Where is speed mentionned for PTP ? + questions about speed for PTP and LIN

Started by Xylotica, August 08, 2021, 07:51:20 PM

Previous topic - Next topic


I wonder why the speed values are not printed out to a panel from the PTP component (or LIN component).
Also, this might sound like a silly question , but the % value for the PTP speed, errr... what is it a percentage of ?
Max speed of the flange ?
If so, this hardly makes sense because this depends on a lot of factors (extension, posture,...)
In fact I also wonder about LIN speeds because the resulting speed I observe have large variation despite being set as constant.
These variations can come from :
-Frequent direction changes
-Changes in the density of frames along the trajectory
-General tendency of stock market in Burundi
In short, I find that setting speeds on a robot is kind of an illusion of control. The darn thing is just going "generally faster" if you set a high value and "generally slower" if you set a low value.
I find that it makes speed-dependent processes difficult to get right.

Johannes @ Robots in Architecture


I think something to keep in mind is that robots are still very, very widely used for processes lik spot welding and pick-and-place applications, i.e. processes where you generally want the movements to happen as fast as possible. Controlling the speed beyond that is not really a factor.

In any case, 100% is the full speed of the slowest axis involved in a movement.

With a recent software version that supports SPTP and SLIN movements you sometimes can also get better speed ramps. And for CNC using KUKA.CNC, but that is a complex piece of software.
In general, for smooth movement run the robot in T2/AUT at 100% OV (i.e. full programmed speed, not necessarily maximum speed).