How to record a stop point in force mode and create offsets from that point?

General Application Help: How do I?
1

The goal is rather simple: an orbital sander application with an axial compliance device on the EOAT.

  1. Robot moves to “pounce” position above part
  2. Robot lowers EOAT (z-direction) in force mode until it makes contact with the part surface
  3. Robot records this ‘contact’ position into a variable “on_edge”
  4. Robot adds 10mm ‘up’ (+z) to the recorded “on_edge” position and calls it “start_point”
  5. Robot moves to this ‘+10z’ position called “start_point”
  6. Robot then makes a series of moves along the ‘+10z’ plane to sand the part
    I thought I had this but step 4 seems to be giving me trouble. I’m using…

on_edge:=get_actual_tcp_pose()
z_offset:=p[0,0,10,0,0,0]
start_point:=pose_add(on_edge,z_offset)

…then a Move L to start_point, but what’s going into on_edge is some wacky coordinates nowhere near reality somehow. Maybe there is an easier way to achieve my goal too rather than variables which is why I’m asking here. Thanks!

2

Remember that URscript uses meters as unit.
z_offset:=p[0,0,10,0,0,0] is an offset of 10 meters or 10000 mm.
it should be: p[0, 0, 0.01, 0, 0, 0] to offset by 10mm.

Let me know if this helps or if this is not the problem you are facing.