Vibration Monitor (Hyde, Wanttaja?)

"RST Engineering" wrote in message
...
Understood. What I started out to do (and still plan on doing) is to have
a device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to be
good and light a "your engine is about to come apart" lamp at the
appropriate time.


Excuse my ignorance, but couldn't you just feel the vibrations?

If you wait that long, you're probably more concerned if the chain that's
holding the motor to the firewall is going to break after the motor cuts
loose from the mounts. All too often, the vibrations start to pick up
seconds or miliseconds before a catastrophic failure.

To do such a health-monitoring function properly, you really want some
seeded fault data to characterize what a "bad" engine spectrum looks like.
How many engines do you want to sacrifice to get the data? You can approach
it from the "anything different from a healthy engine signature" standpoint,
but that will likely result in a ton of false positive fault indications.

"LCT Paintball" wrote in message
news:_Lq0e.14520$fn3.9681@attbi_s01...
"RST Engineering" wrote in message
...
Understood. What I started out to do (and still plan on doing) is to
have
a device that will stay permanently mounted to the engine that can be
calibrated (adjusted, signed, pick a verb) when the engine is known to
be
good and light a "your engine is about to come apart" lamp at the
appropriate time.


Excuse my ignorance, but couldn't you just feel the vibrations?

If you wait that long, you're probably more concerned if the chain that's
holding the motor to the firewall is going to break after the motor cuts
loose from the mounts. All too often, the vibrations start to pick up
seconds or miliseconds before a catastrophic failure.

To do such a health-monitoring function properly, you really want some
seeded fault data to characterize what a "bad" engine spectrum looks like.
How many engines do you want to sacrifice to get the data? You can
approach
it from the "anything different from a healthy engine signature"
standpoint,
but that will likely result in a ton of false positive fault indications.


Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?

Of course. It has been done. Depends on the failure mode, of course. There
are some failure modes that take a long time to develop that give early
indications, and some that don't. A ton of work has been done in this area
for military jet engines. Seeded fault test data is the key to this.
Unfortunately, that might mean wrecking a bunch of engines to get the data.
It's not a project for the average home-builder.

Personally, I wouldn't bother trying to get a vibration caution together for
a home-built. Doing right would be just way too expensive. It would be
cheaper to just buy something that's turbine-powered and get rid of the
hazards that way. Besides, a huge number of failure modes already show up in
CHT's, EGT's, RPMs, etc. You have to weigh the cost of covering additional
failure modes against the hazards. This is really a job for engine
manufacturers. Additionally, you have to take complexity and reliability of
the sensing and processing into account. A monitor that is always going
haywire on you would be worse than nothing at all.

I'm actually looking at some stuff like this for possible inclusion on a
future project right now for a different type of powerplant. If you can
reliably predict RUL (remaining usable life) for a critical component, it
could be possible to reduce the amount of redundancy in a complex system and
rely on health monitoring functions to let you know when it's time to
replace the part.

PHM (prognostics and health management) has been a big focus in the military
aircraft world in recent years. I'm hoping that some of this technology will
trickle down to us in the GA world. Hmm...maybe I should get with an engine
manufacturer and work something out... SO, how much would people pay for an
engine health monitoring system package as an option for a new engine (i.e.
one of the new generation...maybe a DeltaHawk)? My guess is that it would be
too expensive to ever sell.

Pete


"LCT Paintball" wrote in message
news:ipA0e.102105$Ze3.20828@attbi_s51...
Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?

Pete Schaefer wrote:

PHM (prognostics and health management) has been a big focus in the military
aircraft world in recent years. I'm hoping that some of this technology will
trickle down to us in the GA world.

One useful technology that keeps getting more real are self-powered
sensors that communicate via bluetooth or other wireless, so you could
just stick them on various places and not have to worry about cabling
and all those other points of failure.

Cool. Maybe we should do entire airplanes around bluetooth. That way, any
geek with a PDA can hack our planes when we fly by. Yeah, **** all these EMI
worries!

Sorry, but that idea sounds like an awfully inviting drive-by target.

"nafod40" wrote in message
...
One useful technology that keeps getting more real are self-powered
sensors that communicate via bluetooth or other wireless, so you could
just stick them on various places and not have to worry about cabling
and all those other points of failure.

Pete Schaefer wrote:
Cool. Maybe we should do entire airplanes around bluetooth. That way, any
geek with a PDA can hack our planes when we fly by. Yeah, **** all these EMI
worries!

Sorry, but that idea sounds like an awfully inviting drive-by target.

Bluetooth has a limited range -- about 10m absolute max. Do you often
fly overhead geeks at 36ft AGL?

Not only that, but Bluetooth also allows closed networks to be set up --
no access to anyone outside the selected group of devices.

Sorry, but you shouldn't get all sarcastic about someone suggesting a
technology that you clearly don't have a clue about.

Frank

Pete Schaefer wrote:
Cool. Maybe we should do entire airplanes around bluetooth. That way, any
geek with a PDA can hack our planes when we fly by. Yeah, **** all these EMI
worries!

Sorry, but that idea sounds like an awfully inviting drive-by target.

The idea that some sensors sending their signals via bluetooth to a data
recorder instead of cabling could be "hacked", whether from a PDA
standing outside the plane or from 5,000 feet AGL is silly. The EMI
argument is an open one, but the FAA rule says...

"a) Except as provided in paragraph (b) of this section, no person may
operate, nor may any operator or pilot in command of an aircraft allow
the operation of, any portable electronic device on any of the following
U.S-registered civil aircraft:


(1) Aircraft operated by a holder of an air carrier operating
certificate or an operating certificate; or
(2) Any other aircraft while it is operated under IFR.

(b) Paragraph (a) of this section does not apply to--

(1) portable voice recorders;
(2) hearing aids;
(3) heart pacemakers;
(4) electric shavers; or
(5) any other portable electronic device that the operator of the
aircraft has determined will not cause interference with the navigation
or communication system of the aircraft on which it is to be used.

It's coming to aircraft. In fact, it's already there via people that
don't turn off their cell phones and laptops etc., just uncontrolled.
Good article.

http://developer.intel.com/technolog...cles/art_4.htm

Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?


My company makes ~200MM/yr on this premies.

Adam
N7966L
Beech Super III

oops... I meant "premise".

"mindenpilot" wrote in message
...
Are you suggesting that a bad engine will give clues to it's demise
enough in advance that you could actually do something about it? Clues
that a monitor could pick up on, but an experienced pilot wouldn't?


My company makes ~200MM/yr on this premies.

Adam
N7966L
Beech Super III