http://www.beam-online.com/Robots/vwalker1/index.html
This is vWalker v1. The "v" standing for V, as in five. It is a five motor walker that goes towards light and avoids obstacles. The goal was to create a walker that could navigate over rough complex terrain while seeking out the brightest source of light. The base controller for the walker is four master/slave linked bicores. All of the other circuits take input from sensors and modify the signal coming out of the bicores to make the walker backup, turn, and seek light.