JPS5918403A - Method and apparatus for measuring size - Google Patents

Abstract

PURPOSE:To perform accurate measurement, by measuring the size of an object, based on the deviation between image element lines in two or more images of the object, which are picked up at different angles to each other. CONSTITUTION:An object S is picked up by television cameras 3 ad 4 at different angles to each other. The object S is displayed on television sets 5 and 6. Scanning lines including measuring points A and B on the television sets 5 and 6 are separated one by one by image processing circuit 7, and the results are displayed on a display device 8. In correspondence with each scanning line, image element lines 11 and 12 and synchronization signals 9 and 10 are displayed on the display device 8. Based on the deviation between the image element lines 11 and 12, the size of the objects S is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dimension measuring method and apparatus for measuring the dimensions of an object using a television camera.

For example, in cases where it is difficult for humans to measure using a scale, such as when inspecting corrosion on the inner surface of petroleum pipeline piping, a method using a television camera has been proposed. However, with this method, although the degree of corrosion can be determined to some extent from the television image, it is difficult to measure the depth of corrosion. For this reason, there were some inconveniences regarding maintenance of pipeline piping.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a dimension measuring method and apparatus that can accurately measure the dimensions of a subject using a television camera.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an example of the dimension measuring device of the present invention, and FIG. 2 is a block diagram. Reference numeral 1 in the figure is a self-propelled trolley, which is driven by a remote controller, for example, inside an oil pipeline.

On the truck 1, an illumination lamp 2 for illuminating the inner surface of the pipeline pipe and a television camera 3.4 for taking an image of the inner surface are installed.

The television cameras 3.4 are arranged on the trolley 1 at predetermined intervals, can be swung in a universal direction, and can change the imaging location by remote control.

The subject S (inner surface of the pipeline piping) imaged by the television camera 3.4 is shown on a television 5.6. When photographing the subject S with the television camera 3.4,
When images are captured at different angles, the viewing angles of the television camera 3 and the television camera 4 will be different, and the televisions 5 and 6 will broadcast images with different viewing angles. Note that the number of scanning lines for television 5.6 is 525 in the case of the NTSC system.

The input of the television 5.6 is connected via a video processing circuit T to a display device 8. The video processing circuit T separates one scanning line including measurement points M and B of the subject S from the television 5.6 and sends them to the display device 8. In addition, if the television cameras 3.4 and 4 are operated in synchronization (7), it is not necessary to synchronize the above-mentioned lines in the video processing circuit 7, but for example, if one television camera operates with a pair of reflective mirrors, When images of the subject S are taken alternately at different angles using the image processing circuit 7, it is necessary to synchronize the scanning lines in the image processing circuit 7.

The display device 8 is composed of, for example, a two-phenomenon synchroscope and displays video element lines 11.12 containing synchronization signals 9.10 corresponding to the scanning lines input from the video processing circuit T. The interval between synchronization signals 9 and 10 is fc 31.746 μse respectively in the case of the NTSCt system.

It is.

The video element line 11 corresponds to the scanning line of the image broadcast on the television 5, and the video element line 12 corresponds to the scanning line of the image broadcast on the television 6. The images are taken at different viewing angles, and when the video element lines 11.12 are compared using the synchronization signal 9.10 as a reference, a temporal shift Δt (see FIG. 3) occurs. This shift Δt corresponds to the difference in viewing angle between the television camera 3 and the television camera 4.

The difference in the viewing angles between the television cameras 3 and 4 corresponds to the difference ΔH between the measurement points large and B, as shown in FIG. In FIG. 4, the arrangement interval between television cameras 3 and 4 is L, and television cameras 3,
The focal length of the lens 4 is f, the distance from the television camera 3.4 to the measuring point M is HA, the distance from the television cameras 3, 4 to the measuring point B is HB, and the viewing angle of the television camera 3 is α.

Let the viewing angle of the television camera 4 be α, the light for the television camera 3.4 at the measurement point M be β1, and the light for the television camera 3.4 at the measurement point H be β2. Also,
ΔmCD (1) ΔOKG, ΔBCDc, zΔCDy1β
,=γγ+α, β, -γ+α, ,RG==P,,D
Q with F=Pb. Nao, r=lKOv.

Since ΔmCD and Δage are similar, ΔB
CD and ΔODF are similar rounding, measurement points and B
The difference ΔH is ΔHeHB −HA By the way, P corresponds to β, and P corresponds to β2. Therefore, the difference between P and Pb corresponds to the difference between β and β2. The difference between β1 and β is the difference in viewing angle between the television cameras 3 and 4, as is clear from the following equation.

β1−β,=(γ+αri−(γ+αI)=α2−α1) That is, the difference between P and PbO corresponds to the difference in viewing angle between the television cameras 3 and 4.

If P, -Pb=ΔP, L-f ΔH HA　HA+ΔH Therefore, ΔH is ■Transform the formula 1- (Mb is the scale factor).

Therefore, =□・ΔP. . . . ■ Since ΔP corresponds to the above-mentioned Δt, by obtaining Δt from the display device 8, ΔH1, for example j, the depth of corrosion can be measured.

Note that 13 to 16 in FIG. 2 are signal transmission lines.

Next, an example of the dimension measuring method of the present invention using the above-mentioned apparatus will be explained.

While a trolley 1 is driven within the pipeline piping by remote control, the inner surface of the pipeline is illuminated with an illumination lamp 2 and an image is taken with a television camera 3.4.

At this time, the TV camera 3.4 is the same as the inside of the pipe: l!
One location (subject S) is imaged from different angles.

The subject S will be broadcast on television 5.6. and,
When the corroded portion is displayed, the video processing circuit 7 separates the scanning lines including measurement points M and B from each television 5.1+ one by one and displays them on the display device 8. On the display device 8, the video element line 11 corresponding to the scanning line input separately from the television 5 is displayed together with the synchronization signal 9.
Also shown is the scanning line input separately from television B and the corresponding video element line. Matching the synchronization signals 9 and 10, the video element line 1
When comparing 1 and 12, a deviation Δt occurs.

This Δt corresponds to the above-mentioned ΔP, and therefore,
The depth ΔH of the corroded portion is measured by measuring Δt, converting it to ΔP, and substituting it into the above-mentioned equation (2).

In the above embodiment, the same place was imaged from different angles using two television cameras 3.4, but it is also possible to use one television camera and take images alternately using a reflective mirror. Alternatively, the same place may be imaged from different angles using a standard television camera or higher.

The dimension measuring method and dimension measuring device of the present invention can be used not only for measuring the corrosion dimension of oil pipeline piping, but also for various purposes such as measuring the dimension of foreign matter attached to oil pipeline piping, and determining the position of objects etc. in the manufacturing process. It can be applied to dimension measurement in the field of.

As explained above, according to the present invention, scanning lines including measurement points are separated from images on the lily of a subject taken from different angles by a television camera, and these scanning lines are input to a display device to display each scanning line. The dimensions of the object are measured from the deviation between the video element lines displayed in correspondence with the lines.
Not only can dimensions be measured accurately, but remote control is also possible.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a front view of the device of the present invention, Fig. 2 is a block diagram thereof, Fig. 3 is an explanatory diagram of the video element line, and Fig. 4 is an illustration of the viewing angle. FIG. 3 is an explanatory diagram of the relationship between the difference and the difference between measurement points. 3.4...TV camera, M, B...Measuring point, S...
...Subject, 5.6...Television, T...Video processing circuit, 8...Display device, 11.12...Video element line. Patent applicant: Asia Kikou Co., Ltd. Ogiya Kogyo Co., Ltd. Karasu-ichi

Claims (1)

[Claims] FI+ Scanning lines including measurement points are separated from images on the lily of the subject taken from different angles by a television camera, and these scanning lines are inputted to a display device to be displayed in correspondence with each scanning line. 1. A dimension measurement method characterized by measuring the dimensions of a subject from the deviation between video element lines displayed. (2) A television camera, a television on a lily that broadcasts images of objects taken from different angles by the television camera, and scanning lines that include measurement points from the images of the objects in these television stations are separated from each other, and these scanning lines are and a video processing circuit for inputting the image into the display device, and is configured to measure the dimensions of the object from the deviation between the video element lines displayed in correspondence with each scanning line on the display device. Dimension measuring device.