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.
Cobot
Cobots resulted from a 1994 General Motors initiative led by Prasad Akella of the GM Robotics Center and a 1995 General Motors Foundation research grant intended to find a way to make robots or robot-like equipment safe enough to team with people. The first cobots assured human safety by having no internal source of motive power. Instead, motive power was provided by the human worker.
The cobot's function was to allow computer control of motion, by redirecting or steering a payload, in a cooperative way with the human worker. 
Later cobots provided limited amounts of motive power as well.