As robotics companies push the boundaries of automation, human operators and robots are working in closer collaboration than ever before.
"Your new colleague is a robot.” This is a favourite line of Thomas Visti, chief commercial officer for Denmark-based Universal Robots, which is at the forefront of a revolution in automation that some maintain is as important as GM’s first manufacturing robot in 1961.
Known as collaborative robots, this new breed can work safely alongside humans courtesy of a newfound awareness which means that no protective cage is needed. These nimble machines thus have the potential to conquer the last remaining areas in vehicle manufacturing to have so far resisted wholesale automation: trim and final assembly.
Universal’s robots are currently at work in two factories: VW’s vast engine plant in Salzgitter, Germany, and BMW Spartanburg in South Carolina, US. These are the two projects Visti can talk about, but he says Universal is testing with nearly all major car companies in 50 countries. Not bad for a company which sold its first robot in 2009, but of course Universal isn’t the only one. Established robot maker Kuka has a project with Daimler and Swiss giant ABB is investigating similar collaborative technologies.
At VW, Universal robots insert glow plugs into diesel engines, a fiddly job which was previously done by hand. Its six-axis arm has the dexterity to access the cylinder head and it works comfortably and safely alongside human operators. “By using robots without guards, they can work together hand-in-hand with the robot. In this way, the robot becomes a production assistant in manufacture and as such can release staff from ergonomically unfavourable work,” says Jürgen Häfner, project manager at Volkswagen’s Salzgitter plant.
VW can do away with guards because of the robots’ safety feature; they stop if they experience pressure, such as contact with a human. The robots are also relatively small, Universal’s two models having a lifting capacity of 5kg and 10kg respectively, so they easily fit alongside the production line.
The benefits are two-fold, according to Visti. “From what the car companies tell me, it gives them more productivity, but many times they say it’s also an improvement of quality,” he says.
It’s also about flexibility. “Robots are typically programmed in the same position doing the same stuff for seven years, because that’s the lifecycle of a type of car,” he says. With plants having to become increasingly flexible as to the models they build, a lightweight, easily re-programmable robot is a real asset. However, Universal is not involved with the actual programming. For VW, this is done by supplier and robot specialist Faude Group, while BMW in Spartanburg keeps its programming in-house.
In fact, Universal did not have automotive companies in mind when it designed the UR5 and UR10. According to Visti, the company initially targeted small and mediumsized manufacturing industries. “Automotive has taken us by surprise. We didn’t expect it,” he said. There were no special demands from the car companies, he adds: “It’s up to us to make it so flexible it fits into all applications.”
Similarly, Kuka’s collaborative robot iiwa (intelligent industrial work assistant) was originally designed for use in space before it was adapted to help build gearboxes for Daimler at its Mercedes plant in Stuttgart, Germany.
This ‘third hand’ robot is ideal for assisting in situations where the ergonomics are difficult for human workers, for example overhead work. Daimler is impressed. “We see its enormous potential to further improve the flexibility and efficiency of our manufacturing operations,” said Dr. Wolfgang Bernhard, board member for manufacturing and procurement, in a statement last year. Similarly, Universal’s five robots at BMW Spartanburg help out by applying a sealant ahead of an operator fitting a windscreen; previously, employees could not do this job for longer than two hours.
Examples like this support Visti’s assertion that collaborative robots make factories more productive, something he claims leads to companies actually employing more staff as business grows, rather than reducing head count. He predicts that his robots will be popular even in countries where labour is cheap, such as China, where employees jump ship at the promise of even very small salary increases at rival car companies.
Recent figures from the International Federation of Robotics show that China’s automotive industry has gone from 51 robots (of all types) per 10,000 employees in 2006 to 213 in 2012. That is still a long way from the 2012 robot density of Japan – the world’s highest at 1,562 per 10,000 – or 1,137 in France, just above Germany, but Universal believes China will close the gap. “It’s the fastest-growing market for robots,” says Visti.
No matter where cars are made, robots are more accurate than humans and that will drive their sales, according to Nigel Platt, global product line manager for welding and cutting at ABB. “At the moment you’ll see a higher manual content in the low-wage economies, however it’s much more difficult to maintain quality, consistency and output. Automating in a high-cost country actually puts it at a similar cost base,” he says.
ABB is working on a collaborative robot called Frida which it says will be available in “a couple of years” and will be used in the assembly of electronics such as instrument panels and electronic control modules. However, it has also incorporated into its traditional body-in-white (BIW) robots some of the safety technology which has allowed collaborative robots to flourish.
Called SafeMove, the technology involves in-built scanners which monitor the space around the robots. If an operator comes near, for example to change a spot weld, the robot slows down; if an operator moves closer still, it stops altogether. According to Platt, this saves valuable time compared with the traditional method of stopping and starting.
The real enabler for this development has been legislative change. “Not so many years ago you weren’t allowed to do this,” said Platt. “You had to be in power-off condition. If the guard was open, you weren’t allowed to have the machine on with the motors live. Now, they can stay live.”
Visti at Universal makes the same point. All his applications are subject to a risk assessment, but the safety is such that 80% can be run without guards.
ABB says car-makers can even get rid of cages altogether with SafeMove, but according to Platt many keep them in order to prevent workers straying into the scanned zones and accidently slowing or stopping the robots. According to Platt, around 10% of the BIW robots ABB sells are now equipped with the technology and he expects that proportion to grow. He declined to say which manufacturers have bought into the new technology.
The idea that robots can work in close harmony with employees has been taken one step further by a development at Canada’s University of British Columbia with funding from GM. This robot, built by the University’s Collaborative Advanced Robotics and Intelligent Systems Laboratory (CARIS), is designed to interact with the line worker, even in “unscripted” scenarios.
A video produced by the lab shows the robot handing the worker parts to fit onto a car door. The worker extends his arm to tell the robot to hand over the part, after which the robot goes back for the next part. If the worker makes a different gesture he can prompt the robot to repeat an action, for example if he finds the part is faulty. After fitting, the robot can check the work. All of this is simple for a human, but incredibly complex for a robot.
Platt at ABB is in no doubt that car production will eventually become completely automated: “Robots are still very little used in trim and final assembly where manual workers most operate, whereas in BIW assembly most factories are 80-90% automated,” he says. “It has to come within the near future.”
For Visti, the more delicate, precise work in those areas of assembly is perfect for the new breed of lightweight robot. He remarks: “You’re getting closer to a human and the whole idea of robots is that you are replacing humans.”