[ros-users] Issues with rviz

Jan Elseberg j.elseberg at jacobs-university.de
Wed May 26 08:42:12 UTC 2010


Hi,

The issue was indeed due to the time_increment. It was set using 
milliseconds instead of seconds.
Thanks alot for the help.

Jan

Tully Foote wrote:
> Jan, 
> Based on your topic name it looks like you are using a Sick LMS. 
>  There is a ROS driver for it in the sicktoolbox_wrapper which you 
> might find useful to either use or for a reference.  It is documented 
> at http://www.ros.org/wiki/sicktoolbox_wrapper
>
> Tully
>
> On Tue, May 25, 2010 at 3:31 PM, Josh Faust <jfaust at willowgarage.com 
> <mailto:jfaust at willowgarage.com>> wrote:
>
>     Hi Jan,
>
>     It looks like the time_increment field in your laser scans are set
>     to 0.0924214...  this field is meant to be the amount of time
>     between each reading in the scan, so 90 milliseconds is quite
>     high.  rviz multiplies this by the number of readings in the scan
>     to set the time tolerance on the filter it uses, to ensure that
>     the entire message can be transformed correctly, not just the
>     first reading.
>
>     A more reasonable time_increment would be a few orders of
>     magnitude smaller.  An example from our tilting laser is
>     1.73611115315e-05
>
>     I've filed a ticket to make rviz warn in cases of unreasonably
>     large time_increment values:
>     https://code.ros.org/trac/ros-pkg/ticket/4123
>
>     Josh
>
>
>     On Tue, May 25, 2010 at 1:45 AM, Jan Elseberg
>     <j.elseberg at jacobs-university.de
>     <mailto:j.elseberg at jacobs-university.de>> wrote:
>
>         Hi,
>
>         I uploaded a short bag.file of the robot. You can get it under
>         http://plum.eecs.jacobs-university.de/exchange/volksbot.bag .
>         There's also
>         http://plum.eecs.jacobs-university.de/exchange/only_laser.bag
>         where only
>         the laser topic (/volksbotRT/LMS) and /tf is recorded. If you need
>         anything else, please let me know.
>
>         Jan.
>
>         Josh Faust wrote:
>         > Can you post a bag file with /tf and the laser scan topic
>         somewhere?
>         >
>         > Josh
>         >
>         > On Fri, May 21, 2010 at 5:21 AM, Jan Elseberg
>         > <j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         > <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>> wrote:
>         >
>         >     Wim,
>         >
>         >     I have played around with the timestamps of the laser
>         scan message.
>         >     Neither increasing nor decreasing
>         >     the timestamp changes the behaviour, except that for
>         large enough
>         >     offsets either of the following errors
>         >     is produced:
>         >
>         >     For frame [/front_laser]: No transform to fixed frame
>         >     [/base_link].  TF
>         >     error: [You requested a transform that
>         >     is 2.637 miliseconds in the past, but the most recent
>         transform in the
>         >     tf buffer is 8.092 miliseconds old.]
>         >
>         >     For frame [/front_laser]: No transform to fixed frame
>         >     [/base_link].  TF
>         >     error: [You requested a transform that
>         >     is 3.212 seconds in the past, but the tf buffer only has
>         a history of
>         >     3.138 seconds.]
>         >
>         >     I have also changed the publishing frequency of the
>         laser scan
>         >     messages
>         >     to 5 Hz. Unfortunately, this also had
>         >     no effect on the error.
>         >
>         >     Jan
>         >
>         >
>         >     Wim Meeussen wrote:
>         >     > Jan,
>         >     >
>         >     > When rviz receives laser scan messages, it only keeps
>         the 10 most
>         >     > recent messages in a buffer. So, if you send
>         laserscans at 50 Hz (it
>         >     > looks like that's the rate you use), that means rviz
>         only stores 0.2
>         >     > seconds worth of laser scans. So when your laser scans
>         are more than
>         >     > 0.2 seconds ahead of your tf transforms, rviz would be
>         unable to
>         >     > transform any laser scans. To find out if this is the
>         problem
>         >     you hare
>         >     > seeing, you should modify the timestamps of your laser
>         scan
>         >     messages,
>         >     > by deducting something like 1 second from each
>         timestamp before
>         >     > sending out the message from the laser scanner driver.
>         Or you could
>         >     > create a node that takes in laser scanner messages,
>         modifies the
>         >     > timestamp, and send out the modified laser scans.
>         >     >
>         >     > Wim
>         >     >
>         >     >
>         >     > On Thu, May 20, 2010 at 9:33 AM, Jan Elseberg
>         >     > <j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>> wrote:
>         >     >
>         >     >> 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
>         >     >>> <j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>>>
>         >     >>> 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 <http://ros.org/wiki/tf>
>         <http://ros.org/wiki/tf>
>         >     >>>    <http://ros.org/wiki/tf>
>         >     >>>    >>> <http://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"
>         >     >>>    <j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>
>         >     >>>    <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>>
>         >     >>>    >>>> <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>
>         >     >>>    <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>
>         >     <mailto:j.elseberg at jacobs-university.de
>         <mailto:j.elseberg at jacobs-university.de>>>>> 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
>         >     >>>    >>>> <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
>         >     >>>    >>>>
>         >     >>>    >>>> _______________________________________________
>         >     >>>    >>>> ros-users mailing list
>         >     >>>    >>>> ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>
>         >     <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>>
>         >     >>>    <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>
>         >     <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>
>         <mailto:ros-users at code.ros.org <mailto:ros-users at code.ros.org>
>         >     <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>>>
>         >     >>>    >>>> https://code.ros.org/mailman/listinfo/ros-users
>         >     >>>    >>>>
>         >     >>>    >> _______________________________________________
>         >     >>>    >> ros-users mailing list
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>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>
>         >     <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>>
>         >     >>>    >> https://code.ros.org/mailman/listinfo/ros-users
>         >     >>>    >>
>         >     >>>    >>
>         >     >>>    >>
>         >     >>>    >
>         >     >>>    >
>         >     >>>    >
>         >     >>>    >
>         >     >>>
>         >     >>>    _______________________________________________
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>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
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>         <mailto:ros-users at code.ros.org> <mailto:ros-users at code.ros.org
>         <mailto:ros-users at code.ros.org>>>
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>         >     >>>
>         >     >>>
>         >     >>> --
>         >     >>> Tully Foote
>         >     >>> Systems Engineer
>         >     >>> Willow Garage, Inc.
>         >     >>> tfoote at willowgarage.com
>         <mailto:tfoote at willowgarage.com>
>         <mailto:tfoote at willowgarage.com <mailto:tfoote at willowgarage.com>>
>         >     <mailto:tfoote at willowgarage.com
>         <mailto:tfoote at willowgarage.com>
>         <mailto:tfoote at willowgarage.com <mailto:tfoote at willowgarage.com>>>
>         >     >>> (650) 475-2827
>         >     >>>
>         >     >> _______________________________________________
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>         >     >> https://code.ros.org/mailman/listinfo/ros-users
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>         >     >
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>         >
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> -- 
> Tully Foote
> Systems Engineer
> Willow Garage, Inc.
> tfoote at willowgarage.com <mailto:tfoote at willowgarage.com>
> (650) 475-2827




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