Vibration Monitor (Hyde, Wanttaja?)

Frank:

I do have quite a clue about EMI, and clearly have a better clue than you
about systems engineering in general. Here's a question for you:

Why bother?

If you're trying to cert bluetooth for aviation, maybe with the thought of
selling some other bluetooth product that you think you can make a big chunk
of cash with, then, yeah, maybe going off to play with bluetooth on your
airplane makes sense. Personally, I can't see it. Maybe it makes sense for
using it to reprogram boxes on your airplane, but to go to the extent of
making it useful/safe in flight....nah. Way too much effort for too little
return, given that the inclusion of an RS-232 port is so freakin' easy.

If you have some other goal in mind, maybe some other sensing or data fusion
tech (e.g. may you have a huge array of air data sensors for some advance
stall detection method), then you have to look at whether or not the tech
risk buys you something that you can't get otherwise. Why bluetooth rather
than the 1/2 dozen other wired data communication protocols (e.g. 1392, .
422, 232, 485, CAN, etc.) that are out there?

I get rather frustrated with people who get really !@#$ing enamored with
technologies for implementation and loose sight of what their goals are. All
too often, risk variables get introduced where none is warranted, resulting
in zero or negative value added. I beat on my guys daily about issues like
this. (Kelly Johnson (...yeah, I work at that place.....) had a lot to say
about where it was acceptable to take project risks..too bad so much of it
never got captured in "the rules").

So, back to Blue Tooth....

Why bother?

For data collection, I've already got a half-dozen options in my hip pocket
that I know will work just fine with very well understood EMI issues that I
know how to mitigate. What's my goal? Blue tooth airplane or getting the
data for some other purpose?

I have very little room for Geek Factor on any airplane that I'll ever
build. If it can't buy it's way on (I'd lump Blue Tooth in here), then !@#$
it.


Pete

P.S. I just got done with a 5 hour drive and am tired as all !@#$. I've got
4 beers in me to diffuse stress. Please forgive my abbrasiveness. I'm not
really that bad of a guy. I just don't want people to pursue ideas that
will get them killed.


"Frank van der Hulst" wrote in message
...
Sorry, but you shouldn't get all sarcastic about someone suggesting a
technology that you clearly don't have a clue about.

Pete Schaefer wrote:
Frank:

I do have quite a clue about EMI, and clearly have a better clue than you
about systems engineering in general. Here's a question for you:

Why bother?

For the same reason that we build planes instead of buying them.

If you're trying to cert bluetooth for aviation, maybe with the thought of
selling some other bluetooth product that you think you can make a big chunk
of cash with, then, yeah, maybe going off to play with bluetooth on your
airplane makes sense. Personally, I can't see it. Maybe it makes sense for
using it to reprogram boxes on your airplane, but to go to the extent of
making it useful/safe in flight....nah. Way too much effort for too little
return, given that the inclusion of an RS-232 port is so freakin' easy.

I agree totally. except maybe about RS-232. I suggest that some sort of
current-based rather than voltage-based signalling would be more
noise-immune. Bring back 20mA current loop! :-)

If you have some other goal in mind, maybe some other sensing or data fusion
tech (e.g. may you have a huge array of air data sensors for some advance
stall detection method), then you have to look at whether or not the tech
risk buys you something that you can't get otherwise. Why bluetooth rather
than the 1/2 dozen other wired data communication protocols (e.g. 1392, .
422, 232, 485, CAN, etc.) that are out there?

The TWO key ideas in the proposition (wasn't mine, BTW) were wireless
comms and self-powered. If you can do BOTH of those, then wired comms
and power is best. Wireless comms has been pretty much solved. For
example, I saw a projection in an engineering mag that within 25 years
wireless will replace wired as the cheapest comms technology to the home.

But without "self-powered" it is pointless. Are there any devices out
there that can turn (e.g.) vibration into *useful* amounts of electricity?

I get rather frustrated with people who get really !@#$ing enamored with
technologies for implementation and loose sight of what their goals are.

Hmmm... so what are *my* goals? Maybe I want the geekiest plane on the
block? I suggest that one or other of your 4 beers has introduced some
patronisation (as well as abrasiveness) into your system.

All
too often, risk variables get introduced where none is warranted, resulting
in zero or negative value added.

I'll choose what risks are warranted on *my* project, thanks.

I beat on my guys daily about issues like
this. (Kelly Johnson (...yeah, I work at that place.....) had a lot to say
about where it was acceptable to take project risks..too bad so much of it
never got captured in "the rules").

This is fine where *you* get to set the goals.

So, back to Blue Tooth....

Why bother?

*With* self-powered devices, it gives options not available via wired
systems.

For data collection, I've already got a half-dozen options in my hip pocket
that I know will work just fine with very well understood EMI issues that I
know how to mitigate. What's my goal? Blue tooth airplane or getting the
data for some other purpose?

I have very little room for Geek Factor on any airplane that I'll ever
build. If it can't buy it's way on (I'd lump Blue Tooth in here), then !@#$
it.


Pete

P.S. I just got done with a 5 hour drive and am tired as all !@#$. I've got
4 beers in me to diffuse stress. Please forgive my abbrasiveness. I'm not
really that bad of a guy. I just don't want people to pursue ideas that
will get them killed.

Hey, I prefer to talk straight too. And also don't want people to kill
themselves. But if people don't experiment with Experimental category
aircraft, then nothing is going to change.

Frank

Frank van der Hulst wrote:

*With* self-powered devices, it gives options not available via wired
systems.


Couple of sources. This is a hot research area.

http://www.sandia.gov/media/NewsRel/...eredsensor.htm

http://www.perpetuum.co.uk/

Frank van der Hulst wrote:

Why bother?


*With* self-powered devices, it gives options not available via wired
systems.


Even if you have to run 12V to it, in a metal airplane that will only be
one wire and one connection. Assuming they can build a wireless device
that can stand up to typical airplane abuse for a while*, this would
make for a much simpler and safer installation. At these power levels,
the EMI issue is a red herring that would be easily defeated with a
$0.98 roll of aluminum foil, and once defeated on the ground the
problem isn't likely to pop back up in flight (like loose cabling will).

IMHO

*It seems that your standard store bought router is designed to die
after a few years. I wouldn't trust this quality control with my
comfort. I barely trust it with my ability to read this newsgroup.


--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

So, what things on the airplane are you guys going to replace with
self-powered blue tooth devices?


"Ernest Christley" wrote in message
om...
Even if you have to run 12V to it, in a metal airplane that will only be
one wire and one connection. Assuming they can build a wireless device
that can stand up to typical airplane abuse for a while*, this would
make for a much simpler and safer installation. At these power levels,
the EMI issue is a red herring that would be easily defeated with a
$0.98 roll of aluminum foil, and once defeated on the ground the
problem isn't likely to pop back up in flight (like loose cabling will).

IMHO

*It seems that your standard store bought router is designed to die
after a few years. I wouldn't trust this quality control with my
comfort. I barely trust it with my ability to read this newsgroup.

Pete Schaefer wrote:
So, what things on the airplane are you guys going to replace with
self-powered blue tooth devices?

First thing would be Bluetooth headsets... no more cords tangling round
the cockpit.

Next would be various engine instruments... EGT, CHT, etc.

Maybe move the entire radio receiver out to a wingtip or somewhere well
away from the engine's RF noise. But I can't see that being
self-powered. Perhaps we could use Tesla's beam-power technology to run
those.

Frank

Frank van der Hulst wrote:
Pete Schaefer wrote:

So, what things on the airplane are you guys going to replace with
self-powered blue tooth devices?


First thing would be Bluetooth headsets... no more cords tangling round
the cockpit.

That's a good one. Keep an old pair if wired sets stuck in an
accessible hole someplace...just in case.


Next would be various engine instruments... EGT, CHT, etc.

Perfect. If the signal dies, the plane won't know it. The Cherokee I
trained in didn't even have a working EGT.


Maybe move the entire radio receiver out to a wingtip or somewhere well
away from the engine's RF noise. But I can't see that being
self-powered. Perhaps we could use Tesla's beam-power technology to run
those.

Frank

Oooh. You just lost me on that one. To much complication with the radio
to human interface there. You've got a device in front of the pilot to
select a station, which must transmit it to a device out on the wing,
which has to recieve and interpret it correctly, then transmit the
correct station's signal back over bluetooth. You'd still have to run
signal wires for the physical backup. I just don't see the advantage
when remoting the antennae is all that's necessary to avoid the engine EMI.

How about stress monitors built into the prop (I have no idea if anyone
makes such a thing). Would help you to carve a perfect prop.

Miniature temp probes and air pressure sensors that you can stick all
over the place. Would make it real easy to map out the pressure regions
on the airplane and design a better cooling system or decide if wing
modification would be necessary/beneficial.

Vibration sensors stuck inside control surfaces and different parts of
the skin. Early warning system for flutter. Might only give you time
for a short prayer, but it may save your butt if you can react quick enough.

Nothing is stopping anyone from doing any of this with wired sensors.
It would just be cleaner and easier if the wire can be left on the spool.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

Ernest Christley wrote:

Maybe move the entire radio receiver out to a wingtip or somewhere
well away from the engine's RF noise. But I can't see that being
self-powered. Perhaps we could use Tesla's beam-power technology to
run those.

Oooh. You just lost me on that one. To much complication with the radio
to human interface there. You've got a device in front of the pilot to
select a station, which must transmit it to a device out on the wing,
which has to recieve and interpret it correctly, then transmit the
correct station's signal back over bluetooth.

This kind of stuff is bread-and-butter for Bluetooth. Remember that one
of its original design goals was moving (high-quality stereo) audio in
real time from a player to headphones. Sending channel-select signals in
the opposite direction isn't a biggy either... Bluetooth devices are
continually communicating digitally amongst themselves.

You'd still have to run signal wires for the physical backup.

Why? The airplane will keep flying if the radio fails. Granted that,
depending where you live and fly, losing access to your radio could be a
bit, um, difficult. But, for many, a radio isn't a necessity.

I just don't see the advantage
when remoting the antennae is all that's necessary to avoid the engine EMI.

You said it yourself in your last sentence: It would just be cleaner and
easier if the wire can be left on the spool.

How about stress monitors built into the prop (I have no idea if anyone
makes such a thing). Would help you to carve a perfect prop.

Prop blade pitch control... a motor in the spinner to adjust pitch,
controlled via Bluetooth. No hollow crankshafts and oil pressure
systems, no slip-rings.

Frank

"Ernest Christley" wrote in message
om...
How about stress monitors built into the prop (I have no idea if anyone
makes such a thing). Would help you to carve a perfect prop.

How much would someone pay for the software to analyze this data? Also,
you'd probably need structurally integrated sensors, which would have to be
strong enough to support the loads. This would be a pretty tough engineering
problem in itself.

Miniature temp probes and air pressure sensors that you can stick all
over the place.

More software. Sure it could be done, but cheaply enough for the average
home builder?

Vibration sensors stuck inside control surfaces and different parts of
the skin. Early warning system for flutter.

Might be really expensive to get the signals characterized well enough for a
warning system.

Nothing is stopping anyone from doing any of this with wired sensors.
It would just be cleaner and easier if the wire can be left on the spool.

There's a ton of stuff stopping people from doing this right now. It's
money. None of the stuff you've mentioned is even remotely innexpensive. I
know people who've researched this stuff with the wired sensors for several
years, and haven't gotten much of it out of the lab. Yeah, with steady
improvements in computational fluids, finite element, mems tech, sensing
tech, etc., this stuff will be eventually packaged into something us
home-builder types can afford to use. However, most of it is still too
damned expensive, manpower intensive, and technically immature for even the
military to employ on huge aircraft development programs like JSF. By the
time this stuff really becomes generally available, I'm sure there will be
something better than blue tooth around.

"Frank van der Hulst" wrote in message
...
First thing would be Bluetooth headsets... no more cords tangling round
the cockpit.

That would be pretty nice. But now you need batteries in your headset to
power the audio amp.

Next would be various engine instruments... EGT, CHT, etc.

I guess you'd need some devices (i.e. wires) for routing the signal through
the firewall or around it. How much lighter would this be than, say, a
twisted pair for CAN?

Maybe move the entire radio receiver out to a wingtip or somewhere well
away from the engine's RF noise.
But I can't see that being self-powered.

The receiver could be, but not the transmitter. An antenna wire is probably
a lot lighter than running power out, so I guess that would need to stay in
the cockpit.