Page 196 - Introduction to Autonomous Mobile Robots

5 Mobile Robot Localization

5.1 Introduction

Navigation is one of the most challenging competences required of a mobile robot. Success
in navigation requires success at the four building blocks of navigation: perception, the
robot must interpret its sensors to extract meaningful data; localization, the robot must
determine its position in the environment (figure 5.1); cognition, the robot must decide how
to act to achieve its goals; and motion control, the robot must modulate its motor outputs to
achieve the desired trajectory.
Of these four components (figure 5.2), localization has received the greatest research
attention in the past decade and, as a result, significant advances have been made on this
front. In this chapter, we explore the successful localization methodologies of recent years.
First, section 5.2 describes how sensor and effector uncertainty is responsible for the diffi-
culties of localization. Then, section 5.3 describes two extreme approaches to dealing with
the challenge of robot localization: avoiding localization altogether, and performing
explicit map-based localization. The remainder of the chapter discusses the question of rep-

?

Figure 5.1
Where am I?