JPH02254303A - Detector for strip-shaped material - Google Patents

Abstract

PURPOSE:To detect the snaking amount and the width of a strip-shaped material accurately and stably by providing a pair of mounts, a pair of three-dimensional image sensing devices, purging devices, an image processing device, and an operating device. CONSTITUTION:Mounts 13 and 13 have moving means for movement in the width direction of a strip-shaped material. Three-dimensional image sensing devices 18 and 18 using optical cameras 18a and 18b and 18c and 18d accommodate both edge parts of the strip-shaped material 11 in the direction of the width in the fields of view. Purging devices 22 and 22 always purify the fields of view of the three-dimensional image sensing devices 18 and 18 effectively. An image processing device 20 computes the edge positions in the fields of view of the cameras based on the image signals from the cameras. An operating device 17 computes the two-dimensional position coordinates of the edge positions in the direction of the height and the direction of the width based on the edge positions by a triangulation method. The snaking amount or the width of the strip-shaped material is computed based on the position coordinates of both edges and the position coordinates of the mounts. In this way, the snaking amount and the width of the strip-shaped material can be detected accurately without the effects of up and down movement and the inclination of the strip-shaped material.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to an apparatus for detecting the meandering amount and width of a strip used in production facilities for strips such as steel plates, paper, and films.

<Prior Art> FIG. 4 is a configuration diagram of a meandering detection device for a belt-like object according to a conventional example. As shown in FIG.
Optical cameras 12a, 12 are installed above the edges of both ends of 1.
b are each installed substantially perpendicular to the surface of the strip 11, and each optical camera 12a, 12b is connected to a moving device (not shown) for moving according to the width of the strip 11. has been done. And optical camera 12a
, 12b and the positions of these cameras 12a, 12b
The meandering amount and width of the belt-like object 11 are calculated from the edge position of the belt-like object 11 within the visual field obtained based on the image signal from.

That is, in FIG. 4, the distance between the two optical cameras 12a and 12b is measured from the optical camera moving device. Next, the same camera 12 &.

From the image signal 12b, the band-shaped object 11 is observed by the camera.
The edge position of is detected. In other words, since the viewing angle of the camera is known, the angle θ from the optical axis of the optical camera 12,
, θゎ are determined. Further, in the figure, Y indicates the camera installation height.

Based on these amounts, the meandering amount ΔX and the width W of the belt-shaped object 11 are calculated by the following (11, (21).

ΔX=Y (-θ −-θ)...(1) W=D-Y
(mu θ, +−θl,) (2) <Problem to be solved by the invention> However, the above-mentioned conventional method has the following problems.

First, as shown in FIG. 5, if we consider the case where the strip 11 moves in the vertical direction, the strip 11 moves ΔYf! When the edge is moved upward, the edge that should originally be detected as the position θ is instead detected as the position θ'. Here, if the detection device does not have a means for measuring the height of the strip 11, @W of the strip 11 is Δ shown in equation (3).
This results in an error of W.

ΔW=Y ((-θ,'+-θ,')-(-θ,+-θ
6))...(3) Furthermore, as shown in FIG. 6, when the strip 11 is tilted, in addition to the error ΔW of @W mentioned above, the meandering amount ΔX is also expressed by equation (4). An error will occur.

Δx-ΔX' = Y((-θ,--θ6)-(-〇,'
--66')) (4) On the other hand, conventional detection devices do not have a device to purify (verge) the field of view of the camera to obtain a clear image, and if used in a bad environment. Another problem was that the reliability of detection was significantly reduced.

The present invention has been made in view of these points,
It is an object of the present invention to provide a detection device that can accurately and stably detect the meandering amount and width of a belt-shaped object under adverse environments without being affected by vertical movement or inclination of the belt-shaped object.

Means for Solving the Problems> A belt-shaped object detection device according to the present invention that achieves the above-mentioned object is a device that detects the widthwise edge portion of a moving belt-shaped object using an optical camera. a pair of three-dimensional imaging devices each having a pair of mounts movable in the width direction, and two optical cameras each attached to each of the mounts and respectively capturing images of both edge portions in the width direction of the strip; a barge device that is attached to each mount to clearly image the edge portion; an image processing device that calculates the edge position as viewed by the camera based on image signals from the two cameras; The two-dimensional position coordinates of the edge position in the height direction and the width direction are calculated by the triangulation method, and the meandering amount and/or width of the strip is calculated based on the position coordinates of both edges and the position coordinates of the mount. It is characterized by comprising a calculation device.

Function> Since the two-dimensional position coordinates of the edge of the strip in the height and width directions are obtained using a stereoscopic imaging device with two optical cameras, accurate edge detection is possible regardless of the vertical movement or inclination of the strip. can.

On the other hand, the barge device moves together with the three-dimensional imaging device, making it possible to always take clear images even under adverse environments.

<Example> An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a configuration diagram of a detection device according to an embodiment of the present invention;
FIG. 2 is an explanatory diagram of its operation.

In FIG. 1, the strip 11 moves in a direction perpendicular to the plane of the paper. A pair of mounts 1 are provided on both sides of the strip 11 in the width direction (left and right directions in the figure) so as to sandwich it and face each other.
3.13 are arranged, and each mount 13, 13 has a moving means (not shown) for moving in the width direction of the strip 11. This movement of each mount 13.13 is input as a movement signal 14 to the mount position detection device 15, where it is converted into a mount position coordinate signal 16 indicating the position of each mount 13.13 and input to the calculation device 17.

At the top of each mount 13.13 are two optical cameras 18a, 18b and 18c, respectively.

A stereoscopic imaging device 18.18 using 18d is installed. Each stereoscopic imaging device 18.18 has a field of view of both edges of the strip 11 in the width direction, and the image signal 19 of each stereoscopic imaging device 18.18 is inputted to an image processing device 20, where it is processed by a camera. The position of the edge within the visual field is calculated, and this edge position signal 21 is input to the arithmetic unit 17.

Here, two optical cameras 18 a, 18 b and 18 c each for detection of both edges of the strip 11.

By using a pair of stereoscopic imaging devices 18.1.8 using 18d, two cameras 18a.

Band-shaped object 11 in the field of view of 18b, 18c, and 18d
Based on the difference in edge position, it is possible to detect the absolute position from the camera mounting reference point to the edge by triangulation.

In addition, the increase in image data due to an increase in the number of cameras used can be easily handled by decentralizing image processing, and the deviation in the detection position of each camera can be corrected by using the same synchronization signal. This can be prevented by operating the camera.

Therefore, in the arithmetic unit 17, the edge position signal 21
The two-dimensional position coordinates in the height and width direction of the edge position of the strip 11 are calculated by triangulation based on the above, and the meandering amount and width of the strip 11 are calculated from these position coordinates and the 13th place Mf11m. do.

In addition, each mount 13.13 has a barge device 2
2.22 is installed. This barge device 22.22
For example, it injects compressed air from a nozzle,
Stereoscopic imaging device 18 attached to each mount 13.13
．． It blows off foreign matter such as water droplets attached to the camera lens surface of the camera lens 18, and also blows away water vapor and floating matter within the field of view of the balance gymnastics imaging device 18.18, thereby making it possible to take clear images.

Here, this barge device 22.22 is vertical ([image device 18
．． The barge device 22.22 is always attached to the mount 13.13 to which the stereoscopic imaging device 18 is attached, and the two move together.
．． Be able to effectively purify 18 visual fields.

Next, a method of calculating the absolute position, meandering amount, and width will be explained with reference to FIG.

In FIG. 2, the camera mounting reference point of each mount 13.13 is the position of the outer camera 18a, 18c, respectively, and from that reference point the inner camera 18b, 18 is located.
The distance to d is accurately measured in advance, and here it is assumed that the distance is h1 in the height direction and df in the width direction. Furthermore, in FIG. 2, α, α, ac, and α6 are the inclination angles of the cameras 18a, 18b, 18c, and 18d, respectively, and D is the distance between the cameras 18a and 18c that serve as reference points on both sides. θ,, θ5. θ. , θ- respectively, the camera 18a,
This is a value obtained by converting the edge position in the field of view detected by 18b, 18c, and 18d into an angle from the optical axis. Therefore, the positions of both edges from the reference point can be found using the following equations (5) to (8).

X = Y tag (a, -θ) = -d + (Y, +h
) −ram Ca, −θ, )−(5) Y =(−
d+htam (α, -θ-) / (taa (a,
-〇,)-jan (a, -θ-1...+61X=Y
cm(a.-θ)=-d+(Y,+h)m(a
, -〇, )・f7) Yc=(-d+hlam(cr
, -θ-)/k(a, -θ, J-m(a, -〇,))・
= (8 + further, kot:o (x,, y,) t(X
, Y, ) it, the meandering amount ΔX and the width W are determined as in equations (9) and (11).

ΔX= (X −X ) /2...(9)(91
As is clear from Equation 01, the meandering amount and width are calculated after calculating the edge position, so it is not possible to accurately calculate the meandering amount and width because it is affected by the vertical movement and inclination of the strip. can.

Next, FIG. 3 shows a block diagram of meandering control in an example in which the present detection device is applied to a rolling mill. In the third S, 23 is a position control device for the reduction cylinder, 24 is a position control signal, 25 is a main detection device, 26 is a meandering amount signal, 27 is a fine-tuning calculator, 28 is a meandering control signal, 29 is a meandering control device,
30 is a rolling control device, 31 is a rolling operation signal, 32 is a rolling mill, and 33 is an image signal from a camera.

As shown in FIG. 3, since the present detection device 25 directly detects the meandering amount of the rolled material, which is a strip, the meandering control device 29
can be easily realized using only proportional feedback. Therefore, since there is no differential element that utilizes the load difference between the reduction cylinders, the stable region is wide.

<Effects of the Invention> As described above in detail with reference to embodiments, according to the present invention, a three-dimensional imaging device having two optical cameras can capture two-dimensional images of the edge of a strip in the height direction and width direction. Since the position coordinates are determined and the meandering amount and width of the strip are detected from there, the meandering amount and width of the strip can be accurately detected without being affected by vertical movement or inclination of the strip. Furthermore, since it has a barge device that moves together with the stereoscopic imaging device, high reliability can be obtained even under adverse environments.

On the other hand, by directly detecting the amount of meandering, it is possible to easily and stably realize a meandering control device using the output signal using proportional feedback.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a belt-like object detection device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of its operation, and Fig. 3 is a block of a meandering subshaft in an example in which the present detection device is applied to a rolling mill. FIG.
The figure is an explanatory diagram of a malfunction of the conventional device when the strip-shaped object moves up and down, and FIG. 6 is a diagram FIJ1 explaining the malfunction of the conventional device when the strip-shaped article is tilted. In the drawings, 11 is a strip, 13 is a mount, 15 is a mount position detection device, 17 is an arithmetic device, 18 is a stereoscopic imaging device, 18 a, 18 b, 18 c, and 18 d are optical percentage types, and 22 is a barge. It is a device. Figure 3

Claims (1)

[Claims] A device for detecting the widthwise edges of a moving strip using an optical camera, which includes: a pair of mounts that are movable in the widthwise direction of the strip; and a pair of mounts that are respectively attached to the mounts and detecting both widthwise edges of the strip. a pair of three-dimensional imaging devices each having two optical cameras that respectively take images of the edges; a barge device that is attached to each of the mounts to clearly image the edge; and a barge device that captures image signals from the two cameras. and an image processing device that calculates the edge position in the camera field of view based on the edge position, and calculates the two-dimensional position coordinates of the edge position in the height direction and width direction from the edge position by triangulation method, and calculates the position coordinates of both edges and the above. 1. A belt-shaped object detection device comprising: a calculation device that calculates the meandering amount and/or width of the belt-shaped object based on the position coordinates of the mount.