Re: Choosing a shaft encoder? At 08:34 28/11/98 -0600, you wrote:
>As a neophyte robot builder and HandBoard user, may I ask
>for help in choosing the best shaft encoder? What vendor/supplier
>should I use? The current project is a very simple robot with a
>goal of accurate navigation. Thanks!
>
hy,
I used HewlettPackard shaft encoders HEDL5540 (500 steps per revoltion)
with HCTL2020 quadrature shaft counters/decoders. With them you get
500*4=2000 steps per revolution, which is quite a lot. For me They seem to
be a good (but not cheap) solution. I know that other members of the
mailing list are also using them.(You can find them in the mailing list
archiv)
I haven't done it yet but the software part seems to me more problematic.
You will have to use sin and cos functions, and therefore the lack of
precision may not only come from your encoders but from your software since
errors add up. It's also CPU time consuming.
I will work on this part during the chrismas hollidays. Meanwhile, if you
are able to achieve a good positionning system, don't hesitate to tell me...

Bye 
Francois

