Hello,
I have created a program using the ethernet XML interface on the Kuka (version 1.1) and am having a very strange problem. Please pardon the verbosity as I try to explain it...
The initial behavior:
Short Cartesian moves worked without much issue. However, for long moves the arm more often than not tries to move through a singularity. This caused rapid joint motion that exceeded the arm constraints and shuts down the arm.
The initial fix:
Since short moves from a “good configuration” seemed to work, I noted several good configurations and chose one as the initial location of the arm for a Cartesian move. This showed very irregular behavior with the same code working sometimes and not others.
Observation:
After much experimentation, it seems to me that I am able to perform valid Cartesian moves until I issue a joint movement (also with the XML interface). It seems that the arm does not recalibrate the Cartesian frame after the movement and attempts to move as if the joint movement never happened. For example, when the arm is oriented to the left (axis 1 is at about 85 degrees), +X is forward and an XML command to move in the +X direction works correctly. If I move with a joint movement so that the arm is oriented to the right (only change is axis 1 is now at about -85 degrees) and command a +X Cartesian move, it actually moves in the –X direction (although the position status remains correct and shows the X decreasing).
Has anyone else tried mixing joint and Cartesian moves? If not, how did you perform long moves? If so, did you see the same behavior?
Thanks in advance for any help.
Stephen