Bristol turtles

In the late 1940s, a British neurologist named Grey Walter started tinkering with small machines that could operate autonomously. He built two turtles, named because of their shell, which would move around a room and avoid bumping into objects and even return to a base to charge batteries. Although limited, these simple machines were a leap in robotics because they operated without preset directions. Here's a video of Walter and the "Bristol turtles" at work, and here is more information on the history of the original machines.