Dancing omnidirectional robot base controlled via Linux shellscripts based on IGH EtherCAT Master

Dancing omnidirectional robot base

Here's a quick intro to what I'm hacking on at university. This is a new omnidirectional robot platform we got in the lab. It's controlled via CanOpen-over-EtherCAT (which is a realtime Ethernet protocol "extension", more or less). As we don't want to deal with any of the Windows software that's usually used for such stuff, we're employing the IGH EtherCAT Master (r1549) implementation (GPL/LGPL) on Linux and it works quite nicely.

I hacked together a few shell scripts that invoke the ethercat command line tool with certain parameters to control the motor velocities "by hand", which then soon turned into a "dancing" demo of the robot ;-)

See http://www.youtube.com/watch?v=n_vF4NK26fM for the YouTube video of the dancing bot. It's just a quick (hardcoded) hack for now, there's lots of room for improvements, of course (e.g. detect baselines of random music you throw at it). The demo in the background is the fantastic Masagin by Farbrausch.

I've also hacked up a small Python script to control the robot with a Wiimote (using cwiid on Linux), which also works quite nicely. I further plan to make a small program for controlling it via a 3D mouse or the like in the future...

The longer-term plan for the robot platform is that it'll get a "backbone" and two very nice robot arms for grabbing stuff etc.


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rt implementation

hello there!

what kind of linux kernel solution have you applied?
preemption patch only? or + rtai or xenomai?



Neither. The stuff in the video runs on a stock Debian kernel, invoking the ethercat tool from shell scripts (I'm not kidding). That's just a quick demo, of course, and a better solution is being worked on.

The Igh EtherCAT Master code can be used with RTAI or other solutions AFAIK, but it also works on non-realtime "normal" kernels.

HTH, Uwe.


You have done a great work i am impressed by your work you have made an amazing robot but hacking is not a good thing this is wrong thing to do.

Operating system

Hacking is a bad activity. But i think you hacked the shell scripts for good purpose. That's better.