Hi all,
I have a robot doing pick and place in 2 CNC facing each other and recently secured the zone so we can run it in normal mode. I want it to be in reduced mode when outside of the machines so I created a safety plane at each CNC’s door to trigger a normal mode by flipping the plane’s Z axis by 180 degrees. Now both planes contradict eachother and prevent the robot from ever being in normal mode.
Does anyone have a workaround or solution to this problem?
Can you post a screenshot of your teach pendent showing the Planes setup?
And what is the behavior if you were to rotate those planes 180 degrees around x or y? (So that Z is facing the other way)
If I flip them, the robot is in reduced mode when it goes through the zone (inside the machines) and accelerates to normal mode when outside of the machines.
I tried having one safety plane active only with my current setting and it works as intended. Meaning the robot is fast while inside the machine and slow outside. That’s how I came to the conclusion that both planes work against eachother with my current configuration.
Oh. I see the problem now. Since each plane spans out to infinity, when they point at each other, you’ve essentially created everything being inside the zone. vs maybe the intuitive expectation that one plane’s influence would stop when encountering a different plane.
As far as I’m aware, there’s no way to resolve that with just the safety planes. They aren’t conditional, and aren’t particularly flexible (as you’re finding out)
Depending on your risk assessment, you could probably get by with a thread monitoring the TCP and trigger reduced mode based on that. Jump one of your digital outputs to a pair of Safety Inputs set to Reduced Mode and have your thread turn that output on and off. This isn’t really dual channel anymore, and really doesn’t maintain the same Safety Level, but that’s up to your risk assessment to determine. Otherwise consider an area scanner (or 2) around the base so the robot can move full speed everywhere unless someone is standing in the area.
I like the ingenuity of your workaround, sadly I can’t do safety without real safety rated I/O.
This is our first attempt to secure a cobot’s working area to augment it’s capacity. Due to area constraint, we couldn’t respect safety distances if the cobot were to be fast outside of the machines. We’re glad the be able to atleast accelerate the cobot inside the bottleneck machine. We’ll keep what we just learned in mind for our next project.
Thanks alot 
the only proper way to do this safely is an area scanner on each side of your robot pedestal. UR can only handle 1 safeguard stop input so if you want the robot to stop completely if an operator is near, you would need to get scanners that have parent/child capabilites and daisy chain their signals. if you only want the robot to slow to reduced when operator is in the zone, then the UR can handle that no problem.
As I understood, they dont want a condition regarding where the human is, but regarding where the robot currently is…
6 of one, half dozen of the other. They only need to know where the robot is so they can make sure it’s safe in the zones where the operators are. With area scanners, you avoid the need to slow down in any zone unless the scanner is tripped. Outcome ends up being the same except the scanners likely improve your cycle times significantly.
We already have an area detection system but our robot cell is quite restricted so we can’t have the robot be at full speed in it’s full range of motion and respect the safety distances. We thought we could use the safety plane feature the same way Fanuc’s DCS work. We found out it can’t be done the way we want to.
