Navigation Functionalities for an Autonomous UAV Helicopter

Chapter 1
Introduction
An Unmanned Aerial Vehicle (UAV) is an aerial vehicle without a human
pilot on board. It can be autonomous, semi-autonomous or radiocontrolled.
In the past, the use of UAVs have been mostly related to military
applications in order to perform the so-called Dirty, Dull and Dangerous
(D3) missions such as reconnaissance, surveillance and location acquisition
of enemy targets. Recently, interest for UAV systems has grown in
the direction of civil applications as a consequence of the cost reduction of
this technology.
Aircraft navigation can be accomplished by safely solving four tasks:
decision making, obstacle perception, aircraft state estimation (estimation
of position, velocity and attitude) and aircraft control. In the earlier days
of aeronautic history, the on-board pilot had to solve these tasks by using
his own skills. Nowadays the situation is quite different since a high level
of automation is present in modern military and civil aircrafts. In order
to replace the pilot completely a number of problems have to be solved.
For example, it is difficult to replace the skills of a pilot in perceiving and
avoiding obstacles. This is one of the reasons why the introduction of UAVs
in non-segregated airspace still represents a challenge.
The work presented in this thesis was initiated as part of the WITAS
UAV Project [17, 2], where the main goal was to develop technologies
and functionalities necessary for the successful deployment of a fully au-
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