Needed: Inexpensive AHRS module to work with Oudie, XCsoar, LK8000, etc...

All the recent threads on the danger of inadvertent VMC into IMC flight without proper instrumentation has highlighted what I think is a needed bit of kit for the modern glider (i.e. one that has some sort of PDA/PNA/nav display in it's cockpit: An inexpensive stand-alone AHRS module that would output continuous attitude information (pitch, roll, yaw, turn rate) which could be used by programs such as SeeYouMobile, XCsoar, and LK8000 to provide an instant-on useable attitude display, for those rare but dangerous times that a glider inadvertently gets stuck IMC (or for the Brits, when they want to do it!).

I'm thinking a nice BIG attitude screen showing pitch and roll, with a turnrate "needle/ball" at the bottom, and if possible, showing other data that the display device/software would know from other sources: airspeed, altitude, basic GPS nav info.

I would start with a basic AHRS MEMS module, add a small rechargeable battery to provide backup if the ownship power fails, and output the attitude data in NMEA via usb to the display device. Price point would be around $500 or less, and of course the software providers would need to integrate it.

We already spend a lot for FLARM, to cover a threat that is also relatively remote (mid-air collision). But not all of us want to drop the big bucks (or euros) for a Butterfly or S80 - and the price of stand-alone AHRS modules seems pretty low.

And at the risk of restarting the RAS-war about attitude indicators in contests, well, I think the cat is already out of the bag on that issue - but having the device add an "attitude on" or whatever flag on the logger trace should be sufficient, IMO.

Anyway, just thinking...

And if this already exists - please send me a link!

Kirk
66

Hi Kirk

I'm not aware of any AHRS units in the price range you are looking for. But
here are some options.

http://www.lxnav.com/accessories/ahrs.html - available soon for about $1300.

http://www.cumulus-soaring.com/trutrak.htm - $520 for Pictorial Turn &
Bank - not full AHRS but much better than nothing.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"kirk.stant" wrote in message
...

All the recent threads on the danger of inadvertent VMC into IMC flight
without proper instrumentation has highlighted what I think is a needed bit
of kit for the modern glider (i.e. one that has some sort of PDA/PNA/nav
display in it's cockpit: An inexpensive stand-alone AHRS module that would
output continuous attitude information (pitch, roll, yaw, turn rate) which
could be used by programs such as SeeYouMobile, XCsoar, and LK8000 to
provide an instant-on useable attitude display, for those rare but dangerous
times that a glider inadvertently gets stuck IMC (or for the Brits, when
they want to do it!).

I'm thinking a nice BIG attitude screen showing pitch and roll, with a
turnrate "needle/ball" at the bottom, and if possible, showing other data
that the display device/software would know from other sources: airspeed,
altitude, basic GPS nav info.

I would start with a basic AHRS MEMS module, add a small rechargeable
battery to provide backup if the ownship power fails, and output the
attitude data in NMEA via usb to the display device. Price point would be
around $500 or less, and of course the software providers would need to
integrate it.

We already spend a lot for FLARM, to cover a threat that is also relatively
remote (mid-air collision). But not all of us want to drop the big bucks
(or euros) for a Butterfly or S80 - and the price of stand-alone AHRS
modules seems pretty low.

And at the risk of restarting the RAS-war about attitude indicators in
contests, well, I think the cat is already out of the bag on that issue -
but having the device add an "attitude on" or whatever flag on the logger
trace should be sufficient, IMO.

Anyway, just thinking...

And if this already exists - please send me a link!

Kirk
66

I understand that an AHRS, compared to a Truetrak, is going to produce more consistent results in the hands of a trained and current pilot.

But will the AHRS require more training to use and stay current compared to the Truetrak? And not being a power pilot, I've zero experience with a panel mounted attitude indicator. My tactile attitude indicator is stick position fore-aft.

Seems like (after a few hours of IFR training) I could practice using the Truetrak and ASI in my routine VFR thermaling. And Kirk mentioned the desirability of a large AHRS display... I only have space for a 57mm display in my panel.

Seems like the Truetrak would be the clear best bet for me. The visual simplicity is intuitively appealing. Am I missing something?

I understand that an IFR-rated pilot would want an AHRS in a glider, but that is not me.

I have flown with Truetrack.
I don't think there is any way to say that a Truetrack is a more natural...less complex....easier to learn instrument than an AHRS.
An AHRS is an accurate representation of the aircraft's attitude to the horizon. Dead simple graphics.

On Monday, April 27, 2015 at 4:44:34 PM UTC-5, Paul Remde wrote:
Hi Kirk

I'm not aware of any AHRS units in the price range you are looking for. But
here are some options.

http://www.lxnav.com/accessories/ahrs.html - available soon for about $1300.

Integrating those with PDA/tablets can be a challenge, as most hardware can either take a single source or need more complex solutions to integrate multiple sources, especially if you want an instant on solution.
I found space for both PowerFlarm and TruTrak 57mm displays in my panel by getting rid of all redundancies, such as mechanical vario etc, as I found those to be significantly more useful and helpful than many things I find in other panels: multiple varios, compas, g meter etc...

Ramy

On Monday, April 27, 2015 at 7:32:13 PM UTC-5, son_of_flubber wrote:
I understand that an AHRS, compared to a Truetrak, is going to produce more consistent results in the hands of a trained and current pilot.

Some definitions are in order:

AHRS stands for Attitude Heading Reference System. In the big expensive iron, it's the suite of expensive sensors (gyros, accelerometers, magnetic heading sensor) that provide data to the attitude displays.

Nowadays there are tons of inexpensive solidstate devices that have been developed for cars, RC helos, UAVs etc that can provide basically the same data: real time attitude (pitch, roll, yaw).

Using this data to drive a big, modern attitude display makes flying IMC a LOT easier, as it comes closer to "a window on the real world", instead of a pictorial representation of what your aircraft is doing. Old school instruments such as a turn and bank, turn coordinator, Tru-Track, or even a mechanical attitude indicator are really just mechanical ways to present attitude information, and require lots of training and practice to use safely. A good attitude display, on something like an Oudie or equivalent, would be easier to use, IMO. It would still need training to use, and it's really tough to simulate the feeling of vertigo that can result from flying in real IMC, but it would sure beat not having anything!


But will the AHRS require more training to use and stay current compared to the Truetrak? And not being a power pilot, I've zero experience with a panel mounted attitude indicator. My tactile attitude indicator is stick position fore-aft.

I would say the opposite. A modern glass cockpit attitude indicator is pretty intuitive, while a Trutrak is an old-school instrument. A PC simulator could be used to show how to interpret and use an attitude display - but if you have never flown under the hood or in real IMC that kind of training would be HIGHLY recommended! Vertigo is nothing to be sneezed at!


Seems like (after a few hours of IFR training) I could practice using the Truetrak and ASI in my routine VFR thermaling. And Kirk mentioned the desirability of a large AHRS display... I only have space for a 57mm display in my panel.

Forget the small instrument display - get a cheap PNA and have a big 5 in color display! That's what I want!

Seems like the Truetrak would be the clear best bet for me. The visual simplicity is intuitively appealing. Am I missing something?

Yes. Truetraks are meant to be backup, emergency instruments. My idea is to provide a modern attitude display, available instantly, on our pretty much ubiquitous moving map displays. Trust me, the difference is night and day! Or more likely, life or death!!

I understand that an IFR-rated pilot would want an AHRS in a glider, but that is not me.

Take some time to look at all the latest cockpit display coming out for airplanes - they are all going to big screen attitude displays - for a good reason! As far as cost, solid state AHRS sensors combined with a good display is cheaper and more reliable than ANY hardware attitude indicator, and provides so much more situational and attitude awareness that there is really no comparison. The only thing better is a wide angle HUD, but those get a bit heavy and use a lot of power ;^).

Cheers,

Kirk
66

ixGyro Pro.
About $70, pluS à Galaxy smartphone (which carries gyros, magnetic & accelerometer).

Bert
TW

On Monday, April 27, 2015 at 11:54:29 PM UTC-5, Tango Whisky wrote:
ixGyro Pro.
About $70, pluS à Galaxy smartphone (which carries gyros, magnetic & accelerometer).

Bert
TW

Sure, or Xavion and an iPhone. But it would be nice to integrate something "simple" with the displays that are already in our cockpits, not add another thing to carry. I can just see getting sucked into a cloud and fumbling for my iPhone ;^(

Kirk
66

We're a tiny market. The biggest cost of any device like this is the fixed cost of developing software etc. The massive sales of 100 or so worldwide are unlikely to be a huge investment.

FWIW, there's a very nice device that a lot of power pilots like, the Stratus 2. It ain't $70, and the software is another $75 a year, but anyone who's willing to risk IMC should probably be willing to spend more than $70 anyway.