Periodic defect detecting device and method for the same
A defect detection and periodic technology, applied in the direction of measuring devices, instruments, scientific instruments, etc., can solve problems such as inability to cope
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment approach 1
[0088] figure 1 It is a block diagram of the periodic defect detection apparatus of Embodiment 1. exist figure 1 Among them, 1 is a steel plate (shown in a perspective view to make the equipment placed under the steel plate easy to see), 2 is a periodic defect, 3 is a magnetizer, 4 is a magnetic sensor, and 5 is signal preprocessing with a built-in amplifier and filter circuit 6 is an A / D conversion device, 7 is a periodic defect detector, and 8 is a defect determination device.
[0089] In the steel plate 1, as the periodic defect 2 in this example, the rolling surface defect caused by the rolling roll is in the rolling direction (in the figure 1 where is the direction of travel) there are more than one. A plurality of sets of magnetizers 3 and magnetic sensors 4 face each other across the steel plate 1 and are arranged along the width direction of the steel plate 1 (the direction perpendicular to the direction in which the periodic defects are arranged). The magnetize...
Embodiment approach 2
[0121] Generally, in a defect meter, in order to improve the discrimination accuracy of the harmless part which discriminate|determines a defect, it is common to raise the resolution of a defect signal. In the present invention, as described in Embodiment 1, first, as the first stage, a process of judging whether or not a periodic component is included in the measurement signal (that is, detection of a periodic defect candidate) is performed. Next (when a periodic defect candidate is detected), as the second stage, the defect signal for determining the harmfulness of the defect is enhanced using the period and occurrence position information, and the type and degree of the defect are determined.
[0122] Phase 1: Periodic defect candidate detection (judgment of the presence or absence of periodic components)
[0123] Detection of defect candidates (step S5) based on periodic evaluation (repetition of similarity evaluation based on correlation calculation: above steps S1 to S8)...
Embodiment approach 3
[0140] exist figure 1 In the measurement of Embodiment 1, excitation is performed in the longitudinal direction, but it can also be used as Figure 7 As shown in , the sensors sensing the magnetic field in the vertical direction are arranged in the width direction and magnetized along the width direction. In this case, the magnetic flux generated by the defect has a positive and negative distribution along the width direction ( Figure 8 ). When evaluating the periodicity, in Embodiments 1 and 2, the similarity between two-dimensional regions is evaluated. However, by utilizing the magnetization in the width direction in this way, the defect signal has characteristic positive and negative peaks. Such data sampling as shown in (C) can also reduce the probability of non-detection and improve the accuracy of periodicity evaluation. Thereby, even if thinning is performed as described above, periodicity can be evaluated.
[0141] Furthermore, focus on defect signals generated ...
PUM
| Property | Measurement | Unit |
|---|---|---|
| Length | aaaaa | aaaaa |
| Length | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More