what features are in the next generation of flight computers

Except for that I'd like to see the real-time position of each glider
around (flarm, Mode-S?) including vertical speed so that you can see
lift ratios accurately...

Doesn't this still exist four flarm?

Andreas

"Bill Daniels" bildan@comcast-dot-net wrote:

Inertial variometry with instantaneous response and no gust sensitivity.

Do you really think this is possible? How many times did you bump into
a canopy in a rotor? OK this is extreme and yes, I know this is
vertical.

Cheers,
Henryk Birecki

Yep, it's possible. Total energy variometry can be done entirely in the
inertial domain. It's rapidly becoming affordable with MEMS Inertial
Measurement Units. I-FOG gyros are better but more expensive. The enormous
demand for UAV autopilots is driving the development of low cost ADAHRS
units that would be suitable for the purpose.

The IMU has to maintain an accurate euler angle reference but not to great
precision since it's a cosine function but the accelerometer(s) on the
vertical axis has to be pretty good although it can be constantly
recalibrated by reference to a pressure datum. It also takes a bit of
computer power.

The advantages are many since this approach eliminates the TE probe with its
inherent errors and gust sensitivity. An inertial vario would have no
trouble differentiating a horizontal gust from a thermal. The instantaneous
response should give a 1:1 butt-to-vario correlation.

Oh yes, once the euler angles are available to a degree of precision,
measuring L/D is simply a matter of measuring the angle between a pitch vane
and the horizontal. That means that bug degradation can be accurately known
in real time.

Bill Daniels


"Henryk Birecki" wrote in message
...
"Bill Daniels" bildan@comcast-dot-net wrote:

Inertial variometry with instantaneous response and no gust sensitivity.

Do you really think this is possible? How many times did you bump into
a canopy in a rotor? OK this is extreme and yes, I know this is
vertical.

Cheers,
Henryk Birecki

Then the next step is to use that data on a Heads-Up Display (HUD),
and show the velocity vector, so that you have a "bug" which shows
exactly where you would get to with your current state. Having flown
a Harrier simulator which has that, you'd be amazed how valuable that
is. Then there's the pitch ladder, which isn't that useful to a
glider, and the speed and altitude tapes. And, somewhere there's a
secret government program to make almost exactly this instrument.

Hey, we're dreamin' here.

Ed

An instrument panel top HUD in a glider wouldn't be too difficult with
current technology. Perhaps an even better approach for a glider would be a
HEAD Mounted Display (HMD) with a head tracker. That way you could display
anything that shows on a computer screen but indexed to aircraft attitude.

There are currently see-through HMD's for PDA's that provide a large virtual
display screen.

Bill Daniels


"flying_monkey" wrote in message
ups.com...
Then the next step is to use that data on a Heads-Up Display (HUD),
and show the velocity vector, so that you have a "bug" which shows
exactly where you would get to with your current state. Having flown
a Harrier simulator which has that, you'd be amazed how valuable that
is. Then there's the pitch ladder, which isn't that useful to a
glider, and the speed and altitude tapes. And, somewhere there's a
secret government program to make almost exactly this instrument.

Hey, we're dreamin' here.

Ed

J. Nieuwenhuize wrote:

A videocamera at the tail sounds nice in really tight thermals; those
basterds tends to hide at your six.

Small video cameras are numerous, and we already have a screen in the
cockpit. Does anyone know how to connect a video camera to an Ipaq?
Perhaps a Bluetooth camera and software exist for Ipaqs? That would make
it easy - just a little video "bump" on top of the fuselage a few inches
aft of the canopy, looking aft. Tap a button on the Ipaq to switch to
the video, tap to switch back to the flight computing.

I've tried mirrors of various type without much success. This might work
better.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Henryk Birecki wrote:
"Bill Daniels" bildan@comcast-dot-net wrote:

Inertial variometry with instantaneous response and no gust sensitivity.

Do you really think this is possible? How many times did you bump into
a canopy in a rotor? OK this is extreme and yes, I know this is
vertical.

Take a look at Eagle Tree systems:
http://www.eagletreesystems.com/Sail...sailplane.html

These guys sell an electronic TE compensated audio vario for RC gliders,
so the vario plus down-link transmitter are small and light enough to
fit into a model. The vario's operating principles are not described.
Its only external sensors are static and pitot inputs MEMs are not
mentioned.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

"Bill Daniels" bildan@comcast-dot-net writes:

Yep, it's possible. Total energy variometry can be done entirely in
the inertial domain. It's rapidly becoming affordable with MEMS
Inertial Measurement Units. I-FOG gyros are better but more
expensive. The enormous demand for UAV autopilots is driving the
development of low cost ADAHRS units that would be suitable for the
purpose.

How does that compare with a full x,y,z,dx,dy,dz,t GPS solution?
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GPS is a position finding system, an IMU is a position keeping system. The
IMU adds pitch, roll, & heading. Attitude data can also be obtained from a
multi-antenna GPS carrier phase system but not with the same accuracy or
data rate.

GPS and inertial systems complement each other as the inertial system can
continue providing data during a GPS dropout while the GPS system keeps the
IMU accurate over long time periods. Inertial systems provide acurate
high-rate data over shorter time spans. The IMU effectively "smooths" the
GPS data. A GPS positioning plus an AHRS system makes it possible to use a
less accurate MEMS IMU.

It's the accurate high-rate vertical acceleration data that is useful for an
inertial variometer. Accurate heading data when combined with ground track,
ground speed and ture airspeed provides real time vector winds. These
systems are now being used in UAV's and as performance increases and prices
decreases, there is no doubt they will find their way into gliders.

Bill Daniels

"Paul Repacholi" wrote in message
...
"Bill Daniels" bildan@comcast-dot-net writes:

Yep, it's possible. Total energy variometry can be done entirely in
the inertial domain. It's rapidly becoming affordable with MEMS
Inertial Measurement Units. I-FOG gyros are better but more
expensive. The enormous demand for UAV autopilots is driving the
development of low cost ADAHRS units that would be suitable for the
purpose.

How does that compare with a full x,y,z,dx,dy,dz,t GPS solution?
------------ And now a word from our sponsor ------------------
Do your users want the best web-email gateway? Don't let your
customers drift off to free webmail services install your own
web gateway!
-- See http://netwinsite.com/sponsor/sponsor_webmail.htm ----