4 ms·

Could somebody, please, explain me what I need in addition to ROS for functional safety. Some certified laser scanner? Do I understand it right, that ROS comple

by lnsru 8y ago

Could somebody, please, explain me what I need in addition to ROS for functional safety. Some certified laser scanner? Do I understand it right, that ROS completely ignores functional safety?

TickleSteve 8y ago
If you're meaning trying to create a safety-related or safety-critical system then the particular set of libraries you use is one very small part of the problem. The system design itself is examined as well as how it is implemented. The examiners will want to see proof that your system fails in predictable and deterministic ways suitable for their usage. Also systems dealing with the motion-control typically require hard-real-time response so you would not be running this on your average Linux system either. You need to be prepared to have your code and system design examined in great depth, a very long and expensive process generally.
- lzr_io 8y ago
  Note concerning the system: you will most likely need dedicated, redundant and/or diversified HW all the way from sensing over computing down to the actuator system. At least for industrial robots and cobots, not sure about social robots and such.
lzr_io 8y ago
ROS is not a suitable tool at all. Functional safety is a totally different beast and SW is only a small part of it. Don't even think about implementing functional safety on your own without a few years of practical safety experience. Even if you get your hands on all the required hardware parts, you will need to spend a lot of time on making sure you tick all the boxes in relevant standards and convincing notified bodies you did your homework. Don't try to do this on your own, hire an experienced professional right from the start of any project which might touch on functional safety.
roland35 8y ago
The best thing to do, if you can, is to isolate all functional safety related hardware and software to a smaller and simpler subcomponent of your entire system. Then you can prove that no matter what ROS does, it cannot cause harm. This also makes it easier to be certify since your safety related functions are isolated and hopefully smaller and simpler!
lnsru 8y ago
Thank you for explaining this issue. So commercially available robot needs Jetson TX2 (or Wandboard) with ROS and some hardware from safety tools vendor like Pilz or Sick. And the whole safety assessment from TÜV with official certificate. That was helpful!
- lzr_io 8y ago
  Depends on what your market is. The suitability of Jetson TX2 for industrial robots is quite debatable, for instance. Might be sufficient for service robots, but really depends on the notified body accepting your argument. Also don't forget that the actuators (brakes? power?) are part of the safety architecture as well. Word of advice: You need to have a 100% waterproof concept, otherwise your product will _not_ make it to market. Don't try to guess your way around the safety system, it will cost you dear later on.
- TickleSteve 8y ago
  What market are you looking at? Its all about risk... if you're targeting the medical domain for example, you have a multi-year project just to get thru the certifications. Conversely if you're just looking at creating a toy with limited movement, weight and power then the risk is significantly less. Get an engineering safety consultant to have a look.
  - lnsru 8y ago
    Industrial cleaning, machine is slow, but has many liters clean and dirty water inside. Just prototyping it and thinking how to achieve reasonable price. 30-50k is too expensive, janitor is cheaper.
    - rcxdude 8y ago
      Robotic lawnmowers may be a good application to draw inspiration from. They need to be low cost and likely have similar safety requirements to meet in terms of avoiding collisions and going out of bounds.
    - AlotOfReading 8y ago

by lnsru 8y ago

Could somebody, please, explain me what I need in addition to ROS for functional safety. Some certified laser scanner? Do I understand it right, that ROS completely ignores functional safety?

TickleSteve 8y ago

If you're meaning trying to create a safety-related or safety-critical system then the particular set of libraries you use is one very small part of the problem. The system design itself is examined as well as how it is implemented. The examiners will want to see proof that your system fails in predictable and deterministic ways suitable for their usage. Also systems dealing with the motion-control typically require hard-real-time response so you would not be running this on your average Linux system either. You need to be prepared to have your code and system design examined in great depth, a very long and expensive process generally.

lzr_io 8y ago
Note concerning the system: you will most likely need dedicated, redundant and/or diversified HW all the way from sensing over computing down to the actuator system. At least for industrial robots and cobots, not sure about social robots and such.

lzr_io 8y ago

ROS is not a suitable tool at all. Functional safety is a totally different beast and SW is only a small part of it. Don't even think about implementing functional safety on your own without a few years of practical safety experience. Even if you get your hands on all the required hardware parts, you will need to spend a lot of time on making sure you tick all the boxes in relevant standards and convincing notified bodies you did your homework. Don't try to do this on your own, hire an experienced professional right from the start of any project which might touch on functional safety.

roland35 8y ago

The best thing to do, if you can, is to isolate all functional safety related hardware and software to a smaller and simpler subcomponent of your entire system. Then you can prove that no matter what ROS does, it cannot cause harm. This also makes it easier to be certify since your safety related functions are isolated and hopefully smaller and simpler!

lnsru 8y ago

Thank you for explaining this issue. So commercially available robot needs Jetson TX2 (or Wandboard) with ROS and some hardware from safety tools vendor like Pilz or Sick. And the whole safety assessment from TÜV with official certificate. That was helpful!

lzr_io 8y ago
Depends on what your market is. The suitability of Jetson TX2 for industrial robots is quite debatable, for instance. Might be sufficient for service robots, but really depends on the notified body accepting your argument. Also don't forget that the actuators (brakes? power?) are part of the safety architecture as well. Word of advice: You need to have a 100% waterproof concept, otherwise your product will _not_ make it to market. Don't try to guess your way around the safety system, it will cost you dear later on.
TickleSteve 8y ago
What market are you looking at? Its all about risk... if you're targeting the medical domain for example, you have a multi-year project just to get thru the certifications. Conversely if you're just looking at creating a toy with limited movement, weight and power then the risk is significantly less. Get an engineering safety consultant to have a look.
- lnsru 8y ago
  Industrial cleaning, machine is slow, but has many liters clean and dirty water inside. Just prototyping it and thinking how to achieve reasonable price. 30-50k is too expensive, janitor is cheaper.
  - rcxdude 8y ago
    Robotic lawnmowers may be a good application to draw inspiration from. They need to be low cost and likely have similar safety requirements to meet in terms of avoiding collisions and going out of bounds.
  - AlotOfReading 8y ago