osrf · gerkey · Jun 17, 2020 · Jun 5, 2020 · Jun 5, 2020 · Jun 5, 2020
diff --git a/src/SUMMARY.md b/src/SUMMARY.md
@@ -2,6 +2,10 @@
 
 - [Introduction](./intro.md)
 - [ROS 2](./ros2.md)
+ - [ROS Resources](./ros2_tools_resources.md)
+ - [ROS Concepts and Design Patterns](./ros2_design_patterns.md)
+ - [The ROS Command Line Interface](./ros2_cli.md)
+ - [The ROS API](./ros2_api.md)
 - [Traffic Editor](./traffic-editor.md)
 - [Simulation](./simulation.md)
 - [RMF Core](./rmf-core.md)

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diff --git a/src/ros2.md b/src/ros2.md
@@ -1,3 +1,53 @@
-# ROS 2
+# An Introduction to ROS 2
 
-Herein we shall discuss Deep Thoughts about ROS 2
+In this chapter we will cover the basics of Robot Operating System (ROS) and
+give you all the tools you need to build, debug, and understand robotic
+applications. This chapter is laid out from the most general concepts, necessary
+for decision makers to make sound decisions, to specific API references needed
+by engineers to develop new robotic applications. Somewhere in between high
+level concepts, and low level API commands lives the knowledge necessary for
+those maintaining and supporting multi-robot deployments in the field.
+
+A good analogy to learning about ROS is the process of learning about motor
+vehicles. At the practical, day-to-day level, most people will learn how to
+start a vehicle and safely use it on a motorway. For these individuals, learning
+about the high level concepts behind ROS, along with application-specific
+commands is probably sufficient. Those who enjoy driving often choose to learn
+how to repair and maintain their vehicle. If this is your interest level we
+recommend learning the basics of the ROS command line interface. This will allow
+you to "check the oil" of your robotic systems and make sure everything is
+functioning correctly. Finally, if you are the type that would like to swap out
+the engine of your vehicle with something more powerful, or potentially build a
+wholly new vehicle from scratch, then the ROS API is the set of tools that will
+make this possible. Generally speaking, automotive engineers don't appear into
+the world fully formed, and the same is true for roboticists. It is advisable to
+work through each phase of understanding as you develop your skills with ROS.
+
+Following from our analogy above the process of learning how to use robotic
+systems built on ROS can be divided roughly into four parts. This chapter works
+through these four parts of the process, using ROS 2. Subsequent chapters then
+build upon this knowledge and discuss the subtleties of specific
+applications. The four parts of this chapter are as follows.
+
+* Meta-discussion of the tools and resources available to help you in the
+ learning process.
+
+* A high level discussion to the design patterns use in ROS. These patterns are
+ roughly analogous to the subsystems you would find in a vehicle (engine,
+ brakes, safety, climate control, etc).
+
+* A treatment of the command line interface (CLI) for ROS. The CLI is a set of
+ programs for starting, inspecting, controlling, and monitoring a ROS
+ robot. You can think of this topic as teaching you how check a robot's oil,
+ and read the instrument panel.
+
+* An introduction to the ROS application programming interface. This section
+ will show you how to create your own applications and modify existing software
+ for your specific application.
+
+While this books aims to cover the basics it should be made clear that ROS, like
+almost all software is a moving target. Technology moves quickly, and while
+print media is helpful and delivering high fidelity instruction, that
+instruction can become rapidly outdated. For this reason we start this chapter
+with a meta-discussion of ROS resources that can be used to help you in your
+learning process.
diff --git a/src/ros2_api.md b/src/ros2_api.md
@@ -0,0 +1,5 @@
+# The ROS API
+
+This section will show you how to create your own applications and modify
+existing software for your specific application.
+