Collaborative robots (cobots) are created for working directly alongside humans. Their applications are different from traditional industrial robots, which are generally kept away from human workers. As long as cobots remain safe to operate around humans, they may become a staple feature of the future economy.
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Collaborative Working in a Shifting Economy
C3PO and R2D2 were the cobot dreams of a long time ago, but today, machines like these are already a reality. Advances in robotics, sensors, computing, and AI are bringing the technology of galaxies far, far away down to earth – and into your home.
The advent of cobots has blurred the boundary between human and robot workers, enabling the two to work together collaboratively. This means that industries looking to employ some robot assistance can do so with a much greater degree of flexibility than ever before.
The rigid manufacturing processes adopted in the Fordist economy in the industrialized world in the early 20th century are making way for a new kind of industry in the 21st century. Additive manufacturing techniques like 3D printing, IoT-enabled inventory and logistics management, and the proliferation of remote working made possible by information technology are all making today’s economy almost unrecognizable from our ways of working of just a century ago.
Manufacturers now incorporate flexibility into their operations so that factories can switch production mid-shift. Discrete elements of industrial processes are now frequently brought under one roof, and waste is minimized.
Cobots that are easy to use and intuitive to work alongside safely are already providing the power for this new way of working. Just as the regimented Fordist factories of the 1950s were driven by the first industrial robots – rigid, stationary, “dumb” machines – so will the dynamic manufacturing of the 21st century be driven by smart, moving, flexible cobots.
A Brief History of Cobot Technology
Cobots were invented by Northwestern University professors J. Edward Colgate and Michael Peshkin in 1996. A General Motors Foundation research grant sought out a way for robots or robot-like equipment to safely team up with human workers, spurring the pair’s innovation. This is somewhat symmetrical; a similar General Motors initiative led to the development of the first industrial robots in the 1940s.
Colgate and Peshkin’s 1997 US patent, “Cobots” characterized “an apparatus and method for direct physical interaction between a person and a general-purpose manipulator controlled by a computer.”
There was no internal source of motive power in the first cobots to ensure safety for human workers. Instead, motive power was provided by the human operator. The cobot enabled computers to control motion by redirecting or steering a payload in a way that was designed to support the human worker.
Four Levels of Collaboration
Cobots are used in many applications, providing information in public spaces, transporting materials in buildings, automating unergonomic tasks in the industry (like heavy lifting), or working on production and assembly lines.
The International Federation of Robotics (IFR) defines four levels of collaboration:
“1. Coexistence: Human and robot work alongside each other without a fence, but with no shared workspace.
2. Sequential Collaboration: Humans and robots are active in the shared workspace, but their motions are sequential; they do not work on a part at the same time.
3. Cooperation: Robots and humans work on the same part at the same time, with both in motion.
4. Responsive Collaboration: The robot responds in real-time to the movement of the human worker.”
In industry today, the first two levels (coexistence and sequential collaboration) are most common, as cobots and human workers share space but tend to complete separate tasks independently or sequentially. Cooperation and responsible collaboration are less common today.
Standards for Safety
Cobots are regulated by ISO safety standards and certifications and must adhere to strict guidelines to ensure the safety of the people they are working alongside. ISO 10218 outlines four general safety features for cobots: a “safety monitored stop,” “hand guiding,” “speed and separation monitoring,” and “power and force limiting.”
Safety monitored stops are employed when cobots do most of their work alone. When a human enters their workspace, for example, to adjust a part the cobot is handling, the cobot stops moving. It does not completely shut down; it can resume working when the space is clear.
This is the loosest possible interpretation for a cobot, only interacting with humans occasionally and employing proximity sensing technology to automate those interactions.
Hand guiding is a process used for teaching robots how to complete a task. Human workers show the robot the sequence of motions required to complete a task. Robots sense human hand positioning and apply it to their own movement. The robot only performs the tasks that it has been shown to do.
When humans have to interact with large robots more frequently, a laser vision system can be installed to let robots sense humans coming near. Speed and separation monitoring techniques enable the robot to slow down incrementally as the human gets nearer, stopping when they come close enough.
Power and force limiting features equip cobots with sensors to read forces in their joints like pressure, resistance, or impact. Soft, sensing “skin” and fast reaction times enable the cobot to stop or reverse course when encountering an unexpected force.
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References and Further Reading
Colgate, J.E., and M.A. Peshkin (1999) US Patent US5952796A: Cobots. Google Patents. Available at: https://patents.google.com/patent/US5952796
Peshkin, M.A., J.E. Colgate, et al. (2001) Cobot Architecture. IEEE Transactions on Robots and Automation. Available at: https://doi.org/10.1109/70.954751
Pilkington, B. (2021) Lending a Helping Hand with Festo’s BionicCobot. AZO Robotics. Available at: https://www.azorobotics.com/Article.aspx?ArticleID=416
Pittman, K. (2016) A History of Collaborative Robots: From Intelligent Lift Assists to Cobots. Engineering.com. Available at: https://www.engineering.com/story/a-history-of-collaborative-robots-from-intelligent-lift-assists-to-cobots