[ros-users] Best way to set the parameters for the controllers (param or message?)

Josh Faust jfaust at willowgarage.com
Mon Apr 19 18:33:19 UTC 2010


If you're doing this you probably want to use getParamCached(), as
getParam() itself is expensive (it incurs an xmlrpc call to the master).
http://www.ros.org/wiki/roscpp/Overview/Parameter%20Server#Cached_Parameters

Blaise can answer in more detail, but dynamic_reconfigure allows things like
automatic GUI generation and feedback from the node (for e.g. invalid values
etc.).

Josh

On Mon, Apr 19, 2010 at 11:18 AM, Dejan Pangercic <dejan.pangercic at gmail.com
> wrote:

> Hi Ugo,
>
> I am by no means authority but this is the way I update parameters in my
> nodes:
> Define node's member function, e.g.:
>
> /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
>  double param_;
>  void
>      updateParametersFromServer ()
>    {
>      nh_.getParam ("my_param", param_);
>    }
> and then constantly call it in that node's spin function:
>
>      updateParametersFromServer ();
>
> See also an attached example file.
>
> Furthermore, I just recently stumbled upon
> http://www.ros.org/wiki/dynamic_reconfigure which "facilitates dynamic
> node reconfiguration". However I do not really understand in how far
> is it different to conventional updating of parameters as discussed
> before. But maybe Blaise can tell here more.
>
> D.
> On Mon, Apr 19, 2010 at 6:56 PM, Ugo Cupcic <ugo at shadowrobot.com> wrote:
> > Hi,
> >
> > I'm currently setting the parameters for the controllers (PID and so on)
> > via a message (I have a subscriber which updates the values when it
> > receives the corresponding message).
> >
> > It works well, but I wanted to know what was the recommended way of
> > doing that in ROS. Is it better to do it using parameters? (But then how
> > can I  change the corresponding values when the parameters are updated?)
> >
> > Cheers,
> >
> > Ugo
> >
> > --
> > Ugo Cupcic         |  Shadow Robot Company | ugo at shadowrobot.com
> > Software Engineer      251 Liverpool Road
> > need a Hand?           London  N1 1LX       | +44 20 7700 2487
> > http://www.shadowrobot.com/hand/              @shadowrobot
> >
> >
> > _______________________________________________
> > ros-users mailing list
> > ros-users at code.ros.org
> > https://code.ros.org/mailman/listinfo/ros-users
> >
>
>
>
> --
> MSc. Dejan Pangercic
> PhD Student/Researcher
> Computer Science IX
> Technische Universität München
> Telephone: +49 (89) 289-17780
> E-Mail: dejan.pangercic at in.tum.de
> WWW: http://ias.cs.tum.edu/people/pangercic
>
> _______________________________________________
> ros-users mailing list
> ros-users at code.ros.org
> https://code.ros.org/mailman/listinfo/ros-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ros.org/pipermail/ros-users/attachments/20100419/577acfe0/attachment-0003.html>


More information about the ros-users mailing list