wing levelers

Sitting around the hanger and discussing the possibility of somehow using
off-the-shelf electronic/computer components or gadgits for semi-automatic
wing leveling on lightly loaded, short wingspans.

Not being computer guys, the current thought is that something should be out
there that is available cheaply and modifiable to use a simple wing
leveler.

Having heard someplace that automotive computers, as an example, sense data
millions of times leads us to believe that sensing the wing tip initial
movement and counteracting very very quickly would be a good thing.

As an example: One fellow pictured a rolling ball bearing inside a tube
somehow activating a magnetic switch which in turn pulses a dc linear motor
to operate the aileron minutely.

We are not sure how to detect the very earliest initial wing tip movement or
drive the small trim type motor and would appreciate some thoughts or site
recommendations to investigate.

Thanks, Dick

"Dick" wrote

Sitting around the hanger and discussing the possibility of somehow using
off-the-shelf electronic/computer components or gadgits for semi-automatic
wing leveling on lightly loaded, short wingspans.


As an example: One fellow pictured a rolling ball bearing inside a tube
somehow activating a magnetic switch which in turn pulses a dc linear
motor
to operate the aileron minutely.

We are not sure how to detect the very earliest initial wing tip movement
or
drive the small trim type motor and would appreciate some thoughts or
site
recommendations to investigate.


Hmmmm. No free (or even cheap) lunch, here.

The idea of a ball bearing in a tube is not even close. Ever hear of the
graveyard spiral? It is what killed Kennedy. (not the president) In such
a spiral, you experience several 360 degree turns, diving steeply enough
that vertical descent rates of 10,000 feet per minute (if the plane holds
together) are possible. Still, the ball in the tube would stay right in the
middle. One G all the way.

You need a gyroscope, or an electronic equivalent. Some have played using
very sensitive GPS antennae in the wingtips.

Best advice? Trim the plane, stay awake and fly it, or BUY an autopilot, or
wing leveler. Or google wing leveler.
--
Jim in NC

("Morgans" wrote)
snips
We are not sure how to detect the very earliest initial wing tip movement
or drive the small trim type motor and would appreciate some thoughts or
site recommendations to investigate.

The idea of a ball bearing in a tube is not even close. Ever hear of the
graveyard spiral? It is what killed Kennedy. (not the president) In
such
a spiral, you experience several 360 degree turns, diving steeply enough
that vertical descent rates of 10,000 feet per minute (if the plane holds
together) are possible. Still, the ball in the tube would stay right in
the
middle. One G all the way.

You need a gyroscope, or an electronic equivalent. Some have played using
very sensitive GPS antennae in the wingtips.

Best advice? Trim the plane, stay awake and fly it, or BUY an autopilot,
or
wing leveler. Or google wing leveler.


Automotive world is using electronic stability-control (ESC) systems with
documented success. The article says the system used a decade ago wasn't
very good, but they've come a long way since then.

http://www.detnews.com/2005/autoscon.../F01-91164.htm

http://www.caranddriver.com/idealbb/...?topicID=60884

I'm guessing some variant of this is what you'll eventually cobble together
in your garage.


Montblack

"Montblack" wrote

Automotive world is using electronic stability-control (ESC) systems with
documented success.

I'm guessing some variant of this is what you'll eventually cobble
together
in your garage.

More than likely, they are using piezzo electric rate sensors for the
direction information. They are relatively cheap, and do well at sensing
rapid changes. They have been used for a while in the RC airplane world, as
a stability aid, with good success, also. Any really stable electronic gyro
system in the commercial auto-pilots world, are much more expensive, and as
far as I know, not available to the public.

Problem is, piezzo sensors have a fairly fast "drift." which makes the
leveling ability good only for a few seconds. If you handed over control to
one of these units, within 30 seconds, you would be upside down, and the
unit would think everything is still OK.

In the RC world, if the plane makes a sudden move to go upside down, it
senses the sudden move and if the sticks have not commanded the sudden move,
it will move the control surfaces to stay right side up. It counts on you
keeping it somewhat upright, and recalibrates itself often - based on your
MarkII eyeballs telling the plane to fly level.

Same thing with the car unit in the links. It knows that you are going
straight, or following curves. (still reasonably slow changes compared to
sudden loss of control) It continually reminds itself that it is going
straight, and re-sets itself. Only when a real sudden move is made, does it
correctly sense that it is not going straight and the steering wheel wants
the car to go straight. The computer then makes corrections to keep the car
straight.

If a plane wing leveler were based only on these units, and the plane
started banking very slowly, the sensor would not realize it. That is the
drift. It would re-set as level, then the plane banks another slow degree,
and the unit re-sets, and the plane banks...you get the picture.

I believe the concoction that had some success, was a GPS wingtip
differential altitude sensor. It used these rate sensors in unison to help
backup the control movements and make the controls smooth. The units
re-set using the GPS info as the reality of what was level. You have to use
something (MarkII eyeballs or GPS) doing this.

Good luck to the OP, figuring out a homemade wing leveler. It is a tough
problem.
--
Jim in NC

Thanks for everyones input.

Our group was discussing flying in VFR only (no IMC or IFR) and wing leveler
only with respect to roll sensitivity of lightly wing loaded, short wing
spanned experimentals.

Trying to make summer flying in chop somewhat easier. We didn't plan on
turning over controls to the device and would still keep a light grip on the
stick; just wouldn't have to constantly play the stick.

Although we had the impression that a heavier plane would be more stable in
chop and require less than continual input by stick, that wasn't much of an
option G.

Although not discussed among us, I wonder if
an increased dihedral result is possible without actually increasing it
physically..

Still would appreciate a little discussion that I can pass on for the next
non-flying day.

Thanks, Dick


"Morgans" wrote in message
...

"Montblack" wrote

Automotive world is using electronic stability-control (ESC) systems with
documented success.

I'm guessing some variant of this is what you'll eventually cobble
together
in your garage.

More than likely, they are using piezzo electric rate sensors for the
direction information. They are relatively cheap, and do well at sensing
rapid changes. They have been used for a while in the RC airplane world,
as
a stability aid, with good success, also. Any really stable electronic
gyro
system in the commercial auto-pilots world, are much more expensive, and
as
far as I know, not available to the public.

Problem is, piezzo sensors have a fairly fast "drift." which makes the
leveling ability good only for a few seconds. If you handed over control
to
one of these units, within 30 seconds, you would be upside down, and the
unit would think everything is still OK.

In the RC world, if the plane makes a sudden move to go upside down, it
senses the sudden move and if the sticks have not commanded the sudden
move,
it will move the control surfaces to stay right side up. It counts on you
keeping it somewhat upright, and recalibrates itself often - based on your
MarkII eyeballs telling the plane to fly level.

Same thing with the car unit in the links. It knows that you are going
straight, or following curves. (still reasonably slow changes compared to
sudden loss of control) It continually reminds itself that it is going
straight, and re-sets itself. Only when a real sudden move is made, does
it
correctly sense that it is not going straight and the steering wheel wants
the car to go straight. The computer then makes corrections to keep the
car
straight.

If a plane wing leveler were based only on these units, and the plane
started banking very slowly, the sensor would not realize it. That is the
drift. It would re-set as level, then the plane banks another slow
degree,
and the unit re-sets, and the plane banks...you get the picture.

I believe the concoction that had some success, was a GPS wingtip
differential altitude sensor. It used these rate sensors in unison to
help
backup the control movements and make the controls smooth. The units
re-set using the GPS info as the reality of what was level. You have to
use
something (MarkII eyeballs or GPS) doing this.

Good luck to the OP, figuring out a homemade wing leveler. It is a tough
problem.
--
Jim in NC

Dick,

I think that winglets would improve roll stability, and L/D, climb
performance and high alt. performance.

Jan Carlsson

www.jcpropellerdesign.com


"Dick" skrev i meddelandet
m...
Thanks for everyones input.

Our group was discussing flying in VFR only (no IMC or IFR) and wing
leveler
only with respect to roll sensitivity of lightly wing loaded, short wing
spanned experimentals.

Trying to make summer flying in chop somewhat easier. We didn't plan on
turning over controls to the device and would still keep a light grip on
the
stick; just wouldn't have to constantly play the stick.

Although we had the impression that a heavier plane would be more stable
in
chop and require less than continual input by stick, that wasn't much of
an
option G.

Although not discussed among us, I wonder if
an increased dihedral result is possible without actually increasing it
physically..

Still would appreciate a little discussion that I can pass on for the next
non-flying day.

Thanks, Dick


"Morgans" wrote in message
...

"Montblack" wrote

Automotive world is using electronic stability-control (ESC) systems
with
documented success.

I'm guessing some variant of this is what you'll eventually cobble
together
in your garage.

More than likely, they are using piezzo electric rate sensors for the
direction information. They are relatively cheap, and do well at
sensing
rapid changes. They have been used for a while in the RC airplane
world,
as
a stability aid, with good success, also. Any really stable electronic
gyro
system in the commercial auto-pilots world, are much more expensive, and
as
far as I know, not available to the public.

Problem is, piezzo sensors have a fairly fast "drift." which makes the
leveling ability good only for a few seconds. If you handed over
control
to
one of these units, within 30 seconds, you would be upside down, and the
unit would think everything is still OK.

In the RC world, if the plane makes a sudden move to go upside down, it
senses the sudden move and if the sticks have not commanded the sudden
move,
it will move the control surfaces to stay right side up. It counts on
you
keeping it somewhat upright, and recalibrates itself often - based on
your
MarkII eyeballs telling the plane to fly level.

Same thing with the car unit in the links. It knows that you are going
straight, or following curves. (still reasonably slow changes compared
to
sudden loss of control) It continually reminds itself that it is going
straight, and re-sets itself. Only when a real sudden move is made,
does
it
correctly sense that it is not going straight and the steering wheel
wants
the car to go straight. The computer then makes corrections to keep the
car
straight.

If a plane wing leveler were based only on these units, and the plane
started banking very slowly, the sensor would not realize it. That is
the
drift. It would re-set as level, then the plane banks another slow
degree,
and the unit re-sets, and the plane banks...you get the picture.

I believe the concoction that had some success, was a GPS wingtip
differential altitude sensor. It used these rate sensors in unison to
help
backup the control movements and make the controls smooth. The units
re-set using the GPS info as the reality of what was level. You have to
use
something (MarkII eyeballs or GPS) doing this.

Good luck to the OP, figuring out a homemade wing leveler. It is a
tough
problem.
--
Jim in NC

On Fri, 25 Feb 2005 13:27:00 GMT, "Dick" wrote:

Thanks for everyones input.

Our group was discussing flying in VFR only (no IMC or IFR) and wing leveler
only with respect to roll sensitivity of lightly wing loaded, short wing
spanned experimentals.

Trying to make summer flying in chop somewhat easier. We didn't plan on
turning over controls to the device and would still keep a light grip on the
stick; just wouldn't have to constantly play the stick.

Although we had the impression that a heavier plane would be more stable in
chop and require less than continual input by stick, that wasn't much of an
option G.

Although not discussed among us, I wonder if
an increased dihedral result is possible without actually increasing it
physically..

Still would appreciate a little discussion that I can pass on for the next
non-flying day.

Thanks, Dick

My Jungster II has zero dihedral, but 15° of sweepback. The wing
loading is about 13 lb per sq. ft. It is quite stable in moderate
turbulence. While it can be upset it returns to level flight with very
little input. That probably won't solve your problem, but it is
another factor.

Ed Sullivan

Ah. You might consider pursuing developing a "rate damper". This would be
much simpler than trying to control attitude, as it would only require
sensing of rate. This would not act as a wing leveler (well, not exactly,
but it might provide some attitude stabilization without correcting for
drift), but it would respond to bumps. You'd still fly attitude, but the
damper would handle the transients due to turbulence, etc.

Being a flight controls engineer, I won't advise you further on this project
(not willing to assume any liability on a project I don't control), but I
will provide the following advice:
(1) Incorporating such capabilities on an aircraft is LOADED with very
serious potential hazards, all of which can be mitigated by a very careful
and conservative system buildup. These include:
- PIO susceptibility
- runaway servos that can make it difficult/impossible for the pilot to
fly the airplane
- high transient electrical loads
- high mechanical loads on your airplane
(2) Set things up so that you can always turn it off quickly and revert to a
normal airplane (i.e. no mechanical load on flight controls from an
unpowered servo. Set it up so you can always mechanically trim out what you
get from a stuck, hard-over servo.
(3) Instrument the system thoroughly during development and test so that you
know how hard you're working your airplane.

Check with some R/C modelers to get the idea on how to set something like
this up.

"Dick" wrote in message
m...
Trying to make summer flying in chop somewhat easier. We didn't plan on
turning over controls to the device and would still keep a light grip on
the
stick; just wouldn't have to constantly play the stick.

Very difficult to thermal with wing levelers.

Wing leveler suggestion:

Take neighbor kid along. Show him how to move stick to keep wings level.
Give him stick and tell him you will give him a quarter (whoops, $5 in
today's market) to keep wings level. Show him how to keed airspeed with
fore and aft movement of stick and tell him to wake you when ground is near.
Then take a nap.

Take Walkman along so you will not be bothered with the rushing of the wind
noise.

Good god, why would you want to put a wing leveler in the last bastion of
flight where the pilot is still a requirement?

Colin

In an effort not to go too far beyond my own knowledge, I'll avoid detail.

My best recollection, being about twenty years from being current as either
a pilot or a technician, is that "wing leveler" is a very missleading term
applied
to a single axis auto-pilot. Typically, the single axis would be yaw
(heading)
and would have been accomplished be slaving to either a rate gyro (such as
a turn coordinator or turn and slip) and a potentiometer, or a system of an
air jet and heated resistors, to provide a correction signal with
considerable
integration (a/k/a damping or low pass filtering). Although it would seem
intuitive to have the wing leveler steer the plane with the rudder and have
the dihedral roll the wings, the only systems that I have seen used the
ailerons and depended on the vertical stabilizer to keep the resulting yaw
within reason.

If you are still interested in learning more about how autopilots work, I
would
suggest trying to obtain some of the factory trianing manuals for the
technicians who will work on them. Try Bendix/King, S-Tech, and others.
Some books may also be available at college bookstores on booksellers
like Borders or Barnes & Noble.




"Dick" wrote in message
om...
Sitting around the hanger and discussing the possibility of somehow using
off-the-shelf electronic/computer components or gadgits for semi-automatic
wing leveling on lightly loaded, short wingspans.

Not being computer guys, the current thought is that something should be
out
there that is available cheaply and modifiable to use a simple wing
leveler.

Having heard someplace that automotive computers, as an example, sense
data
millions of times leads us to believe that sensing the wing tip initial
movement and counteracting very very quickly would be a good thing.

As an example: One fellow pictured a rolling ball bearing inside a tube
somehow activating a magnetic switch which in turn pulses a dc linear
motor
to operate the aileron minutely.

We are not sure how to detect the very earliest initial wing tip movement
or
drive the small trim type motor and would appreciate some thoughts or
site
recommendations to investigate.

Thanks, Dick