JPH05157549A - Detecting method for camber of band-shaped body - Google Patents

Abstract

PURPOSE:To establish the method nor detecting the camber of a band-shaped body highly accurately regardless of the period. CONSTITUTION:Three or more edge-position sensors 2-6 are arranged along the longitudinal direction of a band-shaped body 7 at the side of one edge 7a of the band-shaped body 7 so as to measure the distance from a detecting reference line 8 to edge 7a in the direction of the width. The distances from the plate edge of the band-shaped body 7 to the reference line 8 are detected at a specified interval with respect to the moving distance in the longitudinal direction. When the camber of the land-shaped body 7 is estimated based on the relative positions of the detecting points, three edge-position, detecting sensors 2, 3 and 4 are arranged at the close equal interval. The edge-position detecting sensors 5 and 6 are arranged at an arranging interval of 2L, which is at least twice or more larger than arranging interval L of the edge-position detecting sensors 2, 3 and 4, and at an interval 4L, which is four times larger than L. The shape of the camber of the band-shaped body 7 is obtained based on a plurality of edge waveforms at the respective periods detected by the edge-position detecting sensors 2, 3, 4, 5 and 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a camber of a belt, and is particularly suitable for use in a method of detecting a camber of a belt using a plurality of edge position detecting sensors.

[0002]

2. Description of the Related Art As is well known, various methods have heretofore been proposed as a method for detecting a camber of a strip.
Some of them have already been put to practical use and have been quite effective. As a typical method of detecting a belt-shaped camber that has been conventionally proposed, for example, Japanese Patent Laid-Open No. 63-66.
As shown in Japanese Patent No. 409, three edge position detection sensors are used to measure the distance from the detection reference point to the edge of the strip in the width direction of the strip. Then, the position in the width direction from the detection reference point to the edge of the band-shaped body is simultaneously detected at three points, and the camber is measured based on the relative position of the detection points.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention JP-A-63-66
The camber detection method proposed in Japanese Patent No. 409 is
The edge position detection sensor is fixed at a certain size and at equal intervals to detect the camber of the band.
As described above, when a plurality of edge position detection sensors are fixed at equal intervals, highly accurate detection is performed for camber of a specific cycle within a range of 4 to 8 times the interval. Can be expected.

However, there has been a problem that highly accurate detection cannot be performed with respect to the camber having a cycle other than the specific cycle. That is, for example, for a camber whose period is very short compared to the arrangement interval of each edge position detection sensor, when the detection point does not come near the extreme point of the bend of the edge, the detected amplitude is the amplitude of the actual edge waveform. However, there is a drawback that accurate detection cannot be expected. In view of the above problems, it is an object of the present invention to provide a belt-shaped camber detection method capable of performing highly accurate detection regardless of the length of the camber cycle.

[0005]

According to the method for detecting a camber of a strip of the present invention, three or more units are provided on one edge side of the strip to measure the distance from the detection reference line to the edge in the width direction. Edge position detection sensors are arranged along the longitudinal direction of the belt-shaped body, and the distance from the reference line to the plate end of the belt-shaped body is set as the movement distance in the longitudinal direction by the three or more edge-position detection sensors. On the other hand, in a method of detecting the camber of the strip from the relative position of the detection points by detecting at a constant interval, a first edge position detecting sensor group in which three edge position detecting sensors are arranged at equal intervals, A plurality of edge position detection sensors are arranged at an arrangement interval 2L to 4L that is at least two to four times the arrangement interval L of each edge position detection sensor in the first edge position detection sensor group. Edge position detection sensor groups are arranged, and the first and second edge position detection sensor groups make the distance from the reference line to the plate end of the belt-like body constant with respect to the distance moved in the longitudinal direction. A plurality of edge waveforms for each cycle are generated by detecting at intervals of, and the camber shape of the strip is obtained based on the plurality of edge waveforms for each cycle.

[0006]

Operation: At least three edge position detection sensors are installed close to each other at equal intervals L, and at least two edge position detection sensors are installed between the edge position detection sensors at one end and the arrangement intervals 2L to 4L. By installing at least 5 edge position detection sensors in total, it is suitable for various camber cycles by detecting the camber of the strip at three sensor intervals L and 2L to 4L. It becomes possible to detect the camber of the belt-shaped body at different sensor intervals, and it is possible to detect with high accuracy only in a narrow cycle range, which is a drawback of the conventional method of detecting with three edge position detection sensors. The inconvenience is solved, and it becomes possible to detect a camber in a wide cycle range with a smaller number of sensors.

Further, the interval L between the edge position detection sensors is set.
Is determined by the minimum value of the camber period desired to be detected by the strip, and the period is usually 1 m or more. Therefore, from this value, it is desirable that the distance L between the adjacent sensors in the first edge position detection sensor group is set to about 100 mm to 500 mm. If the interval between the sensors is smaller than 100 mm, the error becomes large because the camber is estimated from each point having a small interval. On the contrary, if the interval between the edge position detection sensors is larger than 500 mm, the error due to the decrease in the detection amplitude increases. Therefore, the arrangement interval L of the sensors is selected in the range of 100 mm to 500 mm according to the state of the strip, and then the arrangement interval 2L that is twice the arrangement interval L to the arrangement interval 4L that is 4 times the same. The sensor arrangement in the second edge position detection sensor group is determined.
After arranging each edge position detection sensor in this way,
The detection outputs of the three edge position detection sensors are selected from these edge position detection sensors based on a predetermined combination rule, and the camber of the belt-shaped body is detected based on these detection outputs.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining an embodiment of a method for detecting a camber of a belt-shaped body according to the present invention. In FIG. 1, reference numeral 1 denotes a first edge position detection sensor group for detecting a widthwise position variation of the edge 7a, and reference numeral 9 denotes a second edge position detection sensor group. Further, reference numerals 2, 3, 4, 5, and 6 indicate respective detectors (edge position detection sensors), and reference numeral 7 indicates a band-shaped body which is a detection target.

These detectors 2, 3, 4, 5 and 6 are installed so that the reference points for width direction fluctuation detection coincide with each other, and in the present embodiment, L, L, 2L and 4L are arranged respectively. They are arranged at intervals. Then, the position of the widthwise edge 7a of the belt-shaped body 7 that is running under this condition is detected, and the camber of the belt-shaped body 7 is calculated based on the detection result.

As shown in FIG. 2, the calculation formula of the bend θ obtained from the detection results of the detectors 2, 3 and 4 is that the detection results of the three detectors are S2, S3 and S4, respectively. If is set as X, it can be calculated by the following formula.

[0011]

[Equation 1]

This detection and calculation are carried out by a certain plate passing distance ΔL (m
m), and a camber component having a period of about 4L to 8L is extracted by a digital filter (not shown). Further, based on the detection results of the detectors 2, 4 and 5, the same calculation of the bending angle θ is performed, and the camber component having the period of about 8L to 16L is extracted by the digital filter. Furthermore,
A calculation for obtaining the bending angle θ is performed from the detection results of the detectors 2, 5 and 6, and a camber component having a period of 16 L or more is extracted by a digital filter.

On the other hand, in order to restore the camber from the bending angle θ, the sensors may be connected at a bending angle θ for each sensor interval with a distance corresponding to the sensor interval as shown in FIG. Specifically, at the sensor interval X, the bending data is θ for each sensor interval.
1, θ2, θ3 ...

[0014]

[Equation 2]

Is given by Then, since the straight line connecting the first detection point and the last detection point is the reference line,

[0016]

[Equation 3]

By performing the calculation of (1), the curve of the edge 7a of the belt-like body, that is, the camber, with respect to the straight line connecting the detection start point and the detection end point, can be obtained.

By the way, in the method of detecting a bend using only three edge position detection sensors, when the sensor interval is longer than the camber cycle, the intervals between the detection points become long, so the camber is restored from the detection result. Then, the amplitude is detected smaller than the original waveform. That is, the waveform between the detection points is linearly interpolated.
As described above, even if the interpolation is performed with a straight line, as indicated by a circle in the detection principle explanatory diagram of FIG. 4, if the interval between the edge position detection sensors is small, there is not much problem regarding the shape of the restored waveform.

However, as indicated by the triangles in the figure, if the sensors are arranged at large intervals, there is a high possibility that the corrugated portions existing between these sensors will be cut, resulting in the amplitude. Will be restored small. The ratio of the detection error and the original camber amplitude when the decrease of the detection amplitude is maximum is a function of the ratio of the target camber period and the sensor interval, and changes as shown in the graph of FIG.

Further, in the method of calculating the bends from the detection results of the three edge position detection sensors and connecting them to restore the camber shape, the influence of the measurement error of the edge position once when restoring the camber shape. Therefore, if the measurement interval, that is, the sensor interval is longer than the period, the camber restoration error due to the edge position measurement error increases. This error is a function of the ratio of the target camber period and the sensor interval, and is as shown in the graph of FIG.

Therefore, the total detection error is the sum of the graph of FIG. 5 and the graph of FIG. 6, and is as shown in the graph of FIG. That is, the target cycle is 5 sensor intervals.
If it is about double, the camber shape can be restored with high accuracy. However, this means that if the sensor intervals are all the same, the target camber period is limited to a narrow range.

Therefore, in order to detect a camber having a wider range of intervals, the arrangement intervals of the edge position detection sensors are configured as shown in FIG. 1, and the five edge position detection sensors 2 are arranged.
It is configured such that three types of sensor intervals can be obtained in the range from 6 to 6. That is, as shown in FIG. 7, it is possible to maintain the high detection accuracy in the range of 4 to 8 times the sensor interval, so that the sensor intervals are L, L, 2L, and 4L as shown in FIG. Is set so as to enable more accurate detection with a small number of sensors.

The edge position detecting sensor 2 in FIG.
In 3 and 4, the camber having a period of 4L to 8L is used, in the edge position detecting sensors 2, 4 and 5, the camber having a period of 8L to 16L is used, and in the edge position detecting sensors 2, 5 and 6 the period is 16L to 3L.
By detecting a 2L camber and adding and combining the detection results, a much wider range of camber over a period of 4L to 32L can be detected with a much higher accuracy than the conventional method of detecting three edge position detection sensors. Can be detected with.

By performing the above-described processing on the bending angle for each period calculated from the detection result, a waveform in which the camber shape for each period is restored is obtained. And
The camber shape of the belt-shaped body can be detected with high accuracy by adding the obtained waveforms of the respective periodic components.

[0025]

As described above, according to the present invention, the first edge position detection sensor group and the first edge position detection sensor group in which the edge detection sensors are arranged at equal intervals L are provided. By providing a second edge position detection sensor group in which a plurality of edge position detection sensors are arranged at an arrangement interval 2L that is twice the arrangement interval L of the sensor in the above and an arrangement interval 4L that is four times the arrangement interval L. Highly accurate detection is possible even in a region where detection is normally impossible, and the overall detection accuracy can be significantly improved without increasing the number of sensors provided.

[Brief description of drawings]

FIG. 1 is a plan view showing an arrangement state of sensors for carrying out a method for detecting a camber of a belt-shaped body of the present invention.

FIG. 2 is a schematic diagram showing how to determine a bending angle θ from a straight line of an edge based on a detection result.

FIG. 3 is a schematic diagram showing how an edge shape is restored from bending angle data.

FIG. 4 is a diagram showing that the detected amplitude is smaller than the actual waveform when the arrangement interval L of the edge position detection sensor is larger than the camber cycle.

FIG. 5 is a graph showing the ratio of the decrease in detected amplitude to the original amplitude with respect to the ratio of the target camber period and the sensor interval.

FIG. 6 is a graph showing a ratio of an error of a restored waveform due to a detection error of an edge position detection sensor to an original amplitude with respect to a ratio of a target camber period and a sensor interval.

7 is a graph obtained by combining FIG. 6 and FIG. 7, and is a graph showing camber detection accuracy by three edge position detection sensors.

[Explanation of symbols]

 1 First Edge Position Detection Sensor Group 2, 3, 4, 5, 6 Edge Position Detection Sensor 7 Band to be Detected 8 Reference Line of Edge Position Detection Sensor 9 Second Edge Position Detection Sensor Group

Claims (1)

[Claims] 1. On one edge side of the strip, three or more edge position detection sensors are provided along the longitudinal direction of the strip in order to measure the distance from the detection reference line to the edge in the width direction. The three or more edge position detection sensors detect the distance from the reference line to the plate end of the strip at a constant interval with respect to the moving distance in the longitudinal direction, and detect the strip from the relative position of the detection points. A method for estimating a camber of a body, comprising a first edge position detection sensor group in which three edge position detection sensors are arranged at equal intervals, and each edge position detection sensor in the first edge position detection sensor group. 2L, which is at least 2 to 4 times the arrangement interval L of
A second edge position detection sensor group having a plurality of edge position detection sensors arranged in a range from 4 L to 4 L, and from the reference line to the plate end of the strip by the first and second edge position detection sensor groups. By detecting the distances of .. at a constant interval with respect to the distance of movement in the longitudinal direction to generate a plurality of edge waveforms for each cycle, and based on the plurality of edge waveforms for each cycle, the camber of the belt-like body. A method for detecting a camber of a strip, which is characterized in that a shape is obtained.