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From: johne@hpvcfs1.HP.COM (John Eaton)
Newsgroups: comp.lsi
Subject: Re: velocity sensing for robotic joints
Message-ID: <3230001@hpvcfs1.HP.COM>
Date: 22 Aug 90 16:07:33 GMT
References: <1990Aug7.205751.21206@ecf.utoronto.ca>
Organization: Hewlett Packard, Vancouver, WA
Lines: 15

>>>
>assuming one is using optical encoders (with 2-phase output)
>to measure position of a (rotary) robotic joint, what should one use
>to then measure velocity??
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If you are already measuring position then all you need is a way to
measure Time. You simply interrupt your micro at a regular rate and
have it read current position, subtract previous position and save
current position in previous. If you have any sort of closed loop
position control then you will probably need to do this as part of
your compensation loop.


John Eaton
!hpvcfs1!johne