Newsgroups: comp.robotics
Path: brunix!uunet!news-server.csri.toronto.edu!torsqnt!geac!gjetor!herboid!adeboer
From: adeboer@herboid.uucp (Anthony DeBoer)
Subject: Re: Motor Control Problem
Reply-To: adeboer@gjetor.geac.com
Organization: Linda's Dragon Memorial Society
Date: Sun, 23 Feb 1992 03:23:44 GMT
Message-ID: <1992Feb23.032344.7575@herboid.uucp>
References: <1992Feb17.222714.842@gnv.ifas.ufl.edu>

In article <1992Feb17.222714.842@gnv.ifas.ufl.edu> fme@gnv.ifas.ufl.edu writes:
>...
>Now, the problem. When motor-1 settles at some steady speed for whatever
>period of time, motor-2 tries to speed-up or slow-down to match it. Alas,
>there is oscillation in the speed of motor-2 ... it tends to over/undershoot
>the proper speed and then tries to compensate for the overcompensation. 
>As a result, the damned thing never settles nicely. The RPM is correct if 
>you average it out over say 15 seconds ... but that accuracy falls-off 
>sharply when you average over a shorter period. My cheap attempts at making
>a software 'damper' just hurts sensitivity at the very low speed ranges.
>
>Does anyone know of some secret cyberneticists trick for dealing with this
>sort of problem ? ...

Some years ago, I had to do a software damping problem (actually, for a
heartbeat monitor project running on an Apple ][+ that the editor of
_Computers_in_Education_ and I were hacking up for an article), and I just
tweaked on it until it worked.  I'd suggest factoring in the speed range
for your software damper, such that a lot of damping happens at high speed
and little or none happens at low speed.  Of course, this would depend on
whether it's being a problem at low speed or not.

>-- Jim Mason : Please reply via UseNet rather than by Email.

(I would have mailed otherwise, sorry about the bandwidth.)
-- 
Anthony DeBoer       NAUI # Z8800   |   Why watch TV, when Netnews provides
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