JPH0679777B2 - Out-of-groove detection method in steel pipe manufacturing process - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for detecting a groove deviation in a steel pipe manufacturing process and correcting a welding position.

[Conventional technology]

As a conventional technique, as shown in JP-A-61-27178, slit light or scanned spot light is obliquely irradiated from above in the groove longitudinal direction at right angles to the groove longitudinal direction, and on the groove surface. And the reflected light on the surface of the base material is imaged by an objective lens provided above the reflected light, and an elongated slit is positioned on the image forming surface of the reflected light on the surface of the base material in a direction perpendicular to the groove longitudinal direction. The slit plate is arranged in such a manner that only the reflected light that has passed through the slit is detected by the detector, and the detection signal is one-dimensionally processed by the signal processing device to detect the position of the groove edge portion. There is a method of detecting the groove edge portion.

[Problems of conventional technology]

In the related art as described above, even if the groove position is detected, there is no disclosure about means for returning the groove-off position to the normal position.

[Means for Solving the Problems]

The present invention advantageously solves the problems of the prior art.Before welding the steel pipe groove, a CCD camera for image processing is provided in the vicinity of the steel pipe groove, and a laser slit light source is used to open the steel pipe. When the vicinity of the tip is illuminated and the shadow is detected by the CCD camera for image processing above, and the detected groove center exceeds the specified range for reading the groove center analog data at an arbitrary sampling cycle. The control output is performed by determining that the groove is out of alignment, and when the center of the groove is not detected and the deviation analog data is "0" during the detection, it is determined that the vehicle is running in a place other than the groove and the control is output. A method for detecting groove deviation in a steel pipe manufacturing process.

The present invention will be described below with reference to the drawings.

〔Example〕

 FIG. 1 is a diagram showing an embodiment of the present invention.

Reference numeral 1 denotes a steel pipe (pipe), the joint portion of which is arranged and fixed downward.

Reference numeral 2 denotes a CCD camera for image processing, which detects a joint portion of a steel pipe and performs automatic alignment control.

Reference numeral 3 denotes a groove-positioning movable mount, which is a mount for performing automatic positioning by image processing.

A welding head 4 is connected to the carriage 6 via a boom 5, and is inserted into the steel pipe by following the groove on the inner surface of the steel pipe when the carriage travels.

5 is a boom, and a welding head 4 attached to the tip
It is to be inserted into the tube together with.

A traveling carriage 6 is a power carriage for inserting the welding head 4 into the steel pipe.

Reference numeral 7 denotes a groove, which is a welded portion of a steel pipe (V-shaped groove).

Reference numeral 8 denotes a copying roll, which is a guide roller that is inserted and travels inside the groove during insertion into the steel pipe.

FIG. 2 is a diagram showing the configuration of the image processing apparatus.

Reference numeral 2 is the CCD camera for image processing described above, which is a steel pipe groove 20.
The groove-shaped bright line 22 projected by the laser slit light source 12 is input to the image processing calculator 13.

Reference numeral 12 is a laser slit light source, which irradiates the groove portion 20 of the steel pipe to generate a groove-shaped bright line 22.

Reference numeral 13 denotes an image processing arithmetic unit, which performs arithmetic processing for digitizing an image read by a CCD camera for image processing.

Reference numeral 14 denotes a monitor television, which displays a groove shape bright line 22 read by the image processing CCD camera 2.

Reference numeral 15 is a constant setter, which sets various parameters from the outside.

Reference numeral 16 is an output calculator, which is a part for calculating an output element that matches a control target.

Reference numeral 17 denotes an image processing interface section, which is a section connected to another device and which gives a necessary control amount to a control target.

A sequence controller interface unit 18 is directly connected to the image processing interface unit 17 and processes the input / output to be arithmetically controlled by the sequence controller.

Reference numeral 19 denotes a sequence controller arithmetic unit, which performs arithmetic processing on the control output output from the image processing device,
The control output according to the target is output to the control target through the sequence controller interface unit 18.

Reference numeral 20 denotes a steel pipe groove part (a part), which has a groove part to be controlled by image processing.

Reference numeral 21 denotes an image processing area, which processes the video projected in this range.

Reference numeral 22 denotes a groove-shaped bright line, which is used by the laser slit light source 12 to display the shape of the groove portion as a bright line and is read by the CCD camera 2.

FIG. 3 is a diagram showing a control flow of the present invention.

Is the start and start of the automatic truck process, and starts the operation of inserting the welding head into the steel pipe.

Is the deceleration position of the pipe end, and is used to determine whether to detect the groove deviation.

Is a groove misalignment cancellation, and cancels the control operation when the groove misalignment detection is not performed.

Indicates the start of the groove detection mode, and sends a start signal to the image processing apparatus when detecting the groove deviation.

Is an out-of-groove detection, and the left-right deviation of the groove detected and measured by the image processing apparatus is stored as data when the set value is reached. Data outside the setting range will not be processed. Here, the range of ± 3 mm for reading the groove center analog data at the set sampling cycle (setting can be changed).

Is a continuous detection of n times, and when the groove left / right deviation reaching the value set by is detected n times in succession, it is determined that the groove is out of contact and is controlled and output. If it does not reach n times continuously, the deviation data is not processed at that time. Turns ON when groove misalignment detection is detected a set number of times consecutively. n = 3 times (settings can be changed).

Is an output without a groove, and is an output that is output when the groove is not reflected when the image is processed, that is, when the vehicle is running in a portion that is not a groove. It is decided to run in a place that is not a club.
If both inputs, analog output and groove output are not input by AND, control output processing is not performed.

Is a detection confirmation timer and does not become the final output unless the processed and output signal lasts for a set time.

Is the pipe end deceleration position, and the final output is valid if it is not the pipe end deceleration position. If it is the pipe end deceleration position, the groove deviation detection control is canceled. That is, the process ends. This groove misalignment detection is performed only from the start to the pipe end deceleration position.

When the groove output is ON and the final output is output, if the pipe end position is not reached, the groove output is output.

Indicates that the trolley movement process automatic mode has been dropped, and when the output outside the groove is output by, the trolley movement process automatic mode is turned off and automatically stopped.

FIG. 4 shows the output specifications of the image processing apparatus.

A indicates the time when the groove center is detected, and the groove shape bright line appears in the center of the monitor screen, indicating that the groove center.
The state at this time indicates that the insertion is normally performed at the center of the groove.

In B, the groove center is at the time of right shift, and the groove shape bright line appears on the upper part of the screen on the monitor screen, and 0 to + 5V depending on the shift amount.
Outputs analog output in the range. The state at this time indicates that the vehicle is traveling off the groove to the right. This deviation analog data is processed to detect that the vehicle is running out of the groove.

In C, the groove center is at the time of left deviation, and the groove shape bright line appears on the monitor screen at the bottom of the screen, and 0 to -5V depending on the amount of deviation.
Outputs analog output in the range. The state at this time indicates that the vehicle is traveling off the groove to the left. This deviation analog data is processed to detect that the vehicle is running out of the groove.

D indicates that the center of the groove is not shown, and the vehicle is running in a place where there is no groove. In this case, it is detected that the deviation analog data becomes “0” and the output of the grooveless pear is AND-processed, and that the vehicle is running in a place where there is no groove apart from the groove.

〔The invention's effect〕

According to the present invention, when the groove position is displaced, the groove position can be corrected in advance without stopping the progress of the welding machine.

[Brief description of drawings]

 FIG. 1 is a schematic explanatory view of a groove defect detection method of the present invention, FIG. 2 is a block diagram showing a configuration of an image processing apparatus, FIG. 3 is a flow chart showing groove defect detection operation, and FIG. 4 is image processing. It is explanatory drawing of the output specification of an apparatus.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 61-132274 (JP, A) JP-A 62-156077 (JP, A) JP-A 2-37973 (JP, A)

Claims (1)

[Claims] 1. A CCD camera for image processing is provided in the vicinity of the steel pipe groove portion before welding the steel pipe groove portion, a laser slit light source is irradiated to the vicinity of the steel pipe groove portion, and a shadow thereof is obtained in the image. If the groove center detected by the processing CCD camera exceeds the specified range for reading the groove center analog data at the arbitrarily specified sampling cycle, it will be judged as out-of-groove detection and control output will be performed. A method for detecting a groove defect in a steel pipe manufacturing process, characterized in that when the deviation analog data of the groove center becomes "0" during the detection, it is judged that the vehicle is traveling in a position other than the groove and the control is output.