Timestamps of static transforms

asked 2019-11-29 09:12:05 -0600

felipeduque gravatar image

updated 2019-11-29 09:12:28 -0600

I'm trying to run RTAB-Map on my laptop connected to PAL Robotics TIAGo platform. The robot is the ROS master and my laptop consumes the topics from the robot (sensors, poses etc) and runs RTAB-Map. My TF tree looks like the following:


The relevant part is only related to the first frames, e.g.: from "base_footprint" to "base_link". Notice that the most recent transform has a timestamp of 0.000, despite the fact that the transforms are actually being broadcast regularly, as I can see from

rosrun tf tf_monitor base_footprint base_link

The transform from "base_footprint" to "base_link" is a static one. The zeroed timestamps are probably one of the problems preventing RTAB-Map from running correctly in my setup, since sometimes it spits out "TF_OLD_DATA" warnings.

Why does static transforms have zeroed timestamps? How to fix it?

Related questions:

[1] - mentions that zeroed timestamps are expected with TF2, but I didn't understand how he solved it (if at all).

[2] - mentions "use_sim_time", so it's probably related to simulation, which is not my case.

[3] - mentions similar problem to mine but it's not clear if it's been solved.

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First of: Thanks for actually looking around here and describing the problem, as well as linking to related questions! something you don't find here a lot!

Coming to your problem: I doubt that the static transforms are actually responsible for the problem you are seeing. This is basically the outcome of [1] and [3] cited by you as well.

Could you please copy'n'paste the full warning you get in your question (please edit it). Also, please more clearly describe which node you are running and maybe show the launch and config file. Thank you.

mgruhler gravatar image mgruhler  ( 2019-12-02 01:58:51 -0600 )edit

Maybe there's time difference between the computers? You should try running chrony server on one of them and use the other as client.

ManMan88 gravatar image ManMan88  ( 2019-12-03 00:33:47 -0600 )edit