Re: [Playerstage-users] truth proxy

[Brian G. <ge...@ro...>]

On Thu, 8 Apr 2004, Tauseef Gulrez wrote:

> Hi Brian, I have used a command truth( ) for my robots true position, can u
> please tell me, is it possible that while robot is moving on the stage, I'm
> getting the true value of its actual position side by side. Actually I'm
> using a localizer, and want to see whether the localizer's readings are
> conciding with true values or not. How can I do that in my world file.

hi Tauseef,

I'm not entirely sure that I understand your question(s), but I'll try
to answer anyway.  If you give your simulated robot a truth() device,
then you can, on the client side, find out the robot's *true* pose
within Stage.   If you also give your robot a localize() device (using an
auxillary instance of Player, of course), then your client can also find
out the robot's *estimated* pose.  It's very easy to write a client program
that opens both devices and prints out the current data from them.  If
you have trouble with that, then run 'playerprint' twice, once for each
device.

Btw, you can simplify things by passing through the truth data to your
auxillary instance of Player by including the following in your Player .cfg
file:
  truth (driver "passthrough" port <your-port-goes-here>)
Then your client need only connect to the auxillary instance of Player.

Also, be aware that the origin (0,0) for the truth data is the lower
left-hand corner of the map, while the origin for the localize data is the
center of the map.

        brian.

-- 
Brian P. Gerkey                    ge...@ro...
Stanford Robotics Lab              http://robotics.stanford.edu/~gerkey