Re: [CAD_CAM_EDM_DRO] Re: Dedicated mb for PID

Fast PID algorithms I have seen use a finite impulse response digital filter
set
to implement integration and differentiation. This is simply a short list of
coefficients
in memory. Each one is multiplied by a datapoint in time order then the data
is shifted
one and it is repeated, forming a digital approximation of convolution.
Simply by
choosing proper coefficients band pass filters can be used to control high
gains
at high frequencies for derivative (for noise immunity) and at low
frequencies for
integral.

I have written some in c for dos that were blazing fast at least on a pc. I
seem to
recall running some at 100 kHz for a project a while back in a pentium even
though
I used floats.

Les
Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.rabun.net/~leswatts/shop.html

----- Original Message -----
From: "Doug Harrison" <prototype@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Saturday, June 29, 2002 9:47 PM
Subject: Re: [CAD_CAM_EDM_DRO] Re: Dedicated mb for PID


> > Qbasic? My servo amps have a velocity bandwidth of about 3 KHz,
> > higher than the EMC servo update rate in my system. I suspect that
> > you'd have trouble doing a decent PID algorithm at a reasonable
> > rate in software on a $10 micro.
> >
> > Jon
>
> OK, what about some form of compiled basic? 8KHz should be possible in
dos.
>
> Doug