Hi all,
I’m trying to gather feedback on what people usually do with their robots when they are not running 24/7 but only some hours per day like 12h shifts per 24h, we’ve sometimes fully automated the power on/off sequences of the controller, but also let the robot idling and only restarted the program when necessary. One time the motherboard of a CB3 UR10 died overnight after the robot was cleanly shutdown, logs showed it received the shutdown command, cleanly shutdown, and the next morning it was dead. Since then i’ve been wondering what is actually the best for a robot cycling through shifts, mostly relating to thermal cycling stress.
I would instinctively have thought that once the robot is not used, it would be best to power it down, but that also means the entire controller and robot mechanics will go through thermal cooldown and warmup again on the next shift, hence I don’t know if it might not be actually better to let the robot sitting idle, rather than going through a daily warmup and cooldown.
Also because there is no default “shutdown/power off” block in Polyscope, only “Exit”, you must use a script block and run the “powerdown()” command manually, it got me thinking why does UR discourages to shutdown the robot in normal operations?
So what do you often do in this case:
- let it go through its shift, then after operator pushes some stop button let it sit idling in parking position until the program is restarted the next day?
- let it go through its shift, then after operator pushes some button let it park and shutdown the controller?
- do you ever use the Power Off input? which instantly triggers a shutdown of the robot while standing wherever, forcing a “move to start” on the next run, which can be an issue since Operator now has to access the TP, potentially not desirable. We never use it since it can leave the robot in unknown position, potentially causing a crash if Auto moving to the start, we use a digital input button, watched by a thread which raises a flag on push and causing a light to blink, at the next program loop the flag is checked and if True the robot will park and stop the program or powerdown.
- another advantage of letting the robot idling is we’ve seen sometimes after powering off the robot, that the small “fall” until joints’ brakes stop can be far enough to force a “move to start” on start if the joints moved far enough (for example in some position, with a heavy payload and extended, it’s very common to have the robot fall enough to not be able to restart directly from there but to do a tiny “move to start”), again forcing operator to access the TP which can be not desirable, rather than directly starting on pushing a Start button. (btw being able to wire a button on the configurable input which can behave as the “move to start Auto” TP button, and having a configurable output lighting up when the robot is on the start position, so that the pre-program sequence can be run without accessing the TP at all would be really nice.
Anyway I’m curious to hear feedbacks from others.
Thibault