Hi Daniel, The RealtimePublisher will work fine on a non-realtime system. It may be slightly less efficient than normal ROS publishing, but I don't think you'll notice any difference. -Stu On Sun, Nov 7, 2010 at 6:03 AM, Daniel Stonier wrote: > Hi all, > > I've been working over the last few weeks to put together a core robot > subsystem for one of our robots - it's pr2 like with a mobile base, a > manipulator and various other motor driven mounts (14 motors in all), > but on an a real budget and I was wondering what experiences others > have had doing something similar. > > The primary challenges with ours are two fold: > > 1) It isn't running an ethercat based system. i.e. it's non-real time, > though thats something I would like to upgrade on this particular > robot in the future, however its not something that all of our robots > will have. This means the motors are often driven on multiple loops, > some fast and some slow (so not to burden the low spec embedded > board). Also, the controllers in ros are using a real time publisher - > and I made the assumption that is not usable for non real time (please > correct me if I'm wrong!), so rebuilt all the > controllers/transmissions we had to use. > > 2) We're running on a low spec intel atom (the lowest), so topic > communication and loop frequencies need to be kept down. Since its not > centralised, it needed some care designing to ensure callback > frequencies didn't escalate and control loop periods weren't consuming > too much horsepower. Most of it is interrupt driven now too because > different subsystems are cycling at different speeds. > > Finally, its roughly working, but its quite ad-hoc and took alot of > building in the long run and am wondering if there's an easier way to > do it, or a way to genericise components so that they can be recycled > for both non-realtime and realtime systems. > > Regards, > Daniel Stonier > > -- > Phone : +82-10-5400-3296 (010-5400-3296) > Home: http://snorriheim.dnsdojo.com/ > Yujin Robot: http://www.yujinrobot.com/ > Embedded Ros : http://www.ros.org/wiki/eros > Embedded Control Libraries: http://snorriheim.dnsdojo.com/redmine/wiki/ecl > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > -- Stuart Glaser sglaser -at- willowgarage -dot- com www.willowgarage.com