RU2323054C2 - Photo-electronic device for measuring linear dimensions and monitoring position of articles - Google Patents

Abstract

FIELD: touch free measurement of dimensions and monitoring article positions with use of fiber optics.

SUBSTANCE: photo-electronic device for measuring linear dimensions and monitoring position of articles includes fiber-optic converter whose inlet ends are arranged in the same straight line one close to other by their wide sides for forming inlet pupil and whose outlet ends are arranged in the form of rectangular matrix for forming outlet pupil; light source mounted in front of fiber-optic converter normally relative to motion of article; digital video camera and computer for processing digital video image.

EFFECT: simplified design, improved response and resolution.

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Description

The invention relates to the field of non-contact measurement of dimensions and position control of products using fiber optics and can be used in rolling production, for example, to measure the width and displacement of a rolling steel relative to the center line of the unit.

A photoelectronic measuring device is known that converts the position of a light beam into a decimal code containing a digital device with indicators and decoders and an optoelectronic unit with signal bundles from optical fibers [a.s. USSR No. 319837, class СВВ 11/02, 1971].

A disadvantage of the described device of this type is the subsequent conversion of multi-bit parallel binary code to decimal code, which requires the use of complex digital devices. With an increase in the number of discharges, the complexity of the decoders increases excessively quickly, which worsens the parameters of the measuring system as a whole.

For the prototype adopted photoelectronic device for measuring the linear dimensions of the bodies [A. with. USSR No. 335533, class G01B 11/02, 1972], containing a fiber-optic converter, consisting of rectangular optical fibers, the input ends of which are located on one straight line close to each other with wide sides, forming the entrance pupil, and the output ends are located in the form of a rectangular matrix, forming the exit pupil .

The disadvantage of the described device is the subsequent scan of the converted image, which requires the use of a discrete scan generator with two groups of managed keys and a program control unit. With an increase in the number of optical fibers, the number of controlled keys and the complexity of the program control unit grows excessively quickly, which leads to a complication of the design, worsens performance, and limits the increase in resolution of the device.

The technical result of the invention is to simplify the design, increase the speed and resolution of the device.

The technical result is achieved by the fact that the photoelectronic device for measuring linear dimensions and controlling the position of products, containing a fiber optic converter consisting of rectangular optical fibers, the input ends of which are located on one straight line adjacent to each other with wide sides, forming the entrance pupil, and the output ends arranged in the form of a rectangular matrix, forming the exit pupil, according to the invention, it further comprises a light source mounted opposite the fiber optic the transducer and perpendicular to the movement of the product, a digital video camera and a computer for processing digital video images, while the matrix of the output ends of the optical fibers together with the digital video camera is placed in a tube made of sealed material, while the lens of the camera is located above the rectangular matrix and its axis is perpendicular to the plane of the matrix, and the digital video camera is connected to a computer for processing digital video.

By using a light source, optical fibers and a digital video camera, the problem of viewing the width and position of a moving product across the entire width of the unit is solved without loss of measurement accuracy and resolution of the photoelectronic device. The use of a digital video camera to control the position and width of a moving product involves installing it at a certain distance from the product to provide an overview of the entire width of the unit, while with an increase in the width of the latter, the measurement accuracy of the device decreases. Using the luminous flux from the light source allows you to accurately project the position and width of the product onto the fibers of the entrance pupil. The use of a digital video camera together with optical fibers simplifies the transfer of the image of the monitored section of the unit to a computer for processing digital video without losing the resolution of the photoelectronic device and, therefore, increases the accuracy of the measurement, while eliminating the need to change the distance between the camera and the product when changing the controlled width of the unit.

Thanks to the use of a digital video camera and a computer for processing digital video images, the design is greatly simplified, the speed of the photoelectronic device is increased, and therefore, the efficiency of position monitoring and the quality of measuring the width at high transportation speeds of the product are improved.

The invention is illustrated by drawings, where figure 1 shows a structural diagram of a photoelectronic device for measuring linear dimensions and monitoring the position of products; figure 2 - entrance pupil; figure 3 - exit pupil; figure 4 - image of the exit pupil in a computer for processing digital video in the form of a matrix of numbers.

A photoelectronic device for measuring linear dimensions and controlling the position of products (Fig. 1) includes a fiber-optic converter 1, consisting of rectangular optical fibers 2, the input ends of which are located on one straight line adjacent to each other with wide sides, forming the entrance pupil 3, and the output ends are arranged in the form of a rectangular matrix, forming the exit pupil 4, the light source 5, mounted opposite the fiber-optic converter and perpendicular to the movement of the product 6, a digital video camera at 7 and a computer for processing digital video 8. The matrix of output ends of optical fibers in conjunction with a digital video camera is placed in a tube 9 made of a hermetic material, the lens of digital video camera 10 is positioned above a rectangular matrix and its axis is perpendicular to the plane array. A digital video camera is connected to a computer for processing digital video.

The device operates as follows.

The luminous flux from the light source 5 is directed to the fiber-optic converter 7. In the absence of the product 6 in the controlled area, all the optical fibers 2 of the entrance pupil 3 are illuminated. The product 6 enters the measurement zone and occupies the position indicated in the drawing (Fig. 2), blocking the luminous flux from the light source 5. At the same time, part of the optical fibers 2 of the entrance pupil 3 of the fiber-optic converter 1 remains illuminated, which is displayed on the exit pupil 4 ( figure 3) and is transmitted to a computer for processing digital video 8 through a digital video camera 7 that scans and digitizes the image of the matrix of optical fibers. The exit pupil 4 and the lens of the digital video camera 10 are located in a tube 9 made of sealed material, such as plastic, to prevent external radiation from reaching the exit pupil 4. The image of the exit pupil 4, digitized using a digital video camera 7, and received by a computer for processing digital video 8 is represented as a matrix of numbers of dimension n × m (Fig. 4). Each element (number) of the numerical matrix represents the brightness of the corresponding image pixel (n × m is the resolution of the digital video camera). The optical fibers 2, which did not get the light flux from the light source 5, are allocated in the numerical matrix with lower brightness (lower numbers) compared to the illuminated optical fibers. Thus, processing the numerical matrix, we can draw a conclusion about the width and displacement of the rolling steel from the center line of the technological unit.

The value of the product width is determined by the formula

where Shizd - product width, m;

Ksu - the number of optical fibers of the device;

Ksl - the number of optical fibers illuminated on the left;

KSP - the number of optical fibers illuminated on the right;

Шс - width of the narrow side of a rectangular fiber, m.

The value of the displacement of the product from the center line of the unit is determined by the formula:

where Offset - product offsets from the center line of the technological unit, m

Example.

Let Ksu = 600, Ksl = 250, Ksp = 150, Shs = 0.001 m. By the formula (1) Shizd = (600-250-150) · 0.001 m = 0.2 m. By the formula (2) Offset = (250 -150) · 0.001 m = 0.1 m.

Thus, it can be seen from the above example that the smaller the width of the narrow side of the rectangular fiber, the higher the resolution and measurement accuracy of the photoelectronic device.

Claims (1)

A photoelectronic device for measuring linear dimensions and controlling the position of products, for example, for measuring the width and displacement of a rolling steel relative to the center line of the unit, containing a fiber-optic converter consisting of rectangular optical fibers, the input ends of which are located on one straight line adjacent to each other with wide sides, forming the entrance pupil, and the output ends are arranged in the form of a rectangular matrix, forming the exit pupil, characterized in that it further comprises a light source mounted opposite the fiber-optic converter and perpendicular to the movement of the product, a digital video camera and a computer for processing digital video images, while the matrix of the output ends of the optical fibers together with the digital video camera is placed in a tube made of sealed material, while the lens of the digital video camera is located above a rectangular matrix and its axis is perpendicular to the plane of the matrix, and a digital video camera is connected to a computer for processing digital video i.

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