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A safer environment for human-machine collaboration
Published:  02 November, 2021

Garry Kasparov, the world chess champion beaten by IBM supercomputer Deep Blue in 1997, is probably not the first person that comes to mind when you think about human-machine collaboration. But, in recent years Kasparov has been a stark advocate for people working closely with technology — a trend reflected in industrial facilities around the world with the rise of collaborative robots. Here Neil Ballinger, head of EMEA at automation parts supplier EU Automation, shares the latest in collaborative robots, and explains what these developments mean for the safety of their human co-workers.

A lot has changed since 2008, when Universal Robots released the UR5, a collaborative robot that could safely operate alongside employees. Gone are the days where industrial robots mean caging or fencing — robots and colleagues can work safely in a variety of manufacturing environments. With safety technologies ever improving, what is the current state of cobot safety, and what do manufacturers need to know before adding a cobot to their workforce?

Safety — the basics

In 2016, the International Organisation for Standardisation (ISO) released guidelines regarding collaborative robots and human safety, which were last reviewed in 2019. These regulations lay out how manufacturers can take advantage of the wide range of safety equipment available to ensure the safety of their workers. Some of the key points for manufacturers to familiarise themselves with include the addition of emergency stop buttons, the incorporation of safety light curtains and force and speed limits.

Once familiar with the standards, the next step is to perform a comprehensive risk assessment. The risk assessment can be undertaken using the same methodology as for non-collaborative robots, but it must also address some added conditions. It must identify any reasonably foreseeable contact between the robot and an operator, determine the contact type (transient or quasi-static) for each body part affected and predict the frequency and duration of contact.

The risk assessment must be specific to the end-effector, as each one can have very different safety implications. A collaborative robotic arm equipped with a welding tool, for example, requires much stricter safety procedures than one equipped with a simple probe.

Manufacturers must continually assess their safety measures to ensure that all identified risks are being effectively mitigated. So, who to involve? Those with the best insight into the risks of robotics are often the workers themselves, who may see dangers that manufacturing managers might not be familiar with. Manufacturing managers can learn a lot from conversations with shop floor operators, as well as open a two-way dialogue that ensures their safety concerns are addressed.

Technology that improves safety

To make safely introducing a cobot easier for manufacturing businesses, robot manufacturers are developing cobots with faster processors and integrated vision systems. This allows spatial data to be processed fast enough to generate motion control in a way that conventional solutions relying on commodity hardware cannot. Unlike traditional solutions that enable cobots to stop when they detect an obstacle, some newer cobots can determine the best way around an obstacle without having to pause.

This advance in technology means cobots will spend much less time stopping to avoid collisions, and more time being productive. It also means that several cobots will be able to work together independently, performing different tasks without any collisions.

Another exciting area of development is touch sensing technologies, which increase both the applicability and safety of cobots. Using state-of-the-art sensors, actuators and software, cobots are now capable of experiencing physical sensations that allow them to feel and identify the object being touched. Early research from the USC Viterbi School of Engineering simulated human touch using embedded tactile sensors with conductive fluid, resulting in a robot that could differentiate between the texture of wool and cotton.

In-built tactile sensors could allow cobots to function in demanding applications that require handling delicate materials safely and precisely, such as healthcare. It will also allow for defect detection, as the cobot will be able to recognise problems with the texture of the object. As this technology develops further, it will allow closer collaboration between humans and cobots, as they perform increasingly complex tasks together while still maintaining safety standards.

The future of cobot safety

Collaborative robot technology has made huge leaps forward in the last few years. However, the current ISO regulations focus heavily on stopping or slowing the cobot in the presence of a human. Because recent advances suggest that this is no longer necessary if the cobot can problem-solve and determine a safe and collision-free route, we may soon see updated regulations. Being aware of the current developments in the field will help manufacturing managers both meet current and prepare for future safety standards. Industry will also need solid maintenance and repair procedures to ensure cobots function as intended, and that they can take steps to order replacement safety automation parts or perform troubleshooting quickly when needed.

Chess grand master Garry Kasparov has made peace with artificial intelligence and has noted “you have to put the right machine in the right space to do the right task”. This rings true in current manufacturing processes, where more advanced cobots offer a broader range of applications than before. By staying up to date with technological trends, manufacturing leaders can add robot colleagues to their workforce collaboratively and safely.

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