# How to rotate around a defined position

• I would like to rotate around a defined position (P0), from P1 to P2, while also rotating the orientation of the tool. I know that with a circular motion, I can define a point P3 along the arc between P1 and P2, and it will rotate around the center point. This will keep the orientation of the tool constant, as in situation A in the image, which is not desired in this instance. What I want is sketched in situation B in the image attached.

To my understanding this should be possible by assigning an RTCP frame with the origin at P0. However I am uncertain how to continue. What kind of movement command do I issue? I know it requires the 'RTCP' option at the end, but I can still choose between Linear and Circular motion. Any information on how to achieve the desired motion (situation B) would be appreciated.

• Hi,

I would try this (I'm not sure) :

1-Set a Uframe on your P0

2-Teach your first and last points oriented (ex: the z tool face the center of the uf (eq P0) )

3-You can find the second point to by trigo (a paper and a pen can be usefull ) or you can teach it

4-Set the angles (W, P, R) of your 3 points (Details point) after teaching & be care with the Config (can change)

• Since you are using P and not PR, I assume these are taught positions.
Which frame do you teach them in? And are they of Cartesian or Joint representation?

• Have you tried doing a circular motion with the orientation changed at the mid and end point?

Yes I've tried this, and it is indeed a solution to achieve the desired motion; but it makes computing the points relatively complex and I was hoping to escape this by using an RTCP motion

• Since you are using P and not PR, I assume these are taught positions.
Which frame do you teach them in? And are they of Cartesian or Joint representation?

They are PR positions, not taught positions, I should have clarified. I have them in cartesian representation. The frame I express them in would have the same orientation as an RTCP frame defined at P0 as its origin.

• Hi, I did this motion long time ago. You have to move the robot in the start position and use this position to create a Frame. Shift the frame along the direction than is your radious, the shift distance is the selected radious. Save the point with the new frame and rotate the frame with the selected angle (example 30 Grad). Use a Linear movement with the speed in Grad and the RTCP option at the end of the movement.

The robot will execute a movement along the arch with the selected radious with the tool facing the arch.

But do you need this? It´s work but is a bit complicated and need time to be executed by the robot (stop with fine and wait 0.1 sec, save frame, save point, restart again)