Universal Robots Forum

Axis 3 absolute position offset by 360deg after power loss

Our robot was mistakenly powered off when someone pulled the power cord unknowingly.

I restarted the robot, it said the robot had moved so I had to visually confirm that the 3d robot model matched the real model and confirm that. Once done the axis 3 is now offset by 360deg of the original position and I can only jog it from -180deg to -360deg, instead of the normal ±180 (i know the joint can do ±360 but axis 3 can only reach ±180 before colliding with the base).

Seems to me that somehow the encoder position has been offset during re-sync. How can I manually go and perform an axis calibration again in this case?


Move arm to a different pose, power arm off, delete .urcontrol/.last_seen_joint_positions.conf, and power arm back on.
Possibly it was near the point where position wraps around.

Great thanks, that’s also what I suspected.