FEATURE Machine Safetyy

Are cobots inherently safe? Nigel Smith, Managing Director of TM Robotics, dispels some common myths about collaborative robot safety S

ome 79% of automation distributors have doubts about their customers’ understanding of safety requirements when installing

a collaborative robot, states the Global Robotics Report 2019. Considering this is one of the fastest growing sectors of the robot market, lack of knowledge can be dangerous.

Cobots and their safety Collaborative robots, also known as cobots, are meant to work seamlessly alongside human operators, and easily integrated with other machines, without being guarded. Nevertheless, they are not exempt from the safety regulations associated with regular industrial robots. Whilst there are signifi cant diff erences between cobots and their industrial counterparts, the industry doesn’t diff erentiate them as a separate entity – cobots are still subject to the same stringent regulations as traditional robots, such as SCARA, six-axis and Cartesian models. Manufacturing robots are subject to two distinct standards, ISO 10218-1:2011 Robots and Robotic Devices – Safety Requirements for Industrial Robots and ISO 10218-2:2011 – Part 2: Robot Systems and Integration. Currently there’s no comprehensive standard developed exclusively for the safety of collaborative robots, but there’s plenty of guidance available. Cobot users should stick to the most relevant published guidance contained in the ISO 10218 standards, a report called “Collision and Injury Criteria When Working with Collaborative Robots”. Additionally, a technical specifi cation was released in February 2016 – ISO/TS 15066 – published to provide safety guidelines for the use of robots in collaborative applications and to determine guidelines for force limitation, maximum allowable robot power and speed.

Risk assessment There’s plenty of literature on the safety requirements of collaborative robots, but the problem is that this information is often overlooked. Due to the way cobots have been presented, many plant managers mistakenly assume that all of them are safe for use alongside their employees. However, this isn’t true.

28 July/August 2020 | Automation

Cobots are often lightweight and portable, making them ideal for many factory environments Using a cobot safely requires a

comprehensive risk assessment, including risks that may occur whilst the robot is in operation and between tasks. Unlike traditional variations, cobots are often lightweight and portable, making them ideal within many factory environments. But it’s imperative that the plant manager assesses how safety could be compromised when a cobot moves about that environment. In addition, assessment is required for every separate activity and task the cobot will perform.

In packaging applications as an example, a risk assessment may fi nd that, in order to operate at full speed and meet palletising KPIs, fencing around the cobot is required to maintain worker safety. Albeit standard practice with traditional industrial robots, fencing usually isn’t considered when purchasing a cobot. Therefore, these additional safety features often are not budgeted for.

Best way forward

Motivation for most automation investments is to increase productivity and output. Therefore, reducing a cobot’s operating speed to remove safety fencing does not make sense from a business or manufacturing perspective. What’s more, physically separating the robot from

human workers removes the entire nature of the machine. Put simply, it is no longer collaborative.

In these instances, it is worth considering if a cobot is what you really need or whether a traditional robot might be more suitable. Six-axis robots, for instance, have long been used to increase productivity in packaging applications. For many of these packaging and palletising tasks, there’s no real need for human interaction with the robot. As a result, enabling this collaboration through investment in a cobot doesn’t assist productivity or output. There’s no doubt that cobots have their place in the factory. In fact, reports suggest that the global cobot market will grow to a staggering $3,811.483 million by 2021. This optimistic forecast represents the view that cobots can be an ideal fi rst step toward automated processes. However, as the results of the Global Robotics Report 2019 suggest, lack of understanding of these machines and their safety requirements is a problem that needs addressing. To avoid hazards in the factory – and poor investments from end users – greater clarity of what makes a cobot is necessary.


TM Robotics

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