Analog robot
An analog robot is a type of robot which uses analog circuitry to go toward a simple goal such as finding more light or responding to sound. The first real analog robot was invented in the 1940s by William Grey Walter. The name of these robots were ELSIE and ELMER (Electro Mechanical Robot). The original circuitry was developed using two vacuum tubes and a photocell to search and follow a light. Recently a kind of analog robots was developed by Mark Tilden.
History of robots
In 1951 Walter published the paper "A Machine that learns", documenting how his more advanced mechanical robots acted as intelligent agent by demonstrating conditioned reflex learning. The first digitally operated and programmable robot was invented by George Devol in 1954 and was called the Unimate. This later laid the foundations of the modern robotics industry.