Robots have evolved impressively since the 3-D manipulator built by C.W.
K- ward (1957), the two little electromechanical turtles Elmer and Elsie
[Walter, 1950, Walter, 1951], and the ?rst mobile robots controlled by
comp- ers, Shakey [Nilsson, 1984], CART [Moravec, 1979, Moravec,
1983], and - lare [Giralt et al., 1979]. Since then, we have seen
industrial robot manipu- tors working in car factories, automatic guided
vehicles moving heavy loads along pre-de?ned routes,
human-remotely-operated robots neutralising bombs, and even
semi-autonomous robots, like Sojourner, going to Mars and moving from
one position to another commanded from Earth. Robots will go further and
further in our society. However, there is still a kind of robot that has
not completely taken off so far: autonomous robots. Autonomy depends
upon working without human supervision for a considerable amount of
time, taking independent decisions, adapting to new challenges in
dynamic environments, interacting with other systems and humans, and so
on. Research on autonomy is highly motivated by the expectations of
having robots that can work with us and for us in everyday environments,
assisting us at home or work, acting as servants and companions to help
us in the execution of different tasks, so that we can have more spare
time and a better quality of life.