Thanks for your research Tom.
I should have at least posted the basic specs for the Renishaw encoders, sorry about that.
The 6 axes are for the Hexapod (I should also say more correctly, Stewart-Gough platform). PID loops obviously required for the "legs" and are covered BUT the 3 other analog encoders are for position only. They're not required for any PIDs. They are used to solve the kinematics without resorting to a potentially complex algorithms normally used.
Speed is not a priority actually so 6000mm/min sounds sufficient for my purpose I believe.
As far as the encoder output voltages goe, could I not scale the output with a pre-amp to 20V for the resolver inputs? On the other hand, 1um might be enough.
Sounding promising so far.
Thanks!
--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> There is a "resolver" input mode that might work with the Analog Encoders. I
> used Google and researched your encoders for you and found this:
>
> http://resources.renishaw.com/en/Data+sheet%3A+RGH22+series+readhead(16703)
>
> It looks like they output 1V pp sine/cosine signals with a 20um pitch.
>
> The Kanalog ADC input range is 20V so a lot of the resolution would be lost
> feeding the signal straight in but the resolution would probably still be 1um or
> better.
>
> There would also be a speed limitation. KFLOP samples the ADCs every 90us and
> needs to see several samples per cycle. Â If I did the math right the highest
> speed without dropping cycles comes out to 6000mm/min.
>
> KFLOP only supports 8 axes but you apparently need 6+3=9?
>
> TK
>
>
>
>
> ________________________________
> From: bb_lazar <bb_lazar@...>
> To: DynoMotion@yahoogroups.com
> Sent: Thu, April 28, 2011 8:07:18 PM
> Subject: [DynoMotion] DIGITAL + ANALOG encoders, is it possible?
>
> Â
> I have a dream.... connect up a hexapod to the KFLOP+KANALOG I have.
>
> SO.... I have 6 digital encoders for the hexapod PLUS need 3 more axes but with
> *analog* (RGH22A15L00) Renishaw encoders.
> Can I I/F analog at all?
>
> Thanks!
>
