Incorrect Joint Value by Multiple of 360

Technical Questions
1

I’m using a UR5 robot. The problem is that it currently think the joint value for the shoulder is 720 degrees higher than it should be. Because of this, it is stuck in safety configuration mode. I’m hoping for any advice about how to reset the joint value.

Here are some more details:
Most of the time, when we aren’t using the robot, it is stored in the home configuration. However, it wasn’t stored in the home for about 4 days, and I guess the joint got out of alignment. I went through the reboot options that came up on the screen. However, after the robot was reset, the angle now reads as 720 degrees higher than it actually is. Note that because of how the robot is installed, it is not physically possible for the shoulder joint to make a complete 360 degree rotation. So, it is not possible that I accidentally rotated the joint through a full rotation.

One possibility is to unbolt the robot from the table and allow the joint to rotate -720 degrees. However, since I know the joint did not do this initially, I’m worried this would create more problems.

Another possibility I found was going into expert mode and then doing joint zeroing for the shoulder joint. Since I believe that it is off by a factor of 720, I think this would solve the problem. However, this screen says that joint zeroing should only be done by a professional.

Has anyone ran into this issue before? Any suggestions or advice?

Thanks!

2

Hi ksnapp.

Assuming you are using a e-series robot. Try updating the robot software can see in the release note that something similar to this should have been fixed in 5.10.

" PolyScope should no longer suggest joint angles outside the reach of the robot for a waypoint when changing TCP settings."

It might be worth a try to downgrade it as well but no promises here.

Best Regards Casper

3

Casper,

Thanks for the suggestion. This could be the problem. According to the pendant, we are currently running only 5.1.0

However, I ended up trying the joint zeroing option, and that worked for me. I don’t know if that was the best way to go about it, but it got the robot up and running, so good enough for now.

Thanks for your response. If I run into this problem again, then I’ll probably update the software.

Sincerely,
ksnapp