The International Organization for Standardization last week published a supplement to the “Safety Requirements for Industrial Robots” standard (ISO 10218) that describes guidelines for conducting risk assessments for collaborative robots, or cobots.

According to Esben Ostergaard, chief technology officer at Universal Robots A/S, the addition to ISO/TS 15066 is an important step for human-robot interactions in industrial settings.

“The ISO wrote the standard years ago, but it has been revised many times since then,” he explained. “There is some openness to collaborative robots in the 2011 revision of the standard, but the specifications are not well-defined.”

“That provision said that further guidance could be found for collaborative robots in ISO/TS 15066, but this document didn’t exist until today,” Ostergaard told Robotics Business Review.

“For the past five years, we’ve been participating in that workgroup, trying to push the understanding that robots can work outside of cages, alongside people,” he said. “It’s hard to imagine a future where you don’t have robots working alongside people.”

“It takes a while for the world to accept technical change,” Ostergaard said. “The U.S., Europe, and Asia have different views, making it a political and commercial fight, and different companies also have different views.”

“In Europe, there are safety laws based on the European machinery directive,” he explained. “The standards are just guidance. This standard points to the technology specification, which has an annex [appendix].”

Companies and countries can impose the safety guidelines on themselves, Ostergaard said. “India seems to adopt the machinery directive, but follow-up is not so strict,” he observed. “There’s not the same level of worker safety as one would expect in Europe, but that will change.”

“Most of the world is leaning toward international standards, which level the playing field,” Ostergaard said. “I was at a meeting in Germany for global industrial safety, and it was clear that Asian organizations take it pretty seriously. A huge number of people needs to learn about them.”

Accepted and already compliant

“The new spec was finally accepted,” he said. “This is a big step for collaborative robots and a big step for us, since we’re one of the pioneers in this area. The world has accepted that this is a class of robots that’s viable, that we can have in the future.”

“This is the first time that an ISO document mentions these robots in the way that we actually use them,” he said.

“UR already has systems that fit these specifications,” Ostergaard claimed. “We’ve made a safety system with 15 adjustable, patented safety functions, based on the application and risk assessment.”

“For instance, if a robot is moving a car bumper, it should move more slowly, so we’d define its maximum speed as low,” he said. “If it’s moving eggs with a vacuum cup, it could move faster, since the speed depends more on the eggs than worker safety.”

Confusing numbers

“What I’m not so happy about is the ease of use of this tech spec,” Ostergaard said. “It’s supposed to provide guidance, but it’s not the law or really a standard. I’m worried that it will create confusion, since there are lots of numbers.”

“There is a focus on some impact units and shapes hitting people in different body parts that’s hard to figure out,” he said. “The numbers are pretty conservative, in my opinion. They were moved to an informational annex to make them less significant, because that?s what people look at first.”

The units are based on a pain-threshold study at Johannes Gutenberg University in Mainz, Germany.

“In my opinion, the data are good enough, but … the numbers may not provide the right guidance,” Ostergaard noted. “There’s more work ahead to make it understandable, easy to adopt, and acceptable for a number of industries.”

Raising red flags

Ostergaard cited the Locomotive Act of 1861, also known as the Red Flag Act.

“When the first cars came out, nobody knew what the technology was,” he said. “In England, the law was that you had to have someone walking ahead with a red flag to warn people. Yes, that was safer, but it took away a lot of the benefits of potentially faster transport.”

“But on the other hand, it was the first time that the car was mentioned in law, so it acknowledged that it was a mode of transport that could be used,” Ostergaard said. “It’s a gradual process.”

“We’re dealing with the same thing here — new technology, problems but promise, and the world needs to understand and use it,” he said. “You could include other robots and self-driving cars here. The question is how to limit hazards, plus the degree of acceptance.”

More work to come

While Universal Robots has its own global compliance officer on the ISO committee, Ostergaard himself is not a member of the ISO working group, but he attends occasional meetings in an advisory capacity. The next one is in Quebec.

“This 10566 is a published document, but there will be more work,” Ostergaard said. “In reality, the robot’s arm is the least dangerous part. The end tool and the workpiece — what the robot is lifting — are bigger hazards. That’s probably what the group will start working on now.”

“There’s a lot to be understood to get better values in the annex,” he said. “Energy dissipation, not force, is what causes injuries. You could hit your knuckles on a table at 800 to 1,000 newtons, but there’s no injury. We don’t know what the right measure is — we’re that far away.” Current robots are rated as low as 50 newtons.

“The standard says the annex numbers can be used, but we’re welcome to come up with our own,” Ostergaard said. “Ideally, a study saying that the numbers could be higher wouldn’t come from a company like Universal Robots but from an independent university or a government agency.”

“The law is based on risk assessment; there’s no such thing as a 100-percent risk-free machine,” he said. “It’s always common sense: Is the risk acceptable? If not, you can do something about it and reassess. The laws define what you have to do.”

“We need to take time with big and small companies, as well as work-safety authorities to help them understand this,” Ostergaard said.

The positives outweigh the negatives, Ostergaard concluded. “As with the Red Flag Act, it will be a continuously evolving process,” he said. “Safety regulations for automobiles are still being made more stringent after 150 years.”

“The same thing will happen to robots,” Ostergaard said. “In the future, robots and cars will be navigating between people, so we need to develop standards. We’ll have to accept some risks, but we need to keep the benefits from new technologies.”