Robert Bonomi wrote:

In article .com,
Predictor wrote:

Ernest Christley wrote:
"Dan, did you ever get a chance to work with fuzzy logic?"

Pete Schaefer responded:
"I have. It's been a while. I'd never, ever use it on an airplane.
Maybe a washing machine controller or something like that. I'm not
saying that it can't be done, but just that it's a risky design
approach."


Why is fuzzy logic "risky"?


BECAUSE it _is_ fuzzy. grin

Seriously, the nature of fuzzy logic is that it it _not_ deterministic.
Given a specific set of inputs, you cannot predict exactly what the
fuzzy logic will do for every occurrence of those inputs.

Fuzzy logic is deterministic. The rules are well defined, there is no
random number generator in any fuzzy logic implementation that I've seen.


Identifying and analyzing "boundary" conditions in fuzzy logic is
"difficult, at best". _at_ a boundary condition, there is no telling
how far back one must trace to find the 'bias' that changes the output,
when all 'intermediate' inputs are identical. Even worse, the decision
may be based on 'noise' in the system.

Noise will make any system behave randomly, but that is because you are
providing random inputs. Fuzzy logic is no different than PID or any
other control algorithm in this regard. However, the identical inputs
will produce the same outputs if the software is designed correctly.


This like this can lead to "unexpected" behavior in "unusual" circumstances.

Baloney.

Matt