JPH09318448A - Judgment apparatus for irregular color of metallic finish and evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a judgment apparatus by which the degree of an irregular color on the surface of a coating can be judged by a method wherein the difference between a luminance at a definite value or higher and a luminance at the definite value or lower and a movement distance up to the luminance at the definite value or lower from the luminance at the definite value or higher are found on the basis of the mean value of measured lumiances. SOLUTION: A projector 2 and a photodetector 3 are built in an optical probe 1, and the probe 1 is connected to an arm 5 at a robot so as to be freely movable. The output to the probe 1 is output to a computer 10, provided with a display 11 and with a printer 12, via an A/D converter 8 and a signal line 9. An upper-limit level and a lower-limit level are set at a constant width from the mean of the intensity of reflected light. When the intensity exceeds their range, the intensity of the reflected light and its position in the point of a peak level in its section are stored in the computer 10. On the basis of the difference ΔV between the upper peak level and the lower peak level and on the basis of the movement distance L between them, ΔV/L is found so as to be used as the evaluation value of an irregular color, and the degree of the irregular color on the surface of a coating is judged on the basis of the value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for quantitatively evaluating and evaluating the degree of color unevenness of metallic coating.

[0002]

2. Description of the Related Art As a conventional coating unevenness determination method for metallic coating, for example, the brightness of the coating surface is continuously determined by irradiating the coating surface with light and receiving the amount of reflected light received from an angle at which regular reflection light does not enter. Japanese Unexamined Patent Publication No. 5-288690 discloses a method in which measurement and FFT processing are performed at a spatial frequency and the degree of unevenness is determined from the magnitude of the amplitude level.

[0003]

However, in the case of the above-mentioned conventional coating unevenness determination method, when the amplitude is large at one place at the same frequency, the FFT processing averages out and the actual visual evaluation value of unevenness is obtained. However, there was a problem that it was not possible to know where and how much unevenness was present on the painted surface.

It is an object of the present invention to provide a color unevenness judging apparatus and evaluation method for metallic coating, in which the degree of coating unevenness of a metallic coating film is matched with human visual evaluation and quantified.

[0005]

In order to solve the above problems, a color unevenness determination apparatus and evaluation method for metallic coating according to the present invention illuminates a coating film surface with light and receives light from an angle at which regular reflection light does not enter. In a color unevenness determination device and evaluation method of metallic coating that continuously measures the brightness of the reflected light,
Determining the degree of color unevenness on the coating surface by calculating the difference between the average value of the measured brightness and the brightness below a certain value, and the distance from the brightness above a certain value to the brightness below a certain value. .

In addition, in a metallic paint color unevenness judging apparatus and an evaluation method for irradiating light on a coating film surface and continuously measuring the brightness of reflected light received from an angle at which regular reflection light does not enter, The degree of color unevenness on the coating surface is determined by calculating the slope of the regression line between the average value and the brightness below a certain value and the slope of the regression line and the distance from the brightness above the certain value to the brightness below the certain value.

Further, in a metallic coating color unevenness judging apparatus and an evaluation method for continuously illuminating the coating film surface with light and continuously measuring the brightness of reflected light received from an angle at which regular reflection light does not enter, continuous measurement is performed. After passing the specified luminance waveform through a filter that cuts in a specific wavelength range, the luminance distance between the average point of the luminance waveform that exceeds a certain value and the inflection point of the luminance waveform that falls below a certain value, or the regression line The degree of color unevenness on the coated surface is determined based on the inclination of and the brightness difference at each inflection point.

Further, the type of color unevenness is displayed based on the average value of luminance and the periodicity of the luminance waveform.

Further, the luminance waveform and the degree of unevenness are superimposed and displayed on the picture on the display imitating the shape or silhouette of the painted object, and the picture can be printed out if necessary.

[0010]

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

(First Embodiment) FIGS. 1 and 2 show the configuration of the first embodiment.

As shown in FIGS. 1 and 2, the optical probe 1 has a light projector 2 and a light receiver 3 built therein. The optical probe 1 is connected to the arm 5 of the robot 6 and can move freely. The intensity of the light received by the optical probe 1 is digitized by the A / D converter 8 and input to the computer 10 via the signal line 9. A display 11 and a printer 12 are connected to the computer 10.

Reference numeral 4 denotes a vehicle body, which is mounted on a carriage 7 to move and stops at a predetermined position. Then, the arm 5 of the robot 6 moves the optical probe 1 while keeping the same distance from the vehicle body 4, and measures the reflected light intensity of the coating film surface. Optical probe 1
The moving distance is input to the computer 10 from the controller of the robot 6 (not shown).

Next, the operation of this embodiment will be described. FIG.
Is a diagram showing a part of the reflected light intensity at each moving position of the optical probe 1, where the horizontal axis is the moving distance and the vertical axis is the reflected light intensity.

As shown in FIG. 3, 20 is the average of the reflected light intensity, and the upper limit level 21 of the reflected light intensity and the lower limit level 22 of the reflected light intensity are set with a certain width from the average, and the upper limit,
If the lower limit is exceeded, the computer 10 stores the reflected light intensity and position at the peak level in that section.

In FIG. 3, points B and C are stored, ΔV × 1 / L is calculated from the distance L between them and the absolute value ΔV of the reflected light intensity between BC, and this value is taken as the evaluation value of unevenness. .

At point A, the upper limit of the reflected light intensity is exceeded, but since point B exceeds the upper limit again, the degree of unevenness is judged to be below the reference value, and the reflected light intensity at point A is used. The calculation is not performed.

(Second Embodiment) FIG. 4 shows a second embodiment.

In this embodiment, a peak point B exceeding the upper limit of the reflected light intensity and a peak point C exceeding the lower limit of the reflected light intensity.
Between the angle θ of the regression line of the reflected light intensity between and the absolute value ΔV of the reflected light intensity, θ × ΔV is calculated, and this value is used as the evaluation value of unevenness.

(Third Embodiment) FIG. 5 shows a third embodiment.

In this embodiment, first, a low-pass filter is applied to the waveform of the reflected light intensity with respect to the moving distance,
Performs smoothing processing. Next, the absolute value ΔV between the inflection points of the reflected light intensity and the distance ΔV × 1 / the inflection point are calculated from the distance between the inflection points, and this value is set as the evaluation value of the unevenness.

Table 1 shows the evaluation values of unevenness in FIG.

[0023]

[Table 1]

(Fourth Embodiment) FIG. 6 shows a fourth embodiment.

FIG. 6 shows the screen of the display 11, in which the reflected light intensity with respect to the moving distance is superimposed on the picture of the vehicle body imitated on the display 11, and the evaluation of unevenness in the first to third embodiments is performed. Among the values, the ones with a certain value or more are displayed. Also,
The contents displayed on the display 11 are the printer 1
2 is recorded as needed.

Further, as shown in Table 2, the magnitude of ΔV,
It is possible to easily correct the unevenness by discriminating and displaying the type of the unevenness from the difference between the periodicity and the average value of the reflected light intensity and the reference light intensity of each paint.

The upper and lower limit levels of the reflected light intensity in the evaluation of unevenness may be changed for each color of the paint.

[0028]

[Table 2]

[0029]

As described above, according to the present invention, the following effects can be obtained.

(1) An apparatus for evaluating color unevenness of metallic coating and an evaluation for continuously measuring the brightness of the surface of a coating film by irradiating the surface of the coating film with light and receiving the intensity of reflected light received from an angle at which regular reflection light does not enter In the method, the degree of color unevenness on the coating surface is calculated by calculating the difference between the average value of the measured brightness and the brightness below a certain value, and the distance from the brightness above the certain value to the brightness below the certain value. Since the evaluation method is used for determination, it is possible to quantify the color unevenness of the metallic coating film that matches the visually evaluated value of the color unevenness.

(2) By displaying the type of color unevenness based on the average value of the brightness and the periodicity of the brightness waveform, it is possible to easily correct the unevenness.

(3) Since the luminance waveform and the degree of unevenness are superimposed and displayed on the picture on the display imitating the shape or silhouette of the painted object, and it is possible to print out if necessary, the location of the unevenness can be confirmed. Can be done easily.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a measurement state of a vehicle body by the optical probe according to the first embodiment of the invention.

FIG. 3 is a diagram showing a waveform of the intensity of reflected light with respect to a moving distance and a method for determining unevenness according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a waveform of the intensity of reflected light with respect to a moving distance and a method for determining unevenness according to the second embodiment of the present invention.

FIG. 5 is a diagram showing a waveform of intensity of reflected light with respect to a moving distance and a method for determining unevenness according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a waveform of intensity of reflected light with respect to a moving distance and a method for determining unevenness according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Optical probe 2 Emitter 3 Light receiver 4 Car body 5 Robot arm 6 Robot 7 Bogie 8 A / D converter 10 Computer 11 Display 12 Printer

Claims (5)

[Claims] 1. A color unevenness determination apparatus and evaluation method for metallic coating, which comprises irradiating light on a coating film surface and continuously measuring the brightness of reflected light received from an angle at which specularly reflected light does not enter. Characterized by determining the degree of color unevenness on the coating surface by calculating the difference between the average value and the brightness below a certain value and the distance from the brightness above a certain value to the brightness below a certain value Color unevenness determination device and evaluation method for metallic coating. 2. A color unevenness determination apparatus and evaluation method for metallic coating, which irradiates light on a coating film surface and continuously measures the brightness of reflected light received from an angle at which specularly reflected light does not enter, Determining the degree of color unevenness on the coating surface by calculating the slope of the regression line between the average value and the brightness below a certain value, and the distance from the brightness above a certain value to the brightness below a certain value. And a method for evaluating unevenness in color of metallic coating. 3. A color unevenness determination device and evaluation method for metallic coating, which continuously illuminates the coating film surface with light and continuously measures the brightness of reflected light received from an angle at which specularly reflected light does not enter. After passing through the filter that cuts the specified wavelength range of the luminance waveform, the inflection point of the luminance waveform that exceeds a certain value from the average value of the luminance and the distance between the inflection points of the luminance waveform that falls below the certain value or the regression line 3. The degree of color unevenness on the coating surface is determined from the difference between the inclination of the color change point and the brightness at each inflection point.
And a method for evaluating the color unevenness of the metallic coating described in. 4. The color unevenness determination device for metallic coating according to claim 1, wherein the type of color unevenness is displayed based on the average value of the brightness and the periodicity of the brightness waveform. And evaluation method. 5. The method according to claim 1, wherein the luminance waveform and the degree of unevenness are superimposed and displayed on the picture on the display imitating the shape or silhouette of the painted object,
The color unevenness determining apparatus and the evaluation method for metallic coating according to claim 1, wherein the apparatus can be printed out if necessary.