JP2000266527A - Method and apparatus for measuring shape of metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically obtain measurements matching the operation results of flatness F performed by an inspector using a metal measure. SOLUTION: Flatness F of a metal plate 17 mounted on a surface plate 14 is operated based on the output from a detecting means 22. Peak and bottom are then detected along the longitudinal direction of the metal plate 17 using a sensor. Subsequently, a peak tangent connecting the peaks is determined and a maximum height H is determined out of heights Hi between the tangent and the bottoms. Thereafter, the wavelength L of peak corresponding to the maximum height H is determined and the flatness F=H/L is operated. The volume of data to be processed can be reduced by decreasing the number of peak tangents to be determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the shape of a metal plate such as a coiled metal strip, and more particularly, to a method and a method for measuring the flatness of the surface of the metal plate. Related to the device.

[0002] In the specification, the term "tangent" refers to a straight line connecting a peak and a peak and a straight line connecting a bottom and a bottom, and further includes a tangent tangent to a curve or a curved surface near the peak and near the bottom. Must be interpreted as

[0003] In the specification, the term "slope" refers to the slope of a straight line (tangent line) drawn between a certain peak and a peak downstream of the peak in the transport direction with respect to the horizontal direction, and a peak on the downstream side. Is low, the slope is negative.

[0004]

2. Description of the Related Art It is necessary to measure flatness in order to detect shape defects such as ridges and ear waves occurring in a rolled steel sheet. Conventionally, an inspector applies a 2 m metal rule to the surface of a steel plate to be inspected, measures the gap between the steel plate and the metal scale between two points where the steel plate and the metal scale are in contact, and determines the maximum gap as the peak height. H is obtained, and the horizontal distance between the peaks of the two points at which the maximum gap is obtained is obtained as the wavelength L, and the flatness F is calculated.
It is necessary to measure such flatness on both sides of the steel sheet and the center position in the width direction along the longitudinal direction of the steel sheet. In this case, in order to improve the measurement efficiency, inspection is performed on both sides of the steel sheet. Each inspector measures the flatness of each side edge of the steel plate, or one of the inspectors measures the flatness of the center of the steel plate. The flatness of the steel plate is measured every 100 m of the steel plate, and the measurement time for each measurement is about 5 minutes, and the flatness of the side end alone is 2 to 3 minutes. During this measurement, the steel sheet production line must be stopped,
Therefore, the decrease in the line operation rate is remarkable due to the long measurement time.

Another prior art solution to this problem is shown in FIG.
It is shown in FIG. The wave shape along the longitudinal direction of the steel sheet
Detected by a sensor, and the flatness is calculated using the output of the sensor. In this prior art, in FIG. 28, a line 1 representing the uneven shape of the surface detected by the sensor is shown.
Are connected by a straight line 4 and a perpendicular line 6 is drawn from the straight line 4 to the bottom 5 to obtain a peak height Ha of the perpendicular line 6 and obtain the peak height Ha
The flatness F is calculated with La being the horizontal distance between the two peaks 2 and 3 obtained. In the same manner, the flatness is similarly obtained for the peak tangents 7 and 8 connecting two adjacent peaks by a straight line.

In this prior art, two adjacent peaks 2 and 3 are simply connected by a straight line to obtain peak tangents 4, 7, and 8, and the flatness is calculated. The peak tangent 10 is obtained by applying a gold scale between the points 2 and 9, the peak height Hb between the peak tangent 10 and the bottom 11 at which the maximum peak height Hb is obtained, and the wavelength Lb is obtained to obtain the flatness. Is calculated, different peak heights, wavelengths, and flatnesses are obtained.

The prior art for detecting flatness is disclosed, for example, in Japanese Patent Application Laid-Open No. 3-11711 and Japanese Patent Publication No. 4-1472.
Despite the existence of the device 8, there is no device for automatically obtaining a measurement result similar to the method of measuring flatness using a gold scale by an inspector.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus for measuring the shape of a metal plate which enable an inspector to automate a shape such as flatness measured by using a gold scale. It is to be.

[0009]

According to the present invention, a distance to a surface of a metal plate is detected along a longitudinal direction of the metal plate corresponding to a position in the longitudinal direction. The protruding peak on the surface and the concave bottom are detected in correspondence with the position in the longitudinal direction, and a peak tangent connecting the peak is obtained by the detected distance and the detected peak / bottom. Among the mountain heights Hi between the peaks, the maximum mountain height H is determined, and the maximum mountain height H is determined.
Is obtained by calculating the wavelength L of two peaks along the longitudinal direction of the peak tangent line obtained by the calculation and calculating the flatness F = H / L.

According to the present invention, there is provided a detecting means for detecting a distance to a surface of a metal plate along a longitudinal direction of the metal plate in accordance with a position in the longitudinal direction, and detecting a distance of the metal plate in response to an output of the detecting means. Peak / bottom detecting means for detecting a raised peak and a concave bottom on the surface corresponding to the position in the longitudinal direction, and a peak tangent line connecting the peaks in response to outputs of the detecting means and the peak / bottom detecting means. And the maximum peak height H among the peak heights Hi between the peak tangent and the bottom is determined, and the wavelength L of two peaks along the longitudinal direction of the peak tangent at which the maximum peak height H is obtained. And a means for calculating the flatness F = H / L.

According to the present invention, the unevenness on the surface of the metal plate is detected by the detecting means along the longitudinal direction of the metal plate, and the position in the longitudinal direction and the detection distance are obtained in correspondence. The metal plate may be, for example, a coiled metal band, but may be a plate cut at intervals in the longitudinal direction, for example, a steel plate. Based on the output of the detecting means, a peak / bottom which is a peak and a valley on the surface of the metal plate is detected by the peak / bottom detecting means.

The calculating means determines a peak tangent which is a straight line connecting two peaks which are present at an interval in the longitudinal direction of the metal plate, and calculates a peak tangent with one or a plurality of bottoms present below the determined peak tangent. Mountain height Hi, which is the length of the perpendicular between
Ask for.

According to the present invention, as will be described later with reference to FIG. 17, for example, all the peaks obtained by the detecting means are connected to a brute force line to obtain a peak tangent, and thus obtained. A perpendicular line is drawn from all the peak tangent lines to the bottom, and a peak height H having the maximum perpendicular length is obtained, and a wavelength L which is a horizontal distance between two peaks having the maximum peak height H is obtained. With this configuration, the same result as the result of the shape measurement performed by the inspector using the gold scale is automatically obtained. In order to reduce the amount of calculation processing for obtaining the peak tangent, the method according to claims 2 to 4 may be executed.

The maximum peak height H is obtained from the peak heights Hi thus obtained. The wavelength L of two peaks along the longitudinal direction for forming a peak tangent line at which the maximum peak height H is obtained is obtained. The wavelength at which the flatness F is calculated in this manner is the longitudinal distance along the average surface of the metal plate.

Therefore, conventionally, the inspector is, for example, 2 m
It is possible to automatically obtain a measurement result substantially the same as the result of measuring the flatness using the gold scale.

The metal plate is placed on a surface plate having a horizontal surface, and the tension in the longitudinal direction acting on the metal plate is cut off to be in a natural state. In this state, the shape of the metal plate is measured. Although good, in another embodiment of the present invention, the shape of the metal plate may be measured while tension is applied to the metal plate, and the platen may be omitted, and the metal plate may be omitted. May not be horizontal, but may be vertical, for example.

In the present invention, instead of the flatness, the surface shape such as the elongation rate and steepness of the metal plate may be detected.

Further, according to the present invention, starting from a certain peak, a peak tangent is obtained for all of a plurality of peaks present on one side in the longitudinal direction, and a peak tangent having a maximum inclination is obtained from the peak tangents. , And with the obtained peak as a new starting point, peak tangents are obtained for all peaks on the one side in the longitudinal direction, and the operation of obtaining a new peak is repeated.

Further, according to the present invention, the calculating means obtains a peak tangent from each of a plurality of peaks existing on one side in the longitudinal direction from a certain peak as a starting point, and finds a peak having the largest inclination among the peak tangents. A peak for obtaining a tangent is obtained, and using the obtained peak as a new starting point, peak tangents are obtained for all the peaks on the one side in the longitudinal direction, and an operation for obtaining a new peak is repeated.

In accordance with the present invention, to reduce arithmetic processing, as described below in connection with FIGS.
The peak tangent is determined by drawing straight lines on all the plurality of peaks existing on one side in the longitudinal direction, for example, on the downstream side in the transport direction of the metal plate, with a certain peak Pc1 as a starting point. Peak tangent TL13 with the largest slope
Ask for.

The same operation is repeated with the new peak for obtaining the peak tangent having the maximum slope obtained as described above as a starting point. Therefore, the number of peak tangents for which the peak height should be calculated can be reduced, and the amount of calculation processing can be reduced. Thus, the same result as the shape measurement by the inspector using the gold scale can be obtained.

Further, according to the present invention, a bottom tangent connecting each bottom and two adjacent bottoms along the longitudinal direction is obtained, and an inverted mountain height Hr between the bottom tangent and the peak is obtained.
And peaks whose inverted mountain height Hr is less than a predetermined threshold are excluded from the peaks for which the peak tangents are to be determined.

Also, in the present invention, the calculating means comprises:
A bottom tangent connecting two adjacent bottoms along the longitudinal direction is determined, and a reverse peak height Hr between the bottom tangent and the peak is determined. From the peak for which the peak tangent is to be determined, the reverse peak height Hr is calculated. It is characterized in that peaks smaller than a predetermined threshold value are excluded.

According to the present invention, as will be described later with reference to FIGS. 20 and 21, the number of peaks for which a peak tangent is to be obtained can be reduced in order to further reduce the processing amount. In FIG. 20, starting from a certain bottom B1, a bottom B2 adjacent to the downstream side in the longitudinal direction of the metal plate
Is drawn by drawing a straight line to obtain a bottom tangent line TR12. Starting from the bottom B2, the bottom B3 adjacent on the downstream side
Is drawn by drawing a straight line to obtain a bottom tangent line TR23. Furthermore, starting from the bottom B3, the bottom B adjacent to the downstream side
4 and draw a straight line to obtain a bottom tangent line TR34. Thereafter, a bottom tangent is sequentially obtained in the same manner. A perpendicular is drawn from each bottom tangent to a peak above the bottom tangent, and the inverted mountain heights Hr1, Hr2, Hr3, which are the lengths of the perpendiculars.
... (overall, Hr). The level discrimination is made as to whether the inverted mountain height Hr obtained in this way is less than a predetermined threshold value Hr0. When the inverted mountain height Hr2 is less than the threshold value, a peak Pd2 at which the inverted mountain height Hr2 is obtained.
Are excluded from the target of the peak for which the peak tangent should be determined. In this way, by calculating the inverted mountain height, the number of peaks for which a peak tangent is obtained is reduced, and the processing speed is improved.

Also, the present invention provides a method wherein each peak is sandwiched along a longitudinal direction by a peak higher than the peak.
It is characterized in that a peak sandwiched between the high peaks is excluded from the peak from which the peak tangent is to be determined.

Further, according to the present invention, in the arithmetic means, each peak is
When sandwiched in the longitudinal direction between the peaks higher than the peak, from the peak to determine the peak tangent,
The method is characterized in that peaks sandwiched between the high peaks are excluded.

According to the present invention, as will be described later with reference to FIGS. 22 and 23, small peaks P2 and P3 sandwiched between high peaks P1 and P4 are excluded from peaks for which peak tangents are to be obtained. The amount of calculation processing is reduced, and the calculation processing speed is improved. According to the present invention, attention is paid to a certain peak P2, and peaks P1 and P3 larger than the peak P2 are obtained.
If sandwiched in the longitudinal direction of the metal plate, the low peak P2 is excluded from peaks for which a peak tangent should be determined. Thus, the number of peaks for which peak tangents are to be obtained can be reduced, and the amount of calculation processing can be reduced.

Further, according to the present invention, a distance to the surface of the metal plate is detected along the longitudinal direction of the metal plate in accordance with the position in the longitudinal direction. And the concave bottom are detected in correspondence with the position in the longitudinal direction, and the detected distance and the detected peak /
The bottom determines the peak height H between the single peak and the lower one of the one or more bottoms, and calculates the distance 2 along the longitudinal direction between the peak and the lower bottom. A method for measuring the shape of a metal plate, comprising: determining a magnification as a wavelength L and calculating a flatness F = H / L.

According to the present invention, there is provided a detecting means for detecting a distance to a surface of a metal plate along a longitudinal direction of the metal plate corresponding to a position in the longitudinal direction, and responding to an output of the detecting means,
The raised peak on the surface of the metal plate and the concave bottom
A peak / bottom detecting means for detecting corresponding to the position in the longitudinal direction, and a single peak and a lower bottom of one or a plurality of bottoms in response to outputs of the detecting means and the peak / bottom detecting means. Means for calculating the height L between the peak and the lower bottom and doubling the longitudinal distance between the peak and the lower bottom as the wavelength L, and calculating the flatness F = H / L. An apparatus for measuring the shape of a metal plate, comprising:

According to the present invention, as will be described later with reference to FIGS. 26 and 27, even when at least two peaks do not exist within the predetermined measurement range W10 in the longitudinal direction of the metal plate. That is, when only a single peak Ph1 exists in the measurement range, it is possible to extrapolate the waveform and calculate a shape such as flatness. That is, if no valid peaks are found in the measurement range,
The height difference between the peak Ph1 and the lower bottom Bh2 is defined as a mountain height H, and twice the horizontal distance D1 between the peak and the bottom at which the mountain height is obtained is defined as the wavelength L. With such a device of calculation, it becomes possible to obtain a measurement result equivalent to a measurement result obtained by an inspector using a gold scale in a short time.

[0031]

FIG. 1 is a perspective view showing the overall configuration of a steel sheet shape measuring apparatus 13 according to one embodiment of the present invention. On a surface plate 14 having a horizontal surface, a steel plate 17 is arranged from an entrance side 15 to an exit side 16. At the time of shape measurement, the traveling of the steel plate 17 in the traveling direction 18 is stopped,
The steel plate 17 is placed on the surface plate 14 and the tension of the steel plate 17 becomes zero, so that the steel plate 17 is in a natural state. In this production line, the position of the steel plate 17 in the width direction is controlled so that the center position 107 in the width direction of the steel plate 17 substantially coincides with the center position 108 of the platen 14 and the vehicle runs. The longitudinal direction of the steel plate 17 matches the running direction 18. Along the traveling direction 18, a detecting unit 22 fixed to the floor is provided in association with the surface plate 14.

FIG. 2 is a diagram schematically illustrating the surface 24 of the steel plate 17 for explaining the definition of the flatness F. The flatness F represents the degree of the plate wave of the steel plate 17, and the flatness F
A smaller value indicates that the steel plate 17 has a flatter shape. A straight line 27 connecting the two raised peaks 25 and 26 of the plate wave on the surface 24 of the steel plate 17 is drawn and drawn, and this straight line 27 is called a peak tangent. From this peak tangent 27, a perpendicular 29 is drawn to the concave bottom 28 of the surface 24 of the steel plate 17, and the peak height H1, which is the length of the perpendicular, is determined. Similarly, a similar peak tangent 31 is drawn between the peaks 26 and 30, and a peak height H2 of a perpendicular 33 between the peak 26 and the bottom 32 is obtained. In this way, the maximum peak height H among the plurality of peak heights H1 and H2 within the measurement range is obtained. For example, in FIG. 2, since H1 <H2, the maximum mountain height H is H2. The horizontal distance between the peaks 26 and 30 from which the maximum peak height H was determined is determined as the wavelength L.
The flatness F is defined by Expression 1. F = H / L (1)

FIG. 3 is a plan view of the shape measuring device 13.
FIG. 4 is a front view, and FIG. 5 is a side view. The shape measuring device 13 includes a surface plate 14 having a horizontal upper surface and a detection unit 22 provided on the surface plate 14. Surface plate 14
Are arranged parallel to the running direction 18 of the steel plate 17 whose shape is to be measured, and are fixed to the floor by legs 42. Detecting means 22
Has a detector 67 that can be moved up and down by a pedestal 68 having an elevating mechanism. When the pedestal 68 is at the lower limit position shown in FIGS. 3 to 5, a measurement operation is performed, and the detector 67 is raised. When in the upper limit position, the operation of the production line of the steel plate 17 is in operation.

In the detector 67, a pair of horizontal first guide rails 69 extending substantially parallel to the steel plate 17 in the running direction 18, which is the longitudinal direction of the steel plate 17, are fixed to a gantry 68 having a lifting mechanism. These guide rails 69 are provided on the platen 1
4 respectively. The traveling body 71 can travel while being guided by the first guide rail 69 in the traveling direction 18. In order to drive the traveling body 71, a traveling drive means 92 includes a forward / reverse rotating motor 72.
And a screw rod 73 rotationally driven by the motor 72
And a nut member 74 screwed to the screw rod 73 and fixed to the traveling body 71. Motor 72, screw rod 73
The nut member 74 constitutes a traveling body driving unit. The motor 72 is provided with an encoder EN21 which is a traveling body position detecting means. The traveling position of the traveling body 71 in the traveling direction 18 can be detected by the encoder EN21.

FIG. 6 is a side view showing a part of the traveling body 71, FIG. 7 is a front view showing a part of the detecting body 67, and FIG.
FIG. 5 is a simplified front view showing a part of the detection body 67. The traveling body 71 is provided with a second guide rail 75 in the width direction of the steel plate 17 (the vertical direction in FIG. 3 and the horizontal direction in FIG. 7). A plurality of (eg, 5 in this embodiment) sensors S21 to S25 are commonly guided by the guide rail 75 and are movable in the movement direction 76. In FIG.
Each of the sensors S21 to S25 is located at the outermost position (the leftmost position in FIG. 7) of the steel plate 17, that is, the platen 14. These sensors S21 to S25 are sequentially arranged in the width direction of the steel plate 17, and detect the distance to the surface of the steel plate 17 at that position. Above the sensors S21 to S25, a sensor moving means 77 for moving these sensors S21 to S25 in the moving direction 76 is arranged.
7 is provided on the traveling body 71.

FIG. 9 is a plan view of the sensor moving means 77, and FIG. 10 is a front view of the sensor moving means 77.
The moving member 81 is moved along a pair of third guide rails 82 provided on the traveling body 71. Third guide rail 82
Is the width direction of the steel plate 17 (the left-right direction in FIGS. 9 and 10)
Extends horizontally. The moving member 81 includes
Thereby, the gripping member 84 is provided so as to be vertically movable. The gripping member 84 has an inverted U-shaped engagement recess 85 opened downward, and the engagement recess 85
The engaging projection 86 (see FIGS. 7 and 8) formed on the upper part of S25 can be vertically engaged / disengaged.

The sensor moving means 77 moves the moving member 81 in the moving direction 76.
A threaded rod 87 parallel to the guide rail 82 is provided. A screw member 87 has a nut member 88 fixed to the moving member 81.
To screw. The screw rod 87 is rotationally driven by a forward / reversely rotatable motor 89. The encoder EN22 constituting the sensor position detecting means detects a position along the moving direction of the engaging convex portion 86 engaged with the engaging concave portion 85 of the moving member 81, and accordingly, a position along the moving direction 76 of each of the sensors S21 to S25. I do.

FIG. 11 is a block diagram showing an electrical configuration of the steel sheet shape measuring apparatus 13 according to one embodiment of the present invention. Input means 95 is connected to a processing circuit 94 realized by a microcomputer or the like. Input means 9
5 is, for example, an identification number for identifying a steel plate 17 whose shape is to be measured, which is realized by a keyboard or the like;
For example, the coil number and the width of the steel plate 17 are input. Push button 9 operated by operator to start measurement
6 is connected. Instead of the output from the input means 95 and the push button 96, the processing circuit 94 may be provided with a command signal from a host computer or the like. The memory 97 is connected to the processing circuit 94, and the detecting means 22 is connected to the processing circuit 94.
The output from S25 is provided and the encoder E
Outputs from N21 and EN22 are provided. Processing circuit 9
The output of 4 controls the operation of the detection means 22.

FIG. 12 is a flowchart for explaining the overall operation of the processing circuit 94. The process proceeds from step a1 to step a2, where the coil number which is the identification number of the steel plate 17 and the plate width W1 of the steel plate 17 are input by operating the input means 95. In step a3,
For the measurement of the flatness F, the operation of the production line of the steel plate 17 is stopped, whereby the running of the steel plate 17 is stopped,
Further, the tension in the longitudinal direction of the steel plate 17, that is, the running direction 18 is released and cut off. Thus, the steel plate 17 whose shape is to be measured is placed on the surface of the surface plate 14.

During operation of the steel plate 17 and in the initial state of the measuring operation according to the present invention, the detecting means 22 detects that the gantry 66 is at the upper limit position by the elevating means 68 and the traveling body 71
Are located at the upstream end position in the traveling direction 18 and the sensors S21 to S21
S <b> 25 is at the outer end position in the width direction of the steel plate 17, and the lifting / lowering displacement unit 83 is at the upper limit position where the gripping member 84 has been raised.

In step a4 of FIG. 12, when the operator presses the push button 96 for measurement, the processing circuit 94 causes the pedestal 68 having the elevating mechanism in the detection means 22 to move down the detection body 67 and lower the lower limit. Bring to position.

FIG. 13 is a simplified plan view of a part of the steel plate 17. The side end 37 of the steel plate 17 is displaced in the width direction (vertical direction in FIG. 13) during the driving operation. Effective measurement width W2
Is set to a range in which the side end 37 is always included. The effective measurement width W2 is determined by adding the plate width W1, the maximum meandering amount of the steel plate 17 during the driving operation, and a predetermined margin value margin as described above. For this purpose, the side edges are detected in step a5 and stored in the memory.

In step a6, in the detecting means 22, the sensors S21 to S25 are detected by the sensor moving means 77.
Is moved to the right in FIG. 7 in the moving direction 76 from the state near the side end 37 of the steel plate 17 shown in FIG. 7, and the stored side end 37 and the width of the steel plate 17 previously input are Based on
Each of the sensors S21 to S25 is, as shown in FIG.
It is distributed at equal intervals in the width direction of the steel plate 17 (vertical direction in FIG. 13).

FIG. 14 is a simplified front view corresponding to FIG. 7 for explaining the operation of the sensor moving means 77 in the detecting means 22. As shown in FIG. 14A, first, the engaging concave portion 85 is lowered by the vertical displacement means 83, and the engaging concave portion 85 is engaged with the engaging convex portion 86 of the sensor S21 on the most upstream side in the moving direction 76. Combine. In this state, the motor 89 is driven, and the moving member 81, and hence the engaging projection 8
6 and the sensor S21 move rightward as shown in FIGS. 7 and 14 (2). When the sensor S21 is moved, the remaining sensors S22 to S25 located downstream of the sensor S21 in the movement direction (to the right in FIG. 14B).
Is also moved with the sensor S21. Also steel plate 1
7 is input to the input means 95 and stored in the memory 97 as described above, so that the motor 89 is stopped at a predetermined distance W4 from the side end 37 and inward in the width direction. The lifting / lowering displacement means 83 includes an engagement recess 85.
To set the sensor S21 at a position where the side end 37 is inward in the width direction by the distance W4. Then, the motor 89 is driven to lower the engagement concave portion 85 at the top of the next sensor S22 by the vertical displacement means 83, and as shown in FIG. Engaging recess 8
5 engage. In this state, the motor 89 is further moved, and the sensor S22 and the sensors S23 to S25 downstream of the movement direction 86 (to the right in FIG. 14C) are moved. By an equal interval W5 of the sensors S21 to S25,
When moved by the action of the motor 89, FIG.
As shown in (4), the motor 89 is stopped, and the elevating / lowering displacing means 83 again moves up the engaging recess 85, and the sensor S2
2 is installed at a position separated from the sensor S21 by an interval W5. The motor 89 is driven again and brought on the sensor S23, where the lifting / lowering displacement means 83 descends the engaging concave portion 85 and engages with the engaging convex portion 86. In this state, the motor 8
9 is further driven, and the sensor S23 is moved, so that the sensors S24 and S25 are also moved. The above operation is repeated, and the sensor S23 is installed at a distance W5 from the sensor S22 as shown in FIG. Similarly, the sensors S24 and S25 are installed in the same manner as shown in FIG. 14 (6), and this state is also shown in FIG.

In step a6 in FIG. 12 described above, when the setting of the distribution of the sensors S21 to S25 in the width direction of the steel plate 17 by the detecting means 22 is completed, in the next step a7, the operation of the motor 72 of the traveling body driving means 92 is performed. The traveling body 71 moves from the rest position in the traveling direction 18 to the downstream side (to the left in FIG. 3) in the traveling direction 18, whereby the sensors S <b> 21 to S <b> 25 move in the traveling direction 18 at each position in the width direction of the steel plate 17. Along with the surface, that is, the distance is detected, and stored in the memory 97 corresponding to the position in the traveling direction detected by the encoder EN21.

When the traveling body 71 reaches the downstream end position in the traveling direction 18 in step a8, the lifting means 68
The gantry 66 is raised to the upper limit position, travels in the opposite direction to the upstream side in the traveling direction 18, and returns to the standby position. In step a9, the sensors S21 to S25 of the detecting means 22 are returned to the position side end of the surface plate 14 as shown in FIG.

At step a10, the sensors S21 to S2
5 and the output of the encoder EN21, the flatness F
At each position in the width direction of the steel plate 17, that is, each sensor S21
To S25. Thus, a series of operations is completed in step a11.

FIG. 15 shows the sensors S21 to S21 of the detecting means 22.
9 is a flowchart for explaining the operation of a processing circuit 94 that calculates flatness F based on S25 and an output from an encoder EN21. The operation shown in FIG. 15 is achieved in step a10 in FIG. The process proceeds from step b1 to step b2, where the sensor S2
1 to S25, a peak Pi (i = 1 to N) and a bottom B along the longitudinal direction of the surface of the steel plate 17 for each position of each of the sensors S21 to S25 in the width direction of the steel plate 17.
j (j = 1 to M) is detected.

FIG. 16 is a diagram showing the stored state of the peak Pi and the bottom Bj in step b2 stored in the memory 97. Sensor S21 shown in FIG.
X is the running direction 1 which is the longitudinal direction of the steel plate 17.
8, and z is a coordinate position in the vertical direction perpendicular to the horizontal surface of the surface plate 14, and is a value corresponding to the distance detected by the sensor S21. Remaining sensor S22
Similarly, the coordinates (x, z) of the peak Pi and the bottom Bj are also stored in the memory 97 for S25.

In step b3, a plurality of peaks Pi are detected within the measurement range of the detecting means 22 along the traveling direction 18.
It is determined whether it exists. Peak P within the measurement range
When there are a plurality of i, step b3 to step b4
Then, a flatness F is calculated by obtaining a tangent to each peak in a round robin manner. Such a method of calculating by brute force will be described in relation to steps b4 to b8.

FIG. 17 is a simplified view of the surface of the steel plate 17 for explaining the method of calculating the flatness F using the tangent line by round robin shown in FIG. In step b4, the tangent lines TL12, TL13, TL1 are connected to all of the peaks Pb1 to Pb4 by straight lines in a round robin manner.
4. Draw TL23, TL24 and TL34.

Then, in step b5, each tangent line TL
12, TL13, TL14, TL23, TL24, TL
A perpendicular line is drawn on each of the bottoms Bb1 to Bb3 existing below the bottom 34, and each peak height Hr is obtained. The mountain height Hr is, for example, the height of a vertical line drawn from the tangent TL12 to the bottom Bb1 with respect to the tangent TL12, and the tangent TL14 is drawn from the tangent TL14 to each of the bottoms Bb1, Bb2, and Bb3. The length of the perpendicular. Other tangents TL13, TL23, TL24, T
The same applies to L34. In the next step b6, the maximum peak height H is searched for and obtained from the plurality of peak heights Hr obtained in this manner. In the embodiment of FIG. 17, the length of the perpendicular drawn from the tangent TL24 to the bottom Bb3 is the maximum peak height H.

In step b7, the maximum peak height H was obtained.
The wavelength L, which is the horizontal distance between the two peaks Pb2 and Pb4, is obtained. Such peak heights Hr, H and wavelength L are 1
The calculation can be performed based on the stored contents of the memory 97 described above with reference to FIG. That is, the peak heights Hr, H can be obtained from the coordinate values in the z direction in the x, y, z coordinate system, and the wavelength L
Can be obtained from the coordinate values in the x direction. The board width direction is the y direction. Using the maximum peak height H and the wavelength L obtained in steps b6 and b7 in this way, the flatness F is calculated in step b8 based on the above-described equation 1, and step b9
Then, a series of operations ends.

When there is only one peak Pi in the measurement range of the detecting means 22 along the traveling direction 18, the process proceeds from step b3 to step b10, as will be described later with reference to FIGS. 26 and 27 described later. Next, extrapolation of the waveform of the uneven shape of the surface of the steel plate 17 is performed, and the flatness F can be calculated in step b8.

The above-described calculation method based on round robin in FIGS. 15 and 17 is effective for a steel plate 17 which is known to have a small number of peaks because the arithmetic processing logic itself is simple. However, when the number of peaks is n, the number of calculations N1 required for the straight line calculation and the perpendicular line calculation is expressed by Equation 3, respectively.

N1 = n (n-1) / 2 (3) For example, when the number of operations when the number of peaks is 10, 50, 100 is obtained, n = 10 operations N1: 45 n = 50 operations N1 : 1225 n = 100 Number of operations N1: 4950, and when the number of peaks increases, an enormous amount of arithmetic processing is required.

Therefore, for a steel sheet having a large number of peaks, a more efficient calculation method is applied as described below.

FIG. 18 is a flow chart for explaining the operation of the processing circuit 97 for explaining a method for sequentially obtaining the tangents having the maximum inclination in calculating the flatness F. Steps c1, c2, c3 and c10 are:
Steps b1, b2, b3, b1 in FIG.
Same as 0. In order to reduce the amount of calculation processing drawn by drawing a tangent line, in step c4 of FIG. 18, low peaks due to the calculation of the height of the inverted peak, which will be described later with reference to FIGS. 20 and 22, are excluded. In step c5, FIG. 21 and FIG.
The low peaks sandwiched by the high peaks described below in relation to are excluded. After reducing the number of peaks drawn by drawing a tangent in this way, a tangent is calculated in step c6, and the operation will be described later with reference to FIG.

FIG. 19 is a view showing the surface shape of the steel plate 17 for explaining a method of sequentially obtaining the tangents having the maximum inclination in step c6. The peak is at step c4 described above.
In a state not excluded in c5, step c6
When the tangent is calculated by the calculation shown in FIG. 19, the first peak Pc1 in the measurement range is set as a starting point, and all the peaks Pc2 to Pc6 downstream of the peak Pc1 in the traveling direction 18 are shown in FIG.
Draw a tangent line as shown in (1). Among the tangents, the tangent TL13 having the largest inclination is found. Among the peaks for which the tangent line TL13 having the maximum slope was determined,
A peak Pc3 other than the peak Pc1 at the starting point is set as the next starting point, and is drawn by drawing a tangent line as shown in FIG. That is, a tangent line is drawn from the next starting point Pc3 to each of the peaks Pc4 to Pc6 on the downstream side in the traveling direction, and a tangent line TL36 having the maximum inclination is obtained. The obtained tangent line TL3
The peak Pc6 on the downstream side in the traveling direction 18 for obtaining 6 is the next starting point. In this way, the number of tangents to be obtained is determined by the method of sequentially obtaining the tangent having the maximum slope described in connection with step c6 of FIG. 18 and FIG. Can be reduced.

The method for obtaining the tangent at step c6 thus obtained will be described later with reference to FIG. According to such a method of sequentially obtaining the tangents having the maximum inclination, the amount of calculation processing is reduced, the flatness equivalent to the measurement by the inspector is obtained, and the number of peaks and bottoms is relatively small with respect to the measurement span. Even in the case where the number is large, the flatness can be calculated in a short time. FIG.
In the example of No. 9, since the number of peaks is 6 in the above-described brute force calculation method, the calculation of the straight line and the calculation of the perpendicular line are performed 15 times each, that is, 30
In this method, the tangent line having the maximum slope is sequentially obtained nine times for calculating the straight line, five times for calculating the peak height,
A total of 14 calculations are required. This difference becomes more pronounced as the number of peaks increases.

In the method of sequentially obtaining the tangents having the maximum inclination shown in FIG. 19, when the number of peaks is enormous, the number of calculations also becomes enormous. Therefore, according to the concept of the present invention, the pre-processing of steps c4 and c5 in FIG. 18 makes it possible to reduce the number of peaks for which a tangent is to be obtained without affecting the flatness calculation. First, in step c4 in FIG. 18, a method of excluding peaks by calculating the height of the inverted mountain is performed.

FIG. 20 is a diagram schematically illustrating the surface shape of the steel plate 17 for explaining the method of removing peaks by calculating the height of the inverted peak in step c4 of FIG. FIG.
7, the calculation of the peak height is opposite to the calculation of the peak height.
The two bottoms adjacent to the running direction 18 which is the longitudinal direction of 7 are connected by a tangent line, a perpendicular line is drawn from the bottom tangent line to the peak, and a peak whose length is less than a predetermined threshold is excluded. . This threshold value may be a fixed value determined in advance, or may be determined by calculation from a representative value of the peak and the bottom.

FIG. 21 is a processing circuit 9 for explaining the method of removing peaks by calculating the height of the inverted peak shown in FIG.
4 is a flowchart for explaining the operation of FIG. The process moves from step d1 to step d2, where the bottom Bj (j = 1
To M), the calculation is started from the bottom B1 at the most upstream in the traveling direction to the first bottom B1. In step d3, the bottom tangent line TR12 is drawn on the bottom B2 on the downstream side in the running direction 18 adjacent to the bottom B2. Step d
4, the peak Pd1 existing on the bottom tangent line TR12
Is calculated by calculating the inverted mountain height Hr1. This inverted mountain height Hr
1 is set to a predetermined threshold value Hr0, and level discrimination is performed in step d5. As a result of this level discrimination, Hr1 ≧ H
If r0, the peak Pd1 is left, and if Hr1 <Hr0, the peak Pd1 is excluded. In step d7,
The bottom Bj is advanced by one, and the above-described calculation is performed from the bottom B2 next to the bottom B1 in FIG. Thus, in step d8, the calculation of the bottom within the measurement range is performed.

When the inverted mountain height Hrj is equal to or greater than the threshold value Hr0, the peaks are left, and the process proceeds to the next bottom B (j + 1) in step d10, and the above-described operation is repeated. After the peak Pd2 in FIG. 20 is excluded in this manner, the peak tangent T between the peaks Pd1 and Pd3
L13 will be required. As a result, the number of peak tangents required can be reduced, and the amount of calculation processing can be reduced.

In order to exclude a peak for obtaining a peak tangent, a low peak sandwiched by a high peak is excluded in step c5 in FIG. Paying attention to each peak, if it is sandwiched between the peaks higher than the peak on both sides in the traveling direction 18, the low peak is excluded from the tangent calculation target.

FIG. 22 is a simplified view of the surface of the steel plate 17 for explaining a method of excluding a low peak sandwiched between high peaks shown in step c5 of FIG. 18, and FIG. 18 is a flowchart for explaining the operation of the processing circuit 94 for executing a method of removing a low peak sandwiched between high peaks in Step c5 of Step 18; The process moves from step e1 to step e2 in FIG. 23 to set a peak P2 next to the peak P1 at the most upstream in the traveling direction.
Move to step e3. In this step e3, the peak P
It is determined whether a higher peak P1 exists upstream of P2, and if so, it is determined in step e4 whether a higher peak P3 exists downstream of the peak P2. If there are peaks P1 and P3 higher than peak P2 in steps e3 and e4, respectively,
The low peak P2 existing between 3 is excluded. Step e
6, the next peak P3 adjacent on the downstream side in the traveling direction 18
In step e7, the above operation is repeated up to the peak P (N-1) immediately before the most downstream in the traveling direction, and then a series of operations is ended in step e8.

After the peak P2 has been excluded as described above,
In the peak P3 which is adjacent only to the downstream side in the traveling direction 18, it is determined in step e3 whether or not there are higher peaks P1 and P4 on both sides thereof.
If so, peak P3 is excluded. Step e3
, Two high peaks Pk1 and Pk2 present on both sides of the peak Pi may be peaks adjacent to each other in the traveling direction 18 or may be peaks separated by one or more peaks.

As shown in FIG. 18 described above, the method of removing peaks by calculating the height of the inverted peak in step c4 is performed first, and then the method of removing low peaks sandwiched by high peaks in step c5 is performed. By executing the method, the inspector can calculate the exactly matched flatness F by a method of measuring the flatness F using a gold scale.

Thus, in FIG. 22, the peaks P2 and P3 are excluded, and only the tangent line TL14 connecting the peaks P1 and P4 needs to be obtained. This makes it possible to reduce the calculation processing amount of the tangent line.

FIG. 24 is a flowchart for explaining the operation of the processing circuit 94 for calculating the tangent at step c6 in FIG. The process proceeds from step f1 to step f2, where the most upstream peak Pi in the traveling direction 18 is set. Next, in step f3, it is determined whether or not the peak is excluded by the above-described steps c4 and c5, and the peak is excluded. If it is a peak, in step f4, the determination of step f3 is performed for the next adjacent peak.

If the peak is not excluded, step f
From 3, the process proceeds to step f 4 a, where it is determined whether or not there is a remaining peak, that is, not excluded, on the downstream side in the traveling direction 18. If so, the process proceeds to step f 5.
A tangent line is drawn to all remaining peaks starting from Pi. If there is no peak remaining on the downstream side in step f4a, the process ends in step f9. In the next step f6, a peak P for obtaining a tangent having the maximum slope is obtained.
k3, and the peak Pk3 is determined, for example, by the aforementioned FIG.
9, Pc3 and Pc6. In step f7, a tangent between the peak Pi that has become the starting point and the peak Pk3 is obtained. In FIG. 19 described above, in step f7, the tangent line TL1
3, TL36 is obtained.

In step f8, the above calculation is repeated for the peak Pk3 obtained in step f6. In step f4, all peaks P1 to P
After the arithmetic processing is performed on N, the operation ends in step f9.

FIG. 25 is a flow chart for explaining the operation of the processing circuit 94 according to another embodiment of the present invention. This embodiment is similar to the previous embodiment.
It should be noted that, in this embodiment, step c5 in FIG. 18 described above is omitted, and only the method of removing the low peak by calculating the inverted mountain height, which is step c4, is executed. In still another embodiment of the present invention, step c
4 and c5, step c4 is omitted and step c
5 is performed to execute a method of excluding low peaks sandwiched by high peaks.

FIG. 26 is a diagram showing the shape of the surface of a steel plate 17 according to another embodiment of the present invention. In a case where two or more effective peaks are not found in the range W10 for measuring the flatness F and only a single peak Ph1 exists, according to the present invention, the above-described step b10 in FIG. 15 and step c10 in FIG. The method of extrapolation of the waveform shown in FIG.

FIG. 27 is a flowchart for explaining the operation of the processing circuit 94 for executing the method of extrapolating a waveform. The process proceeds from step h1 to step h2, where the peak Ph1 and one or more bottoms Bh1, Bh in FIG.
The height difference between the lower bottom Bh2 and the lower bottom Bh2 is determined as the peak height H. In step h3, the peak Ph1 and the bottom Bh of the peak height H obtained in step h2 described above.
2 is obtained. In the next step h4, the wavelength L is obtained by L = 2 · D1 (4). Thus, the wavelength L which is twice the horizontal distance D1
And the shape of the surface of the steel plate 17 is determined on the assumption that the peak Ph2 exists. Mountain height H obtained by this
The flatness F is calculated and calculated by Expression 1 based on and the wavelength L. In step h5, a series of operations is ended.

[0076]

According to the first and sixth aspects of the present invention, the inspector obtains the peak height H by using a conventional metal rule of, for example, 2 m, and the wavelength of the peak at which the peak height is obtained. The same measurement result as the flatness F obtained by the method of measuring L can be obtained. In particular, according to the present invention, the number of inspectors can be reduced by reducing the number of inspectors by hand, or the number of inspectors is not required, the measurement time is further reduced, and the shape of the metal plate can be measured with high speed and high accuracy. Will be able to In addition, since the measurement is performed in such a short time, the time for stopping the production line of the metal plate can be shortened, and the decrease in the line operation rate can be suppressed as small as possible.

According to the second and seventh aspects of the present invention, all the detected peaks are drawn by brute force tangent lines to obtain peak heights.
By sequentially obtaining the tangent of the maximum slope, the peak below the peak tangent is excluded, thereby reducing the process of calculating the peak height, which is the length of the peak tangent and the perpendicular, and efficiently reducing the metal plate. Shape measurement becomes possible.

According to the third and eighth aspects of the present invention, in order to reduce the number of peaks as compared with the above-described method of obtaining a brute force tangent to all the peaks, or
In order to further reduce the number of peaks that can be excluded in the method of No. 7, the peak height Hr is calculated and peaks are excluded, thereby further reducing the amount of computation and increasing the speed and speed of the metal plate. Shape measurement becomes possible.

According to the fourth and ninth aspects of the present invention, when each peak is sandwiched by larger peaks, the sandwiched lower peak is excluded from the calculation of the peak tangent. As a result, the amount of calculation processing can be reduced.

According to the present invention, the methods of claims 3, 8 and 4, 9 may be performed sequentially, or only one of them may be performed. When the methods of claims 3, 8; 4, 9 are performed sequentially, it is preferable that the method of claims 3, 8 is performed first, and then the method of claim 4, 9 is performed. This makes it possible to calculate an accurate flatness that is more similar to the method of an inspector using a gold scale. Each of the methods of claims 3, 8; 4, 9 may be performed after the method of claims 2, 7, but in another embodiment of the present invention, all peaks have a brute force tangent line. It may be performed after the method required.

According to the fifth and tenth aspects of the present invention, when two or more peaks are not found in the longitudinal measurement range of the metal plate detected by the detection means, one peak Ph1 is set to the lower one. The height difference between the peak and the bottom Bh2 is defined as a mountain height H, and a twice the horizontal distance D1 between the peak and the bottom at which the mountain height can be obtained is defined as a wavelength L, thereby calculating the flatness F. be able to. In this way, the shape measurement can be performed by the present invention up to about twice the wavelength of the measurement range.

[Brief description of the drawings]

FIG. 1 shows a steel sheet shape measuring apparatus 1 according to an embodiment of the present invention.
FIG. 3 is a perspective view illustrating an entire configuration of a third embodiment.

FIG. 2 is a diagram schematically illustrating a surface 24 of a steel plate 17 for explaining the definition of the flatness F.

FIG. 3 is a plan view of a steel sheet shape measuring device 13;

FIG. 4 is a front view of the steel sheet shape measuring device 13;

FIG. 5 is a side view of the steel sheet shape measuring device 13;

FIG. 6 is a side view showing a part of the traveling body 71.

FIG. 7 is a front view showing a part of the detection body 67.

FIG. 8 is a simplified front view showing a part of a detection body 67;

9 is a plan view of the sensor moving unit 77. FIG.

FIG. 10 is a front view of the sensor moving means 77.

FIG. 11 is a block diagram showing an electrical configuration of a steel sheet shape measuring apparatus 13 according to one embodiment of the present invention.

FIG. 12 is a flowchart for explaining the overall operation of the processing circuit 94;

FIG. 13 is a simplified plan view of a part of the steel plate 17;

14 is a simplified front view corresponding to FIG. 14 for explaining the operation of the sensor moving means 77 in the detecting means 22. FIG.

FIG. 15 is a flowchart for explaining the operation of a processing circuit 94 that calculates a flatness F based on outputs from sensors S21 to S25 of a detection means 22 and an encoder EN21.

FIG. 16 is a diagram showing a state in which a peak Pi and a bottom Bj are stored in step b2 stored in the memory 97;

17 is a simplified diagram showing the surface of a steel plate 17 for explaining a method of calculating the flatness F using the brute force peak tangent shown in FIG. 22;

FIG. 18 is a flowchart for explaining the operation of the processing circuit 97 for explaining a method of sequentially obtaining a peak tangent having the maximum slope in calculating the flatness F.

FIG. 19 is a diagram showing a surface shape of a steel plate 17 for explaining a method of sequentially obtaining a peak tangent having a maximum inclination in step c6.

FIG. 20 is a simplified diagram showing the surface shape of a steel plate 17 for explaining a method of removing peaks by calculating the height of a reverse peak in step c4 of FIG. 25.

21 is a flowchart illustrating an operation of a processing circuit 94 for describing a method of removing a peak by calculating a reverse mountain height illustrated in FIG. 27.

FIG. 22 is a simplified diagram showing the surface of a steel plate 17 for explaining a method of excluding a low peak sandwiched between high peaks shown in step c5 of FIG. 25.

FIG. 23 is a flowchart illustrating an operation of a processing circuit 94 that executes a method of excluding a low peak sandwiched between high peaks in step c5 of FIG. 25;

FIG. 24 is a flowchart for explaining the operation of a processing circuit 94 for calculating a peak tangent in step c6 of FIG. 25;

FIG. 25 is a flowchart illustrating an operation of a processing circuit 94 according to another embodiment of the present invention.

FIG. 26 is a diagram showing a shape of a surface of a steel plate 17 according to another embodiment of the present invention.

FIG. 27 is a flowchart for explaining the operation of a processing circuit 94 that executes a waveform extrapolation method.

FIG. 28 is a view showing the shape of the surface of a steel sheet for explaining a technique for calculating flatness F in the prior art.

[Explanation of symbols]

 13 Steel Plate Shape Measuring Device 14 Surface Plate 15 Inlet 16 Outlet 17 Steel Plate 44 Base 58, 77 Sensor Moving Means 72 Motor 66 Mount 67 Detector 68 Elevating Means 69 First Guide Rail 71 Traveling Body 75 Second Guide Rail 81 Moving member 82 third guide rail 83 elevating and displacing means 84 gripping member 85 engaging concave part 86 engaging convex part 91 protective member 92 traveling body driving means 94 processing circuit 95 input means 96 push button 97 memory

Continued on the front page (72) Inventor Yoshikazu Fujito 5th Ishizu Nishicho, Sakai City, Osaka Prefecture Nisshin Steel Co., Ltd. F term (reference) 2F065 AA09 AA22 AA24 AA25 AA47 AA51 BB13 CC06 DD03 DD06 FF16 FF67 MM03 PP02 QQ05 QQ23 UU05 4E024 AA02

Claims (10)

[Claims] 1. A distance to a surface of a metal plate is detected along a longitudinal direction of the metal plate in accordance with a position in the longitudinal direction. The bottom is detected in correspondence with the position in the longitudinal direction, a peak tangent connecting the peaks is obtained by the detected distance and the detected peak / bottom, and the peak height Hi between the peak tangent and the bottom is determined. The maximum peak height H is determined, and the wavelength L of two peaks along the longitudinal direction of the peak tangent line at which the maximum peak height H is obtained is determined, and the flatness F = H /
A shape measuring method for a metal plate, wherein L is calculated. 2. Starting from a certain peak, a peak tangent is obtained for all of a plurality of peaks present on one side in the longitudinal direction, and a peak for obtaining a peak tangent having a maximum slope is obtained from the peak tangents. The method according to claim 1, wherein the obtained peak is used as a new starting point, peak tangents are obtained for all peaks on the one side in the longitudinal direction, and an operation for obtaining a new peak is repeated. Shape measurement method. 3. Each bottom and two adjacent ones along the longitudinal direction.
Bottom tangents connecting the two bottoms are obtained. Inverted mountain heights Hr between the bottom tangents and the peaks are respectively obtained. One peak,
The method for measuring the shape of a metal plate according to claim 1, wherein the method is excluded. 4. When each peak is sandwiched along a longitudinal direction by a peak higher than the peak, excluding a peak sandwiched between the high peaks from a peak from which the peak tangent is to be determined. The method for measuring the shape of a metal plate according to claim 1, wherein: 5. A distance along the longitudinal direction of the metal plate to the surface of the metal plate corresponding to the position in the longitudinal direction is detected. And a peak height between a single peak and one or a plurality of lower bottoms according to the detected distance and the detected peak / bottom. H, and twice the distance along the longitudinal direction between the peak and the lower bottom is defined as the wavelength L.
And means for calculating the flatness F = H / L. 6. A detecting means for detecting a distance to a surface of a metal plate along a longitudinal direction of the metal plate in accordance with a position in the longitudinal direction; Responding to the output of the peak / bottom detecting means for detecting the raised peak and the concave bottom in accordance with the position in the longitudinal direction, and the detecting means and the peak / bottom detecting means;
A peak tangent connecting the peaks is determined, and among the peak heights Hi between the peak tangent and the bottom, the maximum peak height H is determined, and two peaks along the longitudinal direction of the peak tangent at which the maximum peak height H is obtained. And the flatness F =
And a means for calculating H / L. 7. The calculation means obtains a peak tangent from each of a plurality of peaks existing on one side in the longitudinal direction from a certain peak as a starting point, and obtains a peak tangent having a maximum slope among the peak tangents. 7. An operation of obtaining a peak, using the obtained peak as a new starting point, obtaining peak tangents to all peaks on the one side in the longitudinal direction, and repeating the operation of obtaining a new peak. An apparatus for measuring the shape of a metal plate according to claim 1. 8. The calculating means obtains a bottom tangent connecting each bottom and two adjacent bottoms along the longitudinal direction, and obtains an inverted mountain height Hr between the bottom tangent and a peak. From peaks for which peak tangents are to be determined, peaks whose inverted mountain height Hr is less than a predetermined threshold are
The metal plate shape measuring device according to claim 6, wherein the metal plate shape measuring device is excluded. 9. The calculating means, when each peak is sandwiched by a peak higher than the peak along the longitudinal direction, calculates a peak sandwiched between the high peaks from a peak from which the peak tangent is to be determined. The shape measuring apparatus for a metal plate according to any one of claims 6 to 8, wherein the apparatus is excluded. 10. A detecting means for detecting a distance to a surface of a metal plate along a longitudinal direction of the metal plate corresponding to a position in the longitudinal direction; Responding to the output of the peak / bottom detecting means for detecting the raised peak and the concave bottom in accordance with the position in the longitudinal direction, and the detecting means and the peak / bottom detecting means;
The peak height H between the single peak and the lower bottom of the one or more bottoms is determined, and twice the distance along the longitudinal direction between the peak and the lower bottom is calculated as: A means for determining a wavelength L and calculating a flatness F = H / L.