Re: [ros-users] Best way to set the parameters for the contr…

Top Page
Attachments:
Message as email
+ (text/plain)
+ (text/html)
Delete this message
Reply to this message
Author: Josh Faust
Date:  
To: ros-users
Subject: Re: [ros-users] Best way to set the parameters for the controllers (param or message?)
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 <
> 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 <> 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 | 
> > 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
> >
> > 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:
> WWW: http://ias.cs.tum.edu/people/pangercic
>
> _______________________________________________
> ros-users mailing list
>
> https://code.ros.org/mailman/listinfo/ros-users
>
>