Moving targets from wobj1 to wobj2

ziga

Hello experts

I have a question about moving targets from wobj1 to wobj2. Example: I synchronize target1 (in wobj1) from VC to station. Then, in station, I move it from wobj1 to wobj2 and rename it to target2. I synchronize target2 (in wojb2) back to VC. Now, the sum of target1 and wobj1 positions should be equal to the sum of target2 and wobj2 positions, or am I wrong? But I get more than 1mm difference. Is this OK?

Another question: is it possible to change the tooldata in move instructions in a similar way (the position of the robot should remain the same, the robtarget position and orientation should apply to the new tool).

Thanks in advance,

Ziga 

Henrik Berlin

 Hi,

Changing workobject of an instruction is one of the fundamental features of an offline programming tool such as RobotStudio. A deviation of 1 mm would be totally unacceptable for such an operation. I have tried to reproduce the problem you are describing but have failed to do so, i.e. I get the same global coordinates with a very high accuracy after the target has been copied to another workobject. When moving the workobject you get the question "Do you want to reposition the target?". Ensure to answer "No" on that question if you want to keep the global position of the target.

If you still have the problem I would recommend you to upload the failing station so that we can have a look at it or to get in touch with your local ABB support. Please check http://www.robotstudio.com/contacts.html for the contact information of your nearest ABB office. (You can reach the page from www.abbroboticssoftware.com -> Contacts.).

Henrik Berlin

... as for changing the tooldata...

Usually, the interesting part of a production process involving a robot is the robtarget position. The tooldata is just there to define the tip of the tool (and some other information.). The concept of tooldata has been introduced to separate the process information (the robtargets) from the production equipment (the tooldata).  The tooldata can easily be changed using the "Modify Instruction" command, but that will keep the robtarget position. The positon of the robot will adjust according to the new tool. This is what most people are interested in.

If you want to maintain the robot position (i.e. the actual joint angles of the robot) regardless of the tool used, I suggest you to use tool0 instead. Tool0 is the default tooldata and located at the tool mounting point of a real robot. But this is not really offline programming my opinion, more like online programming done offline. I am not sure this is what you really want?

ziga

Hello Henrik,

I send you a mail with pack&go of my station yesterday.

Kind regards,

Ziga

Henrik Berlin

Hi,

The observed difference was due to non-zero orientation of the workobjects. When the orientation of a work object is non-zero, then the global coordinates of the target is NOT equal to the sum of the coordinates of the work objects and the target respectively. The orientation of the work object (user frame and object frame) must be taken into account. This is taken care of by RobotStudio. But trying to verify the number by just adding the coordinates may lead to an incorrect conclusion.

The second problem of changing tool orientation can be handled by the "Rotate Target" function of the "Modify Target" context menu.