Robots have evolved impressively since the 3-D manipulator built by C.W. Kward in 1957, the two little electromechanical turtles Elmer and Elsie in the early 1950s, and the first mobile robots controlled by computers, such as Shakey, CART, and Alare. Since then, we have seen industrial robot manipulators working in car factories, automatic guided vehicles moving heavy loads along predefined routes, and human-remotely-operated robots neutralizing bombs. We have even witnessed semi-autonomous robots, like Sojourner, traveling to Mars and moving from one position to another under commands from Earth. Robots will continue to advance in our society. However, there is still a type of robot that has not fully developed yet: autonomous robots. Autonomy relies on the ability to operate without human supervision for a considerable amount of time.