ros.md

ROS

Run ros on any distro

ROS-DOCKER

Basic commands

• catkin_make builds the project.
• roscore Start the root node.
• rosrun <package> <program> execute a node.
• rospack list list all installed packages.
• rostopic list list all the current active topics
• rostopic info <topic> print all the information about the topic(publishers / subscribers).
• rostopic pub <topic> <mssg-typ> <mssg> send a message to a topic.
• rostopic echo <topic> subscribe to a topic.
• rostopic hz <topic> get frequency of messages.
• rosnode list list all avaliable nodes.
• rosnode info <node> get detailed information about the node.
• rosparam list list all available parameters
• rosmsg info <message> e.g. geometry_msgs/Twist check the message structure.
• rosbag record <topic> --duration=<X in seconds> record some topic
• rosbag play <topic_file> replay the recorded topics (very usefull for debugging)

RQT

It is basically gui for command tools -> topic monitor gui topics

Compiled packages are not listed?

Re-source: . ./devel/setup.zsh --extend. Check for successful source: echo $ROS_PACKAGE_PATH

Launchfile

<launch>
  <node pkg="turtlesim" type="turtlesim_node" name="turtlesim_node" output="screen"/> # define node
  <node pkg="exercise2" type="pubvel" name="pubvel"  output="screen">
    <param name="scale_linear" value="1" type="double"/> # Parameters for our nodes (basically constants)
    <param name="scale_angular" value="4" type="double"/> # Use rosparam list to list them all
    <remap from="cmd_vel" to="/turtle1/cmd_vel" /> # Remap topic
  </node>
</launch>

CmakeLists.txt

# Here you add addidional packages:
- rospy: to compile with python libraries
- roscpp: ROs c++ compiler
- geometry_msgs: Useful structs for position estimation
find_package(catkin REQUIRED COMPONENTS rospy roscpp geometry_msgs)