By Les Earnest
The Stanford Cart has had a 46 year career of ups and downs. It was born as a research platform for studying the problem of controlling a Moon rover from Earth. It then was reconfigured as a robot road vehicle for research in visual navigation, then went into show business for a few years. It now is on display in a home for retired robots at the Computer History Museum .
Stanford Cart with cable, 1961
1960-61 - The Stanford Cart was originally constructed by Mechanical Engineering (ME) graduate student James L. Adams to support his research on the problem of controlling a remote vehicle using video information. He had been working at the Jet Propulsion Laboratory on a NASA project called Project Prospector, which was proceeding with the assumption that someone on earth could drive around the Moon using a TV camera on a vehicle and a radio control link However Adams showed that assumption to be false.
The Cart had four small bicycle wheels with electric motors powered by a car battery and carried a television camera with a fixed view in the forward direction. Tests were conducted using both 2-wheel steering, like a car, and 4-wheel steering, in which the wheels and television camera swivel together. The cart was connected by a very long cable to a control console with a television display and controls for steering and speed. A magnetic tape loop made it possible to vary the time delay of steering commands, to simulate communication delays.
Stanford Cart with radio links, 1963
1962-63 - Mechanical Engineering graduate student Paul W. Braisted devised a scheme to improve the controllability of the vehicle by adding an analog computer that functioned as a predictor that took into account preceding steering commands and put a bright dot on the television screen at the predicted location of the cart when a current steering command would begin to take effect. With this addition the vehicle could be controlled at 5 mph (8 kph). Still there was a fundamental limitation on teleoperation in that if the travel during the time delay is greater than the distance from the vehicle to an unseen obstacle there is no way to avoid hitting it. Braisted completed his dissertation in 1963.
the immediate prospect of applying this technology was put off as a result of
President John F. Kennedy's announcement on
Stanford Cart configured as an autonomous road vehicle at SAIL
1964-71 – The cart evidently sat unused in a Mechanical Engineering laboratory until 1966 when Les Earnest, who had recently joined the Stanford Artificial Intelligence Lab (SAIL) as Executive Officer, found it and talked its creator, James Adams, into letting SAIL use it to try making a robot road vehicle using visual guidance. However the radio links and other electronics that had existed earlier had vanished, so he recruited Electrical Engineering PhD student Rodney Schmidt to build a low power television transmitter and radio control link to undertake the visual guidance project.
was granted an experimental TV license by the Federal Communications Commission
for Channels 22 and 23 and experimental operation began with a human operator
controlling the cart via the computer based on television images. This
initially allowed students to drive it around the neighborhood while seated at
a desk watching television views, which became a popular pasttime.
John McCarthy then became interested in the project at this time and, as
Director of SAIL, took over its supervision. Using the KA10 processor, which
ran at about 0.65
Stanford Cart with slider, 1979
1971-80 - The cart was changed from 4-wheel to 2-wheel steering during this period. Hans Moravec, who had come to Stanford specifically to work on visual navigation, stayed with it but suffered a setback in October 1973 when the cart toppled off an exit ramp while under manual control and ended up with battery acid throughout its electronics.
Moravec was able to enlist the aid of roboticist Victor Scheinman in 1977 to build a “slider,” a mechanical
swivel that moved the television camera from side to side allowing multiple
views to be obtained without moving the cart. Using the KL10 processor then
available, which ran at about 2.5
– After SAIL was shut down in 1980 the cart again went into storage until 1987
when, at the request of the
in 1980, upon completion of his PhD, Hans Moravec
recently SAIL, under the direction of
Sebastian Thrun, developed a robot vehicle called Stanley, which in
2005 won the DARPA
Grand Challenge, a race across the
Sebastian Thrun and some of his colleagues then moved to nearby Google and created the Google driverless car which is still under development though Thrun has gone elsewhere.
Thanks to James Adams, Bruce Baumgart, Hans Moravec, Oliver Strimpel and Sebastian Thrun for providing information for this account.
following Ph.D. dissertations at
 Adams, James Lowell, Remote control with long transmission delays, PhD in Mechanical Engineering, 1961.
 Braisted, Paul Wilder, Study of a predictor for remote control systems operating with signal transmission delays, PhD in Mechanical Engineering, 1963.
 Schmidt, Rodney Albert, Jr., A study of the real-time control of a computer-driven vehicle, PhD in Elecetrical Engineering, 1971.
 Moravec, Hans Peter, Obstacle avoidance and navigation in the real world by a seeing robot rover, PhD in Computer Science, 1980.