AsianScientist (Jan. 30, 2020) – Humans have a strange propensity for putting things in cages. From the things we admire and are afraid to lose, to the things we fear and want to keep at arm’s length, we place them inside a meshwork of metal, and in doing so gain some measure of control over them.
For years, manufacturers have subjected robots to the same treatment: confine the machines to a dedicated floor space and have them toil away autonomously ‘behind bars.’ For safety reasons, humans only ever approach the robots when they are shut down, typically to perform maintenance works.
This paradigm of factory automation is changing as some machines are ‘liberated,’ so to speak, to work alongside human employees. Known as collaborative robots, or co-bots, these machines are not meant to completely take over human tasks, but to assist human workers in parts of a factory’s workflow that are tedious, strenuous or dangerous.
“Co-bots are very useful for automating difficult processes in which human involvement is still needed to generate a final product,” said Mr. Junji Tsuda, president of the International Federation of Robotics (IFR) and representative director chairman of the board, Yaskawa Electric Corporation, Japan. “Through easier set-up and reasonable costs, co-bots are creating new opportunities and applications, particularly in small- and medium-sized enterprises.”
Baby don’t hurt me
Asia, often referred to as the factory of the world, is now also the world’s largest market for industrial robots, according to a 2019 IFR report. Of the 422,271 units of industrial robots installed in the year 2018, more than one-third were set up in China alone. However, only an estimated 3.3 percent of all industrial robots installed in 2018 were co-bots, suggesting that reservations remain in terms of co-bot deployment—among them, concerns over worker safety.
For co-bots to be of assistance without posing a hazard to their flesh-and-blood colleagues, fundamental changes to robot design have to be implemented. Unlike the large and heavy-set metal frames of traditional manufacturing robots, co-bots are generally smaller in size, made of lightweight materials, and are ‘curvier’—they have rounded edges, making them less likely to cause grievous hurt to humans in the event of a collision. This is known as “inherently safe design,” to use the industry’s parlance.
But reducing the damage from a human-robot collision is not enough; prevention of collisions remains a top priority. This is easier said than done. Not only must the co-bot be aware of its human co-worker, it must also be able to track the position of its own limbs in three-dimensional space, as well as monitor the speed and torque of its motors and joints.
Laser-based sensors or cameras coupled with computer vision systems can help co-bots gauge distances between themselves and humans. Should someone get too close to the co-bot, it will either slow its movements or come to a stop, thereby preventing collisions.
The external torque of robotic limbs can also be estimated by measuring the current of each motor. This allows for the creation of a motion feedback system to reduce the likelihood of high-speed contact between co-bot and worker, said Professor Oh Jun-Ho of the Korea Advanced Institute of Science and Technology, South Korea, whose humanoid robot DRC-HUBO bested 23 other international teams to win the top prize at the 2015 DARPA Robotics Challenge.
“Signals from inertia, force and torque sensors attached at the end effector—usually a gripper—can also be analyzed to ensure the proper movement and posture of a robot,” Oh added.
Like how our eyes and nerves help us coordinate limb motion, these sensors, built into co-bots, will help reduce the likelihood of injury to human workers sharing a workspace.
From co-existence to collaboration
As co-bots become more sophisticated, workplace dynamics will continue to evolve. The IFR highlights four different levels of human-robot interaction: coexistence, sequential collaboration, cooperation and responsive collaboration. The first two levels are already seen in factories today, but true cooperation and responsive collaboration remain technically challenging since the co-bot needs to adjust to the motion of its human colleague in real time.
“The multiple axes of robotic limbs should move in harmony. For that to happen, synchronicity and periodicity of communication are needed, and even at the time of communication failure, the robots have to be safely controlled,” Tsuda said.
This is where the advent of 5G wireless networks could be a game changer. Boasting higher data rates, lower latency and greater reliability, 5G wireless networks pave the way for the rapid integration of sensor data and near-instantaneous feedback, which in turn makes for more nimble control of co-bot limbs.
Tsuda also noted that 5G wireless networks will enable greater flexibility in the deployment of industrial robots, since the machines need not be tethered by Ethernet cables to a specific area. This is analogous to how wireless LAN technology allowed personal computing to become more mobile, he said.
The cost of connectivity
Nonetheless, greater connectivity brings with it greater cybersecurity risks. Security reports by companies like Microsoft, IBM, TrendMicro and Kaspersky collectively paint an alarming picture of increasing frequency and severity of cyberattacks on industrial automation systems.
“Industrial robots are not exempt from cybersecurity issues, and the consequences of a cyberattack on industrial robots could be even more severe since the robots move,” warned Oh.
The security of industrial robots is therefore inextricably linked to their safety around human operators and co-workers, and ought to be a key consideration in robot—especially co-bot—design.
Having said that, the barriers between humans and robots are already falling, and factories of the future are likely to feature even more co-bots performing increasingly complex tasks alongside human workers. Oh even expects that “some applications in lightweight handling in areas like unmanned stores, cafés, restaurants and logistics hubs, will be appearing.”
Let out of their ‘cages’ on the factory floor, our mechanical allies look set to play an even greater role in the global economy and society. So, have you greeted your co-bot colleague yet?
This article was first published in the January 2020 print version of Asian Scientist Magazine.
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Copyright: Asian Scientist Magazine.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.