 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
charlieboccaccio(at)yahoo
Guest
|
 Posted: Mon Mar 27, 2006 12:06 pm Post subject: Trutrak - Laser Gyros |
 |
|
Besides my Kitfox 3, I fly commercially a Pilatus PC12 which is equipped with laser gyros. The gyros are not solid state, but rather are very high precision electric motor driven gyros that use laser beams bounced off the spinning gyro (mirrors) to give high precision angular information. A laser gyro is installed some where in the floor of an aircraft and the information is displayed with a remote indicator, usually a EFIS (Tube display).
Michel Verheughe <michel(at)online.no> wrote:
On Mar 27, 2006, at 6:10 PM, alnanarthur wrote:
| Quote: | I still don't understand solid state gyros.
|
Nor do I, Allan, and I wish someone could explain it to me. From the
days before I became a pilot, and was simply an aviation aficionado, I
remember reading that the old mechanical gyro was being replaced by
laser gyros in big expensive aircraft. This must be something entirely
different. I wonder if it works like a flux gate compass that senses
the variation in magnetic fields.
| Quote: | I assume that it responds to both roll and yaw, as does a mechanical
turn coordinator.
|
Er, rather the rate of yaw and roll, Allan. From what I understand,
there are two types of gyroscopic turn indicators. The first one, the
"12 o'clock" needle moving left or right, is based on a horizontal gyro
that indicates only the turn rate, i.e. at which speed the turn is
effectuated in degrees per second. Then, in the 60s or 70s came the
gyro that was tilted about 30 degrees with the horizon. That gyro would
detect both the turn rate but also the rate of roll. The display was
then the horizontal aircraft symbol moving on one side or the other.
| Quote: | Is it calibrated to do a 180 deg turn in one minute with the red dot
at the top in a "dog house".
|
Although it is not documented, my testing seems to indicate that it is
indeed the 1 min for 180 degrees, or often called the standard two
minutes turn.
| Quote: | Is there any problem in turbulence? How does it respond to a 360
deg. turn at a 45 or 60 deg bank angle?
|
I haven't yet been flying in very turbulent air nor taken turns more
that 45 degrees but, with a bit of turbulence and the plane rolling on
one wing then the other, the instrument is following extremely quickly
all small variations. Turning 180 or 160 at say 45 degrees bank, you
may overshoot but it may simply be me not being a very good pilot.
When I got the instrument, at home, I connected it to a 12 V power
source. I then rolled the instrument keeping the same heading and it
showed the horizon keeping horizontal. I then turned the heading
without banking, and it showed the horizon moving, as it does when e.g.
I turn when taxiing on the runway. However, when flying and going into
a sideslip, it kept horizontal. My conclusion was then this: It shows
the rate of turn (yaw) and the rate or roll. But it doesn't show the
actual banking if it is sustained as it is in a side slip. Does it
makes sense? I don't know enough about gyro instrument and if anyone
else can shed some more light on this, I'd be as grateful as you.
Cheers,
Michel
---------------------------------
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
 |
Michel
Joined: 10 Jan 2006
Posts: 966
Location: Norway
|
| Posted: Mon Mar 27, 2006 12:29 pm Post subject: Trutrak - Laser Gyros |
|
|
On Mar 27, 2006, at 10:03 PM, Charles Boccaccio wrote:
| Quote: | The gyros are not solid state, but rather are very high precision
electric motor driven gyros that use laser beams bounced off the
spinning gyro (mirrors) to give high precision angular information.
|
Thank you, Charles. I thought the laser gyro didn't had moving parts
and was simply measuring the time a laser ray would travel through a
round tube, thus sensing a yaw by a slightly shorter or longer time. I
stand now corrected as I must have misread the book about navigation it
came from.
Cheers,
Michel
do not archive
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
_________________
Kitfox 3 - Jabiru 2200 |
|
| Back to top |
|
|
temco(at)telusplanet.net
Guest
|
| Posted: Mon Mar 27, 2006 1:12 pm Post subject: Trutrak - Laser Gyros |
|
|
Hi Michael and others
The ring laser gyro is a truly solid state piece of equipment --- no moving
parts. Go to the link below and you will find a very good explanation of how
it works. Basically a laser beam is split in two, with the two beams going
around the ring in opposite directions. Where the beams meet again, there is
a detector which measures the difference between the times it took the beams
to arrive at the detector. For example, if the device is rotated clockwise
then the beam traveling clockwise takes longer to reach the detector ---
conversely the beam traveling anti clockwise will take a shorter time to
reach the detector. This difference is then processed and presented as a
rate of change in to the various components of an HSI or other attitude
sensing device in the cockpit.
It's been years since I fooled with this stuff --- was very interesting.
http://en.wikipedia.org/wiki/Ring_laser_gyroscope
Hope this helps
Ted
Edmonton, Ab
Subject: Re: Trutrak - Laser Gyros
On Mar 27, 2006, at 10:03 PM, Charles Boccaccio wrote:
| Quote: | The gyros are not solid state, but rather are very high precision
electric motor driven gyros that use laser beams bounced off the
spinning gyro (mirrors) to give high precision angular information.
|
Thank you, Charles. I thought the laser gyro didn't had moving parts
and was simply measuring the time a laser ray would travel through a
round tube, thus sensing a yaw by a slightly shorter or longer time. I
stand now corrected as I must have misread the book about navigation it
came from.
Cheers,
Michel
do not archive
| | - The Matronics Kitfox-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kitfox-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
