Logging

last_letter uses the ROS bag system to record logs.

The record executable of the rosbag package is called in the last_letter/launch/simulation.launch file with the argument

<node if="$(arg log)" pkg="rosbag" name="recorder" type="record" args="-O UAV_recording.bag -a"/> <!-- topic activity recorder node -->

, provided that the log argument of the launch file is set to true.

This command starts a rosbag/record executable with the name recorder, with the arguments -O UAV_recording.bag -a. The arguments tells the executable to write a .bag file wit the name UAV_recording.bag and puts in there all of the topics which appear in the simulation.

The .bag file is stored in the ~/.ros directory.

You can extract the information of each topic in the .bag file separately, or replay them to playback the simulation. These functions are described in the ROS documentation pages of the .bag files.