Safety for robotics

Reading about robots and "cobots", and how the former evolved into the latter, or what both of them have to do with safety, could be really fascinating. After all, it has a lot to do with Industry 4.0, the "new" industrial revolution, which will (and already) shape the way goods are produced, maintained, or how people are serviced (in hospitals, in stores, in restaurants etc.), or how the supply chain which they rely onto, is organized.

Some observations about what have in common industrial (but not only) robots with safety:

1. First of all there are many more types of robots, there is even an ISO standard listing and classifying all of them, namely the ISO 8373:2012. Depending on the environment where they're deployed and on the degree of interaction with the user they can be broadly classified in two groups: industrial and service robots, but there are gray areas in between.
2. Industrial robots are basically the ones working in a very controlled environment and NOT freely moving on the ground, or on a plant floor, performing quite defined tasks. They are machinery used for different automatized tasks in various industries (manufacturing, moulding, sealing, welding, sorting and packaging various types of products), in other words everything related to industrial automation.
3. Service robots, defined as robot that performs useful tasks for humans or equipment, excluding industrial automation applications (since covered by industrial robots), range from applications like mobile servants, to medical, surgery robots or personal care robots.
4. In between, there are various types of "robots", not covered by the previous two ones, among them the AGVs as the most notable ones.
5. When it comes to robotics safety it is mainly the area of machinery safety, and corresponding standards, covering that. An essential aspect here is how are those standards structured. There are basically three types of them:

• risk assessment standard (which is actually only one - ISO12100); this one, apart from providing guidelines on how to assess risks, generally describes which types of risk reduction measures can be employed.
• type B machinery standards - provide guidelines on different safety aspects or measures, generally referred by the ISO12100. ISO13849 is probably the most known type B standard, providing guidelines on how to assess the Performance Levels (equivalent for SILs in the machinery industry, though SIL could be used too). Apart from it there are also standards for typical machinery safety functions, like emergency stop, or two-hand control devices. Essential aspect about type B standards is that they can apply to a wide range of machinery products: industrial trucks, industrial robots, service robots, agricultural machines, baggers, and the like
• type C machinery standards - are about one particular type of product. Industrial robots have their own standard (ISO10218), AGVs (or driverless industrial trucks) also theirs (ISO3691-4), service robots also theirs (ISO18646).

6. Essential aspects in considering the safety of robotics are following:

• degree of automation (this is determined on one side by their mechnical structure and kinetics and on the other by the degree of interaction with the humans/operators, meaning to which extent are they collaborative, or cobots)
• based on their mechanical structure industrial robots are classified in: linear, SCARA, articulated, parallel and cylindrical robots
• based on their degree of interaction with the operator they can require a safe stop, can be hand-guided, speed monitored, power & force limited
• there are two standards providing safety requirements for industrial robots:

1. the original ISO10218 - Safety requirements for industrial robots - this contains guidelines about how different robot stopping, or speed control functions can be realized and which performance criteria should they fulfill; also recommendations about stopping time and distances
2. the newer ISO15066 - Safety requirements for collaborative robots - contains guidelines about collaborative operations: safety-related monitored stop, hand-guiding, speed and separation monitoring and power and force limiting