[From Bruce Abbott (950507.1855 EST)]

Remember our little discussion about anticipation in Rick Marken's control

system, the one that used both p and dp/dt in its perceptual input function?

Well, here's a little quote from a text on control system theory:

A proportional-plus-derivative control system is defined as a feedback

control system in which the output forcing function is a linear

combination of the actuating signal and its first derivative. . . .

This type of control system is often referred to as an ANTICIPATOR

since the derivative control causes changes in the output forcing

function in anticipation of an error in the immediate future.

(Milhorn, 1966, emphasis mine)

So, Rick, you've designed an anticipator. Amusing twist, don't you think? (;->

Regards,

Bruce