Five things to consider before buying a cobot

A panel discussion about collaborative robotics at Expoplast in Montréal last week took what I thought was an unexpected turn. An anecdote from panelist Yarek Niedbala from Kuka Robotics Canada (Mississauga, ON) set the tone.

“The industry has done a great job promoting cobots, so much so that customers come to us wanting to buy a cobot when sometimes a conventional industrial robot is a better fit,” said Niedbala. “Just last week a customer asked for a quote. So, I asked him about the application."

Collaborative robot
Image courtesy fotomek/Adobe Stock.

“‘It’s for precise drilling,’” he replied.

“You realize that with a dangerous tool like that you will most likely have to put the cobot in a cage,” Niedbala told him.

“He considered that and then said, ‘OK, but I still want a cobot.’”

Niedbala persisted. “So, you want to use hand guiding to teach the cobot where to drill?”

‘“No, we have so many patterns to drill we’re going to use offline programming.’”

“So, let me ask you this,” replied Niedbala. “Why do you want to pay extra for a cobot when an industrial robot would be more appropriate?”

“He couldn’t really answer me.”

Collaborative robotics panel at Expoplast 2018
Panelists (left to right): Marc Fallon, Advanced Motion; Yarek Niedbala, Kuka Robotics Canada; Peter Fitzgerald, Fanuc Canada; and Jim Beretta (moderator), Customer Attraction Marketing.

There’s no denying that collaborative robots have caught the fancy of manufacturers, particularly small and medium size businesses, which tend to be the largest customer base. Growth has been remarkable: The global market for cobots is expected to expand more than 60% this year and will represent almost 30% of the industrial robot market by 2027, according to market research group Interact Analysis. While cobots fulfill a set of unique roles on the shop floor, as Niedbala points out, it’s easy to be blinded by the buzz. In the course of the discussion at Expoplast, the panelists shared some advice on determining the most appropriate automation technology for an application.

  1. Understand the four modes of collaboration. International standard ISO 10218 parts 1 and 2 defines four types of collaborative features: Safety-monitored stop, hand guiding, speed and separation monitoring, and power and force limiting. The latter category describes the quintessential cobot that can work alongside humans without any additional safety features. The question to ask yourself, said panelist Peter Fitzgerald of Fanuc Canada (Mississauga, ON), is what you are trying to accomplish with automation. The answer will point you in the appropriate direction.
  2. Start by defining your application. If Niedbala’s customer had begun with his application—precision drilling—it would have been readily apparent that a cobot was not going to fit the bill. “Don’t buy a cobot and then try to squeeze it into an application,” stressed Niedbala. “In arc welding, for example, you need to protect human workers from the torch and flash. Don’t forget that industrial robots can have collaborative features, too.”
  3. Do a risk assessment. “There is a presumption that you don’t have to do a risk assessment with collaborative robots, and that is just not true,” said Fitzgerald. “You have to take into consideration everything beyond the robot—peripheral equipment, tooling and so forth to define the risk.”
  4. Accept that calculating ROI is going to be messy. “High-labor content applications are where we see people investing in cobots,” said Fitzgerald, “with the staff being redirected to higher value tasks. The return on investment is not obvious,” he added. “But companies are willing to take that step because it has an impact on their image and reputation. And sometimes you just need to jump in with both feet.”
  5. You can’t have it all. If you want a fenceless cobot with a great cycle time, you’re asking for the impossible. The cobot, by definition, has to work at a slower pace for safety reasons, said Marc Fallon from Advanced Motion. “On the other hand, if you have someone doing a repetitive job—dipping a part for one or two hours, for example—let the cobot do that and apply your employee’s skills to value-added work,” said Fallon.

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