Robotic Welding Systems: An Overview

The robot&#;Unimation 001&#;was developed by George Devol and Joseph Engelberger in to perform welding tasks deemed hazardous for manual operators. However, robotic welding did not gain momentum until the s. At that time, manufacturers influenced by General Motors began to realize the potential of automation. The path was followed by many other metal-working and manufacturing industries for improved efficiency and productivity.

OLIVET are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

Continued developments in technology and automation have enabled more industries to adopt robotic systems and increase their productivity. The welding industry has responded to the &#;robotic revolution&#; by leveraging these technologies to build robotic welding systems.

Use of Robotic Welding System in Industries

New technologies have enabled automated and programmable robotic welding systems to handle the workpiece and perform the welding procedure. As companies have transitioned to technology-driven solutions like robotic welding, they have realized an array of benefits for weld quality, efficiency, and safety.  

Improved Quality

Programmable robots can perform high-precision welding. Additionally, robotic welding systems ensure that high-precision welding is also highly-consistent welding. Thus, each automated welding process provides consistent weld results. The degree of quality attainable by robotic systems may be difficult to achieve with manual welding.

Greater Productivity

Manufacturers can employ robots on the assembly line to achieve higher productivity. Not only can robots perform complicated welds that produce consistently high-quality results, but they can also work more easily in tight, cramped spaces. And since robots work longer hours than their human counterparts, companies can generate further productivity gains.

Safety

The manual welding process presents several associated health risks, including exposure to toxic fumes and gases, as well as electrical shock. Robotic welding helps reduce risks to human health and safety.

Minimized Waste

The accurately optimized robotic system provides high-quality, consistent welds with far fewer errors than manual welding. Fewer welding errors translate to less wasted materials.

Reduced Cost

Robotic welding facilitates production and labor cost reductions. By integrating robotic welding systems, manufacturers can reduce or eliminate the need for highly skilled technicians and the associated high costs. 

The future of welding resides in technological innovations like robotic welding systems. As manufacturers continue to recognize advantages like those described above, more industries will look for ways to incorporate automated and robotic welding into their operations. 

The Future of Robotic Welding

Advances in automated and collaborative welding have paved the way for further developments in welding technology. Although welding robots are available on the market, the technology should continue to progress in the coming years with the growing need for efficient arc welding technology. Additionally, smart factories integrated with the Internet of Things (IoT) are further expanding the need for welding technology innovations. Future robotic welding systems dedicated to precision and cost-reduction will likely focus on weld process control, parameter optimization, simulation, and programming. Artificial Intelligence (AI) should also become a more prominent characteristic of technologically advanced welding operations.  

Robotic Orbital Welding

Conventional orbital welding is a mechanized process that uses an automated weld head to move the electrode and perform the weld. In robotic orbital welding, robots rotate the arc 360 degrees along the workpiece&#;such as a pipe or tube. The use of robots for orbital welding enhances consistency, productivity, and product quality. Likewise, robotic welding systems help manufacturers reduce waste, production costs, and human interference. New developments in robotic welding will seek to enhance these advantages in cost savings and increased efficiency. As these new welding technologies are integrated into smart factories, the return on industry investments should continue to accelerate.

Arc Machines, Inc., a welding technology leader, brings decades of experience creating orbital TIG welding schedules for our clients. Solutions like AMI orbital weld heads are compatible with your robotic welding systems. Contact AMI to learn more about training, or contact to learn more about AMI orbital weld heads and power supplies.

The big question about Artificial Intelligence, other than whether it will destroy human civilization, is the effect it will have on employment. Large language models already seem poised to automate large fractions of the work in certain industries, and the technology is only getting more capable.

There are, broadly, two schools of thought about this issue, what we might call the optimists and the pessimists. The optimists note that we&#;ve been automating work for hundreds of years, and it has yet to result in sustained, large-scale unemployment. Certain jobs, like switchboard operators or dockworkers, get automated away or see drastically reduced employment as technology improves, but on an economy-wide basis workers get reallocated to other jobs that still require human labor. In this view, AI will simply be a repeat of this historical pattern.

The pessimists, on the other hand, think that this time will be different. If an AI can do everything, or nearly everything, that a human can do, and do it for cheaper, there&#;s no longer any economic reason to hire a human. In this view, AI will structurally reduce the demand for all human labor, the same way that cars structurally reduced the demand for all horse labor.

Horse population in the US over time.

As the saying goes, it's hard to make predictions, especially about the future. It's not yet clear what the ultimate impact of modern AI technology will be. But one thing we can do to try and understand the problem is take a closer look at the mechanics of how automation has happened historically. Understanding the specifics of how automation has happened in the past might give us clues as to how it will proceed in the future.

A good job for drilling down into the specifics of automation is welding. Welding today exists right on the &#;automation frontier&#; &#; some industries, like car manufacturing, have automated nearly all their welding, while others, like construction, have automated very little of it. Welding also encompasses a fairly narrow set of tasks that have changed comparatively little over a long period of time. This makes it easy to understand what, specifically, is being automated, how automation capabilities have advanced, and how advancing automation has affected welding employment.

How welding works

There are two main types of welding to consider when talking about welding automation.

The first is resistance welding. With resistance welding, the parts to be welded are pressed between two electrodes. Current then runs across the electrodes, and the electrical resistance of the metal between them causes the parts to heat up, melt, and weld together. Resistance welding can be done as &#;spot welding&#; (where just a single point is welded), or as &#;seam welding&#; (where a continuous seam is welded). Resistance welding is generally used to join thin materials, such as sheet steel.

Resistance welding diagram.

The second type of welding is arc welding. With arc welding, an electric arc is created between a metal electrode and the metal to be welded, and the heat of the arc melts the metal. The arc is then moved along the joint to be welded. There are several different types of arc welding, such as MIG, TIG, and SMAW, which differ in things like the material of the electrode, whether the electrode is consumed in the process, and how the weld is shielded from the air.

Gas Metal Arc Welding (GMAW), also known as Metal Inert Gas (MIG) welding, a common type of arc welding.

In addition to these, there are other types of welding such as forge welding, laser welding, friction welding, and oxyacetylene welding. But for the last 100 years most welding, and most welding automation, has been done with either resistance or arc welding.

A brief history of welding automation

Machines to automate the welding process were built very early. Resistance and arc welding were both developed in the late 19th century, and by the early 20th century automatic machines had been built to do both. Resistance-welding machines were particularly simple to build, as all the machine had to do was position the welding electrodes correctly with respect to the parts to be welded, press them together, and run the current.

Chain-making machine from that would automatically bend the wire and spot weld the ends together, via

American Machinist

.

Automating arc welding was more complex. Unlike resistance welding, arc welding had a variety of parameters that needed to be controlled such as the feed rate of the welding electrode, the traveling speed of the machine, the current and voltage, the distance and angle the electrode was held from the base metal, and so on. Many of these parameters affected each other, and they were also affected by things like variation in current from the electrical generating equipment. Arc welding parameters also needed to be tailored to the specifics of the metal being welded and the configuration of the joint. A butt weld on inch-thick steel plate demanded different welding parameters than a fillet weld on quarter-inch aluminum. But these problems were solved, and by the s automatic and semi-automatic arc welding machines were in use.

Types of weld joints.

Automatic arc welding machine built by GE circa , via

Electric Welding

.

Early welding machines were what today we&#;d consider &#;hard automation.&#; They were built to repetitively perform some specific series of motions, and had little flexibility. An automatic welding machine could be adjusted to accommodate things like differently sized parts of the same type, but variation beyond that, such as different weld geometry, would require a different machine to be built. Because of this, these machines were most useful for producing large volumes of very similar parts.

These types of welding machines became popular, and by the late s there were automatic or semi automatic machines for nearly every type of welding process. Car manufacturers developed special machines for performing multiple spot welds at once, and manufacturers ranging from boiler makers to locomotive builders used automatic arc welding machines for things like steel tanks, pistons, and pipes. By the late s, welding machine operators (who probably mostly operated resistance welding machines) made up more than half of all welders.

Automatic machine for arc welding diesel locomotive pistons, circa , via

The Welding Journal

. This type of machine could only make circular welds by rotating the workpiece, though it could probably accommodate parts of different sizes by raising or lowering the welding electrode.

For more information, please visit Programmable Welding Positioner Manufacturer.

Semi automatic pipe welding welding machine circa , via

BLS

.

The next stage of welding automation was with robots. The first industrial robot in the world, the Unimate, was used to unload die-casting machines at a General Motors plant in , and three years later GM decided to install 66 Unimates for spot welding at its Lordstown, Ohio plant. By there were several thousand robots working in the car industry around the world, and 65% of them were being used for welding.

Unlike previous &#;hard&#; automation, which only did one thing, a robot could be adapted to different types of tasks by reprogramming it. This was especially important for the car industry, which had historically retooled or scrapped a significant amount of machinery whenever a new car model was introduced. But with robots, retooling could be done just by feeding them a new program, greatly reducing capital costs. The car industry quickly became the largest consumer of industrial robots.

As with the early 20th century welding machines, spot welding, being simpler than arc welding, was automated with robots first. By the early s, spot welding robots were common in the automobile industry, while arc welding robots were still somewhat experimental. With spot welding, the robot just had to move the spot-welding gun into the correct position &#; it (mostly) didn&#;t matter how it got there or how smooth the motion was. With arc welding, however, the robot needed to move smoothly over a specific path, something that was beyond the capabilities of the early point-to-point, hydraulic-powered robots. And the robot had to control not only the motion of the welding gun, but also its orientation, taking into account how both affected the heating rate of the piece being welded.

Part alignment was also a more complex problem with arc welding robots. With spot welding, the force of pressing the electrodes together eliminated any gaps between the metal sheets being welded. But with arc welding, which was done on thicker, heavier parts, there wasn&#;t any way to squeeze them together to eliminate gaps, and variation in part thickness or part fixturing could slightly change the joint geometry. A human welder could naturally compensate for this sort of variation by making adjustments on the fly, but a robot programmed to follow a specific path with specific welding parameters could not.

Spot welding vs arc welding robot installations in West Germany in .

There were basically two strategies for addressing this. The first was to reduce variation and increase the precision of the arc welding process and the processes upstream of it, so a preprogrammed, repetitive process would work reliably. The second was to use sensors and feedback mechanisms to give welding robots the ability to compensate for variation that did occur.

Getting robots to arc weld successfully seems to have required both. On the variability reduction side, electric-drive robots were introduced in the s, which were more precise and could more easily trace smooth, continuous paths than hydraulic-powered robots. More powerful computers and higher-capacity computer memories made it possible to calculate and store the proper continuous paths &#; prior to this, arc welding systems would &#;cheat&#; and use point-to-point movement with closely-spaced points. Manufacturers adjusted their upstream processes to produce more uniform parts with less variability. Part tolerances were reduced in things like metal stamping, jigs and fixturing were made more precise, new handling methods were introduced to prevent parts from being damaged moving between stations, and parts were thoroughly cleaned before welding.

To compensate for variation, a variety of weld-sensing technologies were developed that would allow the robot to maintain the proper position with respect to the weld. These technologies basically fell into three categories. 

The first were basic touch sensors: the robot would move until the welding wire touched the part, which completed an electrical circuit and indicated that the robot was touching the part to be welded. By moving along different axes, a simple &#;map&#; of where the part was with respect to the robot was created. Touch sensing was simple and reliable, but it was slow, and couldn&#;t do much more than help the robot find the part. (Touch sensors could also be used to ensure a welding gun was following a groove to be welded, but this was more common in hard automation welding.)

The second type of weld sensing technology was through-arc sensing. With through-arc, the robot would be programmed to weave back and forth as it welded. This would cause the length of the arc to change as it got nearer and farther from the base metal, which would change the current and voltage in the arc. This allowed the robot to stay centered on the weld seam, compensating for things like part misplacement or heat distortion.

Through-arc sensing. As the arc weaves back and forth, the voltage changes, enabling the robot to stay centered on the weld seam.

The third type of weld sensing was vision based. By measuring the reflection of laser light, a robot could calculate the location of the piece to be welded, similar to touch sensing but without having to actually touch the workpiece. Lasers could also be used for seam tracking: by measuring the reflection of laser light in front of the weld location, the seam could be located and the robot could follow it exactly. Laser seam tracking could also compensate for variation in the gap between the parts to be welded. The laser could measure the thickness of the gap, and then automatically compensate by changing weld parameters.

Other types of weld-sensing technology were developed, such as acoustic seam finding, but touch, through-arc, and laser-based became the most dominant. By the late s these technologies were well established, and they remain the most common type of weld-sensing technology today.

Robotic welding also benefited from more general advances in robotics technology. Lifting capacity increased which enabled larger welding guns. More degrees of freedom were added, which gave robots more flexibility and enabled them to reach previously inaccessible places. Computer power continued to increase, which enabled faster seam tracking calculations and allowed the robot to move faster.

Over time, robot manufacturers and automation integrators developed ways to make it easier to integrate robotic welders into manufacturing environments. Manufacturers learned how to design parts that were easy for a robot to weld. Programming the robot was simplified. Historically, programming a welding robot was a slow, tedious process that required entering commands into a teach pendant, but modern welding robots can be programmed quickly with user-friendly software, or by physically moving the robot through the proper motions. In some welding machines, the welding program can be created automatically by feeding it a CAD file of the part to be welded.

Robot manufacturers also introduced collaborative robots, or &#;cobots&#;. A conventional industrial robot isn&#;t safe to work near, just like any other piece of rapidly moving industrial equipment. But a cobot is designed to limit the amount of inertia it exerts, and has feedback sensors that can stop it if it impacts something, making it safe for humans to work near. This makes a cobot somewhat easier to integrate into an existing shop. Today, automation integrators sell &#;turnkey&#; robot welders that consist of a collaborative robot and welding equipment mounted to a movable cart. The robot can be moved into position, programmed, and start welding in a matter of minutes.

Integrated cobot welding tool from

Vectis

.

There are also efforts to apply AI and computer vision technology to welding automation. Startups like Path Robotics and companies like Abagy, for instance, have robotic welding systems that don&#;t require programming at all. These systems look at the part to be welded using a 3D camera, and compare what they see to a CAD file of the part or parts to be welded. They then work out where the welds are, and the path that the robot needs to take to create the weld. This lets the robot compensate for things like changes in part position, variation in part dimensions or gaps, and clamps or fixtures that might interrupt the path of the welding robot. It's currently something of an open question whether this technology will be competitive with manual programming, which continues to get easier.

So, welding automation started with specialized machines that repetitively performed some specific welding motion. These early machines had no ability to sense or respond to feedback from their environment, had limited ability to handle different sorts of tasks, and required humans to operate. They could often only be justified for producing large volumes of very similar parts.

With the advent of robots, welding automation gained more flexibility. Instead of scrapping or rebuilding machinery when the welding task needed to be changed, you could simply reprogram the robot. Because robots were still expensive capital equipment that required large production volumes to justify, they were initially most widely adopted by automotive manufacturing, which had both very large production volumes and frequent retooling requirements for every new model change.

The first robots could only move from point to point in jerky, uncontrolled motion, which only made them suitable for spot welding, but as the technology advanced robots were able to successfully arc weld as well. Over time welding robots gained slightly more ability to sense their environment and compensate for things like mislocated parts and variable gaps in weld joints, but these capabilities were specific and narrow. They couldn&#;t compensate for things like a clamp that impeded that path of a robot, or a part that was too dirty to weld properly, or a part that was oriented vertically instead of horizontally, or any of the other thousand things that a manual welder could automatically adjust for. Today, this sensing ability is still fairly limited. Companies like Path Robots and Abagy are trying to push back this automation frontier somewhat, but their options are still limited in what sort of environmental variation they can handle (such as cleaning dirty parts).

Automation and the welding job market

How have advances in welding automation affected the welding job market?

If we look at welding employment over time, we see a peak in at just under 800,000 welders, declining to around 430,000 welders today (though welding employment has actually risen since ).

Via BLS and census data

Interestingly, we see the largest decline not in manual welders but in welding machine operators. In there were an estimated 200,000 welding machine operators in the US, compared to just over 30,000 today.

Via BLS and census data

Of course, this is confounded by other changes in US industries over time. If output has decreased in welding-intensive industries like shipbuilding, or products have changed such that they require less welding, this would reduce welding employment irrespective of the level of automation.

One way to address this is to look at an industry that has had somewhat static welding demand. The car industry is a good candidate: car bodies are mostly made by welding together pieces of steel, and this has been true since the early 20th century.

If we look at welding in the car industry, we see the same basic trend. Welding employment peaked in , right around when robotic welding was introduced, and has steadily declined since then. But while manual welding employment has fallen by about 50%, welding machine operator employment has fallen by close to 90%. This would be even more stark if we adjusted for vehicle output, which increased from about 9.6 million in to about 12 million today.

Via

Federal Reserve Studies

and BLS data

Advancing welding automation technology, then, seems to have mostly taken tasks that were already automated to some degree, and made them more efficient. Better welding robots and weld sensors reduced the need for expensive machine retooling, and reduced the number of machine operators. It&#;s had comparatively less effect on skilled welder employment: better sensors, cobots, and portable welding rigs have changed the calculus somewhat, but a robotic welding system is still far less capable than a manual welder in terms of the sort of variation that it can cope with and the sorts of problems it can solve.

A robotic welder also remains an expensive piece of capital equipment, starting in the neighborhood of $50-100,000 even before you add in things like laser seam tracking (which might be another $50,000). This is a substantial investment, especially when you consider that the average wage for a human welder is about $47,000 per year, a robotic welder will still require someone to operate it, and there will be tasks that the robotic welder can&#;t do. A robotic welder is faster than a human and can work hour after hour, day after day without taking a break (typical estimates range from 3 to 6 times as productive as a human welder), but taking advantage of that requires a high enough volume of output to spread the costs over. A human welder is less productive, but remains more flexible than a robot, and evidently enough welding tasks require that sort of flexibility that much welding in the US is still done manually. Interestingly, the pitch for a lot of robotic welding systems is often more focused on the difficulty of finding skilled welders, rather than on the potential cost savings of a welding robot.

Abagy&#;s landing page as of 11/22/23

Thanks to Josh Nieman for conversations which informed this piece. All errors are my own.

The company is the world’s best Programmable Welding Positioner Factory supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.