JPH06109455A - Measuring device for straightness of long material - Google Patents

Abstract

PURPOSE:To measure the straightness of a long material with high accuracy by calculating the positional shift quantity of the center-of-gravity position of a reference pattern from a reference origin and correcting detected strain quantity on the basis of the positional shift quantity. CONSTITUTION:When a measuring device 2 is made self-propelled in parallel to the long material 1 positioned at a measuring position to perform measurement, displacement measuring devices 7a, 7b continuously detect the relative displacement with the long material to store the same in an operation device 23 as strain quantity data. In parallel to this, a television camera 21 takes an image grasping a reference pattern at each measuring point and outputs the image signal thereof to an image processing device 22. The device 22 calculates the center-of-gravity position G of the reference pattern on the basis of the image data obtained at each measuring point and calculates the positional shift quantity in the X- and Y-axis directions between the position G and a preliminarily stored center-of-gravity position origin GO. The data on this positional shift quantity is inputted to the operation device 23, the measuring devices 7a, 7b correct actually measured strain data on the basis of the data, and the corrected result is calculated as the strain quantity at each measuring point. Therefore, the accurate straightness of the long material 1 can be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the position of the center of gravity of a reference pattern in which a camera captures the bending and warping (hereinafter referred to as distortion) of a long material such as a bar or strip that is relatively long in one direction. The present invention relates to a long material straightness measuring device capable of measuring strain with high accuracy by a displacement measuring device that moves along a long material by using it as a reference.

[0002]

When a long material is used as a structural member of a mechanical device, its straightness sometimes becomes a problem. if,
If the long material is distorted, its utility value becomes equal depending on its use. For this reason,
For a long material having a distortion, it is necessary to perform a straightening process in advance so as to meet the usage conditions and remove the distortion. In order to carry out this straightening process effectively, it is indispensable to grasp the magnitude and distribution of the strain amount of the long material numerically. In this sense, the straightness of the long material should be high. The technology to measure accurately becomes important. Conventionally, the straightness of a long material is measured by running a measuring device equipped with a non-contact type displacement measuring device such as a magnetic sensor or a laser displacement meter in parallel along the long material, or conversely Measurement is performed by moving the scale material in parallel with the measuring device. At that time, a steel wire such as a piano wire stretched in the traveling direction of the measuring device is used as a measurement standard. With this steel wire, the deviation from the steel wire when the measuring device travels is measured using the steel wire position measuring device, and this measurement result and the measurement result of the displacement measuring device are mutually compared and analyzed. , We are trying to improve the accuracy of measuring the straightness of long materials.

Therefore, a conventional apparatus used for such automatic measurement will be described with reference to FIG. In the figure, reference numeral 1 indicates a long material to be measured, and here,
The long material 1 is a member used as a rail. Code 2
Shows a measuring device capable of running parallel to the long material 1. The measuring device 2 is configured to be self-propelled along a pair of guide rails 4a and 4b laid in parallel with the long material on the upper surface of the traveling table 3 using the guide rails as guides. In this conventional example, a servo motor 5 is provided as a drive source, and a pinion (not shown) rotationally driven by the servo motor 5 meshes with a rack 6 laid between the guide rails 4a and 4b. Further, the measuring device 2 is provided with a non-contact type displacement measuring device 7, which is movable by a cylinder 8 in a direction orthogonal to the traveling direction, and a side surface of the long material 1. It is possible to approach to a predetermined measurement position. On the other hand, on the platform 3,
As a straightness measurement standard, a steel wire 9 is stretched in parallel with the guide rails 4a and 4b. This steel wire 9 has a pulley 10
The tension is applied by the weight 11 so as to be straight through a and 10b. On the other hand, the carriage 2a of the measuring device 2 has an x-axis (horizontal direction) orthogonal to the traveling direction, y
Steel wire position measuring devices 12a and 12b for measuring the relative position of the steel wire 9 and the measuring device 2 with respect to the axis (vertical direction) are provided. In the figure, reference numeral 13 indicates the long material 1.
A roller device for loading and unloading is indicated by reference numeral 14
Shows a clamp device for fixing the long member 1 at a measurement position.

In the above-mentioned structure, when the measuring device 2 moves in parallel with the long material 1 along the guide rails 4a and 4b, the displacement measuring device 7 detects the relative displacement between the long material 1. . At the same time, steel wire position measuring devices 12a and 12b
The relative displacement of the displacement measuring device 7 with respect to the steel wire 9 serving as a measurement standard is measured, and the amount of strain of the long material 1 is measured by correcting the amount of displacement with this amount of displacement. It

[0005]

However, in the above-mentioned prior art, since the steel wire 9 as the measurement reference is bent and the vibration caused by the free running of the measuring device 2 is not a little generated, it is actually shown in FIG. Thus, it does not look like an ideal steel wire 9a without bending, but becomes like a steel wire 9b with bending. FIG. 4 shows the position when the steel wire 9 is bent or shaken in relation to the steel wire position measuring devices 12a and 12b, and the position of the steel wire 9 as the original measurement reference is the x-axis. If the direction is x1 and the y-axis direction is y1, the actual position of the steel wire 9 is shifted to x2 in the x-axis direction and y2 in the y-axis direction. As a result, the relative position of the traveling system including the displacement measuring device 7 measured by the steel wire position measuring devices 12a and 12b is x
| X2-x1 | in the axial direction and | y2- in the y-axis direction
An error has occurred only by y1 |. Therefore, the straightness measurement result also includes the error. That is, as shown in FIG. 5, since there is a deviation in the relative positional relationship between the long material 1 and the displacement measuring device 7 at the time of measurement, if the actual position interval in the x-axis direction is S1,
The bending of the steel wire 9 actually causes | S0-
There is an error of S1 |. Further, if the target measurement range of the displacement measuring instrument 7 exceeds the width U of the target measuring surface, the correct operation of the displacement measuring instrument 7 is not guaranteed, and if the position of the displacement measuring instrument is displaced by T in the y-axis direction, erroneous measurement is performed. It was the cause of getting the result.

Therefore, the present invention solves the above-mentioned problems of the prior art, and corrects the positional deviation with respect to the measurement reference to measure the straightness of a long material with high accuracy. An object is to provide a degree measuring device.

[0007]

In order to achieve the above-mentioned object, the present invention provides a traveling platform which is disposed laterally of a long member whose straightness is measured, and the long platform which is disposed on the traveling platform. In a long material straightness measuring device equipped with a measuring device capable of traveling in parallel with the long material in its length direction and detecting a relative distance between the long material by a displacement measuring device, A reference pattern provided on either one of the bases and defining a reference origin for measurement, and a television camera installed so as to move relative to the reference pattern together with the displacement measuring device, which receives the reference pattern and converts it into an image signal. A barycentric position of the reference pattern based on the image signal, and an amount of displacement of the barycentric position from the reference origin, and an image processing device that outputs this amount of displacement, and the amount of distortion detected by the displacement measuring device. The picture And corrected by the positional shift amount given by the processing device is constructed by providing an arithmetic unit for calculating a straightness of the long material over the entire long material.

[0008]

[Operation] While the displacement measuring device is moving along the long material,
The television camera captures the reference pattern as an image, converts it into an image signal at each measurement point, and outputs it to the image processing apparatus. This image processing device calculates the barycentric position of the reference pattern from the image signal given from the television camera, and outputs the positional deviation amount from the barycenter reference origin previously stored for the barycentric position to the arithmetic device. The amount of strain detected by the displacement measuring device is corrected by the amount of displacement of the displacement measuring device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the straightness measuring apparatus for long material according to the present invention will be described below with reference to the accompanying drawings. The same components as those of FIG. 6 are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, as the displacement measuring device of the measuring device 2, a displacement measuring device 7a for detecting relative displacement in the x-axis direction between the long material 1 and y is used.
The carriage 2a is provided with a displacement measuring device 7b for detecting relative displacement in the axial direction. In addition, on this trolley 2a,
The reference stand 20 is fixed instead of the conventional measurement standard piano wire. A circular mark, for example, is drawn on the reference table 20 as a reference pattern that determines the reference origin of measurement. An image 24 including a reference pattern is provided on the opposite end side of the traveling table 3 so as to face the reference table 20.
A television camera 21 that receives an image (see FIG. 2) and converts the image of the reference pattern into an electric signal by the two-dimensionally arranged image pickup device is installed.

The image signal output from the television camera 21 is input to the image processing device 22. The image processing device 22 processes the image data input for each measurement point to obtain the barycentric position G of the reference pattern, and the position of the barycentric position G from the prestored barycentric position origin G0. Is calculated and this data is output to the arithmetic unit 23. The arithmetic device 23 calculates the actual strain amount of the long material 1 by correcting the positional deviation amount to the strain amount at each measurement point input via the displacement measuring instruments 7a and 7b.

First, the long material 1 which is the object to be measured.
Is rolled on the roller device 13 and carried in, and then the long material 1 is positioned at a predetermined measurement position using the clamp device 14. If the long material 1 is clamped, distortion occurs in the long material 1 and an error occurs in the actual measurement value. Therefore, in order to prevent this, the actual measurement is performed by opening the clamp device 14.

Therefore, when the measuring device 2 is self-propelled along the long material 1 to perform the measurement, the displacement measuring devices 7a and 7b are measured.
The long material 1 and the displacement measuring devices 7a and 7b, respectively.
Relative displacements of and are continuously detected and stored in the computing device 23 as strain amount data. On the other hand, in parallel with this, the television camera 21 captures an image of the reference pattern at each measurement point, and the image signal is output to the image processing device 22.

The image processing device 22 obtains the barycentric position G of the reference pattern as shown in FIG. 2 based on the image data obtained at each measurement point, and the barycentric position G and the barycentric center stored in advance. The positional shift amounts x3 and y3 between the position origin G0 and the x-axis direction and the y-axis direction are calculated, and the data regarding the positional shift amounts are output to the arithmetic unit 23.
The arithmetic unit 23 calculates the result of correcting the strain data measured by the displacement measuring instruments 7a and 7b based on the position shift amount data x3 and y3 as the strain amount at each measurement point. Since the position of the center of gravity of the reference pattern is used as the measurement reference in this manner, the straightness of the long material 1 can be measured without using a piano wire as the measurement reference as in the conventional case. Moreover, since the center of gravity of the reference pattern is obtained and the measurement result is corrected by the amount of deviation from the center of gravity reference position, the error of the traveling system of the measuring device 2 can be corrected, and therefore the correct straightness of the long material 1 can be improved. Can be measured.

In the above embodiment, the reference table 20 provided with the reference pattern is attached to the dolly 2a of the measuring device 2, but the television camera 21 is attached to the dolly 2a of the measuring device 21 (not shown), It can also be configured to receive the reference pattern of the reference platform 20 arranged at one end of the traveling platform 3.

[0015]

As is apparent from the above description, according to the present invention, a reference pattern provided on either one of the measuring device and the traveling platform to determine the reference origin of measurement, and the reference pattern together with the displacement measuring device are used. A television camera installed so as to move relative to each other, which receives the reference pattern and converts it into an image signal, the center of gravity position of the reference pattern based on the image signal, and the amount of displacement of the center of gravity position from the reference origin. The straightness of the long material is calculated over the entire long material by correcting the distortion amount detected by the displacement measuring device with the image processing apparatus that calculates and outputs this positional deviation amount. Since it is configured with an arithmetic unit for calculating, the position of the center of gravity of the reference pattern should be used as a reference for measurement, and a conventional reference such as a piano wire that easily causes an error should be used. Ku, measured with it, since it corrects the positional deviation of the displacement measuring device due to vibration of the traveling system in the deviation amount between the position of the center of gravity and the center of gravity reference position, it is possible to accurately measure the distortion of the elongated workpiece.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a long material straightness measuring device according to the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the origin of the center of gravity of the reference pattern and the center of gravity of the reference pattern at a certain measurement point.

FIG. 3 is an explanatory view of a long material straightness measuring device according to the prior art when measuring with a steel wire in a bent state.

FIG. 4 is an explanatory view showing a positional deviation between a steel wire without bending and a bent steel wire in a long material straightness measuring device according to a conventional technique.

FIG. 5 is a view for explaining a relative positional deviation between a long material and a displacement measuring device, which is obtained by a steel wire without bending and a bent steel wire in a long material straightness measuring device according to a conventional technique.

FIG. 6 is a perspective view showing a long material straightness measuring device according to a conventional technique.

[Explanation of symbols]

 1 Long material 3 Running measuring device 5 Servo motors 7a, 7b Displacement measuring devices 7a, 7b 20 Reference pattern 21 Television camera 22 Image processing device 23 Computing device

Claims (1)

[Claims] 1. A traveling platform which is disposed on the side of a long material whose straightness is measured, and which is disposed on the traveling platform and is capable of traveling parallel to the long material in its longitudinal direction and measuring displacement. In a long material straightness measuring device equipped with a measuring device that detects the relative distance between the long material and a measuring device, a reference pattern provided on either the measuring device or the traveling platform to determine the reference origin of measurement. A television camera which is installed together with the displacement measuring device so as to move relative to a reference pattern and which receives the reference pattern and converts it into an image signal; a barycentric position of the reference pattern based on the image signal; An image processing device that calculates the amount of positional deviation from the reference origin and outputs this amount of positional deviation, and the amount of distortion detected by the displacement measuring device are corrected by the amount of positional deviation provided by the image processing device and the length is corrected. Bar A long material straightness measuring device, comprising: an arithmetic device for calculating the straightness of a long material as a whole.