3D Solid State Gyro

In article v4Mbg.22377$ZW3.15074@dukeread04,
"Jim Macklin" wrote:

Google for "ring laser gyro" and pick from the returns,
146,000 pages available.



Yes, except keep clear that "ring laser gyros" and "fiber optic gyros",
though they both use lasers and optics, and are truly wonderful examples
of modern science and technology, are fundamentally different beasts.

Ring laser gyros are the older technology, with Sperry and Honeywell as
major players in the field at least at one time. I believe they are
heavily used in military and airliner navigation systems, though I'm not
fully up to date on this

Fiber gyros (a k a fiber optic gyros or fiber laser gyros) are the newer
technology, with Litton and Northrup Grumman among the major players,
and are perhaps poised to take over from the ring laser gyro.

Amazing to see what MEMS can do also.

They all depend on frequency phase shift, it is the
principle, not the medium that determines the function.
With the light weight and low cost of a zero friction laser
gyro system, it should be possible to build a triple
redundant inertial navigation system, with GPS updating, for
very little money. It would also provide for flight control
and auto pilot and be economically viable because it could
be used for automotive, marine [including even bass boats]
as well as aviation. When you build millions of units, the
cost becomes affordable. As long as aviation builds systems
by the dozen, the cost will be way too high for general
acceptance.


--
James H. Macklin
ATP,CFI,A&P

--
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But government sees it as an obstacle to be overcome.
some support
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See http://www.fija.org/ more about your rights and duties.




"AES" wrote in message
...
| In article v4Mbg.22377$ZW3.15074@dukeread04,
| "Jim Macklin"
wrote:
|
| Google for "ring laser gyro" and pick from the returns,
| 146,000 pages available.
|
|
|
| Yes, except keep clear that "ring laser gyros" and "fiber
optic gyros",
| though they both use lasers and optics, and are truly
wonderful examples
| of modern science and technology, are fundamentally
different beasts.
|
| Ring laser gyros are the older technology, with Sperry and
Honeywell as
| major players in the field at least at one time. I believe
they are
| heavily used in military and airliner navigation systems,
though I'm not
| fully up to date on this
|
| Fiber gyros (a k a fiber optic gyros or fiber laser gyros)
are the newer
| technology, with Litton and Northrup Grumman among the
major players,
| and are perhaps poised to take over from the ring laser
gyro.
|
| Amazing to see what MEMS can do also.

In article hhNbg.22391$ZW3.1565@dukeread04,
"Jim Macklin" wrote:

They all depend on frequency phase shift, it is the
principle, not the medium that determines the function.

The ring in a ring laser gyro is an oscillating laser. The laser gain
medium is inside the ring. The ring itself is lasing independently in
the two opposite directions around the ring, so it's essentially two
lasers. The measured output signal is a *frequency* (the "beat
frequency" between these two lasers) and this beat frequency is (error
and "lock-up" effects aside) directly proportional to the rotation rate
of the gyro. The ring is a single loop ring: winding the ring around in
multiple loops would do no good -- would not increase the sensitivity or
scale factor of the device.

The ring in a fiber optical gyro has laser light traveling through it,
sent in from outside, but the ring is not itself a laser, and is not
lasing. The laser gain medium -- indeed the entire laser in the system
-- is outside the ring, and there is only one external laser in the
system which generates the light going in both directions around the
ring. The output signal is a (very small!!) phase shift (NOT a
frequency shift) between the optical phase delay in the two directions
around the ring, which is proportional to the rotation rate of the ring.
The ring is wound with many, many loops, and the sensitivity or scale
factor of the device goes up directly as the number of loops.

So, a lot of similar physics in the two devices, but they're still
distinctly different.

"AES" wrote in message
...
Yes, except keep clear that "ring laser gyros" and "fiber optic gyros",
though they both use lasers and optics, and are truly wonderful examples
of modern science and technology, are fundamentally different beasts.

Ring laser gyros are the older technology, with Sperry and Honeywell as
major players in the field at least at one time. I believe they are
heavily used in military and airliner navigation systems, though I'm not
fully up to date on this

Fiber gyros (a k a fiber optic gyros or fiber laser gyros) are the newer
technology, with Litton and Northrup Grumman among the major players,
and are perhaps poised to take over from the ring laser gyro.

Amazing to see what MEMS can do also.

I would think that aviation is getting away from gyros in favor of ADAHRS.

How about these? http://www.xbow.com/Products/product...ls.aspx?sid=30

Jim Macklin wrote

Google for "ring laser gyro" and pick from the returns,
146,000 pages available.

How come I get the impression that he wants information about
the small "hold in the palm of your hand" battery powered
units that I saw for sale at Sun n Fun...about $1500.

Bob Moore

You caught me. I was looking at an advertisement for a handheld and it peeked my
curiosity about solid state gyro's.

On Sat, 20 May 2006 23:29:57 GMT, Bob Moore wrote:


How come I get the impression that he wants information about
the small "hold in the palm of your hand" battery powered
units that I saw for sale at Sun n Fun...about $1500.

Bob Moore

GeorgeC

GeorgeC,

You caught me. I was looking at an advertisement for a handheld and it peeked my
curiosity about solid state gyro's.


In that case, you're interested in the MEMS type also used by the G1000 and
Avidyne's Entegra.

--
Thomas Borchert (EDDH)

The you've already seen:
http://www.appareo.com/index.php

Al


"GeorgeC" wrote in message
news
You caught me. I was looking at an advertisement for a handheld and it
peeked my
curiosity about solid state gyro's.

On Sat, 20 May 2006 23:29:57 GMT, Bob Moore
wrote:


How come I get the impression that he wants information about
the small "hold in the palm of your hand" battery powered
units that I saw for sale at Sun n Fun...about $1500.

Bob Moore

GeorgeC

Bob Moore wrote:
Jim Macklin wrote

Google for "ring laser gyro" and pick from the returns,
146,000 pages available.

How come I get the impression that he wants information about
the small "hold in the palm of your hand" battery powered
units that I saw for sale at Sun n Fun...about $1500.

Don't some of those "gyros" actually use microelectronic-sized metal
beam with a "weight" on the end. Deflection is proportional to
acceleration. Integrate acceleration to get velocity. Again to get
position. You can do the same thing with rotation. I've always
wondered how accurate those little things are and how they react to heat.

IIRC Stanford University was experimenting with them on a DARPA contract
years back. They wanted to build a wing-leveler by using two such
devices, one on each wing tip.