>
> >>>> Allow non-electronics types to retrieve the data and modify the
> >>>> algorithm in the field (I'm thinking USB or SD memory card)
> >>
> >> This and the fact that it probably will be (has to be, considering that
> >> they are "non-electronic types" :) floating point seems to be a
> >> critical thing to look at. There probably needs to be some kind of
> >> limitation to the complexity of the algorithm. [...]
>
> For something like this, Forth would be quite good. Possibly some Basic
> interpreter engines, too.


Hmmmm.....



> > I'm secretly hoping that I can distill it to some sort of lookup table.
>
> If this is about a feedback control system, I'm not sure that makes sense
> or works at all. A simple PID controller is easy enough to parametrize,
> but
> you are indicating that they may want to experiment with something a bit
> more elaborate, possibly with nonlinear portions and characteristics that
> depend on the history. How would that work with lookup tables?
>
> Gerhard


Well, the PID loop would tightly wrap the encoder and the servo. It would be
responsible for making actual_location match desired_location and would be
an unchanging function of the mechanicals. The thought (and at this point
it's nothing more than that) is that I could parameterize the
desired_location as a function of the sensor variables. Think of an
n-dimensional array where one or more of the dimensions could include
historic parameters. Although with even just a few parameters the table
grows exponentialy.
With a spread of just twenty data points and 5 parameters the table exceeds
3MB, 6 parameters makes it 60MB. That might be doable if I can hold the data
in a SD card or something and calculate an index pointer, definitly not
doable if I have to read and parse all the data.

It also might be possible to do a hybrid lookup/calculate option. Several
smaller lookup tables that handle one or two parameters, then some more
strait forward arithmetic with those values.

Like I said before, the math is complex and unspecified. A large part of
this project is developing a reasonable way for non-software folks to
interract with that math. That particular aspect needs to be alot further
along before I build any hardware.

-Denny
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