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.
R. Daneel Olivaw
Daneel is a robot built by Roj Nemennuh Sarton and Han Fastolfe, who are Spacer roboticists from the planet Aurora, in the year 5020 AD. Although designed and built by Auroran roboticists, Daneel was constructed on Earth. He is the first humanoid, or "humaniform," robot ever constructed and is virtually indistinguishable from a human being. This "undercover" attribute enables him to help earth-policeman Elijah Baley solve crimes. Daneel and Baley first meet while Baley is investigating the murder of Daneel's co-creator Sarton in Spacetown. Daneel is physically a perfect likeness of Dr. Sarton.