Pablo,

Our group is working with erratic robots. As we
talked<http://ros-users.122217.n3.nabble.com/erratic-player-vs-ua-erratic-player-td768165.html>the
ua_erratic_player package is the current official erratic package. So
> we've been working with it for a while. However it has some lacks, e.g. we
> can't read sonar sensor values and we can't use neither the vision-ptz
> actuator nor the ranger-tilt-actuator.
>

Unfortunately our erratics don't have a pan/tilt unit, sonar, or IR sensors
that are connected directly to erratic's controller board, so couldn't
really write/test any of those pieces. With that said, I will happily accept
patches that expose this functionality to ROS from the player driver.


> <snip>

- Regarding the vision-ptz actuator. What would be a good way to send
> commands? JointArray + robot_state_publisher? Maybe a look_at command topic
> of type Point3D??
>

The I would do it is the following. Since this is the lowest level driver, I
would just expose each motor separately, i.e. if you have a pan and tilt
motors, you should be able to control each one separately by just sending a
float value that represents an angle of rotation. Things like look_at can be
implemented on top of that.


> - For the ranger-tilt actuator I guess is better a topic of type
> (Header/float).
>

I am not sure that the header is all that useful here. I would assume the
driver will just execute the command immediately, so there's no need for
Header/stamp; frame wouldn't make much sense either. I would just go for
plain float, same as pan/tilt unit.


Thanks,
Anton