Subject:
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RE: Angle Sensor
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Newsgroups:
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lugnet.robotics
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Date:
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Sun, 28 Mar 1999 15:44:36 GMT
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Viewed:
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945 times
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S. Crenshaw wrote:
> > Did someone ever tried to balance a long broom on his hand or finger? I'm
> > creating a car that does just that using fuzzy logic...
>
> You shouldn't need fuzzy logic to do this; it's a fairly well-known
> control problem - easily controllable like this:
>
> motor input = k1 * angle + k2 * rate of angle
> + k3 * car position + k4 * car speed
>
> where you need to find k1, k2, k3, k4 (which will depend on your setup)
Oh Oh, time to get on the flame suit. I agree with Stuart. Fuzzy logic
was one of those fads that was to be applied to ALL control systems.
The problem is that many control system problems are well understood
and solutions are already in place. Fuzzy logic was one of those things
that could be described to management and kind of make sense. Did you
EVER hear a marketing guy say to a client, "No problem, we'll just
solve the differnetial equatins and then do the Z transforms and
have the real time control system handle things." They're more likely
to say, "No problem, We have fuzzy logic"
Getting the solutions involves differential equation solutions in the
time S domain and then transforming them to the digital Z domain, and that's
not easy either. You should be able to look at many basic university level control
systems books and find the solutuions.
The problem is that the Mindstorms kit as shipped is not well equipped to do
the digital control algorithms...you'll have to investigate an alternative
firmware source, like legOS or pbFORTH.
Cheers,
Ralph Hempel - P.Eng
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Check out pbFORTH for LEGO Mindstorms at:
<http://www.bmts.com/~rhempel/lego/pbFORTH/default.html>
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Reply to: rhempel at bmts dot com
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Message is in Reply To:
 | | Re: Angle Sensor
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| (...) So long as your software remembers to count the revolutions, it's surely very simple to gear the Lego sensor to get a real angle... however for your idea below, you might need much too much gearing! (...) You shouldn't need fuzzy logic to do (...) (25 years ago, 28-Mar-99, to lugnet.robotics)
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