Article View: comp.robotics
Article #463Re: balancing_act
From: monty
Date: Thu, 20 Aug 1992 23:17
Date: Thu, 20 Aug 1992 23:17
59 lines
3751 bytes
3751 bytes
In article <1992Aug20.144448.5564@sagpd1> monty@sagpd1.UUCP (Monty Saine) writes:
>In article <1992Aug19.210807.27401@constellation.ecn.uoknor.edu> rwmurphr@uokmax.ecn.uoknor.edu (Robert W Murphree) writes:
>>See my post on wedge innovations electronic spirit level.
>>I suppose my inclination would be to go with accelerometers at
>>3 perpindiculars and some kind of cheap gyroscope.
>>Some cheaper gyroscopes, where cheap means on the order of
>>1000 dollars are now being made available.
>>
>
> I ran across an ad/article about a very small (golf ball size) gyro
> a few months ago and posted information to this group. Since that time I
> have mislaid the orginal article. If any one out there is archiving this
> group, could you please look back and see if you can resurrect my orgianl
> post. This gyro (if memory serves) was real cheap, i.e. about 1-200 dollars
> and was extremely small.
>
>
> In the mean time I'll dig through my paper archives and see if I can
> find the orginal.
>
> Monty Saine
Excuse me for posting a followup to my own article but I found the
article about the small gyro. It was in the Nov 91 issue of Computer
Design pg. 56. The article did not specify a price but made a comparision
between "expensive" gyros costing $1000-$200,000 and their much less
expensive GyroEngine. The device measures 1.25x1.75 in., consumes 0.1W
at +3v. The device is made of injection molded polycarbonate plastic.
The following is extracted from the article:
"One of the major breakthroughs in the GyroEngine was the development
of an optical motion sensor. The optical sensor requires only one sensor
for two degrees of motion and it gives a direct digital readout with out
analog to digital conversion. An LED shines light through a ring
perpendicular to the spin axis of the wheel. On the ring are lines for
optical sensing. In a hole at the gimbal bearing perpendicular to that
axis is another grid with radial lines which light also passes. The
interference or moire pattern created by the two grids changes
characteristically when the housing is rotated along either axis. A
quadrature photosensor picks up the changing pattern which is interperted
by a microcontroller on a small external board.
The grid resolution is 2,300 lines/in. and the angular resolution
is currently 10 bits/degree. Gyration can produce GyroEngines with greater
or less accuracy, with corresponding differences in price, depending on
customer needs, says president and CEO Tom Quinn. The raw output of the
GyroEngine is parallel, but is also convertible to RS-232 or RS-422 for
use in a cursor pointing device for example."
The article goes on to tell about a pointing device that they are
developing using this gyro and vehicle navigation posibilities, robot
arm motion and ... .
The company is Gyration, Saratoga Calif. and the number given in the
article for more information was (408) 255-3016.
Hope this helps someone...
Monty Saine
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Path: arc1-ca.pugleaf.net!sparky!uunet!olivea!hal.com!decwrl!sdd.hp.com!ncr-sd!sagpd1!monty From: monty@sagpd1 Newsgroups: comp.robotics Subject: Re: balancing_act Message-ID: <1992Aug20.231759.6616@sagpd1> Date: 20 Aug 92 23:17:59 GMT References: <1992Aug14.193217.17073@aplcen.apl.jhu.edu> <1992Aug15.043443.25054@magnus.acs.ohio-state.edu> <1992Aug16.214515.4493@microsoft.com> <Bt5GJA.6wy@wpi.WPI.EDU> <1992Aug19.210807.27401@constellation.ecn.uoknor.edu> <1992Aug20.144448.5564@sagpd1> Reply-To: monty@sagpd1.UUCP (Monty Saine) Organization: Scientific Atlanta, Government Products Div, San Diego, CA Lines: 59