What is the difference between user frame and object frame during creating workobject?

    I do not know Kuka, maybe same as base. Same as Fanuc uframe, kind of. A workobject has two components, the user and object frame. Many times the oframe remains unchanged from the user. In the manual is is described like a table which has a part on it. The table can move, and, if so, you update the uframe and all is well. The part's placement on the table can change, but not the table. In this case the oframe needs updated, because it's location is in the coordinate system of the table. Also, the table can be moved, and the part's location on the table can change at the same time. Then both must be updated.

    Often times a vision system might update the oframe, leaving the uframe unchanged.

    ABB WorkObject.UFRAME is the same as KUKA BASE_DATA or Fanuc UFrame. The .OFRAME is, AFAIK, unique to ABB -- it's basically an "extra" frame that treats the UFRAME as it's origin.

    So, in a KUKA, I might dedicate BASE_DATA[1] as my "setup" Base for my vision system, and BASE_DATA[2] as the "moving" Base -- BASE_DATA[1] : VisionOffsets.

    But in an ABB, I get both of those within a single WorkObject: I can set up the .UFRAME as my permanent reference frame between the vision system and the robot World, and just feed the vision offsets directly into the .OFRAME -- WorkObject1.OFRAME = VisionOffsets.

    So the .OFRAME is like an extra frame/offset "stacked" on the UFRAME.

    A specific use case is when using conveyors to index parts into a robot zone.

    During commissioning, the part is placed as close to the desired "locked" position as feasible, and the workobject U-Frame is taught here. For any future indexed parts, it is expected that there will be some variation in the actual position of the vehicle. A vision system can be used to generate offset distances from the original U-Frame, and those offsets are dropped into the O-Frame. This gives an accurate placement of the part every time.

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