[ros-users] Issues with rviz
Tully Foote
tfoote at willowgarage.com
Tue May 25 22:37:59 UTC 2010
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> 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> 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>> 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>> 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>>>
>> > >>> 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> 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>>>> 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
>> > >>> >>>>
>> > >>> >>>> _______________________________________________
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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>>>
>> > >>> >>>> https://code.ros.org/mailman/listinfo/ros-users
>> > >>> >>>>
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>> > >>> >
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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>>
>> > >>> (650) 475-2827
>> > >>>
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>> > >
>> > >
>> > >
>> > >
>> >
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--
Tully Foote
Systems Engineer
Willow Garage, Inc.
tfoote at willowgarage.com
(650) 475-2827
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