JP2003270165A - Evaluation/calibration method of inline inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation/calibration method of an inline inspection device which measures a physical quantity of quality in a process line for continuously manufacturing steel plates. <P>SOLUTION: Artificially-scratched dummy materials are regularly fed to the line to accumulate the information on changes with time of a signal obtained from a non-defective portion of the dummy material and a signal obtained from the artificial scratch portion thereof. The inspection performance of the inline inspection device is evaluated/calibrated based on the accumulated information on such changes with time. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-line inspection apparatus for directly or indirectly measuring a physical quantity relating to quality in a non-destructive manner in a process line for continuously producing steel sheets. The evaluation and calibration method of 2. Description of the Related Art Inspection apparatuses for quality assurance have heretofore often used a destructive inspection method. However, in the destructive inspection, it is impossible to inspect all the objects because the sample is literally destroyed and inspected. On the other hand, in recent years, there has been an increasing demand for quality, and there has been a demand for inspection of all or all of the objects. For this reason, various non-destructive inspection methods have been devised instead of the conventional destructive inspection, and have come into practical use. [0003] However, the physical quantity actually measured by the nondestructive inspection is not a physical quantity that directly contributes to quality assurance.
In general, it is a physical quantity having a correlation with it. Therefore, the physical quantity to be measured and the physical quantity that contributes to quality assurance are associated with each other by another method,
It is necessary to clarify the relationship between the two. Then, it is necessary to constantly monitor the inspection device so that the relationship does not change, and to make corrections as necessary, and it is important to inspect the inspection device itself.
That is, it is important to evaluate the performance of the inspection apparatus and perform calibration as necessary. The method of evaluating and calibrating an inspection device differs from inspection device to inspection device. Here, in a process line for continuously manufacturing steel plates, a physical quantity relating to quality is measured directly or indirectly in a non-destructive manner in an in-line manner. For example, a laser reflection type surface flaw inspection apparatus shown in FIG. In the surface flaw inspection apparatus shown in FIG. 2, first, a fine laser beam from the laser 31 is reflected by a mirror.
The light is reflected by the rotating mirror 33 via 32, and performs high-speed scanning in the width direction of the steel plate 10 as a strip material. Then, the reflected light is received by a photomultiplier (photomultiplier tube) 36 via a lens 34 and a mask 35. Next, the obtained signal is input to the comparator 42 via the differential amplifier 41, and is compared with a separately set threshold to obtain an inspection output. Then, the obtained inspection output is processed by the information processing device 51, and the inspection result is output to the output device 52. On the surface of the steel plate 10, even if there is no defect on the surface, the irradiated laser is irregularly reflected and regularly reflected according to the average surface roughness. After setting the reflection intensity to the noise level, a component of the spatial filter that is strongly reflected in a specific direction, which is generated when there is an irregularity defect on the surface of the steel sheet, is shaped and adjusted in advance with a defect sample. By detecting through 35, the type and degree of defect can be specified. However, in the above-mentioned surface flaw inspection apparatus, various components such as lasers and lenses constituting the apparatus are deteriorated and stained, and the temperature and the temperature of the receiving side components such as photomultipliers. There has been a decrease in receiving sensitivity due to aging and the like, which has been a major cause of erroneous detection and oversight. In such an in-line inspection apparatus, conventionally, as a method for evaluating and calibrating the inspection performance, a method in which the in-line inspection apparatus is withdrawn from the in-line state, or the operation of the process line is stopped and there is no steel sheet on the line There is a method that is performed in a state. Then, by setting the in-line inspection apparatus to the above state, a cut plate sample of a steel sheet having an artificial flaw is placed at an inspection position of the inspection apparatus, an inspection is performed, and the detection performance of the target artificial flaw is evaluated. Evaluation of the inspection performance of the inspection apparatus has been performed, and calibration has been performed as necessary. [0007] However, all of the above-mentioned methods are carried out in a state where the inspection target is almost stationary, and have the following disadvantages. (1) The difference between the effects of disturbances caused by the stationary state and the moving state of the steel plate to be inspected cannot be reflected in the evaluation of the inspection performance. (2) In order to perform the inspection, it is necessary to stop the target process line or to temporarily manufacture the product without inspection. [0008] As another method, in an online operation in a target process line, a sample material is periodically designated and measured by the nondestructive inspection apparatus, and then a sample is taken. There is also a method of evaluating the inspection performance by measuring. However, this method requires a destructive inspection every time, so (1) the amount of work required for implementation is increased. (2) If an abnormality is found in the inspection, the quality of the product manufactured up to the previous inspection cannot be guaranteed. There was a problem. For this reason, it is necessary to shorten the inspection cycle, but if the frequency of the inspection increases, the line stop time will increase accordingly. In addition, for quality assurance, it is necessary to add another inspection device by another method, or there has been an adverse effect such as a decrease in production efficiency due to inspection by an inspector. The present invention has solved the above-mentioned problems, and has made it possible to inspect an inspection apparatus itself under conditions close to a normal inspection measurement state in-line, and to easily evaluate and calibrate the inspection performance of the inspection apparatus. An object of the present invention is to provide a method for evaluating and calibrating an in-line inspection device. By the way, in a process line for continuously manufacturing steel sheets, when manufacturing products having different manufacturing conditions, the operating conditions are generally adjusted to the products. Then, a steel plate called a dummy material is passed through a process line to perform necessary line adjustments and the like. The present inventor makes an artificial flaw to be inspected by the in-line inspection apparatus installed on the process line on the dummy material, and detects the artificial flaw at a timing when the artificial flaw passes the inspection position of the inspection apparatus. By receiving the artificial flaw signal and storing and storing it as a time-series signal together with the signal of the defect-free part, the evaluation and calibration of the inspection device can be performed based on the time-dependent change of the stored and stored signal. Find out what you can do,
The present invention has been accomplished. That is, the present invention is a method for evaluating and calibrating an in-line inspection apparatus for measuring a physical quantity relating to quality in a process line for continuously producing steel sheets,
The dummy material provided with artificial flaws is periodically passed through the line, and information on a temporal change between a signal obtained from a defect-free portion of the dummy material and a signal obtained from the artificial flaw is accumulated and accumulated. The above problem has been solved by a method for evaluating and calibrating an in-line inspection device, which is characterized by evaluating and calibrating the inspection performance of the in-line inspection device from the information on the change with time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method for evaluating and calibrating an in-line inspection apparatus according to the present invention will be described with reference to FIG. In the present invention, the dummy material 4 is passed over the transport roll 2 in the process line 1 such as a continuous steel sheet manufacturing line, and various adjustments and the like of the line are performed using the dummy material 4. It is characterized in that the device 3 is evaluated and calibrated. In addition, as the in-line inspection device 3, the surface flaw inspection device already described with reference to FIG. 2 can be used. Here, the dummy material 4 is provided with a predetermined artificial flaw in advance. Then, the conveyance of the dummy material 4 is tracked by the tracking device 5, and an “artificial flaw passing timing signal” is output to the in-line inspection device 3 at the timing when the artificial flaw passes through the in-line inspection device 3. The in-line inspection device 3 transmits the detected signal of the artificial flaw to the information storage device 6 as an “artificial flaw measurement signal” and stores it. At the same time, the signal of the non-defective portion of the dummy material is transmitted and stored in the same manner. As described above, the signal of the artificial flaw of the dummy material and the signal of the non-defective portion are stored and stored in the information storage device 6 with time, and the change of the stored and stored signal with time is determined. Evaluate and calibrate the inspection device. Note that the tracking by the tracking device 5 is a tracking that is normally performed in a process line, and a description thereof will be omitted. The method for evaluating and calibrating an in-line inspection apparatus according to the present invention was applied to an in-line inspection apparatus installed in a process line for continuously manufacturing steel sheets. Note that the in-line inspection device here is the surface flaw inspection device described with reference to FIG. FIG. 3 is a graph showing the transition of the signal level of the artificial flaw obtained according to the number of times the dummy material is passed through by periodically passing the dummy material and detecting the artificial flaw of the dummy material. This graph can be easily created based on the information stored in the information storage device. In the present invention, the change in the signal level of the artificial flaw is monitored in a time-series manner, and the change in the signal level of a non-defective portion (not shown) is similarly monitored. In this way, the evaluation and calibration of the in-line inspection device can be easily performed, and the stop of the line can be minimized. Further, since the evaluation and calibration can be performed in-line, it is also possible to monitor a change in the signal level caused by a change in the horizontal level of the guide roll before and after the in-line inspection apparatus. Necessary adjustments could be made to changes in the horizontal level of those guide rolls. On the other hand, the conventional method, in which the inspection equipment is taken offline and the evaluation / calibration is performed using the cut sample, requires a stop of the process line, and an abnormality such as a change in the horizontal level of the guide roll is brought online. Can not be monitored by That is, in the in-line inspection apparatus, the measurement performance may be changed not only by the performance of the apparatus itself but also by the surrounding measurement conditions. In some cases, serious flaws were overlooked, but this oversight was resolved by the present invention. According to the present invention, the performance of the inspection apparatus can be inspected without stopping the operation of the process line and under almost the same conditions as the actual object. Of the inspection apparatus can be accurately evaluated, and inspection troubles due to occurrence of abnormalities such as performance deterioration of the inspection apparatus can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a calibration method of an in-line inspection device according to the present invention. FIG. 2 is a schematic diagram of a steel sheet surface flaw inspection apparatus which is an example of an inspection apparatus to which the calibration method of the present invention is applied. FIG. 3 is a graph illustrating a transition of a signal level of an artificial flaw with respect to the number of times of passing a dummy material. [Description of Signs] 1 Process line, continuous production line (of steel plate) 2 Transport roll 3 (inline) inspection device 4 Dummy material (plate) 5 Tracking device 6 Information storage device 10 Steel plate (strip material) 30 Detector 31 Laser 32 Mirror 33 Rotating mirror 34 Lens 35 Mask 36 Photomultiplier (photomultiplier tube) 40 Signal preprocessing unit 41 Differential amplifier 42 Comparator 51 Information processing device 52 Output device

Claims (1)

Claims: 1. A method for evaluating and calibrating an in-line inspection apparatus for measuring a physical quantity related to quality in a process line for continuously manufacturing steel sheets, comprising: Through the board periodically, and accumulates information on the change over time between the signal obtained from the defect-free portion of the dummy material and the signal obtained from the artificial flaw. Evaluate the inspection performance of in-line inspection equipment
Evaluation and evaluation of in-line inspection equipment characterized by calibration
Calibration method.