Author Topic: Tips for Testing KUKA Callibration  (Read 232 times)

thinktankgroup

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Tips for Testing KUKA Callibration
« on: July 13, 2017, 11:07:00 PM »
Hey there! Our new KUKA robot is currently being installed and configured as we speak. Before the team of engineers that are setting it up leave, I would love some feedback and any suggestions on how we can ensure it is being setup, configured, and calibrated properly. We want to make sure that everything is being calibrated perfectly, before the engineers wrap up installation :smile:

I'm hoping someone might have some suggestions, sample files and tests we could run to be able to quickly confirm everything is setup and dialed in perfectly. Any tips on what kind of things to be on the lookout for? Known issues, common problems, etc... Here are some of the questions we have:
- What are the best ways to ensure the 7 axis robot, liner rail, rotary table, and parts change is setup properly?
- Are there any test files that we can use to help us easily test and validate the calibration?
- Are there any other software or tools we should be using?
- What things should we be looking out for in order to ensure the calibration is setup perfectly? (Repeatability, Accuracy, etc...)
- What would be some great projects to test each of the areas?
- What else are we not thinking of?

Robot Cell:
- KUKA KR-150 r3100 on a
- Tools: Mill, Hot Wire, (Extruder, Chainsaw, Plasma Cutter, Coming Soon)
- Wireless Touch Sensor
- Robot sits on a 40ft Linear Rail
- 48" Rotary Table
- ATI Quick Connect Head and Plates
- 10 Part Tool Garage Changer
- Laser Part Setter
- Laser Fence

Software:
- ZBrushGrasshopper
- PowerMill
- Grasshopper
- ArtCam

Thanks again!

Johannes @ Robots in Architecture

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Re: Tips for Testing KUKA Callibration
« Reply #1 on: July 14, 2017, 01:02:50 AM »
Hello,

Basically, you do not need to do complex forms or shapes, as just for drawing a straight line the robot needs to move all axes simultaneously. So maybe just mount a pen, put a big piece of paper on the working table and move the robot in X and Y. If the lines are straight and don't wobble, and if the angles are really 90 degrees between +X and +Y it's already a good sign. If your working table is not perfectly level, you may need to calibrate a base (local coordinate system).

To see if the external axes are calibrated properly, the engineers should show you the following: With a linear axis, it should be possible to move the linear axis, while the tooltip of the robot stays at exactly (!) the same position in space. I.e. the linear axis moves, the robot compensates and moves as well, but the tool stays at the same position.
For the rotary axis it's similar: When you rotate the turntable, the robot should be able to stay in exactly the same position in relation to the turntable. I.e. you move the turntable, and the robot moves along with it, without wobbling.

Ensure that you understand how your safety equipment works, how to confirm errors etc.

Tool changers are usually quite easy to use and reliable, but check with them what happens if you use pressure and similar things.

It may make sense to check the calibration every few months or after a crash. You need a so-called EMD for that. You might have bought one with the robot, if so have the engineers show you how to do it. It's extremely easy to do, just never leave it attached when moving the robot (except for calibration, when it's moving slowly).

Finally have them move the robot at 100%, also along the rail, so that you can check if anything is making any strange noises.

Best,
Johannes