Above: The JOSY 3D weld inspection system mounts to a 6-axis robot to quickly and reliably scan weld joints.

System uses 3D sensors with an algorithmic process to inspect weld dimensions for compliance and defects for rework.

September 2022- A weld defect is a terrible thing to miss. “I’ve experienced those firsthand, unfortunately,” says Jeff Henderson about a time in his career before he became key accounts manager at Abicor Biznel USA Inc. In addition to a variety of welding equipment including manual, robotic and laser welding the Frederick, Maryland-based company offers the JOSY (joining system) 3D weld inspection hardware and software package developed by SmartRay GmbH.

At a Tier 1 automotive supplier, the range of scenarios for missing weld defects starts at the small scale in which several defects are found on a couple of different parts. The OEM then issues a quality report warning that the parts are not up to par, Henderson says.

The OEM has options depending on the severity of the defects. “The OEM can decide to fix them on their own, ship the parts back to have them fixed or have a person come out to their plant and fix them onsite,” he adds. “I’ve been through all three of those different scenarios. All of them cost money.”

When there are continuous issues with weld quality, an OEM is likely to propose third-party inspection in which the Tier 1 supplier is financially responsible for the cost of that inspection on top of the inspection already happening at the plant, Henderson says. The price tag can vary from $10,000 to $50,000 a week or more, depending on part quantity. “Once you dig yourself into that hole, it’s hard to get out of.”

And if any parts with defective welds make it into vehicles on the road, there is a risk of recalls and possible lawsuits, according to Henderson. “First off, it can destroy a relationship between a supplier and a customer. Then there are always major fines coming from the customer, so we’re talking millions of dollars in a blink of eye, depending on the product.”

     The system’s sensor captures 2D images and builds a 3D model of the weld while it’s being scanned.

The list of possible weld defects includes micropores, macropores, pore nests, holes, incomplete groove fills, incomplete welds, spatter and an undercut. To minimize, if not alleviate, those defects, the JOSY system automates the weld inspection process to make it more reliable and accurate and increase the production speed, according to the company.

“Cycle time is what drives the plant,” Henderson says. “If you can’t make cycle time, if you can’t make enough parts, you’re not going to be able to make a profit.”

LASER TRIANGULATION

The laser-based triangulation used with JOSY projects a laser beam onto the weld in question and quickly scans it. The system’s sensor captures 2D images and builds a 3D model of the weld while it’s being scanned and runs it through a software algorithm, which is customized to an end user’s weld specifications. “We use that 3D model to find any defects that would be outside the window of allowable defects in the weld spec.”

Once the system sees something in a weld that is out of tolerance, the system will flag it and enable the worker on the line to repair the weld and record that repair, Henderson adds. “You have all of the data collected from that weld, what’s wrong with it and that it was fixed. All that can be stored and used at a later date, if needed.”

For instance, if a customer brings a quality claim against a parts manufacturer with the JOSY system, the manufacturer can provide proof to defend itself against the claim, he says. The information can be sorted into specific defects that are found on certain welds, such as the worst-off ending welds that might be the result of improper part clamping or repeatability issues at a workstation.

“It helps point the finger in the right direction to be able to focus your continuous improvement properly instead of going around blindly with less data,” says Henderson.

ROBOTS VERSUS HUMANS

An end user requires a six-axis robot to maneuver the sensor, which is about the size of pack of cigarettes, and Henderson says Abicor Biznel will work with any major robot manufacturer. “The robot is probably going to be a vintage within the last 10 years to be able to be compatible with the equipment.”

Various nondestructive methods are available to inspect welds, including X-ray, ultrasound, magnetic particle and die penetrant, which have limitations based on a slow inspection speed, high cost and/or inability to automate, according to Henderson. “The only one that’s actually worked so far with high-volume production is manual inspection. We usually market this system to people doing manual inspection.”

     The scan speed for the sensor is about 130 mm per second, which is typically faster than most welding speed.

Even when a weld is deposited with robotic welding equipment, manual inspection relies on a human to make a judgement call.

“Humans aren’t 100 percent right 100 percent of the time, so it takes some subjective views out of judging these welds and makes them fully objective,” he says. “So, this system is going to be able to quickly scan all the welds that need scanning, make a judgment call on those welds within fractions of second and then display those results for an operator. It takes the guesswork out of visual inspection and manual repair, and it also gives you a whole lot more information about what’s going on with the weld health on your line.”

Henderson recalls his time as a welding engineer, which involved training repair operators about what defects to look for, what to let pass and what to fix. “It was always one of the most difficult parts of my job, trying to get everybody on the same page when looking at a part.”

The scan speed for the sensor is about 130 mm per second, which is typically faster than most welding speeds, he notes. However, when the welding cycle time is quicker, the system’s controller can run two sensors mounted on two robots simultaneously.

TWO ON ONE

Running a dual-sensor system can provide cost savings when one sensor inspects one part at one weld station while the second one inspects a different part at another station. “You’re able to keep the amount of hardware down and keep the cost a little more reasonable on the dual-sensor system,” Henderson says. What our customers are going to use it for mainly is within the same cell to help them save on cycle time.”

In addition to inspecting for weld defects, the JOSY system can determine weld dimensions, he says. That capability is possible even though the system cannot look beneath a weld surface because it performs topical inspection on only the surface. Instead, the system’s algorithm accurately estimates the cross-sectional area and determines weld thickness, length and width. JOSY can also indicate whether the weld is off location, “which is a huge issue.”

      Software is included in the JOSY 3D weld inspection package.

Henderson claims the SmartRay JOSY 3D weld inspection system has been well-received by companies that have implemented it. “We have a couple customers that will not install a new MIG welding line or laser welding line without this inspection process in place.”

In addition to selling JOSY throughout the U.S. and Canada, Abicor Biznel can commission the system alongside an integrator, provide robotic programming assistance and training, create the tolerances needed within the algorithm, and service the system on site or remotely.

“If there is an issue on the customer’s floor and somebody can’t figure it out, we’re a phone call away,” Henderson says. “All I have to do is hop on my computer, connect with the system and it’s like I’m right there.” FFJ