The Xiris Blog

Monitoring Tube and Pipe Production to Find the TOE ANGLE

Posted by Cameron Serles on Tuesday, September 02, 2014 @ 04:30 PM

 Recent advancements in machine vision technology have made a new type of inspection, capable of finding defects related to the forming and welding area of a tube or pipe.  The result is improved quality assurance and process control on the production line.  The new inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld. 

Typically NDT (non-destructive testing) systems are placed at the end of a production as a final check.  However, the laser inspection system can be placed directly after the weld box.  This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for a closely monitored measurement on ERW/HFI production mills:  the Toe Angle.

The Bead Slop Angle

The Left and Right Bead Slope Angles are measured in degrees at either edge of the weld bead, and represent the angle subtended by a line that follows the contour of the weld bead on either side and a horizontal line.  Also referred to as the Toe Angle, it can indicate the strength of the weld, and the correct forming of the parent material during the creation of the weld, particularly on an ERW/HF process.  A forming problem could be detected because of a larger or smaller than normal slope angle.  It is important to measure both the left and right slope angles separately. This is because the forming of the parent material could be asymmetric on a pipe mill, causing the slope angles to be different on either side of the weld bead, and thereby indicating a forming problem.

als;kdgjdsa;lghfdag resized 600The Bead Slope Angle or Toe Angle, measured in degrees from the horizontal.

 

How the WI2000p System Measures the Bead Slope, or Toe Angle

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line, and a camera with an optical axis that is offset to the axis of the laser line by an “offset angle”.  The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube, and capturing an image of the line using the camera.  The resulting image shows a profile of the tube surface as if it were cut in cross section.  If a tube is the ideal round, the laser image will represent a section of an ellipse and any anomaly such as the bead can be mathematically detected and the bead slope, measured. 

The WI2000p bases all of its measurements on the differences between the actual laser profile line (seen by the camera), and the ideal mathematical profile based on the tube parameters.  By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect weld bead profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques.

Conclusion

Overall, laser-based 3D imaging systems, such as the WI2000p from Xiris, offer an excellent measurement option for tube mill owners/operators who want additional, real-time monitoring of weld features. They can be used in a proactive manner, warning operators what is changing in their welding process so that they can perform corrective action before significant scrap occurs. Laser--based 3D imaging systems can operate on any type of material, regardless of its reflectance or magnetic properties, using a single head to perform the measurement.

Topics: camera placement, welding instruction, Tube and Pipe welding, bead height, bead roll

Monitoring Squeeze Pressure on Tube and Pipe Mills

Posted by Cameron Serles on Tuesday, August 12, 2014 @ 03:58 PM

Recent advancements in machine vision technology have made a new type of inspection capable of recognizing defects related to the forming and welding area of a tube or pipe.  The result is improved quality assurance and process control on the production line.  The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld. 

Typically NDT (non-destructive testing) systems are placed at the end of a production as a final check.  However, the laser inspection system can be placed directly after the weld box.  This system can let operators know what is changing in the welding process, allowing them to perform corrective action before significant scrap occurs. This capability is especially helpful for one of the most common defects found across all types of tube manufacturing: insufficient or excess squeeze pressure. This pressure is used to form the tube during welding and can be monitored by measuring the bead ratio of the tube.

The Bead Ratio

The bead ratio is an important measurement for ERW/HF processes to monitor.  It is calculated by measuring the maximum bead height above the parent material, divided by the thickness of the parent material wall thickness.  The bead ratio is an excellent indication of the amount of squeeze pressure used on an ERW/HF mill during welding. When the squeeze pressure is too high, molten material will spill out of the seam, causing a higher bead to form and increasing the bead ratio.  Likewise, when the squeeze pressure is too small, the parent material will not be pushed together enough and a sunken weld will result, causing the bead ratio to fall.  By taking into account the wall thickness, the bead ratio can determine the severity of a sunken or raised weld for a particular weld thickness, making it more of a measurement relevant across all tube thicknesses.

 sadjf;lasdkjfa;lllllllkj resized 600The Bead Ratio (h/e), where “h” = the height of the bead and “e” = the tube wall thickness.

How the WI2000p System Measures the Bead Ratio

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”.  The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera.  The resulting image shows a profile of the tube surface as if it were cut in cross section.  If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such the bead height can be mathematically detected. 

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters.  By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect weld bead profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques.

Conclusion

Overall, laser-based 3D imaging systems, such as the WI2000p from Xiris, offer an excellent measurement option for tube mill owners/operators who want additional, real-time monitoring of weld features. They can be used in a proactive manner, warning operators what is changing in their welding process so that they can perform corrective action before significant scrap occurs And by measuring the outside contour of a weld, laser-based 3D imaging systems can operate on any type of material, regardless of its reflectance or magnetic properties, using a single head to perform the measurement.


Topics: weld inspection, Machine Vision, camera placement, Tube and Pipe welding, Welding Process

Post-Secondary Schools Increase Trade Resources and Improve Student Experience

Posted by Cornelius Sawatzky on Wednesday, July 02, 2014 @ 04:16 PM

Technical trade schools and welding education programs are not new to post-secondary institutions, but as organizations see an increase in admissions, there is also a noticable increase in demand for equipment. This is not only to appease the quantity of new students, but also to ensure safety and efficiency in the curriculums. The most appealing program to a student will have experienced and knowledgeable professors, interesting and extensive material, as well as modern equipment. However, even with all of these tools there are still some major factors that all of these institutions face:

  • The booths to demonstrate and instruct welding are too small for more than just a few students at a time
  • The instruction area has inadequate space for the number of students registered in the program
  • The welding consumables budget is insufficient and will not cover the cost for new equipment

When instructing such a unique trade, it is important that students not only understand what is being taught, but can see the demonstration. Being able to see and understand what is occurring with a weld tip and arc, as well as the environment around it (weld seam, weld pool, shielding gas, and wire feed) are all essential elements to understanding the welding process. Without a grasp on these elements and factors, there is little that can be retained by the student. This is all based on a visual demonstration that can be hard to provide in many welding institution settings.

As technology and equipment advance, the ability to record lessons and welds adds an immense benefit to both students and instructors. Students can learn more outside of the classroom, as well as retain and digest all of the important elements of the lesson using video playback. This can be provided through the addition of weld cameras.

teach paper resized 600

Not any camera can be placed in such a hostile environment, and expected to function normally. Therefore, more research and development has been contributed to constructing a small, clear, and functional camera that can withstand this environment, and provide the best image quality. Xiris Automation Inc. has created such a camera, called the XVC-O (Xiris View Camera for Open Arc Welding). This allows video recording, clear images, storing/saving capabilities, as well as better classroom visuals for welding programs. This live weld feed can be attached to a simple monitor (as demonstrated above), or even a full size projector, and still provide a clear, comprehensive view of all elements. Xiris has also developed a version for submerged arc welding.

Local colleges, such as Conestoga College, have added this kind of technology to their budding trades programs. As the Government of Canada announced this May, they are investing $2.3 million over the next five years towards Conestoga College’s new Centre for Smart Manufacturing establishment. Already using the XVC-O, these improvements have allowed Conestoga to become an extremely competitive College in the area, and one of the most competitive for the welding trade school industry. Other institutions, such as NAIT (Northern Alberta Institute of Technology) have also added systems to their curriculum and have noticed great improvements. NAIT’s Chair of Welding Programs, Chris Manning says “by displaying the captured welding video on a remote screen, the instructors can vastly improve the learning experience of their students, with improved learning success, which is always the instructor’s goal”.

For more information about how welding cameras can assist welding education please visit www.xiris.com.

 

Topics: weld inspection, Machine Vision, camera placement, field of view, welding instruction, quality control, weld camera, weld camera, Education, Welding Process, weld video, Xiris, welding, Conestoga College, NAIT

How System Integrators Use Xiris Weld Cameras in Automation

Posted by Cameron Serles on Tuesday, June 10, 2014 @ 03:15 PM

Systems integrators who build automated welding processes are always searching for improved business models. There are thousands of small and medium sized automation system integrators around the world that are experts in the industry. This challenges each company to differentiate themselves from their competition, and do so by providing a unique value proposition to their customers.

One of the best ways to gain this competitive advantage is for system integrators to leverage rapidly evolving technology. By applying it to their customer’s welding automation solutions this allows companies to capitalize on an evolving technology, with the goal of improving profitability and efficiency.

An emerging technology that many systems integrators are considering is the use of cameras for monitoring the welding process.  While cameras have been used to monitor welding for years, it is only recently that cameras, such as the Xiris XVC-O Open Arc Weld Camera, have provided enough image clarity that system integrators have considered them a useful tool to provide to customers. 

welding line resized 600

 

Many system integrators face the same challenge:  how to build a system to keep operators from having to be in direct proximity of the automated cell in order to monitor the weld.  Most fabricator customers are increasingly dissatisfied with automated welding solutions that don’t permit operators to monitor the weld remotely.  By providing a camera to monitor the welding process, systems integrators can provide their customers with a valuable production tool.

Adding a camera system to a work cell can help increase welding automation business that might not otherwise be gained by a systems integrator. By removing the operator from the immediate work area of the welding environment there are immense benefits to the customer that would increase demand for a system integrator. For example, instead of multiple operators assigned to multiple production lines to manage rollers, material handling, and welding processes, customers benefit from having one operator per line at one control panel managing it all, increasing productivity, quality and reducing human error.

By introducing weld cameras into automated welding work cells, systems integrators can achieve an abundance of benefits. They will be able to differentiate themselves in the market, expand into new market sectors, improve technical competency, as well as improve the functional excellence of the overall product offering.

Topics: remote monitoring, welding automation, weld environment, Machine Vision, camera placement, field of view, quality control, weld camera, Welding Process, Xiris

How to Select the Field of View for a Weld Camera

Posted by Cameron Serles on Monday, April 22, 2013 @ 09:45 AM

The Field of View you choose for your Weld Camera will play a critical role in getting the best-quality images for viewing the required details of your automated welding process. 

But how large an FOV should you use for your camera? There are several factors to consider.

Camera Angle

The first question to ask is: What angle will we place the camera relative to the work pieces? The steeper the angle of the camera, the smaller the view of the weld head in the image and the larger the view of the weld bead and work piece. The shallower the angle, the larger the view of the weld head and the smaller the length of the weld bead and work piece in the image.

Depth of focus is an issue if you are looking at the weld using a camera that has been mounted at a low angle. The most important features in the weld should be kept in focus and be placed in the center of the FOV.

Camera Placement

When viewing the weld from the front, a general rule of thumb is to choose an FOV that is 4 x the bead width to be imaged. This FOV should provide you with most details of the weld in good image resolution.

If the camera is mounted from the side or behind the welding process, you need to ask yourself: What is the distance from the center of the weld head to the point in the weld bead where solidification occurs? It’s most useful to the operator if all these features are visible in one image.

Ideally, you want to be able to see the weld bead as long as it is molten, the torch tip/arc, and some of the parent material (including the unwelded seam) all in a single view.

Type of Welding

For Narrow Groove welding, especially for the root pass where detail of the weld and the seam alignment are most critical, a suggested FOV could be 2 x the bead width. This would allow a closer view of the edges of the seam groove and weld pool to verify the best alignment between groove and weld head.

For subsequent passes after the root pass where weave welding occurs or where multi-pass welding is to take place, a larger FOV should be used to see the full movement of the weld head in a groove. In such cases, the FOV should be large enough to see the entire V groove.

In Cladding/Overlay applications, generally speaking, an FOV of 4 x the bead width should provide enough image size to see 1-2 previous passes of weldment, plus the current pass.

When filler material is used in a welding process, such as in GMAW (MIG), you need to select a FOV that will encompass the filler tip as well as all the other features of interest.

In Laser welding, special care must be made in selecting the appropriate FOV. Laser welding typically has very small welds and the Weld Camera may be limited as to how small an FOV can be used before optical distortions create a problem in the weld images. 

Because Laser welding is typically a higher-speed application, it may be useful to choose a larger FOV (e.g., greater than 4 x the weld bead in this case) so as to see the entire molten pool after the weld head, as the tail of the weld pool may be longer relative to its width than what is found on MIG or TIG welding processes.

Conclusion

Selecting the right FOV is crucial in getting the highest-quality images for remote weld monitoring using a Weld Camera. Your decision should be based on your particular welding environment and operational demands.

Topics: camera placement, field of view, weld camera

Where to Place a Weld Camera

Posted by Cameron Serles on Saturday, April 20, 2013 @ 05:24 PM

A Weld Camera can be placed at various locations around the weld head to see different features that are present—upstream or downstream of the weld head, or from the side.

The benefits of each view depend on:

  • The specific conditions desired for display.
  • The field of view chosen.
  • The mounting angle of the camera relative to the work pieces.
  • Camera placement that can enhance specific features of an open arc for viewing.

Each orientation of a Weld Camera allows certain features to be seen.

Before the Weld Head

By placing the Weld Camera before the weld head (i.e., upstream), the operator can monitor the mechanical features of the seam and wire, the tracking of the seam to the weld head, and related features. Specifically, this would include a good view of:

  • The weld seam (to confirm the quality of the fit-up of the seam edges to be welded).
  • The weld head position relative to the seam (to ensure that the weld head and seam are in alignment).
  • The feeder wire or wire stick-out (to ensure that the feeder wire is being fed correctly and not missing or incorrectly positioned).
  • The penetration of the welding wire and its arc in the root of the seam.
  • The shielding gas around the arc (to determine if the gas quantity and chemistry is correct).

Placing the Weld Camera before the weld head is especially useful for semi-automated welding systems, such as gantry systems, where the operator monitors the weld and its position relative to the seam, then controls the welding manipulator with a remote joystick.

After the Weld Head

By placing the Weld Camera after the weld head (i.e., downstream), the operator gains a real-time post-weld visual tool to monitor the weld pool condition as it solidifies. Specifically, this would include a good view of:

  • The weld puddle (to confirm correct form).
  • The feeder wire when wire feed is made from behind the weld tip, such as on TIG (to ensure that wire is being fed correctly, in the right position, and melting properly).
  • The molten weld pool (to detect the presence of bubbles that are good indicators of potential porosity in the weld). 
  • On TIG and Plasma Tube and Pipe mills, the weld seam position that can be seen through the arc to upstream of the arc.
  • The wetting and cut of parent material (to ensure proper form).
  • The weld puddle solidification (to ensure no cracking, porosity, or surface contaminants).
  • Potential undercut occurring in the weld as a result of incorrect alignment of weld head to seam or incorrect pressure on the parent material.

From the Side

By placing the Weld Camera to look at the weld head from the side, a unique view of the weld head and its parameters can be obtained. Special benefits of a side view include:

  • Better visibility for monitoring some items (e.g., how feeder wire gets positioned, fed, and melted and flows into the weld pool).
  • Easier camera mounting when space is at a premium before or after the weld head.
  • Easier adjusting, positioning, and focusing of the Weld Camera.
  • The best view for monitoring interaction in the weld pool when two or more weld torches are used in tandem (e.g., for thick walled pipe fabrication).
  • Usefulness in Cladding/Overlay applications (e.g., TIG cladding inside a small diameter pipe or vessel) where the wire position relative to the weld puddle is important to monitor while simultaneously viewing the wetting and fusion of the leading edge of the weld.

Conclusion

Your particular welding needs will determine whether you should place your Weld Camera in front, behind, or to the side of the weld held in order to obtain the images of the weld that will provide the unique information necessary to aid in the monitoring of your process.

Topics: remote monitoring, camera placement, weld camera

Latest Posts

Follow Me