KR20110076659A - Correction method and device for measuring roughness - Google Patents

Abstract

PURPOSE: A method and an apparatus for correcting a surface roughness measurement value are provided to correct a measurement value obtained by a surface roughness measurement instrument rapidly and easily regardless of a measurement environment variation. CONSTITUTION: A surface roughness measurement value correcting method includes a step in which a laser generator(32) irradiates laser to one of N standard samples having different surface roughness values, a step in which a laser detector(38) detects a laser beam reflected from the standard sample, a step in which an operating unit receives a signal output from the laser detector to calculate the surface roughness of the standard sample, a step of obtaining a correction factor a and a correction factor b, and a step of correcting a surface roughness measurement value of a steel plate using the correction factor a and correction factor b.

Description

Surface roughness measurement value correction method and apparatus {CORRECTION METHOD AND DEVICE FOR MEASURING ROUGHNESS}

The present invention relates to a method and apparatus for correcting surface roughness measurement, specifically, to calculate a correction coefficient by measuring surface roughness of a standard specimen and to improve the reliability of the surface roughness measurement by correcting the surface roughness measurement using the same. The present invention relates to a method and apparatus for correcting surface roughness measurement values.

In general, the surface roughness of the steel sheet is an important factor that determines the processing characteristics of the steel sheet, such as formability and paintability. There is a need.

To this end, conventionally, the needle was moved in a straight line in contact with the surface of the steel sheet to show the uneven state of the steel sheet cross section, and the average height of the unevenness was calculated to measure the surface roughness of the steel sheet. However, the measurement technique using the stylus can not only take excessive measurement time but also scratches on the surface of the steel sheet by the stylus, which can cause defects. Therefore, only a sample of a portion of the steel sheet can be measured. Therefore, since the surface roughness cannot be measured in real time during the production of steel sheet, a non-contact surface roughness measuring method using a laser has recently been used to solve this problem.

A laser generator and a laser detector are installed inside the non-contact surface roughness measuring device using a laser, and the intensity distribution of the reflected laser light reflected by the steel sheet after the laser is irradiated from the laser generator to the steel sheet is measured by a laser detector. By this, the surface roughness of the steel sheet is calculated.

However, when the surface roughness measuring device is installed and operated in the field, the type of steel sheet to be measured is changed, or the parts of the surface roughness measuring device such as a laser detector are replaced, or the measuring point of the surface roughness measuring device is moved. When a change in the roughness measurement environment occurs, the relationship between the intensity distribution of the laser reflected light measured by the laser detector and the roughness of the steel sheet surface may change.

Therefore, in order to trust the surface roughness value of the steel sheet measured by the surface roughness measuring device, even if the measurement environment changes, the measured value can be calibrated to the true value in a quick and easy way with the surface roughness measuring device installed in the field. I need a way.

The present invention is to solve the above-mentioned problems of the prior art, a surface that can easily and quickly correct the measurement value by the surface roughness measuring device in the state in which the surface roughness measuring device is installed in the field regardless of the change of the measurement environment It is an object of the present invention to provide a method and apparatus for correcting roughness measurements.

The surface roughness measurement value correction method according to the present invention for solving the above problems comprises the steps of irradiating the laser to any one of N standard specimens having a different surface roughness value laser generation unit; Detecting a laser reflected light reflected from the standard specimen by a laser detector; And calculating a surface roughness of the standard specimen by receiving a signal output from the laser detector, and repeating the above steps with respect to the remaining standard specimens of the N standard specimens. After each surface roughness is measured, calculating correction coefficient a and correction coefficient b values using Equations 1 and 2 below; And correcting the surface roughness measurement value of the steel sheet by substituting the correction coefficient a and the correction coefficient b into Equation 3 below.

&Quot; (1) "

<Equation 2>

&Quot; (3) &quot;

R '= a + bR

Where N is the number of standard specimens whose surface roughness is measured,

a, b: correction factor,

R _a : Measured surface roughness of the standard specimen measured by the surface roughness measuring instrument,

R _s : true value of surface roughness of standard specimen,

R: Measured surface roughness before steel plate correction,

R ': Measured surface roughness after steel plate correction)

In addition, the surface roughness measurement value correction apparatus according to the present invention is mounted to the surface roughness measuring device including a laser generating unit for irradiating the laser to the steel sheet and the laser detection unit for detecting the laser reflected light reflected from the steel sheet, the different surface roughness N standard specimens having a value, the laser being irradiated by the laser generator in turn to detect the laser reflected light by the laser detector; And calculating a surface roughness of each of the N standard specimens by receiving a signal output from the laser detector, and calculating a correction coefficient a and a correction coefficient b using Equations 1 and 2, and calculating the correction coefficients. and a calculating unit for correcting the surface roughness of the steel sheet by substituting a and the correction coefficient b values and the surface roughness measurement value of the steel sheet measured by the surface roughness measuring apparatus in Equation 3 above.

Further, the N standard specimens are radially fixed to a rotary specimen holder driven by a motor, and are positioned at an irradiation point of a laser generated from the laser generation unit by the driving of the motor.

According to the method and apparatus for correcting the surface roughness measured value according to the present invention, even if the measurement environment changes, the measured value by the surface roughness measuring device can be quickly and easily without changing or moving the measuring device with the surface roughness measuring device installed in the field. Since it can correct the reliability of the measuring device is improved.

In addition, according to the method and apparatus for correcting the surface roughness measurement value according to the present invention, since the surface roughness measuring device is easily attached to and detached from the existing surface roughness measuring device, the configuration is simple and portable. have.

Hereinafter, with reference to the accompanying drawings will be described in detail preferred embodiments of the method and apparatus for measuring the surface roughness measured value according to the present invention. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a schematic configuration diagram showing the configuration of the surface roughness measurement value correction apparatus according to an embodiment of the present invention, Figure 2 is an operating state diagram showing an optical system of the surface roughness measurement apparatus according to an embodiment of the present invention. .

First, referring to FIG. 1, the configuration of the surface roughness measurement value correction device 10 according to an embodiment of the present invention is mounted on one side of the frame 20 and the frame 20, and the standard specimen 40 is arranged. It may be composed of a specimen holder 60 is mounted, and a motor 50 for rotating the specimen holder 60. The connector 22 is provided at one side of the frame 20 so as to be connected to an operation unit (not shown). The connector 22 may exchange signals with the operation unit, and the surface roughness measurement value correction device 10 may be configured to control operation by the operation unit. The calculation unit may include software for calculating a correction coefficient using the surface roughness measurement value of the standard specimen 40 which will be described later.

Surface roughness measurement value correction device 10 according to an embodiment of the present invention may be configured to be coupled to the top of the surface roughness measurement apparatus main body 70, the fastening means (circumference of the frame 20 for a stable coupling) 24) may be provided.

The specimen holder 60 is configured such that the rotating shaft is connected to the motor 50 to be rotated by the operation of the motor 50, and the motor 50 may be controlled by the signal of the calculator. Specimen holder 60 is formed in a circular shape, two or more standard specimens 40 are fixed radially arranged on the circumference of the specimen holder (60).

Two or more standard specimens 40 attached to and fixed to the specimen holder 60 are installed. In this case, each standard specimen 40 has a different surface roughness value. The standard specimen 40 is a specimen prepared in advance to have a constant surface roughness value as a medium for eliminating the difference between the surface roughness measurement value and the true value by the surface roughness measuring device.

Surface roughness measurement value correction device 10 according to an embodiment of the present invention is configured to be fixed to the top of the surface roughness measurement apparatus main body 70, as shown in Figure 2 is an optical system that is the core of the surface roughness measurement apparatus 30 includes a laser generating portion 32 for irradiating the laser 34 to the steel sheet, a reflecting plate 36 for refracting the laser 34 at a predetermined angle to the steel sheet side, and the laser reflected light 35 reflected from the steel sheet. ) Is composed of a laser detection unit 38 for detecting. A surface roughness measuring device main body 70 is connected to a calculation unit (not shown) to receive the intensity distribution value of the laser reflected light 35 measured by the laser detector 38 to determine the surface roughness value of the steel sheet using a series of algorithms. Calculate Since a more detailed technical configuration of the non-contact surface roughness measuring method of the steel sheet using such a laser is known in various ways, a separate description thereof will be omitted.

Surface roughness measurement value correction device 10 according to an embodiment of the present invention, the surface roughness measurement to correct the surface roughness measurement value of the surface roughness measurement value is suspected of the reliability of the surface roughness measurement value of the steel sheet It may be configured to be mounted and operated on top of the device body 70.

When the surface roughness measurement value correction device 10 is mounted on the surface roughness measuring device main body 70, the standard specimen 40 is positioned at the irradiation point of the laser 34 generated by the laser generator 32 instead of the steel sheet. do. The operation of the motor is controlled by the operation unit so that each of the standard specimens 40 are sequentially positioned at the irradiation point of the laser 34 while the specimen holder 60 is rotated. The intensity distribution of the laser reflected light 35 reflected by 40 is detected by the laser detector 38, and the value is transmitted to the calculator.

The calculation unit includes software for calibrating the measured value of the surface roughness measuring device, which is composed of Equations 1 and 2.

&Quot; (1) &quot;

<Equation 2>

Where N is the number of standard specimens whose surface roughness is measured, a and b are the correction coefficients, R _a is the surface roughness measurement value of the standard specimen measured by the surface roughness measuring instrument, and R _s is the true value of the surface roughness of the standard specimen.

By inputting the measured value and the true value of each of the standard specimens 40 in Equation 1 and Equation 2, simultaneous equations for the correction coefficient a and the correction coefficient b can be obtained. If this is calculated by the calculation unit, the correction coefficient a and the correction coefficient b are obtained. This correction coefficient is stored in the calculation unit to correct the measured value by the equation (3) when measuring the surface roughness of the steel sheet.

&Quot; (3) &quot;

R '= a + bR

Here, R is the surface roughness measured value before correction of a steel plate, and R 'is the surface roughness measured value after correction of a steel plate.

Hereinafter, the operation of the surface roughness measurement value correction apparatus according to an embodiment of the present invention with reference to the above-described components.

When a change occurs in the measurement environment of the surface roughness measuring device while measuring the surface roughness of the steel sheet using the surface roughness measuring device, the surface roughness measuring device main body 70 is seated and coupled to the surface roughness measuring device. Then, when any one of the N standard specimens 40 having different surface roughness values is located at the irradiation point of the laser 34 generated from the laser generator 32, the laser generator 32 is the corresponding standard specimen 40. ) Irradiates the laser 34 to (S1), the laser detector 38 detects the laser reflected light 35 reflected from the standard specimen 40 (S2), and the calculation unit is output from the laser detector 38 Receiving the signal to calculate the surface roughness of the standard specimen 40 (S3). When the surface roughness calculation of the standard specimen 40 is completed, the motor is operated under the control of the calculation unit so that the other standard specimen 40 is positioned at the irradiation point of the laser 34 as the specimen holder 60 rotates. do. The surface roughness is again calculated for the specimen, and then the same operation is performed for all the standard specimens 40.

When the surface roughness is calculated for all the standard specimens 40 provided in the specimen holder 60, the values of the correction coefficient a and the correction coefficient b are obtained by substituting the values into Equations 1 and 2 (S4). After the surface roughness measurement value correction device 10 is separated from the surface roughness measurement device main body 70, the surface roughness of the steel sheet is measured by using the surface roughness measuring device, and the surface roughness measurement value and the correction coefficient a and Substituting the b value into the equation (3) to obtain a corrected surface roughness measurement of the steel sheet (S5).

Referring to the embodiment for correcting the surface roughness measured value of the steel sheet according to the present invention. In the present embodiment, correction coefficients a and b are calculated using 12 standard specimens 40 having different surface roughnesses at intervals of 0.05 μm from 0.9 to 1.45 μm. The surface roughness true value and the measured value of the standard specimen 40 according to the present embodiment are as follows.

R _s (μm) R _a (μm) R _a ^ 2 R _a * R _s Standard Specimen 1 0.90 0.91 0.8281 0.819 Standard Specimen 2 0.95 0.94 0.8836 0.893 Standard Specimen 3 1.00 1.00 One One Standard Specimen 4 1.05 1.03 1.0609 1.0815 Standard Specimen 5 1.10 1.08 1.1664 1.188 Standard Specimen 6 1.15 1.15 1.3225 1.3225 Standard Specimen 7 1.20 1.21 1.4641 1.452 Standard Specimen 8 1.25 1.23 1.5129 1.5375 Standard Specimen 9 1.30 1.33 1.7689 1.729 Standard Specimen 10 1.35 1.35 1.8225 1.8225 Standard Specimen 11 1.40 1.41 1.9881 1.974 Standard Specimen 12 1.45 1.44 2.0736 2.088 Sum 14.10 14.08 16.8916 16.907

Substituting this result into equations (1) and (2) yields the following equations (4) and (5).

<Equation 4>

12a + 14.08b = 14.1

<Equation 5>

14.08a + 16.8916b = 16.907

By combining Equations 4 and 5, a correction coefficient a of 0.027174 and a correction coefficient b of 0.978261 are obtained.

Therefore, the correction value of the steel sheet calculated by the surface roughness measuring device is corrected by substituting this correction coefficient value into the equation (3). If the surface roughness measurement value of the steel sheet measured by the surface roughness measuring device is 1.5 µm, the corrected surface roughness measurement value is about 1.495 µm.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a schematic block diagram showing the configuration of a surface roughness measurement value correction apparatus according to an embodiment of the present invention.

2 is an operating state diagram showing an optical system of the surface roughness measuring apparatus according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: surface roughness measurement value correction device 20: frame

30: optical system 32: laser generating unit

34: laser 35: laser reflected light

38: laser detector 40: standard specimen

50: motor 60: specimen holder

70: surface roughness measuring device body

Claims (3)

Irradiating a laser to any one of N standard specimens having different surface roughness values from the laser generation unit (S1); Detecting a laser reflected light reflected by the laser detector from the standard specimen (S2); And And a calculation unit calculating a surface roughness of the standard specimen by receiving a signal output from the laser detection unit (S3). After measuring the surface roughness of each of the N standard specimens by repeating the steps (S1 ~ S3) for the remaining standard specimens of the N standard specimens, Obtaining a correction coefficient a and a correction coefficient b value by using Equations 1 and 2 below (S4); And And correcting the surface roughness measured value of the steel sheet by substituting the correction coefficient a and the correction coefficient b value into the following Equation 3 (S5). &Quot; (1) &quot;

<Equation 2>

&Quot; (3) &quot; R '= a + bR Where N is the number of standard specimens whose surface roughness is measured, a, b: correction factor, R _a : Measured surface roughness of the standard specimen measured by the surface roughness measuring instrument, R _s : true value of surface roughness of standard specimen, R: Measured surface roughness before steel plate correction, R ': Measured surface roughness after steel plate correction) It is mounted to the surface roughness measuring device including a laser generating unit 32 for irradiating the laser 34 to the steel sheet and a laser detection unit 38 for detecting the laser reflected light 35 reflected from the steel sheet, N standard specimens 40 having different surface roughness values and sequentially irradiated with the laser by the laser generator 32 to detect the laser reflected light 35 by the laser detector 38; And The surface roughness of each of the N standard specimens 40 is calculated by receiving the signal output from the laser detector 38, and the values of the correction coefficient a and the correction coefficient b are calculated using Equations 1 and 2 below. Calculating and correcting the surface roughness of the steel sheet by substituting the correction coefficient a, the correction coefficient b value, and the surface roughness measurement value of the steel sheet measured by the surface roughness measuring apparatus into Equation 3 below; Surface roughness measurement value correction apparatus comprising a. &Quot; (1) &quot;

<Equation 2>

&Quot; (3) &quot; R '= a + bR Where N is the number of standard specimens whose surface roughness is measured, a, b: correction factor, R _a : Measured surface roughness of the standard specimen measured by the surface roughness measuring instrument, R _s : true value of surface roughness of standard specimen, R: Measured surface roughness before steel plate correction, R ': Measured surface roughness after steel plate correction) The method of claim 2, The N standard specimens 40 are radially fixed to the rotary specimen holder 60 driven by the motor 50, and are sequentially generated from the laser generation unit 32 by the driving of the motor 50. Surface roughness measurement value correction device, characterized in that located at the irradiation point of (34).

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