Re: Black box ??

Mr Sausage,

DSPs, "self tuning servoes" and the like have been around for at
least a decade now.

Great claims have been made about their simplicity and idiot-
proofness. Sadly most have not met the expectations of their
proponents.

The PID alogorith is very straight-forward and can be implemented
digitally as well as analogically. Either will suit the need.

The problem becomes how do you set the 3 magic coeffocients. In an
analog version these are set by trimpots. Very easy and intuitive to
adjust. In the digital venue they become data that must be entered.
Now you are seperated from cause and effect by the particular
interface you are using. Not nearly as intuitive now.

There are times when the ancient ways of doing thing are still better.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "Mr. sausage" <sirsausage@h...> wrote:
>
>
> >For servos, hang a DSP chip off the USB micro and let it do the PID
> >algorithms and interpolation calculations. Just send it a list
of 'goto
> >locations'. Plenty of appnotes on
> >TI's DSP site for examples. The micro in the USB interface just
acts as a
> >link
> >between the PC host and the DSP engine.
>
>
> Thank you - this was something I was trying to point out in the
earlier
> discussions regarding 'black box' design. The PID ought to be
software
> based; no sense in having to adjust pots. A DSP can even 'learn'
the
> optimal characteristics. Essentially the hardware is reduced to
little
> more than a large DAC.
>
> Mariss?
>
>
>
>
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