JP3268585B2 - Calibration device for plate width and meandering measurement device using two-dimensional distance meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calibration device for improving the measurement accuracy of a plate width and meandering measuring device comprising a plurality of two-dimensional distance meters arranged in the plate width direction.

[0002]

2. Description of the Related Art A two-dimensional distance meter using a laser or the like as a light projector can obtain a distance distribution of about 500 points per unit within an optically determined visual field. A device for measuring meandering has been proposed (for example, see Japanese Unexamined Patent Publication No.
060405). In a line in which a plate material flows, by arranging a plurality of two-dimensional distance meters in the plate width direction and performing signal processing, it is possible to measure the width and meandering of all the product plate materials.

At this time, individual two-dimensional rangefinders manufactured by a manufacturer are mounted on a line in a manner that only the accuracy of distance measurement is guaranteed. However, when mounting a two-dimensional distance meter on a gantry, it is very difficult to install the two-dimensional distance meter with a tilt of ± 0 degrees in the board width direction. Will do. If each individual two-dimensional rangefinder has some slope, the measured values will include the following errors:

First, an error caused by a difference in resolution per bit in a board width direction of a two-dimensional CCD camera that changes in a height direction in a field of view of a camera of a two-dimensional rangefinder differs from a maker adjustment stage. 2 is an error caused by the difference between the distance measurement value of the two-dimensional distance meter and the path line distance on the equipment. Third, a plate caused by the difference between the measurement center of the two-dimensional distance meter and the measurement center on the equipment. It is a width / meander calculation error.

Further, there is an error peculiar to the two-dimensional distance meter, which is an error between a distance measurement value along the optical path of the projected beam spread in a fan shape and a distance in a vertical downward direction to be actually measured.

The influence of these errors becomes larger as the distance between the two-dimensional distance meter and the plate material to be measured becomes larger, and becomes a value that cannot be ignored in measuring the plate width and meandering.

As a method of removing these errors, for example, a method of re-measuring the resolution in the height direction using a gauge of a known width, a difference between an installation position of a two-dimensional distance meter from a reference path line and a distance measurement value. Method of re-measuring each of the two-dimensional distance meters, checking the distance measurement value of the two-dimensional distance meter using a reference plate or the like placed horizontally on the pass line, and setting a camera for each of the two-dimensional distance meters. For measuring the inclination of the central axis of the object.

[0008]

However, in these methods, since it is necessary to enter the line in which the two-dimensional distance meter is installed and perform the operation, if the measurement operation is performed by an individual device, It takes a long time to start up as a board width and meandering meter, and it takes a long time to adjust the measurement accuracy in the recovery work after repairing the two-dimensional distance meter due to failure etc. There was a point.

The present invention has been made in order to solve the above-mentioned conventional problems, and the four errors generated at the time of installation can be quickly eliminated regardless of how many two-dimensional distance meters are installed in the board width direction. An object of the present invention is to provide a calibrating device of a plate width / meandering measuring device using a two-dimensional distance meter for measuring and correcting with a calculating device.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a calibration apparatus for a sheet width and meandering measuring apparatus in which a plurality of two-dimensional distance meters are arranged in a line in the sheet width direction on a line through which the sheet material passes. A calibration plate consisting of a flat surface that covers the field of view of all two-dimensional rangefinders installed on one side of the line center, and at least two types of widths that fall within the field of view of each two-dimensional rangefinder. Height, and a mechanism that can slide the calibration plates having at least two kinds of heights in the plate width direction, so that the inclination in the plate width direction when each two-dimensional distance meter is installed is provided. Measurement error of the board width and meandering amount caused by the measurement, path line measurement error caused by the distance measurement value of the two-dimensional distance meter and installation error on the equipment, and the fan-shaped spread of the two-dimensional distance meter Distance measurement along the beam path And the error between the distance in the direction desired to be measured by the two-dimensional rangefinder and the resolution per bit of the two-dimensional image scanning type camera in the board width direction that changes in the height direction in the field of view of the camera of the two-dimensional rangefinder. Error caused by
The above object has been achieved by correcting all the data so that the width and meandering amount can be measured correctly.

[0011]

According to the present invention, a flat surface covering the field of view of all two-dimensional rangefinders when calibrating a plate width and meandering measuring device constituted by arranging a plurality of two-dimensional rangefinders in the width direction of the plate. Two-dimensional distance meter using a calibration device that combines a calibration plate composed of: and a device that has a mechanism that can enter the field of view of each two-dimensional distance meter and change the position of the calibration plate in the plate width direction. Of the resolution in the width direction of the two-dimensional image scanning camera, which changes in the height direction in the field of view of the camera, and the distance measurement value along the optical path of the projected beam spread in a fan shape and the height to be actually measured Error caused by the difference between the measurement center of the two-dimensional distance meter and the measurement center on the equipment, and the difference between the distance measurement value of the two-dimensional distance meter and the path line distance on the equipment. All errors that occur can now be corrected Because, it becomes possible to measure accurately the plate width and meandering.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view schematically showing a calibration apparatus to which the present invention is applied, and FIG. 2 is a side view thereof. In FIG. 1, reference numeral 10 denotes a frame for supporting a calibration jig, 12 denotes a jig having a horizontal adjustment mechanism for mounting the equipment and the present calibration apparatus, and 14, 16, and 18 denote calibration plates.

The calibration plate 14 covers the field of view of all two-dimensional rangefinders (one side) attached in the width direction, has a flat measurement surface, and has at least two types of calibration plates 16 and 18 for measuring. The width of the surface is such that it falls within the field of view of the individual two-dimensional rangefinder. Reference numeral 20 denotes a projection having a mechanism for attaching the calibration plates 16 and 18 to the frame 10 and sliding in the width direction of the plate.

The horizontal level of the calibration device is adjusted by a level 22 and a mounting jig 12 having a horizontal adjustment mechanism. or,
Numeral 24 denotes a projection beam spread in a fan shape.

Using the present calibration apparatus, error measurement and correction are performed as follows.

First, for the measurement of the resolution in the plate width direction of a two-dimensional CCD camera that changes in the height direction within the field of view of the camera of the two-dimensional rangefinder, a calibration device is used for the plate width and meandering measurement device. 3. Set as shown in FIG. Here, FIG. 3 is a front view, and FIG. 4 is a side view.

As shown in FIG. 3, the calibration plate 16 is
0 The slide in the sheet width direction, when set to fall within the field of view of the individual two-dimensional distance meter 26-1 and 26-2, the width measured value W _a of the two calibration plates, W _b, the reference distance measurements up calibration plate from the height position (average value) l _a, l _b,
The number of bits N _a and N _b detected corresponding to the calibration plate can be measured from the image of the two-dimensional CCD camera.

Next, changing to the calibration plates 18 having different heights,
Slide at substantially the same position, in the same manner, the width measured value W _a calibration plate ', W _b', the distance measurements up calibration plate (average _{value) l a ', l b'} , corresponding to the calibration plate The number of detected bits _Na 'and _Nb ' can be measured.

These are input to an arithmetic unit, and the following parameters are obtained by the following equation.

[0021] l width resolution at _a point _{δ a = W a / N a} ... (1) l width resolution at point _{b δ b = W b / N b} ... (2) width resolution at l _a 'point [delta] _a ′ = W _a ′ / N _a ′ (3) Width resolution at l _b ′ point δ _b ′ = W _b ′ / N _b ′ (4) Height resolution of width resolution of each two-dimensional rangefinder change rate _{K a = (δ a -δ a} ') / (l a - l a') ... (5) K b = (δ b -δ b ') / (l b - l b') ... (6) each constant term of the width resolution of the two-dimensional distance meter _{B a = δ a -K a ·} l a '... (7) B b = δ b -K b · l b' ... (8)

As a result, the width resolution at an arbitrary height position l from the reference position is K _a ＋ l + B _a , K
represented by _b · l + _{B b.} At this time, the bit number of the CCD camera corresponding to the plate edge position S, the bit number corresponding to the CCD camera center axis and S _c, edge position ΔX from the CCD camera center axis can be determined by the following equation.

ΔX = (K _a · l + B _a ) · (S−S _c ) (9)

Next, with respect to the measurement of the error between the distance measurement value along the optical path of the projected beam spread in a fan shape and the distance in the vertical direction to be actually measured, the calibrating device is compared with the plate width / meandering measuring device. Is set as shown in FIGS. Here, FIG. 5 is a front view, and FIG. 6 is a side view. As shown in FIG. 5, the calibration plate 14-1 is set so as to be horizontal to the plate width direction together with the gantry.

As shown in FIG. 5, for example, in a two-dimensional distance meter 26-1 arranged at _a distance of Ea from the line center, as shown in FIG. _c , the distance measurements at both ends of the field of view are L ₁ ,
L _n, when L ₁ and shorter of L _n the field width (in the example of FIG. 7 L ₁₎ is determined by W _a, 2-dimensional distance meter 26-1 mechanical installation height of the H _a, by measuring the calibration plate 14-1 determines L ₁ and shorter of L _n (L _1), divergence angle alpha _a more field width W _a of the light projecting light source that is obtained in advance is calculated by the following formula .

W _a = 2 ｛min (L ₁ , L _n )｝ sin α _a (10)

Next, the [Delta] L in FIG. 7 by using the distance measurement value Lc in the central axis design of two-dimensional CCD camera, the following formula _{ΔL = L c - {min (} L 1, L n)} cosα a ... (11), the slope β of the two-dimensional rangefinder 26-1 is
Since the following equation cosβ = (W _a / 2) / {(W _a / 2) ² + ΔL ² } , the distance y _c of the two-dimensional rangefinder 26-1 in the vertically downward direction is given by the following equation. Can be expressed.

Y _c = [(W _a / 2) / {(W _a / 2) ² + ΔL ² }] · L _c (12)

[0029] Te smell in the calibration process, cosβ = (W _a /
By keeping seeking _{2) / √ {(W a} / 2) 2 + ΔL 2}, for the distance measurement L _i, as shown in FIG. 7 several
From what biological positional relationship, a total of the distance y _i after the inclination correction by:
Can be calculated .

Y _i = [(W _a / 2) / {(W _a / 2) ² + ΔL ² }] · L _i −ΔH _i (i = 1 to n) (13) where shown in FIG. As shown, the center of the rangefinder tilts to the right
_{Stomach, min (L 1, L n} ) = In the case of L ₁

(Equation 1) In contrast to FIG. 7, the center of the rangefinder is tilted to the left,
(L _1, L _n) In the case of = L _n

(Equation 2)

Next, regarding the measurement of the plate width and meandering measurement error caused by the difference between the measurement center of the two-dimensional distance meter and the measurement center on the equipment, a calibration device is used for the plate width and meander measurement device in FIG. , As shown in FIG. Here, FIG. 8 is a front view, and FIG. 9 is a side view. At this time, as shown in FIG. 8, each of the two-dimensional distance meter 26-1 and 26-2 of the mechanical mounting position E _a, and E _b, so as to match the right or left edge position of the calibration plate 16 State.

Also, for example, from the line center to E_aIn the distance
The two-dimensional distance meter 26-1 installed is shown in FIG.
The camera-designated bit number
S _cCorresponding to the center axis of the two-dimensional distance meter of the calibration plate 16
The CCD camera bit number at the cartridge position to S_a, Two-dimensional distance
L is the distance corresponding to the edge position measured by the_a,distance
Set the measurement reference position to H₀Then, the edge position of the calibration plate
Distance from CCD camera center ΔW_asIs given by
You.

ΔW _as = (K _a · L _a + B _a ) · (S _a −S _c ) (14) Accordingly, the inclination θ _a of the two-dimensional distance meter in the plate width direction can be obtained by the following equation. ^{_{can, θ a = tan -1 {ΔW}} as / (H 0 + l a)} ... (15) the following equation [Delta] W for any distance l from the reference position _{a = {ΔW as / (H} 0 + l a _{)} · l + (ΔW as} - l by _{a · tan θ a) ... (} 16), that the amount of deviation between the measured center of the two-dimensional CCD camera center axis and a two-dimensional distance meter equipment measured, corrected Can be. In equation (16), l _a and S _a are measured,
If H ₀ and S _c are input in advance, the arithmetic unit can automatically determine ΔW _a .

[0034] Incidentally, in exactly the same for the outside of the two-dimensional distance meter, the following correction formula _{ΔW b = {ΔW bs / (} H 0 + l b)} · l + (ΔW bs - l b · tan θ b ) (17) is obtained.

Next, in order to correct the error caused by the difference between the distance measurement value of the two-dimensional distance meter and the path line distance on the equipment, a calibration device is used for the plate width and meandering measurement device, as shown in FIGS. Set as follows. 11 is a front view and FIG. 12 is a side view.
FIG. 9 is a diagram showing that the distance is measured by superimposing the next calibration plate 14-2 after measuring the distance to −1.

For example, the calibration plates 14-1 to 14-
Distance measurement corresponding to the central axis of the 2D rangefinder for n
Value L_c-1, L_c-2, ... L_cnTo the calibration plate surface
(Calibration value) H on the equipment_-1, H_-2, ..., H_-nOr
(H_-1, L_c-1), (H _-2, L_c-2), ...,
(H_-n, L_cn), The process of performing polynomial approximation
If introduced into each two-dimensional rangefinder, it can be placed on the same path line
It is possible to match the distance measurement values of each two-dimensional rangefinder
become.

By using the equations described above,
The board width can be calculated accurately. That is, the height of the plate edge position is 1, the bit number corresponding to the plate edge position is S, and the polynomial obtained by the process of performing the polynomial approximation is
Assuming f (L), the following equation: ΔXa = (Ka · l + Ba) · (S−Sc) + ΔWa + Ea (18) l = f (L) −H0 (19) L = [(Wa / 2) / √ ｛ (Wa / 2) 2 + ΔL2｝] · Li− ΔHi (20), the edge position on one side can be accurately obtained.

Similarly, the edge position ΔX _b on the opposite side to the line center is determined, the plate width is determined by ΔX _a + ΔX _b , and the meandering amount can be calculated by (ΔX _a −ΔX _b ) / 2.

FIG. 13 shows that the present calibrator is used to calibrate a width meter composed of a two-dimensional distance meter, then the width is measured, and the measurement result is compared with the width meter installed on the downstream side. The result of the comparison is shown. As shown in FIG. 13, it was confirmed that by applying the present invention, it was possible to measure the board width with high accuracy.

[0040]

As described above, according to the present invention, 2
A single calibration device can be used to measure four errors generated due to the in-line installation of a plate width and meandering measuring device in which a plurality of three-dimensional distance meters are arranged in the plate width direction, and the necessary information is provided to the plate width and meandering calculation device. Since errors can be automatically corrected simply by inputting, maintenance work and start-up work such as periodic accuracy inspection and accuracy adjustment after repairing the two-dimensional distance meter can be performed in a short time.

Further, since the calibration device calculates the necessary parameters in the arithmetic unit and has a simple structure of the calibration device, accuracy control during maintenance work of the equipment can be easily performed. It has the effect of.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a calibration apparatus to which the present invention is applied.

FIG. 2 is a side view of the same.

FIG. 3 is a front view showing a setting method of a calibration device when calibrating a resolution in a plate width direction that changes in a height direction of the two-dimensional rangefinder.

FIG. 4 is a side view of the same.

FIG. 5 is a front view showing a method of setting a calibration device when calibrating a distance measurement value along an optical path of a projection beam spread in a fan shape to a vertically downward distance.

FIG. 6 is a side view of the same.

Figure 7 is a front view showing the details of the calibration method of the two-dimensional distance meter from the line center at the position of E _a

FIG. 8 is a front view showing a method of setting a calibration device for calibrating an error between a measurement center of a two-dimensional distance meter and a measurement center on equipment.

FIG. 9 is a side view of the same.

Figure 10 is a front view showing the details of the calibration method of the two-dimensional distance meter from the line center at the position of E _a

FIG. 11 is a front view showing a method of setting a calibration device for calibrating an error between a distance measurement value of a two-dimensional distance meter and a path line distance on equipment.

FIG. 12 is a side view of the same.

FIG. 13 is a diagram showing a measurement result of a width meter using a two-dimensional distance meter calibrated using the present calibration device.

[Explanation of symbols]

Reference Signs List 10: Frame for supporting calibration jig 12: Calibration device mounting jig 14 (14-1 to 4): Calibration plate with flat measuring surface 16, 18, Calibration plate with width that fits into the field of view of one two-dimensional rangefinder Reference numeral 20: a protrusion having a slide mechanism 22: a level 24: a fan-shaped light emitting beam 26 (26-1, 2): a two-dimensional distance meter

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Ito 32, Akashi-cho, Chuo-ku, Kobe City, Hyogo Prefecture Inside of Mamba Industry Co., Ltd. (56) References JP-A-4-270909 (JP, A) JP-A-6- 117823 (JP, A) Special table 61-501339 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11/24 G01B 11/02 G01B 21/06

Claims (1)

(57) [Claims] 1. A calibrating device for a sheet width and meandering measuring device in which a plurality of two-dimensional distance meters are arranged in a line in a plate width direction on a line through which a plate material is passed, wherein the calibrating device is installed at least on one side of a line center. A calibration plate consisting of a flat surface that covers the field of view of all existing 2D rangefinders, and a calibration plate with at least two heights that are within the field of view of each 2D rangefinder. By providing a mechanism capable of sliding the calibration plate having at least two kinds of heights in the plate width direction, the plate width and meandering amount generated by the inclination in the plate width direction when each two-dimensional distance meter is installed. Measurement error, and path line measurement error caused by the distance measurement value of the two-dimensional distance meter and the installation error on the equipment, and the distance measurement along the optical path of the projected beam spread in a fan shape of the two-dimensional distance meter Value and two-dimensional distance meter The error with the desired distance in the height direction and the error caused by the resolution per bit of the two-dimensional image scanning camera in the board width direction that changes in the height direction in the field of view of the camera of the two-dimensional rangefinder are all It is characterized by making correction so that the width and meandering amount can be measured correctly.
Calibration device for plate width and meandering measurement device using two-dimensional distance meter.