Re: Higher performance systems

Bill,

Thanks, but all this is being done in Rabbit assembly. This time, no
analog anywhere.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, ccq@x wrote:
> Hi Mariss;
>
> Just to remind you about them, there are such things as log/anti-
log amps, and
> if you don't mind dealling with them, they'll not only do trig,
they'll do it
> in real-time, as in right now, immediately. The ADC's, or DAC's
you might need
> for translation to/from digital signals might waste some time
though.
>
> Bill
>
>
> On Thu Aug 28 16:25:04 2003 Mariss Freimanis wrote:
>
> >Leslie,
> >
> >Ah, a topic near and dear to me just right now! The conundrum is
> >vector path fidelity and a constant vector velocity are mutually
> >exclusive.
> >
> >To accurately follow a path means you have to decelerate to a stop
at
> >the end of every line segment which is irritatingly slow and noisy.
> >
> >You can "round" line segment nodes to keep a constant contouring
> >velocity. It is a computational nightmare though, having to insert
> >arcs between nodes whose start and end angles and radii depend on
a
> >given axis set acceleration and velocity. The "on the fly"
> >trignometry and path look-ahead schemes get real ugly real fast.
> >
> >I have come up with a method that neatly sidesteps those problems
> >entirely; it is computationally trivial and acts automatically. In
> >effect, the faster you go, the "rounder" the nodes are.
> >
> >The method outputs a moving average of velocity, effectively
> >integrating velocity with time. A step change in velocity gives a
> >ramped change, a ramped velocity results in an S-shaped velocity
> >profile.
> >
> >As you probably know the G2002 is up and running using this
> >algorithm, now on 3-D moves (XYZ). The results are very pretty
indeed.
> >
> >Mariss
> >
> >
> >
> >
> >--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Leslie M. Watts"
> ><leswatts@a...> wrote:
> >> Mariss,
> >> I think of the accel in terms of minimum corner radii.
> >>
> >> Radius= velocity squared/acceleration
> >>
> >> ... for more calculator fun.
> >>
> >> With 20 amps x 70 volts peak one can move a lot of
> >> mass pretty quickly!
> >>
> >> I certainly agree with you and Jon that you won't
> >> get to 1000 ips with a 5 TPI ballscrew!
> >>
> >> Leslie M.Watts
> >> L M Watts Furniture
> >> Tiger Georgia USA
> >> http://home.alltel.net/leswatts/wf.html
> >> Engineering page:
> >> http://home.alltel.net/leswatts/shop.html
> >> CNC surplus for sale:
> >> http://home.alltel.net/leswatts/forsale.html
> >> CNC carved signs:
> >> http://home.alltel.net/leswatts/signwp.html
>
> --
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