Running an iiwa at 1kHz

[matthias-mayr]

We are currently evaluating to move from 500 Hz control rate to 1 kHz and I am interested if anyone else has a achieved a setup in which this work reliably.

Without #47 and #48 we had issue running at anything higher than 200Hz and with them we can reliably work at 500 Hz.

However even though we use

• a dedicated and recent 6 core i5 machine with a PREEMPT_RT patch set
• assigning the driver the highest RT priority (see #47 )
• real network ports and a
• a direct cable connection

we are experience interruptions at 1 kHz. Our controller takes about 800 microseconds to evaluate and it does not look like it's causing the interruptions.

One observation is that as soon as the controller is publishing some more data (which does not make it slower, we profiled that), the interruptions happen much faster. So right now the working assumption is that it's related to OS + network.

A second observation is that we never get a connection quality of 3 (excellent), but only 2 (good) and then after some time it immediately drops to 0 (poor) and interrupts.

Does anyone else run this robot at 1 kHz? If yes, which other tricks did you apply?