ROS Robotics By Example

ROS nodes and ROS Master

One of the primary purposes of ROS is to facilitate communication between the ROS modules called nodes. These nodes represent the executable code and the code can reside entirely on one computer, or nodes can be distributed between computers or between computers and robots. The advantage of this distributed structure is that each node can control one aspect of a system. One node can capture and output camera images, and another node can control a robot's manipulator in response to the camera view. We will see that the turtlesim simulator has two nodes that are created when turtlesim is executed.

The ROS site http://www.ros.org/core-components/ describes the communication and robot-specific features of ROS. Here, we will ...