Hi, the issue occurs when using rviz on a seperate computer (synchronized to the robot with ntp) as well as when used only on the robot. The tf-tree of rviz is attached, it is the same as before. Jan Tully Foote wrote: > Jan, > Are you running rviz on a seperate machine? If so make sure that the > clocks are synced using ntp or similar between the multiple machines. > > To see the tf tree that rviz is using try running "view_frames > --node=rviz_******" where ******* is the UUID of the anonymous rviz > process which you can get from rosnode list. > > Tully > > On Thu, May 20, 2010 at 9:19 AM, Jan Elseberg > > wrote: > > Wim, > > the timestamps of the laser scans are concurrent to the ones I'm > getting > with "rostopic echo /tf". > I was under the impression that tf would give me an error of some kind > in this scenario ? > Also, if the issue lies with my tf-tree, shouldn't there be similar > problems in my node > that transforms the laser scans into the /map frame using the > tf::TransformListener ? > > Regards, > > Jan > > > > Wim Meeussen wrote: > > Jan, > > > > Your tf tree looks fine, but it is possible that the timestamps of > > your laser scans are wrong. Your tf buffer keeps a 10-seconds window > > of transformations. When the timestamp of your laser scan does > not fit > > in that 10 seconds window, tf won't be able to transform it. > From the > > data you sent, it looks like your tf buffer is nicely synchronized > > with the current time in your system, so I would suspect that your > > laser scans have timestamps that are either more than 10 seconds in > > the past, or some number of seconds in the future. > > > > You can check the timestamp of your laser scans using "rostopic echo > > laser_scan/header/stamp". > > > > Wim > > > > > > > > > >> I've attached the results of view_frames. I have also tried the > other stuff > >> on the troubleshooting guide. Transformations between the laser > frame and > >> every other frame work fine. Across the longest tf-chain > (/front_laser to > >> /map) the average delay is approx 25ms and the maximal delay is > approx. > >> 55ms. From this it appears to me that the tf-tree is correctly > set up, but > >> maybe there is something else I can check? > >> > >> Regards, > >> > >> Jan Elseberg > >> Eitan Marder-Eppstein wrote: > >> > >>> Jan, > >>> > >>> It sounds like something may be wrong with your transform > tree. Can you > >>> try running "rosrun tf view_frames"? This will generate a PDF > of the current > >>> transform tree structure. You may also want to check the > troubleshooting > >>> link on the sidebar of this page: http://www .ros.org/wiki/tf > > >>> for more information on useful tf > debugging > >>> strategies. > >>> > >>> Hope this helps, > >>> > >>> Eitan > >>> > >>> > >>>> On May 20, 2010 3:38 AM, "Jan Elseberg" > > >>>> >> wrote: > >>>> > >>>> 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 > >>>> 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 > >>>> > >>>> _______________________________________________ > >>>> ros-users mailing list > >>>> ros-users@code.ros.org > > > >>>> https://code.ros.org/mailman/listinfo/ros-users > >>>> > >> _______________________________________________ > >> ros-users mailing list > >> ros-users@code.ros.org > >> https://code.ros.org/mailman/listinfo/ros-users > >> > >> > >> > > > > > > > > > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > > > > > -- > Tully Foote > Systems Engineer > Willow Garage, Inc. > tfoote@willowgarage.com > (650) 475-2827