[Rick Marken (920119.1200)]
Avery Andrews (930119.1919)
Figure 11 on pg. 1446 is supposed to represent a `feedforward' system
operating alternately with a `feedback' system
I think there should be a special corner in the hell of the Devil's
Bibliography for pronouncements about the effectiveness of
feedforward.
Feedforward is just Ashby's "compensating regulator" that Bill
Powers (930118.1600) demolished rather unconfortably with his
newly coined "parable of the bathtub". The corner of hell for
feedforward zealots should have Powers' bathtub attended
by two devils, one with 200 pounds of ice cubes, the other with
50 gallons of boiling water -- AND NO THERMOMETER
ANYWHERE.
feedforward
is described by paraphrasing a (clear and cogent) exposition by Houk and
Rymer (1981)
Houk & Pymer's description of feedforward may be cogent -- but if they
think feedforward actually works (produces control) then it's the Powers
bathtub corner for them too.
Best
Rick