Hi,
I am trying to incorporate a part positioning rotator with my UR10e.
The cobot and the rotator are using modbus TCP to communicate. Currently, I have the cobot program switching on a modbus output to tell the rotator to move, and then the cobot sits in a ‘Wait’ command until the rotator confirms that it is finished moving the workpiece.
My problem is that during the Wait command the cobot locks up and does not enter the protective stop state if it gets bumped by the rotating workpiece. Obviously, I never intend for the workpiece to collide with the cobot, but if it ever did the rotator is strong enough that it could easily damage the cobot. My rotator monitors the Prog-abort signal (Low on unscheduled stop, otherwise High) but because that signal does not switch during a collision the rotator has no way of knowing if the cobot is in its way.
Is there any way to get the cobot to monitor for collisions while it is waiting for the rotator to finish moving?
How about doing it the other way around instead? You can make a safe position in the robot, that switches two safety outputs when the robot is in this position.
Then you can make it so that the rotating table only can rotate when the robot is in a safe position, and you should never get a collision?
Alternatively, if you want to try out your approach, you might be able to achieve your desired function by putting your wait in a Force command. Then choose Frame and set all axis’ to 0 speed.
As far as I remember, the robot will go into a protective stop, if the Force is outside its limits.
Or you can let the robot move like 10mm slowly between two positions, when it’s waiting.
Hi efn
Thanks for your reply - that new function does indeed look like the ideal solution. The UR caps software I am using isn’t compatible with the latest Polyscope version yet, but hopefully the supplier updates it soon.
In the meantime I will have a look at your other suggestions. I don’t want to rely on a robot safe position because I will have no control over the size/shape of additional workpieces that will be attached to the rotator by other people in the future, but the Force mode looks like it should work.
