Is there some diagram or document that clearly shows and/or describes the basic reference x,y,z coordinate system of the robot?
This would be helpful in setting up a procedure to translate from camera pixel coordinates to robot coordinates.
@rkm,
Base coordinate system / Base feature:
Right-hand coordinate system, where Y is into the robot cable and Z-axis upwards through the centre of the Base joint.
Tool coordinate system / Tool feature
Right-hand coordinate system, where Y is away from the Tool connector, and Z is normal to the tool flange.
However, if there is a TCP offset defined, the Tool feature will be transformed by this offset, thus e.g.:
All script code moves or similar will have respect to the Base feature.
If you go to the Installation tab, choose Features > Base, and tick “Show axes”, then you will be able to see the Base coordinate system of the robot.
Then you can e.g. see it in the Move-tab.
4 Likes
Thanks -great diagrams and explanations!
Hi,
I would like to know how could I transfer points that are relative to the Base feature to another feature ? I have generated a milling path in RoboDK and generated all the points relative to a reference frame. When I exported the program all points are relative to the Base feature. This will not help in the real life as I was planning to just measure the reference frame and all my points generated would align.
Looking forward to your suggestions,
Attila
Check this out Creating Waypoints wrt to Custom Features
It will probably take some trial and error but hope this helps and best of luck!
For what it’s worth, I don’t believe you can easily migrate existing taught points to a Feature. So if you’ve already generated all your points with respect to the Base, I think you have to reprogram everything after selecting a Feature. If I’m wrong about that I would love to be corrected because it’s cost me time in the past.
I have a question on TCP coordinate vs Base coordinate, should x and y have the same directions?
Thanks,
Bill
It depends on the z axis’ direction. As you can tell from the illustrations, y and x will always have the same directions relative to the z axis.
If that’s what you mean. 
@jbm Hi, I programmed the UR10e robot to position itself for a linear movement. After reaching each waypoint, I calculate its current position using pose = get_forward_kin() and publish it to an MQTT broker. The broker forwards this data to Unity, where I run an application on HoloLens to display a sphere at the exact position sent by the robot.
However, while I do receive the positions, the sphere doesn’t align perfectly with the robot’s position. After some investigation, I found that the UR uses a right-handed coordinate system, while Unity uses a left-handed coordinate system. I attempted to transform the coordinates accordingly, but the sphere’s position still doesn’t perfectly match the robot’s.
Could someone help me identify what might be causing this discrepancy?