ROS Programming: Building Powerful Robots

Nodes and nodelets

Nodes are executable that can communicate with other processes using topics, services, or the Parameter Server. Using nodes in ROS provides us with fault tolerance and separates the code and functionalities, making the system simpler.

ROS has another type of node called nodelets. These special nodes are designed to run multiple nodes in a single process, with each nodelet being a thread (light process). This way, we avoid using the ROS network among them, but permit communication with other nodes. With that, nodes can communicate more efficiently, without overloading the network. Nodelets are especially useful for camera systems and 3D sensors, where the volume of data transferred is very high.

A node must have a unique ...