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.
HAL (robot)
The first HAL prototype was proposed by Yoshiyuki Sankai, a professor at Tsukuba University. Fascinated with robots since he was in the third grade, Sankai had striven to make a robotic suit in order “to support humans.” In 1989, after receiving his Ph.D. in robotics, he began the development of HAL. Sankai spent three years, from 1990 to 1993, mapping out the neurons that govern leg movement. It took him and his team an additional four years to make a prototype of the hardware.