MobileRobots / ros-arnl

Provides ROS interface to basic ARNL features. Requires ARNL and ArnlBase to be installed separately.
Other
8 stars 14 forks source link

More accurate time stamps for poses #2

Open NikolausDemmel opened 9 years ago

NikolausDemmel commented 9 years ago

Is it possible from ARNL to access a more accurate time stamp for the laser pose. At the moment the current time in the 10Hz loop callback in used (https://github.com/MobileRobots/ros-arnl/blob/19702d6b4e2c5b66608bbe0d2580fe92d26d2a1e/rosarnl_node.cpp#L176), however this is likely not very accurate. E.g. after a laser update of the localization filter, the timestamp of the current pose should be that time when the laser data used in the update was taken by the sensor.

There is a similar issue for the sensor data itself. If we want to add e.g. publishing the laser data to ROS, we currently would also need to use the current time in the loop callback (as done here: https://github.com/TRECVT/rosaria/blob/9e00c4e78bc9e2bb03cdeaf69c194898c1715ba9/src/RosAria.cpp#L678). Is there a way to get the acquisition time of laser scans?

reed-adept commented 9 years ago

I just updated rosarnl_node to use ARNL's timestamp for when it last re-localized (see commit 4c72a627379d2493b6f023443c2b764144d80a25). This is not exactly the time when the sensor data was acquired, since ARNL is asynchronously getting sensor data from various sources, but it should represent the delay between ARNL determining a new localized pose and when rosarnl_node publishes that pose as amcl_pose. If there's a specific need for something more than that, I don't know if it can be done with the existing ARNL API but let me know so we can look into it.