Clarifying Safety with Collaborative Robots

Robot safety practices once focused on keeping robots fenced so people didn’t have any interaction with them. During the past few years, the use of collaborative robots has become widespread and safety design, practices and technical specifications have adapted.

Keep in mind that debilitating and fatal accidents involving robots are rare. OSHA in its Safety and Health topics notes that most “robot accidents occur during non-routine operating conditions, such as programming, maintenance, testing, setup, or adjustment.”

From 1984 to 2013 there were 27 fatalities involving industrial robots, according to figures kept by OSHA. The total number of workplace fatalities in the U.S. in 2013 alone was 4,585.

Safety with robots is a front-burner issue, nonetheless, especially as robots will continue working closely with people.

Safety Specifications

A good definition of a collaborative robot is given in an article from 2014 The Realm of Collaborative Robots – Empowering Us in Many Forms found on the Robotic Industries Association (RIA) website: A robot designed for direct interaction with a human within a defined collaborative workspace. Other definitions say “direct cooperation” between the robot and a human worker.

The use of collaborative robots on factory floors, warehouses, and institutions like hospitals has spiked in popularity. Sophisticated software and imaging systems are leading to a greater use of collaborative robots that are able to respond to unstructured environments.

Pop culture is tempted to describe scenarios where robots are running amok and place people in danger, but the truth is that the global robotics industry has responded swiftly to ensure a collaborative robot’s safe use and operation.

Robot designers, integrators, and end users can now refer to ISO/TS 15066:2016 for “data-driven” guidelines on evaluating and mitigating risks that apply only to industrial robots.

A technical paper on robotics.org, ISO TS 15066 Explained, “brings unprecedented clarity to collaborative robot system risk assessments.”

An outcome that the safety specification sets out to achieve is that “if contact between robots and humans is allowed, and incidental contact does occur, then that contact shall not result in pain or injury.”

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Designers are now working to prevent injuries from occurring, and contact can only take place in power and force limited applications.

Safety Practices and Design

Writing the specification was itself a collaborative effort with input coming from industry leaders in 24 different countries. In ISO TS 15066 Explained, the University of Mainz, one of the leading research universities in Germany, did research on 100 subjects and created a chart that provides a list of force and pressure levels to guide robot design.

Companies that have workers who are skeptical of a robot’s safe operation can do what Honda Canada Manufacturing did as described on Engineering.com in Standardizing Collaborative Robots: What is ISO/TS 15066? Employees were shown why collaborative robots are different than industrial robots that are locked down. Honda leveraged the specification to show associates the safety requirements and features.

Safety with a Heart

Physical safety is of course a major concern, but designers are also working to reduce the emotional stress of people working with robots. Some workers may have a little or a lot of fear which can give way to becoming attached.

Faculty and students at the Ethics and Emerging Sciences Group at Cal Poly are taking a lead in learning how technology impacts users at many different levels.

A robot’s appearance also impacts users. A paper written at the University of Bologna in Italy, Industrial Collaborative Robot Design, explores the designs of robots Baxter and Sawyer that are the creations of Rethink Robots, along with iiwa by Kuka and YuMi made by ABB.

Baxter’s eyes “always visible on the monitor, have the functional aim of revealing to the human operator the next task area” and they create an emotional link. Iiwa is styled with an “organic shape” while YuMi engenders a natural empathy.

When a robot’s movements mimic those of a human arm it’s shown that people are “less stressed.”

Industrial robots not only help companies operate more efficiently as they work alongside people, but people who work closely with them often develop an affinity for the equipment. Workers may take a while to get used to them, but once they do, the relationship becomes positive.

Stay up-to-date on developments that affect both industrial and consumer robotics with resources and trainings available through A3.