Introduction to ROS runtime

I've learned ROS, In a brief summary .
See other blog posts ROS series
This paper records ROS Logical view .

ROS Adopt distributed design idea , Run and process data on a node by node basis . The brief idea is shown in the figure above ：

• The server ： Physical servers
• Node ： Operation node , Each node is an executable
• roscore : A node
  • yes ROS The system is located in the information processing center of the machine , all ROS Messages are sent via the local roscore forward
  • Each physical server must be up and running
• NodeHandle ：ROS Class provided , Handle to the node , As a carrier of service or topic
  • ROS This class handles the interaction between different nodes
  • Automatically reclaim resources when destroyed
• Service : ROS A two-way data transmission mode , Must be NodeHandle As a carrier
  • Client End ： Access one end of the service as client As required msg Format send request
  • Server End ： Receive defined msg Format message , And respond to the request
• Topic ：ROS It provides a single data transmission mode , Must be NodeHandle As a carrier
  • Publisher （publisher） ： By definition msg Format release message
  • Subscribers (suscriber)： Receive defined msg Formatted message

follow-up ROS Working space for