Elon;
It would be interesting to see what his findings were.
Regards, Neil Tucson, AZ
-----Original Message-----
From: 3liter [mailto:saltfever@comcast.net]
Sent: Wednesday, October 01, 2003 12:14 AM
To: LSR submissions
Subject: Rear Wheel Steering
John Whitehead not only understands the physics of rear wheel steering but.
most importantly, he identified the real problem as an almost imperceptible
lag-time (or feedback delay) to the human driver. I think he did his PhD
Thesis on the subject in the early 80s. At any rate I read a paper of his
about 25 years ago. If I recall (and I could be wrong) he proved that rear
steer was just as stable as the opposite. However, because of the human
response time to stimulus, he indicated that only computer control or
augmentation had the response time necessary to make the system work. He
was not just a geek physicist , apologies to Mayf :-), but he actually
built a system. Further, I think he instrumented his commute car and
collected data in real conditions. Two of his articles are referenced
below. But if you really want to understand the fundamentals you need his
Thesis paper from the 80's. I saved it but it is buried under 45 years of
car tech articles. Very few were capable of understanding his work but the
Japanese sure took an interest. (Does that tell you anything!). I'll try to
identify the paper and report back. In the meantime the Journal paper
should be a good read. Ask your local library to get it for you or if you
are close to a University try the engineering library for the SAE article.
-Elon
Whitehead, J.C., "Four Wheel Steering: Maneuverability and High Speed
Stabilization," SAE paper 880642
Whitehead, J., March, 1990. "Rear Wheel Steering Dynamics Compared to Front
Steering", Journal of Dynamic Systems, Measurement, and Control, Volume 112,
pp. 88-93.
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