8 Ways to Improve Productivity With a Weld View Camera

High dynamic range imaging may hold the key to unlocking the secrets of process improvement in automated welding

Xiris Weld view cameras

Weld view cameras with high dynamic range imaging capability, such as the Xiris XVC-O, can image both the super-bright region around the arc and the dark background surrounding the arc, where important detail about the weld process is contained.

During automated welding processes, key features of the weld head and its immediate environment need to be monitored for process and quality control. But how should this be done?

Until recently there hasn’t been a good solution.

Operators directly monitoring a weld don’t have good visibility of either the super-bright region around the arc or the dark background surrounding the arc, where important detail about the weld process is contained.

The weld helmets they wear to protect their eyes from the arc may provide good definition of the arc, but filter out critical information in the background. Also, putting operators in close enough proximity to the weld to see it through a weld helmet or protective screen exposes them to the disagreeable and dangerous conditions of the welding environment, resulting in higher safety and health costs, while making it harder to recruit and retain good operators.

The Dilemma

Using operators to monitor automated welding processes presents a dilemma—how do you keep operators safe while also giving them good visibility into the weld process?

The way to get around the weld-proximity problem has been to video-record the process using cameras that can instantaneously send the video to monitors in a remote location, allowing operators to view the real-time weld process in relative safety and comfort away from the weld head.

However, this approach has been hampered in the past by the inability of the camera to simultaneously view detail in the arc region of the weld and its darker background. The dynamic range of standard cameras, even those retrofitted for weld monitoring, is too low to provide enough detail.

When using traditional cameras, operators have to stop the welding process and adjust the camera’s optics each time they need to shift the visibility between the arc region and the background in order to get the full picture of what is happening with the weld.

New Imaging Technology

Fortunately for manufacturers, a new technological advancement—high dynamic range imaging—has emerged. This technology overcomes the traditional limitations of weld monitoring by simultaneously providing high-quality images of both brightness extremes.

Whereas a standard camera can create an image with a brightness range of only about 1,000-to-1 signal-to-noise ratio (50-60 dB), weld view cameras with high dynamic range capability can process a signal-to-noise ratio greater than 1,000,000-to-1 (120 dB), which is sufficient for clear images of the entire weld scene.

Weld view camera images

High dynamic range capability can process a signal-to-noise ratio greater than 1,000,000-to-1 (120 dB), which is sufficient for clear images of the entire weld scene.

When this is integrated into an industrially hardened, state-of-the-art camera with built-in auxiliary lighting, the visibility/proximity problem of remote weld monitoring is overcome, and production goes up.

Traditional weld view cameras haven’t conquered the challenge, either. While they do get operators away from the weld, they aren’t capable of imaging both the extremely bright arc and the dark surrounding background.

Weld view cameras with high dynamic range imaging capability can image both extremes of the weld head. In so doing, they pre-sent an opportunity for fabricators to improve weld processes, increase productivity, and gain an advantage over competitors still struggling with the question of how to effectively monitor their automated welding process.

The Productivity Impact

1. Lower safety and health costs.

Using a weld view camera frees operators from dangerous proximity to the weld without compromising proc-ess control. The result is a reduction in the many costs related to the riskiness of a workplace, such as:

  • Higher workers’ compensation insurance premiums.
  • More expensive group medical coverage.
  • Lost work time.
  • The hiring and training of replacements.
  • Decreased output due to the lower skill levels of replacements.
  • Litigation exposure.

2. More efficient operators.

When forced to directly monitor a weld, operators are subject to numerous risks, such as weld fume inhalation, electrical shock, contact with weld splatter, “welding eye” (direct exposure to the human eye of the weld arc), and injuries from moving or falling objects.

To protect themselves from these hazards, operators must always be on guard, operating with extreme caution and more slowly than if they weren’t at risk. And, they have to take the time to put on and remove protective clothing and weld helmets as they work.

There’s also a mental factor. Directly monitoring welds is hot, noisy, uncomfortable work that can easily cause an “emotional” exhaustion that cuts into productivity just as much as physical fatigue. And many operators working in that unpleasant environment understandably have relatively low morale, which usually lowers productivity.

3. Less setup time.

The combination of high dynamic range imaging and built-in auxiliary lighting reduces the time required to set up the weld because adjustments to the weld process can be done while viewing the actual result on a screen. In addition, there’s no need to change the lighting each time the arc is off during the initial positioning of the arc tip to the weld seam.

4. Increased run-time productivity.

Arc-on time increases with high dynamic range imaging because operators can see both brightness extremes of the weld scene without having to stop the process to adjust lighting.

Because operators can view every part of the process, they can know exactly when it’s necessary to make productivity-enhancing adjustments, such as:

  • Aligning the weld head to the seam or the filler material.
  • Modifying wire length or shielding gas flow rates.
  • Detecting impurities or porosity in the weld pool.
  • Optimizing the weld process by keeping the shape of the molten metal as ideal as possible.

5. Reduced costs caused by bad welds.

Because high dynamic range imaging enables operators to monitor the full weld scene in real time, operators can use their skilled judgment to catch problems with the torch tip, material flow, melt pool, edge presentation, keyhole, seam alignment, shielding gas barrier, and weld undercut before they result in large batches of defective product.

This high level of process control reduces the cost of rework, such as grinding off spatter, chipping off slag, grinding welds down, or even having to redo the weld. It also lowers the cost of scrap volume, which is particularly important in high-volume production environments where direct material costs are a major variable cost.

Operator visibility into the entire welding process also allows some defects—such as impurities or porosity in the weld pool—to be detected that would otherwise escape detection by postweld inspection equipment (eddy current and ultrasonic). This reduces the costs of returned product, which can be incurred through reworking to improve quality to the customer’s level of expectation, extra shipping and handling, and other costs for placating the customer.

6. Faster troubleshooting.

When operators detect defects, they can use a time-logged video record to quickly pinpoint and correct the causes of the defect. It’s easier for the operators to see the entire process—in both brightness extremes at the same time—to determine what’s going wrong.

7. Fewer final inspections.

Because weld view cameras allow operators to use their expertise to limit defects, the number of defects in the final product will drop significantly, reducing the need for final inspection.

Most defects will already have been caught by the time the welding is complete, and any type of final inspection that is required need be done only on those segments of the weld where the weld parameters went out of control.

8. Continuous improvement and training.

By auditing the camera’s video record, manufacturers can identify opportunities to improve quality and efficiency in their processes. The video record can help reduce or even eliminate recurring quality defects such as porosity or contamination that are otherwise difficult to detect on an ongoing basis.

Trainees, as well as experienced operators, can learn from videos of both successful and problematic welds—increasing their productivity.

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