ROS操作命令：
1)rospack;
2)roscd;
3)rosls;
4)roscore rosnode rosrun
Graph Concepts
Nodes: A node is an executable that uses ROS to communicate with other nodes.
Messages: ROS data type used when subscribing or publishing to a topic.
Topics: Nodes can publish messages to a topic as well as subscribe to a topic to receive messages.
Master: Name service for ROS (i.e. helps nodes find each other)
rosout: ROS equivalent of stdout/stderr
roscore: Master + rosout + parameter server (parameter server will be introduced later)—运行ros系统首先执行此命令。
roscore = ros+core : master (provides name service for ROS) + rosout (stdout/stderr) +
parameter server (parameter server will be introduced later)
rosnode = ros+node : ROS tool to get information about a node.
rosrun = ros+run : runs a node from a given package
rosservices 、rosparam
Services allow nodes to send a request and receive a response.
rosservice list print information about active services
rosservice call call the service with the provided args
rosservice type print service type
rosservice find find services by service type
rosservice uri print service ROSRPC uri
rosparam set set parameter
rosparam get get parameter
rosparam load load parameters from file
rosparam dump dump parameters to file
rosparam delete delete parameter
rosparam list list parameter names
rqt_console and rqt_logger_level（调试模块）， roslaunch
Fatal
Error
Warn
Info
Debug
rosed — 直接编辑代码文件等
msg and srv
msg: msg files are simple text files that describe the fields of a ROS message. They are used
to generate source code for messages in different languages.
srv: an srv file describes a service. It is composed of two parts: a request and a response.
1）msg 添加新内容之后的配置（package.xml 以及CMakeList.txt文件的配置）；
http://wiki.ros.org/ROS/Tutorials/CreatingMsgAndSrv
2）
rosbag
roswtf 检查错误。
There are many other types of problems that roswtf can find. If you find yourself stumped by a build or communication issue, try running it and seeing if it can point you in the right direction.
rosdep（ros update）依赖项添加
ROS tools to help
eg:rosmsg -h rosmst show -h;