Reframing the "Collaborative Robots" Discussion
There’s been a lot of excitement recently about collaborative robots. In September, there was a Collaborative Robotics Workshop in Silicon Valley, and an Advanced Manufacturing Workshop about collaborative robots was held last month at RoboBusiness in Boston. Great events to be sure - events that are building awareness about the accessibility of robots for companies of all sizes. Robots that can increase productivity, make companies more competitive and ultimately create jobs.
At these events and others and in the media there have been discussions about robots that can “work alongside people without fencing or safeguards.” This new type of robot is referred to as a collaborative robot or co-bot. As I hear people talk about co-bots, the message is that “co-bots” are productive and safe. In fact, I’ve heard multiple people give presentations, and they never referred to them simply as “robots” but ALWAYS “co-bots” or “collaborative robots."
This message seems to imply that these are the only robots that are productive and safe to work alongside people, and that traditional industrial robots are suddenly irrelevant. “They are difficult to use, very expensive and have no ROI.” Really? Can over one million robots be wrong? There are well over 1.3 million industrial robots installed around the world. Every day, these robots produce the cars we drive, the goods we use and the foods we consume. “Traditional robots” ARE safe AND productive with a compelling ROI.
A more accurate description of the new “co-bot” would be “power and force limiting” robot (PFLs, see ANSI/RIA definitions below). Granted, it’s not as catchy as co-bot.
In most production environments, an operator needs to interact with the robot infrequently or for a short time. Why then should the robot’s speed, payload or reach be restricted for the entire production cycle? Traditional robots are fast, precise and are capable of moving large, heavy objects. They can also safely work alongside people. The best approach is to allow the customer’s process dictate the robot type and configuration.
Power and force limiting robots certainly fill a gap and are productive within specific applications. These new entrant companies are also addressing a growing market need and enabling people with little or no robotic experience to deploy and support robots.
Mature, well-established robot companies, including Yaskawa Motoman, need to respond to market demands in this area. We have an ongoing emphasis on enabling new robot customers to quickly and easily assess the need for robots, evaluate the ROI and deploy robots when they are a good fit.
For reference, I’ve provided a brief overview of the collaborative modes per the ANSI/RIA R15.06-2012 safety standard. There are four modes in which collaborative robots can interact with people:
- Stand still monitoring: A robot can be powered up and servoing but stopped (not moving) while the operator works in close proximity of the robot. When the operator is finished and away from the robot, the robot can continue moving at high speeds.
- Speed and separation monitoring: A robot can be powered up and moving at a reduced speed (250 mm per sec or less) while the operator works within a predefined zone that is not currently shared with the robot. When the operator is finished and away from the robot, the robot can continue moving at high speeds.
- Hand guiding: A robot can be hand guided by an operator.
- Power and force limiting: The robot that limits the amount of power and force being exerted can work alongside an operator.
All of these modes require a risk assessment of the complete system as installed at the user’s facility, including robot, gripper, conveyance, product being handled, etc.
Many traditional industrial robot brands on the market, including Yaskawa Motoman, have control-reliable functionality in the controllers that meet modes 1, 2 and 3. Please contact the Robotic Industries Association for complete details about the safety standards.