Unwanted Axis Rotation

[krist]

Hi Johannes,

I am trying to create a simple tool path for robotic punching/stippling. The simulation works as intended, but I have notice that for some of the points closer to the robot base, A4 and A6 axis rotates as the robot arm homes in on the points.

I learned from manual jogging the robot that it can home in on any points within the designated work space (the square boundary) without needing to rotate A4 and A6 at all (and this is preferred). And as I increase the number of points for the robot arm to move to, some of the points even become unreachable because of this unwanted axis rotations.

Is there a way to "lock" the axes so that I would't get this rotation? It seem that this problem simply just go away when I move my work space further away (maybe the software limit deem the points too close to the robot?), but still, it is kind of annoying and I am wondering if there is a better way to go about this in case I need to work with a tool that axes rotation matters.

Thank you.


   

[Johannes @ Robots in Architecture]

Hello,

There is no proper way to lock the axis, but in very general terms you want to avoid A5 being close to zero, i.e. the robot being "stretched".
In your project you would have a few options, like e.g. raising the element by ~500mm, tilting it, or using a tool that is not normal to the flange.
PTP movements are also not subject to singularities, but for punching you probably want linear movements.

Hope that helps!

Best,
Johannes

[krist]

I see, so it is the distance between A5 and robot base that are causing these singularities. I understand now, thank you so much for such a quick and insightful reply!