[islandlabs] Multimeter I have, Model-Following control system design

Chris Knadle Chris.Knadle at coredump.us
Thu Apr 9 04:35:09 EDT 2015


This is got to do with stuff I was talking to Bill about tonight.

The multimeter I have: Wavetek 27XT
   http://www.lippaudio.org/Diyfqa/tips/meter.html

It'll measure capacitance down to a range of 2nF (nano-Farad) and
inductance down to a range of 2mH  (milli-Henry).  This isn't terribly
good as the typical small capacitors we'd use in electronic building
are in pF (pico-Farad, 1000x smaller than nano-Farad) and inductors in
uF (micro-Henry, 1000x smaller than milli-Henry), but we can try it
next week on your manually-wound inductor coil to see if we can get
a measurement.  (Assuming I remember to bring the meter.)




Re: control system for "Stick Man": as I mentioned I found the paper
I wrote in 2011 for Advanced Digital Control comparing results between
a "Classical" control system vs a Model-Follower control system; the
Model-Follower system doesn't need to know anything about the "plant"
(i.e. the "load"), and the only data needed to be known is the desired
Overshoot and Settling Time.  These yield the "Desired Roots" (expressed
in complex numbers) which are used to calculate the required
coefficients for the Model Following system.

The end result is a digital control system which uses negative feedback
with multiplied coefficients on the current, previous, and 2nd previous
results to calculate what the next control response should be.

The typical Overshoot is ~16%, so the only real variable is the desired
Settling Time; that is, how quickly the control system should be able to
respond and reach a relatively steady state.  The answer to that when it
comes to "Stick Man" doesn't seem immediately obvious.  Does 2.5 seconds
seem like a reasonable time for it to steady itself, or does it need to
be shorter?

Anyway I copied the paper I wrote to my laptop; if I remember, I'll
print a copy and bring it to the meeting.

   -- Chris

-- 
Chris Knadle
Chris.Knadle at coredump.us


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