Simulation of 4-axis robot in KUKA PRC.

[elena.shilova]

Hello all,

I have a question about the simulation of 4-axis robot in KUKA PRC.

In my project I'm using the robot KR 240 R3200 PA Arctic, which has 4 axis. Unfortunately, there is no robot with 4 axis in the Virtual Robots range.
Is there the way to restrict the movement of the particular axis of the robot, so in 6 axis robot only 4 are actually rotating during the simulation?

Many thanks,
Elena

[Johannes @ Robots in Architecture]

Hello Elena,

Basically, as long as you are only using XY frames (relative to the robot's base, that is) you should get a reliable simulation. The code generation might be a bit trickier.
Now the first question is how the robot reacts when you "feed" it XYZABC frames, as it probably usually runs on XYZA. It would be great if it ignored the BC values.
The next thing we would need to look at are the axes. Are they A1-A3 plus A6, or are they referred to as A1-A4?

I haven't worked with a four-axis robot before, but I'm confident that there will be a way to get it to run with PRC.

Best,
Johannes

[elena.shilova]

Dear Johannes,

Thank you so much for your reply. I understand what you mean by frames manipulation and such. But my the question might be a little bit different.

Basically, I am AA student, I'm doing my thesis in recourse-driver robotic fabrication in Arctic. It our project (in theory, on site) my team is using mentioned Kuka Quantec Arctic due to its temperature and frost resistance which are required for the construction our site.

The project conducts a material system and assembly logic (robotic pick and place), which needs to be tested phisically as a part of a thesis. We have Kuka KR30 and KR60 in our school, so all the simulations must be performed on either one or another robot. Both of them have 6 axis.

So the question is how do we make the transition from the robot we have (Kuka KR60) to the robot we actually propose in our thesis (the Arctic one). Does it make any difference in terms of geometry which can be achieved and such? Does this 4 axis feature put any constrains on the architectural piece we can assemble with the robot?

Best,
Elena

[Johannes @ Robots in Architecture]

Hello Elena,

While palletizing robots are quite common in industry, they are less flexible than your usual 6-axis robot, so I've never used one myself. But from the spec-sheet it looks as if it would "digest" normal XYZABC / A1-A6 code, ignoring elements it does not require. So in order to simulate it, you need to turn your 4-axis palletizing robot into a "pseudo 6-axis robot" by splitting the part of the arm where you would usually have the A4 and turning A5 so that the flange is vertical.
Then just set up your robot like a usual, custom robot with the Custom Robot component. Let me know if you need an example!

That being said, it seems the arctic version does not have any special heating, so I guess (!!! - I may well be wrong) that the main difference between an "arctic robot" and a normal one is the lubrication and extra testing.
It stands to reason that you could also adapt other robots to the cold, so personally I wouldn't limit myself to a 4-axis robot.

Best,
Johannes

[Johannes @ Robots in Architecture]

...and I found a white-paper here: https://www.robotics.org/filesDownload.cfm?dl=KUKA_Arctic_Robot_White_Paper.pdf
It also mentions the tolerances and seals - but I think you could still argue for your thesis that a "normal" robot may be converted for that purpose!

Best,
Johannes