Hy Guys, i have a general question about accuracy of circular motions a high speeds.
Currently i have been programming a milling program that cuts a lot of semi-circles out of plastic and i noticed something strange happening in the circle.
Circle is defined as followed in the program:
circ(x 20,y 0},{x 0,y 20} (start point = x 0,y -20)
So it is a tiny circle.What happened was that as turned up the speed the path of robot changed significantly
I started at $VEL.CP = 0.05 and went up to $VEL.CP = 0.3. When i got to the max speed the circle i measured was more like this:
circ{x 15,y 0},{x 0,y 20} (start point = x 0,y -20) so the path falls about 5mm short to the auxiliary point
So i think that in the kuka circ function there is some sort of approximation to smooth the motion in the circle. which in most cases is no problem but when i am milling i want to be as accurate as possible and if it is possible also at high speeds. i have been trying to set the auxiliary point so that the path goes where i want it to go which kind of works but it is not a perfect solution. The circle is not quite a circle anymore.
Has anyone else encountered this, or maybe can enlighten me a bit on what exactly is going on? And also could it be possible to program something into the robot so that whenever the actual path is is a certain distance from the desired path it gives an error or a warning?
Looking forward to your thoughts
Background information:
Kuka Kr150 robot
Vkrc2 controls (software changed to standard)
during the program no approximate positioning is used.