Page 189 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

Four modes of operation
While primarily of a photovore (light-seeking) type, the robot ex-
hibited four modes of operation. It should be mentioned that the
robot’s steering motor and drive motor were usually active.
Search. Ambient environment is at a low light level or
darkness. Robot’s response: steering motor on full speed,
drive motor on one-half speed.
Move. Found light. Robot’s response: steering motor off,
drive motor full speed.
Dazzle. Bright light. Robot’s response: steering one-half
speed, drive motor reversed.
Touch. Hit obstacle. Robot’s response: steering full speed,
reverse drive motor.

Observed behavior

In the 1950s, Walter wrote two Scientific American articles (“An
Imitation of Life,” May 1950; “A Machine That Learns,” August
1951) and later a book titled The Living Brain (Norton, New
York, 1963). The interaction between the neural system and the
168 environment generated unexpected and complex behaviors.
In one experiment Walter built a hutch, where Elsie could enter
and recharge its battery. The hutch was equipped with a small light
that would draw the robot to it as the robot’s batteries ran down.
The robot would enter the hutch and its battery would automati-
cally be recharged. Once the battery recharged, the robot would
leave the hutch to search for new light sources.

In another experiment Walter fixed small lamps on each tortoise
shell. The robots developed an interaction that to an observer
appeared like a kind of social behavior. The robots danced around
each other, at times attracted and then repelled, reminding one of
a robotic mating ritual or territorial-marking behavior.

Building a Walter tortoise

We can imitate most functions in Walter’s famous tortoise. The pro-
gram we will use simulates the neurons used in the original robot.
To fabricate the chassis, we need to do a little metalwork. Working
metal is made a lot easier with the following tools:
Center punch. Used to make a dimple in sheet metal to
facilitate drilling. Without the dimple, the drill is more likely to
“walk off” the drill mark. To use, hold the center punch in the

Team LRN
Chapter eight