本文主要部分来源于ROS官网的Tutorials.
Description: This tutorial will teach you how to record data from a running ROS system into a .bag file, and then to play back the data to produce similar behavior in a running system.
roscore & rosrun turtlesim turtlesim_node & rosrun turtlesim turtle_teleop_key
rostopic list -v # examine the full list of topics that are currently being published in the running system. # making a temporary directory to record data and then running rosbag record with the option -a mkdir ~/bagfiles cd ~/bagfiles rosbag record -a # Now all published topics will be accumulated in a bag file.
现在可以用方向键控制乌龟运动，所有Topics都会被记录到*.bag文件，本例文件名是当前时间。
接下来回放：
rosbag play <your bagfile>
可以看到乌龟根据回放的message运动。
Recording a subset of the data
rosrun turtlesim turtlesim_node
rosrun turtlesim turtle_teleop_key
rosbag record -O subset /turtle1/cmd_vel /turtle1/pose # 只记录感兴趣的topics， 记录到subset.bag中
The limitations of rosbag record/play
play（回放模拟）的效果可能和record（真实历史）时不完全一样，因为：
- rosbag是通过记录topics来回放模拟历史msgs信息。
- 仿真的轨迹与 初始状态有关系。
- 考虑到系统调度的复杂性，难以保证时间完全精确， 仿真的轨迹与 微小的时间差 也有关系。