Arm loads, cablechains and load-identification

oharley

I'm trying to improve the accuracy of my robots applications which combine 3d printing and milling. To do so I wanted to give better (estimates) for the arm loads and the tooldata.

I have a irb6700, and an igus linear retraction cable system (RSEL)

As the cables + chain I have has some significant weight (~20-27kg) but is attached both on Arm3 and Arm6, how is it usually done to model the cable weights? With about 15kg on Arm3 and 5kg attached directly to Arm6 (in addition to the tool) and the rest of the mass floating between the two. So far I have only attributed the mass to Arm3 - should the rest be included in the 'tooldata' or as an arm load.

Finally what is recommended for specifying the arm loads' centre-of-masses?

Additionally the `LoadIdentify` procedure mention that the cables should be disconnected during the procedure if possible for a more accurate tooldata - should this be the case even if the cable-chain is permanently afixed to Arm6?

(I was reading this: https://forums.robotstudio.com/discussion/11833/definition-of-arm-loads )

lemster68

The arm loads are pretty well documented in the system parameter manual.  Even a best-guess estimation is better than nothing at all.  I would consider the mass of cables hanging from 3 to 6 as the load for three.  As such, I would extend the cog some on the X axis for 3.  Following that, I would run the loadidentify with it all attached.  What generation of controller and what version of robotware are you using?