Cost performance is the “biggest driver in laser applications,” Mike Sharpe, staff engineer in the materials joining group of FANUC America Corp., said. “Fiber lasers… all those types of one-micron wavelength lasers are solid state in nature and that’s really driven the cost down and improved the efficiency of the lasers. Multi-kilowatt lasers now become more mainstay because they’re affordable—affordable to operate versus CO2 and other methods of lasing and they’re easy to manage because of the fiber delivery, which lends itself to robotics.”
The automotive segment in particular pushes the use of robotics “due to their familiarity with the technology and the favorable price point and greater flexibility compared to hard automation or custom solutions,” Doug Hixon, a North Carolina-based robotics application engineer for ABB Robotics’ US unit, said. “Robots are purchased
in such large volumes in automotive that the price is attractive if the robot is capable of performing the task.”
Lasers and robots are natural partners, according to manufacturers. And because of their tenure in two important aspects of the current revolution in making, they serve as two grandes dames in smart manufacturing.
The pair has long worked together. Robots and other automation guide lasers for welding, marking and other processes. Both sides of the partnership have gotten better, improving accuracy for starters. Software has become more sophisticated.
And as a result, laser robotic systems are seeing more applications, including aerospace.
“Laser processing can’t be done manually,” said Andy Hromadka, project integration manager for Trumpf Inc., a maker of fabricating equipment and industrial lasers. “Automation is required in some form. Our collaboration with the robot manufacturers is typically as colleagues in industry. We are both manufacturers of enabling technologies.”
Often, the end customer selects which laser system it wants to pair with which robot.
“We strive to make a robot that will accept and work with any tool, provided it fits within the payload of the robot,” said Daniel Moore, technical support manager for Universal Robots USA Inc.
“While we do not directly work with any laser company, the path repeatability and point repeatability of the robot is available to any application, laser or not,” he said. “We also provide a very open architecture, allowing for companies to design their own plug-ins and software modules to speed up interfacing between the robot and the laser system and allow customization directly on the robot pendant.”
Prima Power Laserdyne, a maker of laser and sheetmetal machinery, is involved with aerospace. “What we do, what the machines we build do is produce holes,” President Terry VanderWert said. “The precision of that hole determines the consistency of the air flow.”
With more precisely made holes, he said, aircraft engines can have improved air flow and lower fuel consumption.
“Increasing the precision of the laser processed feature has enabled new designs and new features,” VanderWert said. “We’re competing against other technologies.”
How auto industry led the way
“Automotive technology has driven laser applications,” FANUC’s Sharpe said. “Automotive tends to have deeper pockets than general industrial and quicker programs than, let’s say, aerospace.
“Back in the late ’90s, it was hydroforming,” he said. “Hydroform is where you blow up a tube to get a net shape and you can then make supposedly cheaper, lighter, stronger or more tailored car parts. But the problem is you can’t cut them with a stamping die; you need to trim them mechanically or with a laser.”
Hydroforming was used on large pickup models. “Those big programs drove volume,” he said. “By driving the volume, that allowed laser manufacturers to invest at lower cost.”
More recently, the industry had used high-strength steels. Such steels are stronger than traditional steels, so less of the material is needed. That’s one strategy automakers are using to make vehicles lighter—to meet federal fuel-efficiency standards.
“Those you can’t really trim in a die,” Sharpe said. If a die is used for trimming, it will only last “a few hundred cycles.” This reality, he said, has encouraged the use of robotic laser devices for cutting.
Other lightweighting strategies include using aluminum, which necessitates new ways of joining aluminum to steel while avoiding corrosion. That also has led to using robotic laser devices more, he said.
“In the last few years, we’re seeing more of the US nameplates doing what the Europeans have been doing probably for a decade: taking aluminum structures and gluing them to a galvanized sheetmetal and riveting it to something else,” he said. “Those things are really coming around.”
FANUC is involved with production of General Motors Co.’s Cadillac CT6, which uses a mix of aluminum and high-strength steels. The luxury four-door is the lead application for a GM-developed steel-to-aluminum spot-welding process.
With lightweighting and using new materials, “it’s very effective for people to apply robotics in those applications,” Sharpe said. “Lasers have gone down [in cost]. Material science is being proved, and that allows them to apply the technologies together and make better vehicles for us.”
Aerospace use jumps
Advancements in laser robotics have spurred increased use in aerospace, he said.
“A lot of the stuff we’re doing is specific to hard facing the struts and the screws of a turbine,” Sharpe said. For repair work, a laser process “with powdered metal or a wire fed system” can be used “to build those back up.”
Also, with composite materials, lasers can be used to clean surfaces before applying adhesives, he said.
Prima Power Laserdyne worked with FANUC on a system for an aerospace customer that VanderWert declined to identify. They used a FANUC robot to load and unload parts.
“Normally one doesn’t think of low-volume production as a case for robotic load and unload,” he said. But the customer found that a machine went underutilized. “Invariably, the operator would be on break when the part was finished,” and so the customer wanted to automate the load and unload of parts.
Prima originally started by making articulated arm robots for inspection applications, then entered into laser systems using Cartesian robots with three linear axes and two rotary axes.
AM has processing needs
Laser robotic systems also have an opportunity with increased 3D printing output of parts.
3D printing produces parts directly from a digital design. However, many 3D-printed parts still have rough surfaces that require additional work. “Laser robotics can be used for processing: machining, smoothing, grinding or whatever,” FANUC’s Sharpe said.
“We are experts at motion and motion planning and control,” he said. “We also have an expertise in laser process and controls. Our scope is to bring that together to market, but we also work together with others as customers require.”
One of FANUC’s priorities is improving precision of its robots. Increased precision expands the number of applications, Sharpe said.
“Laser sources today are more stable,” VanderWert said. “The machines are more stable.”
Robotic laser systems also will be affected by Internet of Things (IoT) technology that helps machines communicate with each other and helps operators monitor things via smartphones and tablets.
“We’re very early in that. In new machines, you can collect a lot of data most customers don’t know what to do with,” VanderWert said. IoT will probably help with preventative maintenance “so there’s no real hiccup in product coming off the laser.”
Lasers now simpler to use
Trumpf’s Hromadka said “the single biggest improvement” is how “lasers are simpler to use, maintenance-free and less complex.” Both the laser and robots “are being driven by the same thing in industry for 24/7 uptime. They’re driven by the same industrial motivations.”
Operators “will probably need more training because of the sophistication of these systems,” he said.
“We’ll see the need for technicians that have a higher skill level. Automation cuts back the need for training in manual tasks. Those folks are going to need to get more sophisticated,” Hromadka said. “I don’t think there will be a cutback on the amount of training.”
Software gets better
“Software has been the biggest improvement with respect to laser applications,” ABB’s Hixon said.
“Robotic offline programming software has improved the quality of programming that was previously relied on by point-to-point programming,” he said. At the same time, he said, “motion algorithms have improved over the years to fine-tune speeds and accelerations while minimizing positional error.”
More improvements are expected in coming years.
“A big advancement on the horizon is the robot learning by doing,” Hixon said. “Integration into self-calibration techniques and self-learning to optimize performance are areas where robots will continue to improve.”
Hixon also said training is important but should be done by a “technology champion” at the customer.
“So rather than a whole staff of trained employees, the newer robotic technology is easier to learn through hands-on experience. But a clear technology leader still needs to be part of the equation.”
Better inspection tools coming
Moore of Universal Robots also said laser systems have gotten more affordable.
“Now, even small shops could conceivably afford a laser welding system,” he said. “The ability to channel a laser down a flexible fiber-optic rather than a system of mirrors means it is easy to mount a small laser system on nearly any robot. Laser scanners and marking tools, particularly inspection tools, have thus seen an increase in demand, which has prompted further innovation.”
Vision systems will improve as processors get better. “This will lead to even better inspection tools and optics,” Moore said. “Galvo scanners will continue to improve, shrinking in size.”
IoT presents the industry potential gains and challenges, he said.
“Our own robot has a system of passwords to protect its operations and only allows operator-selected inputs from outside systems,” Moore said. “Far too many IoT systems have few or zero protections from hacking, script injections or remote monitoring from unintended persons.”