How to safely incorporate cobots in industrial workplaces
Compact industrial robots are now available that can be cost- effectively integrated into even small production lines. Part of their appeal is that such robots can collaborate with a human operator to offload repetitive tasks that would otherwise tire the operator and lead to mistakes. The problem is that working in close proximity to a moving machine poses safety risks for humans. The key to keeping collaborative robots (cobots) safe is to carefully consider the risks involved and configure the robot and its control system to mitigate potential hazards. Fortunately, technical specifications are now available to help guide developers along the path to safety. This article looks at the advantages of adding cobots to a working environment and points out the safety concerns before describing the recent regulatory guidelines and presenting risk assessment
and mitigation strategies. It then introduces cobots with built-in safety mechanisms that allow them to be safely added to any production or workflow environment. Why add collaborative robots? Industrial robots in major manufacturing facilities have long proven their worth in terms of increasing production throughput while reducing costs. Now compact, generalized industrial robots are bringing such benefits to mid and small scale production. Unlike their larger scale counterparts, however, compact robots are designed to operate in cooperation with their human operators rather than in isolation ( Figure 1 ). The two share a workspace, helping to minimize the robot's use of valuable production floor space and improve its cost-effectiveness.
Like all powered machinery, these cobots have the potential to cause injury if not utilized properly. Integration of a cobot into a production line, then, requires that careful consideration be given to the issue of operator safety. Factors to keep in mind include the robot's range and speed of motion, the materials it is handling, and the operator's method and frequency of interaction. Once those are understood, appropriate safety-enhancing features can be incorporated into the system design. Regulatory requirements from organizations such as OSHA (Occupational Safety and Health Administration) in the US, CCOHS in Canada, and the European Commission mandate some elements of cobot operational safety. OSHA 29 Code of Federal Regulations (CFR) 1910, for instance, calls for systems to lock out hazardous energy sources during servicing operations (Section 147) and to prevent electrical shocks from occurring during operation (Section 333). Such regulations, however, were developed to apply to all forms of industrial machinery and have not necessarily kept pace with technology. There is relatively little regulation specific to industrial robots in general or cobots in particular. Industry has filled the gap, however, by developing several technical standards specific to industrial robots. These include the IEC
Written by: Richard A. Quinnell
Contributed By DigiKey's North American Editors
Figure 1: Small industrial robots are designed to operate in cooperation with humans rather than in isolation. (Image source: KraussMaffel/ KUKA Robotics)
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