Physicists train robotic gliders to soar like birds

[OHM Ω http://aviation.derosaweb.net]

https://www.sciencedaily.com/releases/2018/09/180920101605.htm

With this technology could anyone win a soaring contest?

Expiring minds want to know. ;-)

[son_of_flubber]

The slow stall speed of these robotic gliders allows a very small radius of turn. (So it is easier to find exploitable lift.)

[[email protected]]

On Monday, September 24, 2018 at 6:18:10 PM UTC-4, OHM Ω http://aviation.derosaweb.net wrote:
> https://www.sciencedaily.com/releases/2018/09/180920101605.htm
>
> With this technology could anyone win a soaring contest?
>
> Expiring minds want to know. ;-)

Centering thermals is one thing.
Finding them and connecting them for long flight is another. To do that they will have to develop methods to read the ground, as well as clouds. This seems to me to be a couple orders of magnitude harder.
What is described has been done before and doesn't sound new.
UH

[RW[_2_]]

On Monday, September 24, 2018 at 6:18:10 PM UTC-4, OHM Ω http://aviation.derosaweb.net wrote:
> https://www.sciencedaily.com/releases/2018/09/180920101605.htm
>
> With this technology could anyone win a soaring contest?
>
> Expiring minds want to know. ;-)

Person who did Photoshop this picture never flew with birds.
Unfortunately people involved have to start flying gliders first,
to became nice weather pilots, and then try competitions,
and fly less then optimal weather to fully understand most aspect of glider flying.
knownerrorRyszard

[Martin Gregorie[_6_]]

On Mon, 24 Sep 2018 15:18:07 -0700, OHM Ω http://aviation.derosaweb.net
wrote:

> https://www.sciencedaily.com/releases/2018/09/180920101605.htm
>
> With this technology could anyone win a soaring contest?
>
> Expiring minds want to know. ;-)
>
This was done way back in 2007/8 by the ALOFT Project, and the autonomous
soarer that was developed was able to place well when flown against human
RC soaring pilots in an XC contest.

ALOFT used surprisingly simple sensors and off-the-shelf equipment: a GPS
receiver, standard RC autopilot (presumably fitted with MEMS solid state
attitude and rate sensors) and software running on a laptop with a
bidirectional radio link to the model. The model was a carbon 5m ARTF
thermal soarer. The code in the laptop handled navigation and thermal
utilisation strategies.

ALOFT found that the GPS was a less noisy data source than the sort of TE
varios that were commonly used in RC soaring, so all vertical velocities
were derived from it. I'm unclear why that was - possibly it was
something to do with the RC soarer being more affected by small-scale
turbulence than being used to flying a larger, heavier sailplane might
lead you to expect.

ALOFT was a successful Phd project for an aeronautical engineering
student, with the ultimate test being to fly ALOFT autonomously in one of
the Californian RC XC soaring competitions, where they fly tasks of up to
100km with the pilots in convertibles or on the back of pickup trucks.

Links:
======

http://www.xcsoaring.com/contests/mccc/2008/report.html

https://arc.aiaa.org/doi/10.2514/1.C000287

http://www.dtic.mil/dtic/tr/fulltext/u2/a614555.pdf

The first is the contest report, the second is the Phd thesis transcript
and the third is a detailed description of the control system and its
strategies for finding and using thermals. Derivatives of this control
system might be suitable for inclusion in our nav systems, though some
might say that using a nav system to predict thermal locations from
recent flight data is cheating. I couldn't possibly comment about that.


--
Martin | martin at
Gregorie | gregorie dot org

[Bret Hess]

From the summary this paper used accelerations (bumps) and torques as the method to find and center thermals, as opposed to sensing vertical air speed. Has that been done before?

[[email protected]]

On Tuesday, September 25, 2018 at 10:06:14 AM UTC-4, Bret Hess wrote:
> From the summary this paper used accelerations (bumps) and torques as the method to find and center thermals, as opposed to sensing vertical air speed. Has that been done before?

It is use in my cockpit on every flight.
UH

[aivian]

On Tuesday, September 25, 2018 at 10:06:14 AM UTC-4, Bret Hess wrote:
> From the summary this paper used accelerations (bumps) and torques as the method to find and center thermals, as opposed to sensing vertical air speed. Has that been done before?

Sort of.

Folks at the naval postgraduate school have used the time derivative of the vario signal in a controller, this should be pretty highly correlated with the surge acceleration. Their work is here if you have an aiaa subscription (https://arc.aiaa.org/doi/abs/10.2514/1.51691).

The Atlantiksolar team at ETH Zurich has used rolling moment to help figure out where thermals are. (https://onlinelibrary.wiley.com/doi/abs/10.1002/rob.21765)

The paper combines the two ideas but takes a different approach, using machine learning to figure out how to react to the surge and rolling moments instead of designing control laws and thermal estimators.

For those equipped with a biological computer trained in thermal soaring, the results will be familiar. As they note, you could summarize the results on how to respond to accelerations as:

* As climb improves, flatten the circle (approx. 15-20 deg)
* As climb deteriorates, steepen the circle (approx. 15-20 deg)
* If climb remains constant, keep constant bank (approx. 25-30 deg)

Which is page 10 in my copy of Reichmann.

It is interesting to note though that they suggest that rolling moment should generally override surges (i.e. almost always turn slightly into a raised wing, regardless of whether you get a surge or not).

I think UH is right on. Thermalling is relatively "easy," a moderately skilled human doesn't really leave a lot on the table, to say nothing of contest winners. How to find that thermal, and where to go afterward is a much harder problem and has a bigger impact on your speed.

[Tim Taylor]

On Tuesday, September 25, 2018 at 10:06:14 AM UTC-4, Bret Hess wrote:
> From the summary this paper used accelerations (bumps) and torques as the method to find and center thermals, as opposed to sensing vertical air speed. Has that been done before?

It is use in my cockpit on every flight.
UH

UH, I thought you were twerking, not torquing in the cockpit.

[CindyB[_2_]]

On Tuesday, September 25, 2018 at 9:29:50 AM UTC-7, Tim Taylor wrote:
> On Tuesday, September 25, 2018 at 10:06:14 AM UTC-4, Bret Hess wrote:
> > From the summary this paper used accelerations (bumps) and torques as the method to find and center thermals, as opposed to sensing vertical air speed. Has that been done before?
>
> It is use in my cockpit on every flight.
> UH
>
> UH, I thought you were twerking, not torquing in the cockpit.

Oooohhhh. Gosh Tim. That's a picture.
Laughter erupting.

I don't think anyone can twerk or torque in a -27 tub. Now, in the rear of the ASKbus with trainees up front --always.
You know those wingroot baggage boxes were made by CFI shoulders, right?

I agree with Hank. Every flight.

Thanks for the science/software class though to the
OP and supplementers.

Cindy B

[Charlie M. (UH & 002 owner/pilot)]

Yep, called "seat of the pants", instruments just give a value to the pants.


[visions of Hank twerking in a glider.....heck....anywhere!.......ARGGHHHH...."my eyes!".....]

LOL......