JPS5958304A - Device for detecting position and width - Google Patents

Abstract

PURPOSE:To accurately detect a weld line with a simple constitution by comparing and deciding the change in the quantity of reflected light resulted from the scanning of a spot light. CONSTITUTION:Spot light irradiated from a projecting means I strikes a work 1. The reflected light from the work 1 is received by a light receiving means IVand inputted into a comparing means VI through a signal processing means V. Moreover, a scanning means II is composed of a slider 22 and a motor 20 and the projecting means I and light receiving means IV are simultaneously scanned by the scanning means II. The comparing means VI compares AD conversion data from the signal processing means V with a reference value and detects a weld line.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a position/width detection device such as rd tangent detection.

The welding work is difficult to weld because the bath contact of the conventional N4 structure and the 2-way bath contact of large structures such as shipbuilding, steel frame bridges, etc. It has become common practice to process the welded joint into a V-shape, ■-shape, or ■-shape in cross section, and perform welding at °C (when a groove is taken).An example of this groove is (V-shaped groove) is shown in Fig. 1. In the figure, 11, td joint work, 2
is the backing 44. 3 is the nowa nox, 4 is the groove width, and 5 is the groove center. In this welding, in order to make the welding torch follow the welding line, that is, the groove middle/U line, it is necessary to detect the 1st river middle +L> line, and the welding conditions when multiple groove widths move back. In order to control the groove width, it is necessary to detect the groove width.

Traditionally, in order to detect this weld line (herein, the ID line in the groove and the groove width are referred to as the weld line), there have been methods such as V number mechanical type such as lower, pneumatic type such as eddy current, or static type. '^One foot type was researched and a prototype was made.

However, there are reliability problems due to wear and clogging of mechanical devices such as loafs, and the detection accuracy of the mid-bevel/U-line in a groove with a groove difference of 6 than shown in Figure 2. On the other hand, non-contact type sensors such as magneto-electric type and capacitance type have a large detection area, so it is difficult to clearly detect points A and B in the α52 diagram. As a result, the detected viscosity of the groove width and groove center line decreases.The dynamic range of the cut workpiece in the thickness direction is small (1 to 10 degrees), so the thickness of the thick plate is reduced. (20 to 50 degrees thick) could not be applied.

Attempts are being made to detect weld lines using pattern recognition technology using (television) cameras; ”, these will also be detected, so multilevel image processing will be required to detect the weld line from among them. Pattern recognition software for small grooves becomes extremely complex due to the presence of spatter, tack beads, and variations in groove processing accuracy, making real-time control difficult and costly overall. The current situation is that industrialization is difficult.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a position/width detection device that can detect V with low accuracy and can be made inexpensive with a simple configuration.

Structure of the Invention The present invention provides a means for projecting light (spot light);
means for scanning the light in a direction substantially perpendicular to the direction of the welding line, means for detecting the scanning position, means for receiving the reflection 3Th of the spot light from the welding work, and means for controlling the amount of the reflected light during the scanning. It has at least means for storing for each unit scan and means for comparing the stored value with a preset reference value,
It is characterized by detecting a welding line by comparing and determining the opening of the amount of reflected light accompanying the scanning of sub- and l-lights. According to this device, simple and highly accurate detection can be realized, and there are no drawbacks of conventional methods.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention is shown in FIGS. 3 to 16. That is, in FIGS. 3 and 4, I denotes a light projecting means for projecting sport light, and includes, for example, a laser diode 11. It is comprised of a circuit 13 that oscillates a laser diode and a lens system 12 that focuses laser light onto a lens. 7Vi incident light, 8 a spot on one surface of the workpiece, and 9 reflected light. Note that in order to cut out external light, the circuit 13 performs several K)7 modulations to cause the laser diode to emit light. 2 is a light receiving means (sensor) that receives the reflected light 9 of the glare beam irradiated onto the workpiece 1, and includes, for example, a lens system 12' and a photoelectric conversion element 1.
It consists of 4. Here, the positional relationship of the light emitting means 1 and the light receiving means 2 is right behind the light emitting means 1 (in the direction of the welding line).
However, for convenience of drawing, the light receiving means (2) is placed on the right side of the light projecting means (2). l
1 is a scanning means composed of, for example, a sweeper 22 and a motor 20;
Write a poem to LllH and scan in direction 10 at the same time. It is a position detection means for detecting the scan position of the pulse encoder 2J and the microcomputer 18 connected to the motor 20. That is, bus encoder 2
The scanning position can be detected by counting 1 signals by the microcomputer 18. v tit signal processing means,
A signal jtQ width circuit 15, which is composed of an oven amplifier or the like, receives the signal from the light-receiving culm that detects the reflected light f't. Band bus filter circuit 16 (this is used to demodulate the pulse signal of the laser diode 11 for the purpose of external optical power), A/D (analog-digital/L/) conversion circuit 17, and the A/D conversion data is stored in the microcomputer 18, and the amount of reflected light is stored for each position (unit) of scanning by the position detection means. In the equations, (2) is a comparison means for setting a reference value using, for example, the keypad F19 as an input means to the microcomputer 18, and comparing the standard value and the A/I conversion data.

Now, when the sub-socket light (incident light 7) irradiated from I hits the workpiece 1, its position is on the flat surface of the workpiece (E-C, D-F in Fig. 5) and the filler-socket part ( A to B), the amount of reflected light received by the light receiving element is large;
Actually, M16 (i) confirmed that there are few cases where the ball hits the slope part < C-A, B-D).

Based on this principle, when irradiating a flat part of work 1 or a flux, the amount of reflected light is large, so the fourth
If the output of the laser is adjusted so that the input signal of the A/D conversion circuit 17 shown in the figure is saturated, the light receiving element bar and the spot source light projecting means I are moved from E to F direction as shown in FIG. An output value 23 of the circuit 16 is obtained when the circuit 16 is scanned, and an output value 25 is obtained by comparing the value 7'L with a certain reference value 24 as shown in tel in the figure. From this result, the groove width, that is, A'B', and the groove length and L? Cotton position (A'+
B')/2 can be easily obtained. Here, the standard value 2
4, there are cases where a constant value is given, and where the output value 23 of the bandpass filter circuit 16 is A/Di converted, the average value for a constant scanning width is obtained, and this is set as the reference value 2.
It may be adopted as 4. In the latter case, the reference value is calculated by calculating the reference value 24 every -times scanning.

In addition, as shown in Fig. 6 fal, unevenness is created in the groove by the well-known suba vine 26 and gas cutting holes during bevel processing, and the output in this case is as shown in Fig. 6 fhl and fcl.
become that way. In other words, since the reflection from the surface of the sputter 26 increases, there are multiple candidate points for the groove width, but even in this case, the Iu position in the groove is located at how far from the scanning starting point O. By inputting knowledge information about the inside of the groove as data into the microcomputer 18, such as that the width of the groove is approximately the width of the groove, it is possible to avoid misrecognizing spatter as the width of the groove.

Next, an experiment was conducted to detect the groove width of the V-shaped groove and the groove center line. A 15 mW laser diode was used, and the variation was JOK). The diameter of the second groove on the work surface where the laser spot originates is 0.25 m+, and the scanning speed is 1.
00m+n/shu. Scanning Bi-Sochi (unit) is O11
As a matter of fact, I studied the gas cutting V-shaped groove with a difference in land, and found that it was 1'1 within ±0.2 mm ill.
C was able to detect the groove width and medium DIY line in one go. In addition, the V-shaped groove has a groove opening angle I! JL50', gas cut on the groove surface, sensor and workpiece n1 distance N ij 150rr
It's rrn.

In addition, when experiments were conducted to apply not only the V-shaped groove Ω, but also the L-shaped groove and the I-shaped groove, approximately the same 1 moxibustion accuracy was obtained.

Therefore, according to this device, complicated functions (turn recognition, i.e., rEcAGtTI31 in Figure 5 and Figure 6)FJ
It is possible to configure a visual sensor much more simply and at a lower cost than a means of recognizing the groove width and its center line by comparing the pattern of I-ECJKΔGl (BLMDF J) with a reference pattern.

The present invention is applicable not only to the detection of weld lines, but also as a wide range of industrial "eyes", and is not limited to the number of welds.

Effects of the Invention The position/width detection device of the present invention has much quieter accuracy, single-speed IW, and lower By using knowledge data, the reliability of detecting deviation can be greatly improved, and the effect on manufacturing is extremely large.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cutaway diagrams showing RFG tangents, FIG. 3 is an explanatory diagram of an embodiment of the present invention, and FIG.
The figure is a detailed diagram thereof, and FIGS. 5 and 6 are explanatory and clear diagrams showing the detection results. I...Light projecting means, 11...Light travel means,"...Position detection means, Culm...Light receiving means,■...Comparison means, ]8
...Microcomputer, 24...Basic value 3 Figure 2 Figure 3 Figure 5

Claims (3)

[Claims] (1) A light projecting means for projecting a spot light onto the surface of the object to be measured; a light receiving means for receiving the reflected light of the spot light from the object to be measured; a scanning means for scanning upward; a position detecting means for detecting the scanning position [R] of the light projecting means and the light receiving means; A storage means for storing data for each unit set meal scanned by the scanning means, and a comparison means for comparing the stored value of the storage means with a preset reference value, and detects the position of the comparison means and the position detection means. A position/width detection device characterized by detecting a position/width determined based on a position and a position. (2) Claim 11, wherein the reference value is an average value of the negative points of the reflected light in one sweep by the scanning means.
The position/width detection device according to item 1. (3) The comparison means refers to the surface information of the object to be measured.