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ROS Concept Matcher

Run the ROS Concept Matcher MicroSim Fullscreen

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Description

Read six ROS 2 and robot-description terms beside a picture of two nodes joined by one topic. Then match eight short descriptions to the terms Node, Topic, Message, Publisher, Subscriber and URDF. Used in Chapter 13.

The picture shows a node called arm_driver that publishes sensor_msgs/JointState messages on the topic /joint_states, and a node called planner that subscribes to that topic and reads the arm's URDF file. The node and file names are examples made up for this picture.

Lesson Plan

Grade level: Middle school and up (age 12+). Time: 10 to 15 minutes.

  1. Explore. Read the six terms. Use the menu to point out each one in the picture. Which two terms both light up a node, and why?
  2. Say it in your own words. Cover the list and explain the difference between a node and a topic, and between a publisher and a subscriber.
  3. Eight descriptions. Choose Eight descriptions in the menu. Press the term that each description fits. Pressing a button commits your answer. You get one attempt at each, and 7 of 8 is mastery.
  4. Think about it. A publisher does not send to one particular subscriber. What does it send to, and why is that useful when a robot has many programs?

ROS 2 is not an operating system. It is a set of libraries and conventions for building robot software from many small programs.

Specification

The learning objective, evidence of mastery and content for this MicroSim are specified in Chapter 13: Logging, Testing, Simulation, and ROS 2.