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Contents: Part II
Chapter 9: Topological Path Planning

Chapter 10: Metric Path Planning
Chapter 11: Localization and Map Making

Chapter 12: On the Horizon

Overview

The first three chapters in this part focus on navigation, a critical ability for a
robot that claims to be mobile. Navigation remains one of the most challeng-
ing functions to perform, in part because it involves practically everything
about AI robotics: sensing, acting, planning, architectures, hardware, com-
putational efficiencies, and problem solving. Reactive robots have provided
behaviors for moving about the world without collisions, but navigation is
more purposeful and requires deliberation. In particular, a robot needs to be
able to plan how to get a particular location. Two different categories of tech-
TOPOLOGICAL niques have emerged: topological navigation and metric navigation, also known
NAVIGATION as qualitative navigation and quantitative navigation, respectively. Another im-
METRIC NAVIGATION
portant class of problems is how to make maps, which introduces the issue
QUALITATIVE
NAVIGATION of how the robot can accurately localize itself as it moves, despite the prob-
QUANTITATIVE lems seen with proprioceptive sensors in Ch. 6. The final chapter provides
NAVIGATION
an overview of robots and AI techniques on the horizon.

The Four Questions

Part I presented the material in a historical sequence, following the steps
in development of the three AI robotic paradigms. Navigation is more of
a collection of specific algorithms than a linear progression; therefore the
material is organized by functionality. The functions of navigation can be
expressed by four questions presented below.
Where am I going? This is usually determined by a human or a mission
planner. A planetary rover may be directed to move to a far away crater and
look for a specific rock in the caldera. Roboticists generally do not include
this as part of navigation, assuming that the robot has been directed to a
particular goal.
What’s the best way there? This is the problem of path planning, and is
the area of navigation which has received the most attention. Path planning