an A/D converting part 5 and converted into a digital image signal. The digital image information is stored in the frame memory in an image processing part 7 individually. In this way, the size, shape and area of the flaw of the object to be measured can be measured automatically and highly accurately at a high speed.

Description

[Detailed Description of the Invention] <Industrial Application> The present invention automatically and accurately measures surface shape information such as flaws on the side surface of a round bar test piece from multiple directions using image processing technology. It relates to a device that can.

<Conventional technology> Conventionally, to measure scratches on round bar specimens, the round bar specimen was fixed by hand, imaged, and then corrected by image processing, and its size, shape, area, etc. were measured. Was. In the imaging step of this work, since it is necessary to image the back or side surface, the test piece is rotated and images are taken from multiple directions several times. At this time, the test piece was rotated by hand. In addition, in the correction process using image processing, since the test piece has a curved surface, it is flattened and the images taken several times are joined together. This mark is used to correct deviations due to rotation or movement when moving up, down, left, or right.

<Problems to be Solved by the Invention> However, in the above-mentioned joining work, the work of marking to correct misalignment and the work of correcting misalignment using image processing require a great deal of labor and time. is,
The disadvantage was that the measurement efficiency was low. Furthermore, there was also a problem in terms of accuracy in that the error in the image caused by the correction became large.

The present invention solves the above-mentioned problems and uses image processing to create a surface shape that automatically measures the size, shape, and area of scratches on round bar test pieces at high speed, automatically, and with high precision. The purpose is to provide an automatic measuring device.

<Means for Solving the Problems> The present invention is an apparatus for automatically measuring the surface shape of an object to be measured, such as a rod-shaped test piece, which comprises: a rotating jig for gripping and rotating the object to be measured; a moving means for moving the rotating jig vertically and horizontally; an imaging section for capturing an image of the surface condition of the object to be measured;
an analog/digital converter that converts analog image information from the imaging unit into digital information; and an analog/digital converter that performs image processing on the digital image signal from the analog/digital converter.
The above object is achieved by comprising an image processing section that measures the shape of the object to be measured, and a control section 8 that controls the rotating jig and the moving means.

Function> Recently, digital image processing using gradation level processing has advanced.The present invention uses this technology to automatically measure the size and shape of scratches on round bar test pieces, etc. It is something. At that time, since the curved surface is to be imaged, there is a work of flattening the surface and a work of joining the images of the back surface, etc. In order to easily perform this joining operation, it is necessary to prevent displacement due to vertical and horizontal movement or rotation.

FIG. 1 is a block diagram showing one embodiment of the apparatus of the present invention, in which a sample 1 to be measured, such as a round bar test piece, is attached to the chuck part 2a of the rotating jig 2 by attaching its base to the chuck part 2a of the rotating jig 2. It is positioned and attached to the imaging unit 3. Also,
This rotating jig 2 is configured so that it can be rotated and moved vertically and horizontally by a moving means 2b such as a motor. Furthermore, the zero-rotation jig 2 is configured such that this movement operation can be controlled by a control unit 6 and an operation command can be issued from an image processing unit 7.
The sample 1 attached to the sample 1 is imaged by the imaging section 3 while being uniformly illuminated by the illumination section 4 to obtain analog image information. This analog image signal is supplied to the A/D converter 5 and converted into a digital image signal. The image at this time is 1
28 x Number of divisions of 128 pixels or more, preferably 512 x
The number of divisions is 512 or more pixels, and each pixel is at least 1
6111ml! The above is preferably set to 256 gradations.

Digital image information is individually stored in a frame memory in the image processing section 7.

For round bar test pieces, the test was carried out in several batches, and the image processing unit 7
After the process of flattening the curved surface and joining process, −
Obtain two full-circle images. It goes without saying that for square bar specimens, a full-circumference image can be obtained only by the bonding process.
From this all-around image, the image processing unit 7 determines the size of the scratch, etc.
Find the area, etc. of shape 9. During this measurement, the parallel portion of the test piece must be placed perpendicular to the imaging section using a test piece holding jig.

<Example> Hereinafter, the results of measuring the area of the flawed portion A of a round bar test piece S having a diameter of 1O+osφ shown in FIG. 2 as a sample using the apparatus of the present invention will be described with reference to the drawings. In addition, in this measurement, the round bar test piece S was rotated by 90 degrees,
It was decided to obtain a full circumference image by joining the four images.

FIG. 3 is a digital image when the round bar test piece S is mounted on the chuck part 2a of this apparatus. In this figure, the area surrounded by dotted lines is the target area of one image of this round bar test piece S.

In this area, by operating the zero-rotation jig 2 that flattens the curved surface as shown in FIG.
Rotate the round bar specimen S and repeat the above process.

At this time, the rotation is set to 90 @, and the image processing unit 7
Next, as shown in Figure 5, the four images are joined together.Since there is no rotational shift or vertical or horizontal movement shift in each image, the joining process can be easily performed. Needless to say.

Finally, a binary image is obtained from the density change in the all-round image, and the area of the flaw A is measured. In the above example, the round bar specimen S
The time required to measure the area of the wound was within 5 minutes.

On the other hand, the area of flaws on the same round bar specimen was measured using a conventional method. That is, first, rotate the round bar specimen S by 9 degrees by hand, mark each section by hand so that the four corners that appear in the image are rectangles, and image each target area of this image and flatten it. After processing and further bonding processing, a binary image was obtained from the density change of the entire circumference image and the area of flaw A was measured.
It took about 60 minutes.

The present invention is not limited to the embodiments described above, and can be modified in many ways.
The rotation can be made variable according to its use. Further, the diameter of the round bar is up to 15 m, but it can be reduced to several cm by replacing the chuck part. The shape of the test piece can be any shape as long as the diameter is parallel.

<Effects of the Invention> As is clear from the above explanation, the automatic surface shape measuring device of the present invention uses digital image processing to automatically measure scratches on round bar test pieces, etc. at high speed and with high precision. The size, shape, and area of 2 can be determined.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the device of the present invention, Fig. 2 is a perspective view showing the external appearance of a round bar test piece, and Fig. 3 is a digital image of a round bar test piece at a certain position. 4 is a diagram showing an image of flattening a digital image of a photographed round bar test piece, and FIG. 5 is a diagram showing an image of joining processing of four images. 1... Sample (object to be measured). 2a... Chuck part. 3...Imaging section. 5... A/D conversion section. 7... Image processing section. A... Oblique part. 2...Rotating jig. 2b... Means of transportation. 4...Lighting section. 6...Control unit. S...Round bar test piece.

Claims (1)

[Claims] An apparatus for automatically measuring the surface shape of a measured object such as a rod-shaped test piece, comprising: a rotating jig that grips and rotates the measured object; and a moving means that moves the rotating jig vertically and horizontally. An imaging unit that captures an image of the surface state of the object to be measured, an analog/digital conversion unit that converts analog image information from this imaging unit into digital information, and an image processing unit that processes the digital image signal from this analog/digital conversion unit. An automatic surface shape measuring device comprising: an image processing section that measures the shape of an object to be measured; and a control section that controls the rotating jig and the moving means.