Hi everyone,

I am trying to get our robot to work with the navigation stack of ros. 
I've been following the tutorial on 
http://www.ros.org/wiki/navigation/Tutorials/RobotSetup . After setting 
up the robot with a tf-tree and sensor nodes , I have noticed a problem 
with rviz. I am unable to display the laserscan messages in any frame 
other than the laser coordinate system itself, i.e., whenever I select a 
<Fixed_Frame> other than /front_laser the status of the laser scan 
display shows the error:

"Unknown reason for transform failure".

Also, this warning appears in the bash:

[WARN] 1274341043.701801000: MessageFilter [target=/base_link ]: Dropped 
99.03% of messages so far. Please turn the [ros.rviz.message_notifier] 
rosconsole logger to DEBUG for more information.

Doing so gives me these repeating debug messages:

MessageFilter [target=/base_link ]: Added message in frame /front_laser 
at time 1274341252.994, count now 10
MessageFilter [target=/base_link ]: Removed oldest message because 
buffer is full, count now 10 (frame_id=/front_laser, 
stamp=1274341252.813649).

This suggests a problem with the tf-tree to me. However, when using the 
"transformPoint(...)" function of tf::TransformListener in my own nodes 
to transform the laser scan into the global frame everything works as 
intended with no errors/warnings.

Does someone have an idea what I am doing wrong?

Thank you for any help!


Jan Elseberg