Messages in AirborneWindEnergy group.                          AWES2836to2885 Page 37 of 79.

Group: AirborneWindEnergy Message: 2836 From: massimo ippolito Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2837 From: dave santos Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2838 From: Doug Date: 1/5/2011
Subject: Re: "Blocking" Patents

Group: AirborneWindEnergy Message: 2839 From: dave santos Date: 1/5/2011
Subject: Re: "Blocking" Patents

Group: AirborneWindEnergy Message: 2840 From: dave santos Date: 1/5/2011
Subject: Manufacturability- Best Use of Automation in AWE

Group: AirborneWindEnergy Message: 2841 From: Pierre Benhaiem Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2842 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2843 From: Pierre BENHAIEM Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2844 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2845 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2846 From: dave santos Date: 1/6/2011
Subject: Simplest AWECS Yet...

Group: AirborneWindEnergy Message: 2847 From: Doug Date: 1/6/2011
Subject: Re: "Blocking" Patents

Group: AirborneWindEnergy Message: 2848 From: stefano.cianchetta Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2849 From: dave santos Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2850 From: Pierre BENHAIEM Date: 1/7/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2851 From: mmarchitti Date: 1/7/2011
Subject: Re: Kite Carousel Mechanical Design

Group: AirborneWindEnergy Message: 2852 From: dave santos Date: 1/7/2011
Subject: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2853 From: dave santos Date: 1/7/2011
Subject: New Draft Tethered-Aviation Concept-of-Operations (TACO)

Group: AirborneWindEnergy Message: 2854 From: Muzhichkov Date: 1/7/2011
Subject: Dragon kite for tether

Group: AirborneWindEnergy Message: 2855 From: Joe Faust Date: 1/7/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2856 From: dave santos Date: 1/7/2011
Subject: Re: Dragon kite for (pumping ladder-mill)

Group: AirborneWindEnergy Message: 2857 From: Pierre Benhaiem Date: 1/7/2011
Subject: Re: Dragon kite for tether

Group: AirborneWindEnergy Message: 2858 From: Pierre Benhaiem Date: 1/7/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2859 From: dave santos Date: 1/8/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2860 From: Muzhichkov Date: 1/8/2011
Subject: Re: Dragon kite for (pumping ladder-mill)

Group: AirborneWindEnergy Message: 2861 From: KITE GEN / Ippolito Date: 1/8/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2862 From: dave santos Date: 1/8/2011
Subject: Re: Dragon kite for (pumping ladder-mill)

Group: AirborneWindEnergy Message: 2863 From: KITE GEN / Ippolito Date: 1/8/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2864 From: dave santos Date: 1/8/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2865 From: Pierre BENHAIEM Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2866 From: stefano.cianchetta Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2867 From: KITE GEN / Ippolito Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2868 From: KITE GEN / Ippolito Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2869 From: KITE GEN / Ippolito Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2870 From: Pierre BENHAIEM Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2871 From: mmarchitti Date: 1/9/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2872 From: harry valentine Date: 1/9/2011
Subject: Re: Kitegen Carousel - Russian research precedent

Group: AirborneWindEnergy Message: 2873 From: dave santos Date: 1/10/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2874 From: Pierre Benhaiem Date: 1/10/2011
Subject: Re: Welcome Dave North

Group: AirborneWindEnergy Message: 2875 From: dave santos Date: 1/10/2011
Subject: Carousel & Kite Control Notes

Group: AirborneWindEnergy Message: 2876 From: harry valentine Date: 1/10/2011
Subject: Re: Kite Control Notes

Group: AirborneWindEnergy Message: 2877 From: Pierre BENHAIEM Date: 1/10/2011
Subject: Re: Carousel & Kite Control Notes

Group: AirborneWindEnergy Message: 2878 From: dave santos Date: 1/10/2011
Subject: Re: Carousel & Kite Control Notes

Group: AirborneWindEnergy Message: 2879 From: christopher carlin Date: 1/10/2011
Subject: Re: Reliable Kite Auto-Pilots

Group: AirborneWindEnergy Message: 2880 From: Dave Lang Date: 1/10/2011
Subject: Re: Carousel & Kite Control Notes

Group: AirborneWindEnergy Message: 2881 From: dave santos Date: 1/10/2011
Subject: Re: Kite Control Notes

Group: AirborneWindEnergy Message: 2882 From: Pierre BENHAIEM Date: 1/11/2011
Subject: Re: Carousel & Kite Control Notes

Group: AirborneWindEnergy Message: 2883 From: Dan Parker Date: 1/11/2011
Subject: Re: Welcome Dave North

Group: AirborneWindEnergy Message: 2884 From: Doug Date: 1/11/2011
Subject: Re: Kite Control Notes

Group: AirborneWindEnergy Message: 2885 From: dave santos Date: 1/11/2011
Subject: Re: Carousel & Kite Control Notes




Group: AirborneWindEnergy Message: 2836 From: massimo ippolito Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design
Bob Stuart wrote:
The well-known KiteGen Carousel concept involves teaming up multiple
stacks of "pumping" phased power kites to turn a giant turntable. There
are two major challenges to resolve; first there is the need to keep the
kites clear of each other & the ground, for if they foul a terrible
mess can result; & second, the "grunt" power of kites & a slowly moving
carousel is far from the high-speed rotation practical electrical
generators require.
**********

Dear Bob,

the two challenges you cited are not any more an issue:

the precise axial force (rope forces) management maintain a great
manoeuvrability to the kites in all condition, even in total and sudden
absence of wind.
The lightness of the kite and the high forces involved allows to impress
quick path variations due the relative absence of inertia.
The predictive control model knows the whole geometry and the expected
future evolution of each kite. Each control unit is able to make hundred
simulations per second of a time span of one tent of second of the whole
system. So the risk of entanglement could arise only in worst and
concurrent fault conditions of all control units.

The relative high speed of the carousel rotor rim respect the stator
base and the wide diameter of the machine allows to adopt linear and
modular alternators placed all around over the edge, the speed match
the magnetic flux commutation frequency requirement in order to attain
the best conversion efficiency.
the distribution of the linear alternators all around the Carousel is
even more mandatory for heat dissipation.
The idea to conduct the power to a central shaft is wrong, because the
mankind never built in the world such device capable to resist 1 GW of
torque, this is even worst at low angular speed , this was immediately
clear when we start to dimension the machine, for this reason we adopted
such system architecture with the clear advantage to have small devices
arranged in full modular fashion.

We deply refined the Carousel concept in several years, I am strongly
confident that each aspect was already successfully evaluated and
solved with several clever and ready solutions. In my position and
visibility I have collected a precise feeling of the value and strength
of the KiteGen Carousel concept due the often deep acknowledge received
from hundred skilled people in all science and technology domains.

Up to now there isn't another renewable energy concept able to deliver
several GW, with a capital cost that is 10 times less than a nuclear
power plant, this is the main limit of the KiteGen Carousel because this
is considered incredible or far away in the future. Here there is always
a more "credible" technology to be tested in priority, it was the
hydrogen, then the CSP, then CCS and now the Biomass. Nobody in the
decision rooms is able to read a LCA or understand the ERoEI concept, Im
so sorry...


Massimo Ippolito



Bob Stuart wrote:
Group: AirborneWindEnergy Message: 2837 From: dave santos Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design
Massimo,
 
A great virtue of the existing carousel is AWE "Super Density Operation" (SDO), but there are practical limits to how crowded the kites can be. We can agree that the control shallenges of the carousel are more difficult the more kite stacks there are, the closer they are, & the  higher they fly.
 
KiteLab has two predictive axioms to suggest-

Group: AirborneWindEnergy Message: 2838 From: Doug Date: 1/5/2011
Subject: Re: "Blocking" Patents
Saying a patent blocks progress is like saying that building a house causes homelessness. Patents form a foothold for progress. If you like a patented technology, make a deal to license it and you benefit. Inventing is hard work.
:)
Doug Selsam
Http://www.flyingwindturbine.com

Group: AirborneWindEnergy Message: 2839 From: dave santos Date: 1/5/2011
Subject: Re: "Blocking" Patents
Doug,
 
No one crudely said that "patents block progress", but we can agree that patent abuse does. Its not a very equitable system; corporate trolls & minefield filers are on the increase. Where did you get the $$ to file (& presumably defend) so many patents? Imagine your attitude if that considerable money had not been available to you.
 
Sorry to those for whom "inventing is hard work", it should be fun! Inventing a superior work-around to an undeserved patent monopoly, & sharing it, is especially sweet. The many open AWE methods, especially given JoeF's amazing research, seem to promise that AWE can be done wholly without dependence on patent protected art, Hurrah!
 
Consider releasing your patents, as Rogallo did, if you most want to stimulate "progress",
 
daveS
 
 
 

From: Doug <doug@selsam.com
 

Saying a patent blocks progress is like saying that building a house causes homelessness. Patents form a foothold for progress. If you like a patented technology, make a deal to license it and you benefit. Inventing is hard work.
:)
Doug Selsam
Http://www.flyingwindturbine.com


Group: AirborneWindEnergy Message: 2840 From: dave santos Date: 1/5/2011
Subject: Manufacturability- Best Use of Automation in AWE

Some of this is review for those new to the topic-

 

The most promoted use of automation in AWE is to try to fly unstable systems of expensive finely handcrafted composite construction in a chaotic unstructured hostile outdoor environment. Flight-automation is being asked for far too much way too soon & will for a long time fail to deliver the required safety & reliability. By contrast, factory-automation is a mature practical way to manufacture vast amounts of cheap AWE goods, if the product design allows. Such AWE devices would quickest pay for themselves.

 

From the first time i met Wayne German, his top focus has been design-for-manufacturability AWE concepts. He correctly foresaw that good kite wings can be made cheaply at high spaeed by automated production & has concieved methods for blow-molding bundled membrane tubes into inflatable wings. Dave Culp of KiteShip taught me his own version of design-for-manufacturability, of vast single-skin kites of minimal complexity. His brilliant OL kite is a good case of subtle "pattern complexity" enabling simple manual construction to perform amazingly.

 

 KiteLab takes design-for-manufacturability AWE study to even more radical extremes; of a high-speed automated production line able to produce hundreds of kilometers of megawatt-class (~3m x 100m) membrane wings a day. A gigawatt or so of capacity a day would add up to terrawatts in a few years. COTS UHMWPE & COTS generator production would keep pace. A factory is a well-structured low-chaos environment. Super high-speed wing production is possible because "flat-kite" wingmills are not three-dimensionally tailored like Wayne & daveC's wings (but act as "curved plate" thin airfoils). They would consist of a thin-film membrane faces with loadpath fibers & battens sandwiched together along a fast moving line in the blink of an eye. Within manufacturing constraints, lots of design freedom would exist to add vary porosity, elasticity, add turbulators, eddy flaps, etc.. Transformation from COTS roll-stock to final wing planforms could be done with zero scrap, the odd bits of reinforcement using up all cuts. Unlike composite construction, low-skilled labor could repair wings in the field with tapes. A small scale production line of small wingmills would be a nice start.

 

Humanitarian Note- Putting AWE automation investment into manufacture rather than flight-automation promotes the earliest significant energy harvest & shifts jobs from toxic ugly indoor composite work to glorious outdoor kite-pilot jobs.

 

 

coolIP


Group: AirborneWindEnergy Message: 2841 From: Pierre Benhaiem Date: 1/5/2011
Subject: Re: Kite Carousel Mechanical Design
It seems that the three ratios of land,space area and space volume
occupation/power are identical for KiteGen Carousel and farms of KiteGen
Stem (reel-out),and also for other systems like OrthoKiteBunch...For
example on a vertical plan of swept area you have one kite or one array
of kites for Carousel;and for a Stem-farm the same vertical plan is
divided into two or more successive sections,that for an identical total
length of tethers*.

Other subject,questions for Carousel:is not it a problem for an array of
kites that the speed of kites in the top are higher when figure-eight
are realized?The total length of such an array could be calculated
according to an estimation of wind gradient?

PierreB


Note*:the ratio of land occupation/power,generally good for AWECS, is
not the only one.It is necessary to take into account the whole (space)
area according to the length of tethers and the variability of wind
direction,and also the space volume which is taken from aerial
circulation.





--- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@... wrote:
stacks of "pumping" phased power kites to turn a giant turntable. There
are two major challenges to resolve; first there is the need to keep the
kites clear of each other & the ground, for if they foul a terrible mess
can result; & second, the "grunt" power of kites & a slowly moving
carousel is far from the high-speed rotation practical electrical
generators require.
run radiating cableways from a central location to allow properly
spacing any number of kites to all contribute power together. In
particular KiteLab envisions a sort of central sunken crank-&-wheel
carousel, like a giant unicycle laid on its side, with many kite-driven
cables fanning-in from acros the kitefield to drive the crank. The
carousel would turn with great power, but at low rpm. The rim of the
carousel wheel would carry large generators turning at high rpm as
"planetary gears". One might make such a super wheel as a cheap
earth-banked high-speed circular train track with circling COTS TGV
(bullet train) engines in regenerative-braking mode (motoring to get up
to speed), or large industrial generators custom-set as planetary
wheels, the rim driven by torque transmitted by wire rope spokes from
the hub & crank, just like the unicycle model. The crank would be built
applies to tapping coastal ocean currents & scales to the very limits of
civil & mechanical engineering, to multi-gigawatt output comparable to
the largest power projects.
Group: AirborneWindEnergy Message: 2842 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design
Pierre,
You're right on the two geometrical parameters, but the specific power of the Carousel is several times more than reel out/in system and in terms of energy is even better.

Reeling out method imply to waste some wind speed to reach the operational force and then the the excess wind will progressively produce energy.
Carousel is fully operative with the base wind speed, in case of stronger wind the Carousel modulate reducing the airspace path effectiveness.    
The reeling in/out cycle affect the generation continuity, the active phase is roughly limited to a third of the time.
Power is Velocity  * Force, The Stem configuration is prominent in force to energy conversion, Carousel in speed to energy.
More speed imply less relative force, smaller ropes, smaller control winches, better aerodynamic of the wing and ropes, more structural lightness, much more ERoEI. 
Better aerodynamic imply lower base (nominal) wind speed, this extend dramatically the yearly availability.
In the Stem the control winches pilot the kites and produce energy, in the Carousel the alternator ring produce the energy and the winches pilot and manage the kites operations, a further gain in efficiency, durability and  ERoEI.

Stacked kites aren't the better solution, it is required an active attitude trimming that continuously adapt the array behaviour,
the aerodynamic improvement approach based on a single wing is in my view, is the most effective.
pls. have a look of the Carousel offshore in this movie (minute 6.20)  
http://www.youtube.com/watch?gl=IT&v=HMQwYkZEaMk

The ERoEI of Stem configuration is certainly much lower than the Carousel, but in any case is still huge: 350 

Massimo Ippolito

Group: AirborneWindEnergy Message: 2843 From: Pierre BENHAIEM Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design
Massimo,

The shown "train" version of Carousel on the beautiful video lets an important diminution of strengths on the structure in rapport to the first version with "levers".

As you know with figure-eight (or others)kites deliver a good tangential force (that producing torque),and also variable bad axial (towards the top) and radial (towards sides) forces according to the angle of flight in rapport to the horizontal plan and to the ring direction.Its not a great problem if angles are not too high.But with a reel-out/in system (Stem) it is possible to avoid parasitic forces with a good permanent orientation of the moving part of the ground station according to the path of kite.

For electric production Carousel has the great advantage of continuous and regular motion:a temporary storage (different of furthering needed great storages) is not necessary;it is not the case for reel-out because 1) cyclic irregularity of power according to kite position in the flight window 2) retrieval phase with motor production;compensation between unities can limit the problem but it seems that a temporary storage will be necessary.

You pointed on your patents the double use (power,steering) of winches with losses,that from reel-out in rapport to Carousel where the winches are only for steering.Several questions:is it possible to make a good control with very long lines?Other technologies like Skysail or TuDelft an Ampyx advocate a single line and steering control near the kite?

David North makes a good remark for possible perturbation of the grid with wind energy and indicates the necessity of great storage (for example why not pumping-turbinage).Morever no grid could support enormous variations from GW scale AWECS.

So are AWECS impossible for great amounts of energy?
Yes and no.

Why not for a complete global change of policies where coal plants would work as energy storage for adjustments (a little like in German where wind is about 20% and coal 80% but with reverse proportions).For this way competitor solar energy would become a friend as (enough) predictive energy.

So GW scale AWECS like Carousel should be presented into another definition of global energy mix for 2050.

At World Energy Congress Fatih Birol (IEA) gave a favorable answer to my question about HAWE.In some papers he indicates a necessary "revolution" because of depletion of fossil sources.
A good thing if you can work with him.

PierreB  




Group: AirborneWindEnergy Message: 2844 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design
Sorry, before I wrote an erroneous data, the passive phase of the KG Stem is one third the active instead is 2/3,
perhaps the big effort to read my English hide me the errors I'm introducing :-)

Pierre,
Congratulations you are proposing the most interesting questions I ever received all gathered together.

About the parasitic forces:
Considering a rope pitch mean angle of 45 degree and a mean yaw angle of 45  the tangential force is the cosine product, then half of the line forces.
I do not consider parasitic force, the radial resistance is promptly converted in kite speed, and the vertical component is useful to slight lift the carousel poles in order to activate a damping effect clipping all the forces exceeding the design requirement. The weight of the pole or mast is calibrated to actively counteract the vertical component. In the Carousel movie is difficult to see but a guy cable assert the tangential counterforce on the must.

About the single/double line:
Let me introduce an analogy of signal theory domain, please consider the control actuation of the kite (line length differential), like an information transmission.
What are the problems affecting this signal communication?  One issue could be the delay or better defined the round trip time, the other could be the noise superimposed over the sent information.
The delay isn't an issue, the propagation time on the dyneema or vectran lines is about 200 millisecond/km, and the feedback to close the round trip is practically zero because the sensors aboard, are radio linked (light speed) to the ground control. In 200 millisecond the kite fly for 10 - 20 meters in a kilo-metric airspace volume.
The noise isn't again an issue, the two lines act as a balanced transmission media, the symmetrical information flow on the lines in phase opposition (antiphase) and the common mode noise is cancelled.
So in my opinion the claim of the need to actuate close to the kite is again a free and false intuition due to an insufficient methodic investigation.
Two lines from the security and safety point of view, are instead a paramount aids to pay with a very slight drag increment. 

About Storage:
May be, I have missed some previous discussion, but let me know why, the Christina Archer and Ken Caldeira (Global Assessment of High-Altitude Wind Power) opinion  (build interconnecting devices that are geographically dispersed via ground-based transmission lines), isn't any more valid?
200 km of distance to mutual extend the AWECS availability up to 95%, could be a very good result, nuclear reactors have an availability of 90%.
In my opinion this is a very effective solution to mitigate the concern about the wind intermittency.
Energy storage isn't any more an issue, really.
The atmosphere is an huge capacitor of 3000-4000 TWh of energy always available and permanently auto-recharged.

thank you
Massimo Ippolto





 



Group: AirborneWindEnergy Message: 2845 From: KITE GEN / Ippolito Date: 1/6/2011
Subject: Re: Kite Carousel Mechanical Design
Dear Dave,
It is quite easy to align problems and doubt, less easy is look for, find and check solution.

I disagree with your common sense axioms, the control science today is able to produce systems much more effective than human control.
It is possible to stabilise a condition where a system crash, can only occurs in system failure conditions, both mechanical or electronics, but this is addressable by a well known procedure, adopted i.e. in aviation.
The world is plenty of controls that cleverly do their job 24/7/365, but we typically become aware that something is automatically controlled only in case of failure. 

Your statement saying  "a small cyclonic gust could affect the fly" reveal me that you never simulated in real time the fly of a controlled kite with the full lines management. I've certainly simulated, but also directly piloted for almost 1000 hours and implemented the first simple control on a real machine, called the mobilegen or KSU.
The (double) tethered fly have the same reliability of a normal plane fly with additional opportunities, for example it is easy to get out quickly from a stall condition with a small reeling-in pulse or is available the side-slip manoeuvre to quickly get out from trouble, and more, the fly recovery after the side-slip offer a guaranteed successful upshot.

I agree that it could be counter-intuitive, but the wind has a little importance in the manoeuvring precision, the kite could fly at 60 - 120(*)  m/s and the reference wind is 6-10 m/s,  a wind intemperance, including gusts, could at the maximum fluctuate few ten meters around the controlled path.     

The solution to conduct to a central crank, assuming that you want to produce energy at a lower cost, will carry expensive problems in terms of mechanics and electrical machinery, Sorry for my bold opinion, but this was our early design then after a lot of thinking and brainstorming we abandoned that solution for the most credible, cheap, light, modular and technologically feasible ring.

Massimo Ippolito

(*) Belgian experimental C shaped kite, in aluminium foil (NCB)


Group: AirborneWindEnergy Message: 2846 From: dave santos Date: 1/6/2011
Subject: Simplest AWECS Yet...
Attachments :

    Sorry to bore the forum with more tiny wingmill experiments, but they do illustrate KIS & agile-engineering. Here are three videos of a tailed wingmill to show something with crosswind action simpler even than a Chinese varidrogue. You can see the famous Jet Stream above the working AWECS. In some hard gusts the tail actually made tiny sonic booms! The wingmill is the area of a large pizza (a T-plan 4ft WS, 27" LOA, .2m Area) & barely deflected the 14 sq ft sled.

     

    The first clip shows power being extracted by the wingmill in a stiff breeze (~15kts/9hz/25N-2.5cm pulses) to work a spring scale. The second is the wingmill oscillating nice & steady in a medium breeze (~6kts/5hz/10N-1cm pulses). The third is a close-up of the wingmill in a gust (~20kts), acting semi-chaotic, but the pilot stays stable & power is being extracted. A longer tail would restore regularity.

     

    http://www.youtube.com/user/KiteLabGroup

    Attached JPG is a close-up of all components.
     
    OK, this toy is only a single-digit wattage (like many a solar cell), but the individual membrane wingmill can grow to megawatt scale & be aggregated into vast arrays. Its tricky to calculate the actual power of this .2 sq m scrap of Tyvek. Calculating 1-3 watts without optimizing further. A toy kite could carry it as is or the sled shown could lift one 5 times the area. Guyed sidelines &/or cornerblock-drogue would just about double output, as a lot of power is wasted on transverse sloshing. A cornerblock-drogue also enables single-point anchoring. A toy kite & flipwing may max out at 5-6 watts & the sled with wing at about 30 watts. The estimated "installed watt" price, including small gen or pump stage, is about the same as a solar panel, a dollar per watt. Thats not bad for starters, at only thirty-five feet high, plus it flies autonomously, even self-relaunches, & anyone unable to buy can make them in a few minutes from trash.
     
    Old Correction to DaveL- I misread the worn numbers on my smallest Newton scale a couple of years ago, with a much smaller handheld wingmill, the oscillation peaks were only 2.5 not 25 N (missed the decimal).

      @@attachment@@
    Group: AirborneWindEnergy Message: 2847 From: Doug Date: 1/6/2011
    Subject: Re: "Blocking" Patents
    Dave S.:
    To clear up any misconceptions:
    My patent under discussion cost me only about a thousand dollars since I did it all myself.
    I earned the money by selling speakers out of a van. Patents are a great teaching platform, and the default, most widely-recognized forum for recording who invented what and when.
    For the past 10 years I've lived in a 1-bedroom apartment in "the hood", developing, manufacturing, and marketing the most powerful turbines in the world for their diameter (currently using a 3 kw inverter for a 10-foot diameter machine).
    I have several extremely revolutionary AWE concepts that use new ideas not discussed here, that I will talk about after I build them, or at least patent them. For now I'm most comfortable discussing the concepts taught in my existing patents, which are easy to build and run now, with 100 percent certainty that they can actually at least work.
    Doug Selsam
    Http://www.flyingwindturbine.com

    Group: AirborneWindEnergy Message: 2848 From: stefano.cianchetta Date: 1/6/2011
    Subject: Re: Kite Carousel Mechanical Design
    Massimo, thank you for reassuring me!!
    (Massimo said: The reeling in/out cycle affect the generation continuity, the active phase is roughly limited to a third of the time).

    I have promptly opened Fagiano's thesis in which two different cycles are described (page 62-63):
    "low power recovery maneuver" and "wing glide recovery
    maneuver" with about 400 and 40 seconds cycle lengths and active phases lasting approx. 200 and 30 seconds respectively, thus about 50% and 75% of the time!!

    Stefano
    (I am a kitegen supporter)

    --- In AirborneWindEnergy@yahoogroups.com, KITE GEN / Ippolito <m.ippolito@...
    Group: AirborneWindEnergy Message: 2849 From: dave santos Date: 1/6/2011
    Subject: Re: Kite Carousel Mechanical Design
    Caro Massimo,
     
    I agree that autonomous kite flight must eventually reach the reliability you propose (of general aviation), but its strange to hear a wonderful claim that its already come true. Even human-expert kite-pilots lose control of their wings, particularly in turbulent high or low conditions. You seem to be the only one experiencing & claiming kite reliabilty; perhaps its chance, somebody has to be the luckiest of the hundred or so experimenters. I crash all the time, but deliberately pushing the envelope, to make up for the fact that i only have ~3000 "technical" flight hours. Also, my smaller kites live faster & reveal freak failure modes sooner. Maybe your weather & simulation settings are milder than the conditions others experience. Don't you have any state-sensor uncertainty or actuator-bandwidth limitations?
     
    After decades of following robotics & controls, i know of no reliable automation system comparable to the kite application. All successful mass automation seems to only be low-dimensional mostly linear control, including autopilots/avionics. So what successful autonomous control applications have you identified as comparable to the kite problem?
     
    A circular track does contain a downwind-upwind displacement comparable to reeling. True, that a lever/crank rated to gigawatt scale will be fairly short, but thats good, as its the ratio of its length to the carousel's large diameter that provides a high step-up. But the KiteLab variant is a far smaller wheel than yours. Its a nice win if a "little" carousel, with the kites anchored around it, can do the same job,
     
    Saluti,
     
    daveS
     
     
     

    From: KITE GEN / Ippolito <m.ippolito@kitegen.com
     

    Dear Dave,
    It is quite easy to align problems and doubt, less easy is look for, find and check solution.

    I disagree with your common sense axioms, the control science today is able to produce systems much more effective than human control.
    It is possible to stabilise a condition where a system crash, can only occurs in system failure conditions, both mechanical or electronics, but this is addressable by a well known procedure, adopted i.e. in aviation.
    The world is plenty of controls that cleverly do their job 24/7/365, but we typically become aware that something is automatically controlled only in case of failure. 

    Your statement saying  "a small cyclonic gust could affect the fly" reveal me that you never simulated in real time the fly of a controlled kite with the full lines management. I've certainly simulated, but also directly piloted for almost 1000 hours and implemented the first simple control on a real machine, called the mobilegen or KSU.
    The (double) tethered fly have the same reliability of a normal plane fly with additional opportunities, for example it is easy to get out quickly from a stall condition with a small reeling-in pulse or is available the side-slip manoeuvre to quickly get out from trouble, and more, the fly recovery after the side-slip offer a guaranteed successful upshot.

    I agree that it could be counter-intuitive, but the wind has a little importance in the manoeuvring precision, the kite could fly at 60 - 120(*)  m/s and the reference wind is 6-10 m/s,  a wind intemperance, including gusts, could at the maximum fluctuate few ten meters around the controlled path.     

    The solution to conduct to a central crank, assuming that you want to produce energy at a lower cost, will carry expensive problems in terms of mechanics and electrical machinery, Sorry for my bold opinion, but this was our early design then after a lot of thinking and brainstorming we abandoned that solution for the most credible, cheap, light, modular and technologically feasible ring.

    Massimo Ippolito

    (*) Belgian experimental C shaped kite, in aluminium foil (NCB)



    Group: AirborneWindEnergy Message: 2850 From: Pierre BENHAIEM Date: 1/7/2011
    Subject: Re: Kite Carousel Mechanical Design
    Massimo,

    Thank you for your precious indications and the compliment.

    About single/double line:
    I could not imagine such an explain.By chance it could be positive for a furthering automatic version of the two lines
    Manual Flygen  (Youtube) for loading (model airplane,laptop...) batteries and also,with a quick launch of market as model airplane,to create a synergy with high-scale AWECS allowing an acceleration of their development.

    About storage,two different purposes:
    1) The availability you indicate :" ...Christina Archer and Ken Caldeira (Global Assessment of High-Altitude Wind Power) opinion  (build interconnecting devices that are geographically dispersed via ground-based transmission lines)...",also in response to a precedent remark by Dave North towards the necessity of great amounts of storage.
    2) Temporary small storage (hydraulic installations,supercapacitors...)for smoothing the production for a good quality of produced electricity before connexion to the grid.For reel-out systems it can be necessary because of the irregularity of produced power (the same for flygen,listen the variation of sound on Manual Flygen),and also to compensate the retrieval phase.A farm of reel-out allows avoiding a part of the temporary storage with global management of one farm.But Carousel configuration,with its continuous move of conversion system,takes a great advantage:a smoothing device is not needed.

    Pierre Benhaïem     





    Group: AirborneWindEnergy Message: 2851 From: mmarchitti Date: 1/7/2011
    Subject: Re: Kite Carousel Mechanical Design
    Dave, modern combact aircraft like Typhoon are intrinsically unstable: even in a straight and level flight in calm weather condition, they cannot be controlled only by human input, without the aid of a flight control system and computer.

    Group: AirborneWindEnergy Message: 2852 From: dave santos Date: 1/7/2011
    Subject: Reliable Kite Auto-Pilots
    Massimo,
     
    We agree there are embedded  automation loops in modern systems comparable to the Typhoon Eurofighter example you chose. The launch-&-forget kite problem is actually far more complex. For example, the Typhoon's is still only a "pilot-assist" autopilot, & cannot even land itself (approach only), or perform many other basic mission operations, without a human. No autopilot has the sensors or judgement of human procedures. This is why kite-pilots are needed for large AWECS for years or decades to come.
     
    Let me recast my second question- Does your NMPC meteorology model predict breaking-gravity-waves or gustnados (do your sensors even detect such common events)? When these invisible killers hit a kite, its tumbled as if by a washing-machine, with actuation overwhelmed. If the current prototype Stem control-model lacks such features you must expect to be picking the kite out of the trees.
     
    "Common sense" is stubborn ;^)
     
    daveS
     
     

    From: mmarchitti <marchitti@hotmail.com
     

    Dave, modern combact aircraft like Typhoon are intrinsically unstable: even in a straight and level flight in calm weather condition, they cannot be controlled only by human input, without the aid of a flight control system and computer.


    Group: AirborneWindEnergy Message: 2853 From: dave santos Date: 1/7/2011
    Subject: New Draft Tethered-Aviation Concept-of-Operations (TACO)

    Comments invited-

     

    DRAFT

    Proposed FAA Advisory Circular

    Tethered-Aviation Concept-of-Operations (TACO)

    Focus on Experimental Airborne Wind Energy (AWE) 

    Preface to the 6th Draft-
     
    At the second Airborne Wind Energy (AWE) Conference (AWEC2010), the FAA publicly called for the early industry to define the emerging aircraft types into the FAA's Category & Class system. For its part NASA informally tasked industry players with developing ConOps frameworks for AWE in the US National Airspace (NAS). The Airborne Wind Energy Industry Association (AWEIA) responded by initiating this report addressing requirements. KiteLab Group, an AWE R & D pioneer, volunteered to compile a master Tethered Aviation ConOps (TACO), in an open collaborative process. TACO is written to be suitable as an FAA Advisory Circular to properly inform all aviation stakeholders of the issues. While AWE is the priority application of this ConOps, the full scope is TA as a whole. Not only are there exciting new kinds of TA, bit there is a vast pool of historic TA precedent & working models to apply to AWE operations.
    T ethered or not, persistent acceptance-barriers exist to autonomous aviation in the US NAS (National AirSpace).The current FAA requirement for piloted systems will hold for some years.  Thus this early-stage TAConOps Draft is "pilot-centric", embracing the pilot's key stakeholder status, but also is forward-looking toward eventual flight autonomy (Appendix). As a major future energy technology, AWE has the potential to subsidize many of the dreams of aviation planners & general aviation.
    This "living document" is intended to evolve & merge into the NextGen Airspace ConOps. The US regulatory standard is expected to drive the international picture (ICAO, etc). Please send corrections or additions to santos137@yahoo.com
     
    Executive Summary
     
    Tethered Aviation is an old & important branch of Aeronautics, with a erostats, aerotowing , & kites as well-known examples. Tether-based flight systems under current development will enhance aviation capabilities, host infrastructure (ie. communications), spin-off industries, create recreation, & generate clean energy. This "New Aviation" requires the primary stakeholders, pilots, developers, regulatory bodies, & populations, to all come together to resolve the technical & social challenges &  realize the great potential.
     
    Pilots are a key stakeholder, as primary users of airspace & the group most exposed to flight risk. It will be pilots, following their norms & traditions, who lead safe effective Tethered Aviation R & D, who take jobs in the new aviation industries & ensure that operations stay consistent with safe convenient shared airspace. The aeronautic & aerospace industries are tasked with designing systems that pilots accept & the FAA, the gatekeeper stakeholder, can certify as airworthy.While there are new issues to face in TA, for the purposes of private R & D, the current system is not broke, & need only change by increments to transform over time into major mature sectors. All aviation interests must collectively prove to extended stakeholder populations that Tethered Aviation enhances life & is a "good neighbor". General policy developers & decision makers, from the national to the local level, are another key early stakeholder group. The TACO lays out a basis for them to help reach a public consensus regarding the best use of TA in the NAS.
     
    Aviation Self-Regulation Principle
     
    By tradition the FAA relies on all sectors of aviation, via user & industry associations, to refine & promote best practice for their members. Safe operations & responsible leadership by each sector allows the FAA to maximize resources & perform oversight with a light touch. The Airborne Wind Energy Industry Association (AWEIA) undertakes, as part of its formal mission, to perform the leadership role of self-regulation for AWE in particular, but also to serve specialized TA as a whole. This TACO is prepared under the auspices of AWEIA.
     
    AWEIA will coordinate member standards for safety & act as liaison between industry & FAA. There are already urgent R & D safety issues AWEIA is addressing, such as the sharing of safety-critical failure modes & mishap reporting. AWEIA is just one of several associations with overlapping interest in TA. AOPA & EAA have strong interests within the new sectors. The American Kiters Association (AKA) governs recreational & professional kite operations. The American Modelers Association (AMA) is responsible for safe hobbyist aviation. User associations in soaring & other sectors that commonly perform tethered operations also have oversight roles. Key wind energy standards also apply to AWE operations.
     
    TA Excise Taxes & User Fees
     
    The new AWE  technology taps airspace as a source of vast energy. Mature energy sources all have excise taxes, with 5% of producer's selling price typical. Unlike excise taxes on extractive non-renewable energy sources which eventually run out, renewables can generate revenue in perpetuity. Barriers to broad AWE societal stakeholder acceptance. like NIMBY (not-in-my-back-yard) forces, will tend to evaporate before a rich new tax base that more than offsets any negatives. The average US citizen, who does not fly or own aircraft, still shares a birthright to the airspace commons. An equitable AWE Excise Tax can make a huge contribution to basic social welfare & even a new era of sustainable prosperity for all.  Energy excise taxes are also used to offset environmental downsides with mitigation measures.
     
    Airspace is by tradition a Public Commons based on Freedom-of-the-Seas. There is already resistance on the part of existing aviation stakeholders to allowing privatization of AirSpace as some venture-capital AWE stakeholders have proposed. Utility-scale AWE operations can contribute to shared airspace by paying Excise Taxes on energy extracted & maybe even special Airspace User Fees. Airspace User Fees is a toxic idea to existing aviation but could make sense for the new types of aviation.
     
    The AWE industry can gain ready aviation stakeholder acceptance by subsidizing common airspace infrastructure benefiting all. AWE excise charges can offset existing FAA costs, relieving the overall Federal budget, pay for NextGen infrastructure, guarantee liability performance, & fund publicly-shared AWE R & D. The early industry requires a phase-in period for taxes, so as to not choke off early investment & to promote initial growth. As significant mature AWE revenue-base develops, & airspace becomes widely impacted, the tax base can be tapped. Small-scale personal AWE operating at low altitudes should be exempted commercial taxes.
     
    Insurability
     
    TA Operations must carry Liability Insurance proportional to risk. Such insurance is currently unavailable from traditional providers & a special TA Liability Fund may be needed for a jumpstart. TA operations can pay premiums into the fund & Excise Tax funds can help cover special pioneering risks.
     
    A wrongful death these days can cost around ten million USD & there is no AWE liability insurance available. The insurability guaranteed by an excise endowed fund can ensure that a financially weak AWE player in a freak-accident (even an unknown failure-mode) event does not leave victims or families uncompensated.

    FARs Category, Class, & Type Certifications for TA

    The FAA tasked the AWE Industry (AWEC2010) with defining the profusion of designs & new Types into the FAA's Aircraft/Airman/Operations Category, Class, & Type System. Categories naturally grow by added Classes, so special TA Classes are to be defined within current Categories. Note that FARs are sometimes vague, confused,  & contradictory; no clean classification ontology is even possible, only patchwork progress, pending NextGen. There is traditional wiggle-room in the system, with many exceptions & options at the discretion of authorities, including classification under multiple categories & classes. Aviation is increasingly diverse & its new branches may become wholly new Categories. 

    Just like any other aircraft, TA platforms can be classified by gross-weight & airspeed, by the same physics of "consequence".
     
    Far-flung tether geometry is a unique TA feature to account for, but has useful similarity to standard geometry flight trajectories & operations like skydiving.

    Some  major Aircraft Categories- aircraft, rotorcraft, normal, utility, acrobatic, commuter, transport,  manned free balloon, glider, special, restricted, etc. As an example of how TA Class can apply across Categories, many given Types can be modified for aerotowing, with special restrictions accruing. 

    Weight & Speed (mass & velocity) are primary determinants of Class within a Category. In general higher mass/velocity Classes have Higher Consequence Failure-Modes & so require proportionally higher standards for equivalent safety (mortality to flight hours). Stall Speed is a key safety consideration, the lower the better, with the widest possible range of operation between max airspeed & stall speed.

    Single/Multi-Engine Classes- Many TA applications have powered modes that naturally assign them to an Engine Class within a Category. The trade-off of getting improved reliability from multi engines is a higher standard of Pilot training & engineering design required.

    Examples of new Classes created- Tethered-Aerobatic, Tethered-Single-Engine, Tethered-Multi-Engine, Tethered-Normal, Utility, Sport, Ultralight, Moored-Balloon, Aero-Towed Glider, Tethered Rotorcraft

    Note: Many current tethered vehicle platforms are not formally designated as an "aircraft" in the Aircraft Categories under current FARs, but the FAA reserves the right to designate them so. Its now clear that the tethered aircraft must be designated as aircraft so as to be regulated for airworthiness. The irrefutable logic is that any accepted aircraft can in principle be put on a tether, which does not negate its character as an aircraft of a given mass & speed envelope, & even adds to operational hazard. The many large tethered aircraft under development will have to be Type Certified in a suitable Category, a Special Class.

    Some Categories & Classes of aircraft & operations are interrelated. For example, UAS Aircraft & Flight Operations are clearly intimately coupled. On the other hand, a UAS might be operated as a Commercial or Private Aircraft.

    Tethered Aircraft (TAC) that operate aerobatically & incur high G-loadings are Acrobatic Category (limited to 12,500lbs gross). Tether-Weight counts toward rated gross weight. Tether-Drag counts against rated L/D.

    Electrically Conductive Tethers require special standards addressing all safety issues.

    Autonomous Flight of high-consequence platforms (high mass &/or velocity, especially around populations) will require a proportionately more cautious rigorous path to validation & certification.

    Aircraft joined by tethers into arrays is an operational configuration to validate. The proposal is that this method might greatly enhance safety & reliability.

    AWECS are generally high-duty UAS & so merit Utility designation. According to gross weight they can be sorted into Ultralight, Sport, Normal, Commuter, & Transport Weight & Airspeed Categories.

    Operational altitude is a major category criteria. Some relevant ceilings- 400ft for low mass low speed hobbyist model aviation. 500ft as a "floor" for general VFR aviation. Class G airspace, which is  low, but variable, with higher ceilings in remote areas, 2000ft obstruction regulations for mast & tower certification, 18,000ft as an "absolute" ceiling to avoid transport aviation operations.

    Pilot Categories & Training

    The requirement for proper pilot-training is fundamental in every branch of aviation. All pilots in TA-shared airspace require awareness. TA pilots require basic aeronautical training, plus specialized operational proficiency. As high-consequence risk emerges TA Pilots will eventually require the same highest-standard certification as Transport Pilots.

    Sec. 61.31 — Type rating requirements, additional training, and authorization requirements.

    Operational Categories

    Some major Operational Categories- Unmanned Aviation System, IFR/VFR, Weight & Speed Cats., Obstruction

    Models like the Obstruction regs are only partial. For example, an antenna-farm Obstruction is regulated under mast & tower structural codes & does not have the inherent aviation hazards related to aircraft airworthiness & potential to crash far afield. Therefore a TAC regulated as an obstruction also needs to comply with Aircraft regs.

    Current norms & Regulations
     
    The FAA's role of maintaining a safe NAS & especially its job of certificating type airworthiness is essential to prevent TA R & D from presenting a "menace-to-aviation". Most AWE venture starts have no formal aviation background & face acculturation along an FAA approved path. Class G Airspace is the primary realm of current TA R & D.FSDOs are the current arbiters of allowable experiments, with decentralized flexibility. AWE R & D can shop around for a "best-fit" FSDO (generally remote low-traffic NAS regions). Special Airworthiness Certificate in the Experimental Category is the certification currently available to civil operators of UAS. NOTAM & COAs allow pioneering AWE R & D to occur.
     
    Obstruction regs, such as apply to antenna farms, might serve for persistent "static" TA operations under 2000ft AGL.Shielded operations is a current option for a TA operator able to identify sites.
     
    Draft FAA sUAS regs call for Pilot-in-Command & Visual Observer crews.
     
    Key Title 14 Parts of the Code of US Federal Regulations (Aeronautics & Space)

    PART 101 - MOORED BALLOONS, KITES, UNMANNED ROCKETS AND UNMANNED FREE BALLOONS

    Part 77 - OBJECTS AFFECTING NAVIGABLE AIRSPACE

    The FAA regulates skydiving activity as"Parachute Operations" Part 105 (14 CFR 105). Flight operations for skydiving are conducted under Part 91 "General Operating and Flight Rules" (14 CFR 91).

    FAA Advisory Circulars provide additional guidance about operations. A TAConOps circular is a logical step.

    Banner-Towing & Glider Aero-Towing regulations inform equivalent operations in other applications.

    Recreational  NAS use covered by FAA Advisory Circular (AC) 91-57; generally limits operations to below 400 feet ASL well separated from airports & air traffic. This is the appropriate place for virtually all current AWE developers to conduct most experiments without being a "menace to aviation".

    Three acceptable means of operating UASs in the NAS: 1) within “restricted” airspace: or under a Special Airworthiness Certificate (2) Experimental Category or (3) Certificate of Waiver or Authorization (COA). A COA authorizes an operator to use defined airspace under specific provisions unique to the operation.  It may require Visual Flight Rules (VFR) & operation only &/or during daylight. COAs are issued for a specified time period; one year typical. COAs require coordination with air traffic control & may require a transponder in certain types of airspace.

    A UASs inability to autonomously follow ”sense and avoid” rules means a ground observer (PIC &/or VO) must keep visual contact to operating in unrestricted airspace.

    "Sense & avoid" UASs requirement currently means PIC (Pilot-In-Command) & VO (Visual Observer), plus dive or kite-kill capability.
    Possibility of special IFR Rules clearances, especially higher operational ceiling during graveyard shift to help bridge night-time inversion.

    TA Operations Notes

    Separation, Avoidance, Visibility, & Education (SAVE) is a useful mnemonic for the basic principles of safe TA operations. S is for passive Separation; the relegation of TA operations to remote low-traffic airspace; A is for Avoidance; the effective evasive capability of a TA platform (ie. "kite-killers"). V for Visibility is the standard for obstruction markings, transponders, radar-reflectance, etc.. E for Education is the requirement to appropriately inform & train all pilots operating in proximity to TA, as well as the special Type-Rating knowledge a TA PIC needs.
     
    Special Risks- Mid-Air Collisions, Breakaway, Tether Dragging, Conductive-Tethers, Security,
     
    APPENDIX
     
    TACO/Nextgen Transformation Path
     
    The general iterative-spiral validation process toward NextGen Integration-

    Forward-Looking TACO:

    The TACO Draft focuses mostly on near-to-mid-term AWE R & D. The forward-looking capabilities referenced below derive from the NGATS Vision Briefing of 2005 toward the NextGen Airspace CONOPS for 2025. Mature Tethered Aviation Operations (TAO) shall conform to these standards-
     
    Notes:
    Supervisory Override of Semi-Automated Flight is a bridge technology
    NextGen's Moving Constrained Airspace is a capability needed for Tethered Free-Flight development 
    EVFR rules for relaxed visibility will widen the TA flight envelope & be a bridge to Autonomous IFR .

    NASA-FAA Research Transition Teams - JPDO Presentation - Master ...


    Group: AirborneWindEnergy Message: 2854 From: Muzhichkov Date: 1/7/2011
    Subject: Dragon kite for tether
    Some ideas about advantages and problems of using Dragon kite like tether system. Shortly:
    1. A cable isolation feature increases by two strand separation of the small kite sides.
    2. Small kites decrease stretch of cable.
    3. Indication of tether in the sky.

    Some more on on awenergy.ru

    Alex Mu

    Group: AirborneWindEnergy Message: 2855 From: Joe Faust Date: 1/7/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Group: AirborneWindEnergy Message: 2856 From: dave santos Date: 1/7/2011
    Subject: Re: Dragon kite for (pumping ladder-mill)

     

    Alex, Nice thinking about conductive tether problems, but its going to be very hard to beat the safety, high-transmission-efficiency, power-to-weight, & power-to-drag performance of mechanical tethers, especially to high altitudes.

     
    The particular Chinese Dragon kite video you embedded is excellent to show how the entire dragon is easily powered/depowered by adjusting AoA. This is all it takes to make a great Pumping Ladder-Mill, just put a small servo or mechanical flip-flop with a horn pulley shifting tension between leading & trailing lines & one switches a large amount of power.
     
    Note- this dragon is actually flying pretty stable, those stick-&-tuft stabilzers really work.


    Group: AirborneWindEnergy Message: 2857 From: Pierre Benhaiem Date: 1/7/2011
    Subject: Re: Dragon kite for tether

    Alex,

    Dragon kite could make a good association with a static flygen like  Sky WindPower Corporation  for very high altitude and great density of energy.

    PierreB 


    Group: AirborneWindEnergy Message: 2858 From: Pierre Benhaiem Date: 1/7/2011
    Subject: Re: Reliable Kite Auto-Pilots
    DaveS,

    It is a great chance Massimo posts on the forum.I hope KiteGen will want
    to continue to post...

    PierreB

    --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@... wrote:
    comparable to the Typhoon Eurofighter example you chose. The
    launch-&-forget kite problem is actually far more complex. For example,
    the Typhoon's is still only a "pilot-assist" autopilot, & cannot even
    land itself (approach only), or perform many other basic mission
    operations, without a human. No autopilot has the sensors or judgement
    of human procedures. This is why kite-pilots are needed for large AWECS
    for years or decades to come.
    predict breaking-gravity-waves or gustnados (do your sensors even detect
    such common events)? When these invisible killers hit a kite, its
    tumbled as if by a washing-machine, with actuation overwhelmed. If the
    current prototype Stem control-model lacks such features you must expect
    to be picking the kite out of the trees.
    even in a straight and level flight in calm weather condition, they
    cannot be controlled only by human input, without the aid of a flight
    control system and computer.
    Group: AirborneWindEnergy Message: 2859 From: dave santos Date: 1/8/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Pierre,
     
    I hope my low opinion of the robustness of early NLMPC AWE does not offend Massimo & apologise if it does. Its certainly not a personal jab, as i am a great fan of both MarioM & Massimo. Mario was a special pleasure to meet & assist with a computer power supply problem at HAWP2009, & i saw him off at the airport. This is perhaps the top team in AWE, with many a first, & the new Stem powerplant does have a lead role. WOW may be the merit-based leader of major commercial AWE development.
     
    The control issue is critical to the success of the AWE field. As it becomes publicly known that many of the "leading" teams are unable to sustain safe automatic operation, particularly the large high-speed aerobatic electric VTOLs, our entire "industry" will suffer (more). KiteLab & Massimo's choice of bare kites controlled from the ground is at least far safer, & is just one of many "common sense" design precautions worth applying.
     
    All of us have myths we believe, which we need each other to shake off. An example is some high speed platform designers claiming that speed itself is a reliability feature, as the fast-moving kiteplane "cuts through" turbulence. This a partly true, but a fast looping or figure of eight patterns do contain dangerous low-altitude high-G fast phases & slower phases of vulnerability at the top(s) of the manuveur which combined with a high stall speed & possibly slack tether make for high vulnerability (Kitelab's finding is that the slow phase at the top is the time to recover the bit of distance lost downwind during the fast phase. We also face an upcoming NASA finding that "long-reeling" methods are disadvantaged, as an airspace use issue.).
     
    The turbulence danger is mostly based on the vorticity's characteristic dimension, intensity, & helical path. Strong vorticity close to the scale of the kite, or its swept pattern, strongly couples with the kite, & if it has the wrong handedness & "killer" orientation, can take over flight. To our knowledge no NLMPC model yet includes realistic turbulence of this sort (KiteLab generally proposes that hot kite elements be teamed up in large 3D latticework structures that span across most killer turbulence & that the array land or furl when predicted synoptic conditions warrant.)
     
    The Italian Carousel has a particular vulnerability, especially on downwind/upwind  legs, to single-point failures. A single kite control loss has the potential to wrap around the moving track & bring the whole to a stop. Historic kite accidents (100yrs ago) stopped a ship & twice stopped trains. When the requirement is to fly many kites, in close overlapping proximity, the control challenge explodes. When hundreds of AWECS enter the field any weakness in control will emerge with a vengance. There is also a question as to whether the admirable Stem retract cycle can avoid fouling during hundreds of repetitions.
     
    The hope is that we can all pull together around the major AWE challenges, rather than be divided by honest differences in technical opinion,
     
    daveS
    From: Pierre Benhaiem <pierre.benhaiem@orange.fr
     



    DaveS,

    It is a great chance Massimo posts on the forum.I hope KiteGen will want
    to continue to post...

    PierreB


    Group: AirborneWindEnergy Message: 2860 From: Muzhichkov Date: 1/8/2011
    Subject: Re: Dragon kite for (pumping ladder-mill)
    Dave, do you mind something like this?
    http://www.youtube.com/watch?v=rkDn_jXDXwE

    Everybody, please leave comments about this kind of AWECS. Whitch problems can be with this scheme realisation?

    Alex
    Group: AirborneWindEnergy Message: 2861 From: KITE GEN / Ippolito Date: 1/8/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Dear Dave,
    Sorry, I have some difficult to follow you in a polemic exchange, so let me to try to align your concerns and shape answer in a more schematic way.
    I hope this could cool down our high level confrontation, it emerge clearly you are proficient on this domain, don't worry.

    *strange wonderful claim*
    I'm modestly advocated a general status of the art, I avoided to claim my own progress, I prefer to spend well exposed rational thought (with my limits) and eventually facts.

    *human loose control*
    I've loosed the control several times with the KSU prototype, destroying an analogue number of equipments, but if I analyse the events they have always a clear and rational explanation:
    -boring time, after several hours of continuous flight, with the kite appearing like a small dot in the sky, everybody look for newer experience, "pushing the envelope" seems the right expression; 
    -with short line and operations or fly near the ground, the reaction times to be effective are tight (the KG stem address this issue elevating of 25 meters the kite/ropes, useful for more secure ground handling, take off and landing);
    -mechanical equipment fault due overcharge, we are handling actual energy, a better dimensioning was required ;
    -control software experimentation and debugging on field, (this is our unavoidable job). 

    *turbulent hight or low condition, gustnados ecc.* *developing time*
    Here I have to stress again about the availability, the AVECS minimum goal could be to reach quickly the current renewable performances, in terms of economics.
    If I compare a 400 tons windmill with a 40 tons KG Stem, both 3MW it result clear that a first target of 1500  hours/year (average availability of wind turbines) will be a huge initial success, several times better the established break-even.
    This availability requirement means to fly slight more than one day per week. 
    It appear that could be easy to avoid extreme operative conditions, ad it is mandatory to start in the meantime a virtuous circle of development to improve up to the theoretical 6000 h.
    Remember,  with the two lines configuration, just in case, it is easy to get out from trouble conditions in few seconds, annihilating all acting forces with the side-slip.
    To reach the full productive result do you foresee a decade?, not a problem, it will be one the most exiting technological evolutions to live, well supported by productive, even though primordial, AWECS machines.

    *sensors uncertainty*
    The sensor fusion, virtual sensors, oversampling, high redundancy are the obvious answer, the KG Stem is buried of sensors the mast itself is a sensor, the wing is full monitored, all sensors, force, acceleration, orientation, gyro ecc. converge to update a real-time model that provide the combined info to the control.
    No in this case I can claim that the sensors are definitively not a problem.

    *actuator-bandwidth and actuation overwelmed*
    This must be a design concern, in the KG Stem is always available an actuation peak power of almost 8 MW(the alternators are also actuators), and the actuator Bode graph phase invert at 30Hz, we expressively adopted the carbon fibre drum, the torque motor-alternators in order to fulfil the high band requirements.
    Thank you to come out with the actuator actual overwhelming issue, it was, during the design time, a vivacious battle I did. The huge actuating power of the KG stem is become a specific feature.  

    *no reliable automation [existing] in mass production -low dimensional and linear controls*
    I agree with you, but there are a lot of independent clever works,  Boston Dynamics developed a control far superior to the kite control requirements. But it is a brand new concept, a control science that you couldn't study at school.
    Big Dog is one of the most vivid example:
    http://www.youtube.com/watch?v=W1czBcnX1Ww
     
    *what successful autonomous control system identified*
    I was obliged to start from scratch, I've started early to write the control and was soon clear the need of some teraflops computing power, So I decided to address the problem acting in other direction.
    A very big machine like the 3MW KG Stem that could be equipped up to 250 square meters wings.
    The very low inertia of kite and the nervous behavior is greatly mitigated with large kites, bringing the computer power requirement, far beneath the limits of feasible. This is the answer of another infinite discussion with a lot of people that is asking me to develop a very small KiteGen.
     
    *pick the kite out of the trees*
    this I think will be inevitable, but I'm confident to have up and running the procedure of analysis and redress .
    Anyway the first mission of autonomous control must be the operations security and reliability of take off and landing, in comparison, to auto-choose the right path in airspace to be productive is like a promenade.

    Massimo

    Group: AirborneWindEnergy Message: 2862 From: dave santos Date: 1/8/2011
    Subject: Re: Dragon kite for (pumping ladder-mill)
    Alex,
     
    I was thinking about other known mechanisms (like Dave Lang's reel concept), most of them more complex. You seem to have hit on a very clever simple solution, the only suggestion is to use an eccentric flywheel mass to set the crankshaft to an opposed-phase for self-starting. A tunable flywheel might be needed to adjust to varying  resonant frequency at different wind speeds. When you refine your animation you might make a nice looping GIF to run "perpetually".
     
    This design can be tested with just a single kite & would be a great advance for Low Complexity AWE if it works as well as it looks.
     
    daveS
     

    From: Muzhichkov <muzhichkov@yahoo.com
     

    Dave, do you mind something like this?
    http://www.youtube.com/watch?v=rkDn_jXDXwE

    Everybody, please leave comments about this kind of AWECS. Whitch problems can be with this scheme realisation?

    Alex




    Group: AirborneWindEnergy Message: 2863 From: KITE GEN / Ippolito Date: 1/8/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Dave,
    a technical opinion typically looks different, you're repeating with some insistence:
    it is difficult, it is very difficult, gustnados are dangerous, turbulence is a killer, control is impossible, evething is vulnerable and so on. But it is missing an explication, an accomplished and elegant thought, perhaps adding  your solution path.
    All your fear could match with normal aviation, so I suppose you never took a flight!
    Wait a moment...., Now, I reveal you a secret: "I know very well that AWECS are a quite complex adventure, perhaps the reason that is not a reality yet, 40 year after the moon landing, suggest that it isn't so simple, isn't it?".
    unfortunately, the tropospheric wind is the last hope to sustain the human life and civilisation without cooking the planet, so somebody have to look for the exploiting opportunities, it is a mission. 
     
    please could you now explain more in detail:
    The reason of fouling risk during hundred repetitions of the same KG Stem cycle?

    what kind of effect could have a turbulence on a flying C shaped kite, subjected to a constant and artificially stabilised axial force of hundred kN?

    and why you see such vulnerability on the downwind/upwind legs of the Carousel?
    Before your answer let me say, that fully understand the Carousel is an overwhelming mind effort without set-up and playing a complete simulation, one of the main reason of the difficulty is the 3D fly freedom of each kite.
    Myself, I have discovered the Carousel itself, the best design and all the properties, only building and running it in a graphic/physic engine with an autonomous control.  

    Massimo

    Group: AirborneWindEnergy Message: 2864 From: dave santos Date: 1/8/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Massimo,
     
    Boston Dynamics' Big Dog is a great example of complex expensive & ultimately still brittle autonomy. I have been a fan of Marc Raibert's legged robots for thirty years & we attended many of the same AI & robotics conferences. His state machine designs are maximally elegant & strongly influenced my own high-DOF robots. While rough terrain is a challenging robot environment, windfield chaos is far more dynamic & complex, & the CFD problems are far less tractable, so we need to rethink control (see Chris Carlin's bottom note).
     
    You wrote-
     
    Could you now explain more in detail the reason of fouling risk during hundreds of  repetitions of the same KG Stem cycle?

    Group: AirborneWindEnergy Message: 2865 From: Pierre BENHAIEM Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Dave,Massimo,

    Fascinating debate.I learn all days.I do not know anything about robotic and try do understand.

    -Big Dog:mobile object,non variable environment (excepted foot stroke).

    -UAV:mobile object with its own motorisation,variable (airspace) environment.
     
    -AWE:mobile object which environment and tether are "motor",variable (airspace) environment,permanent or very long time operations
    .

    What tells Chistopher Carlin seems pertinent.And also it:“Progress will consist of large high-dimensional real-world wind data sets applied to realistic kite models rich with failure-mode states to actively avoid.”(Dave Santos) .

    So a question to Massimo:when the KG Stem will work at first,do you consider a progressive period where local features of winds and other meteo events in the swept area (environment) are analysed with sensors, allowing for example a sthocastic process to conduct kite steering with enough predictive interpretation of local wind datas?For a fisrt time crashs would be unavoidable but with time and improvment of stochastic process (with more and more datas) crashs would be in an acceptable proportion (in absolute and also according to public perception)?

    PierreB   





    Group: AirborneWindEnergy Message: 2866 From: stefano.cianchetta Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    I probably know less than you about robotics but, as i see it:
    -Big Dog is a mobile object, facing a continuosly changing environment and forces. From the dog point of view a foot stroke is not so different from continuously finding an equilibrium while walking on slippery rocks. A foot stroke is as unexpected as an icy surface (http://www.youtube.com/watch?v=W1czBcnX1Ww at 1'25'')wich is a non-variable environment, but only from a "static" and "external" point of view. It does not seem that the bigdog has or needs an "a priori" highly detailed model of his environment.
    For a kite could be the same: it will face an unexpected "icy" wind gust and try to recover equilibrium as fast as possible and without permanent damages.
    But, does the kite has the same number of "legs" and "feet" to recover from a severe wind gust?

    Stefano


    Group: AirborneWindEnergy Message: 2867 From: KITE GEN / Ippolito Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    dave,

    Sideslip;
    the kite roll during the retracting phase, certainly happen with this kind of kites, the first effect are the lines crossing, this isn't a problem because with a max. of about ten twist the control actuation is unaffected.
    After that will be easy to unwrap during the following resumed flight, a twist counter is provided by the sensors model.
    The risk to wrap around the kite itself depend of the length of the loose line, the actuators drive precisely the line differential close to the length of the wing span.
    It could be possible to add a stabilising drag on the loose lines that appear only during the side-slip, in order to keep a minimum distance from the kite itself.

    Turbolence on kite:
    Sufficient strong turbulence appear typically at lower altitude and in specific conditions, so this is an issue that could affect the system availability.
    Experience tell me that the laminar flow condition in altitude is more frequent and stable.

    Carousel:
    obviously the wind reverse in downwind and increase in upwind, but only at the leg level not at the kite altitude, The reeling-in/out and mostly the 3D path of the kite provide geometrically the needed variation in length of  the component parallel to the wind, without spending energy. 
    from the point of view of the kite, the fly conditions all around the carousel are the same. 
     
    Chris note:
    I agree with Chris, a stabilised axial force on kite allows to have only a pre-set, a single attitude set-up point, apparent speed is stable, reaction time is predictable. this eventually make superfluous the kite model.
    Only in the phase of take-off it is required a different set-up and it could be asserted with a bridle programmed elasticity.

    Massimo



    Group: AirborneWindEnergy Message: 2868 From: KITE GEN / Ippolito Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Pierre,

    The remarkable behaviour of big dog is the recovering time, with a lot of precise decision to taken in a very small time.
    We are not interested in wind data set, the good wind to fly is artificial provided by the lines management, if the wind is stronger the reel-out will be faster, and vice versa, the kite side condition are stabilised.
    The crash is always possible but only for failures or errors during the set-up time.

    Massimo





      



    Group: AirborneWindEnergy Message: 2869 From: KITE GEN / Ippolito Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Stefano,

    I agree.
    Yes the system, lines and actuation, kite,  has enough resource to recover from any kind of situation, get out from a side-slip recovering the normal fly is a good demonstration, as documented in the movie. 
    Massimo


    Group: AirborneWindEnergy Message: 2870 From: Pierre BENHAIEM Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Thank for the explain

    PierreB




    Group: AirborneWindEnergy Message: 2871 From: mmarchitti Date: 1/9/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Dave, a traditional aircraft can fligh also inside high turbulence conditions: I think we all have experienced the shaking effect that produces the phenomenon inside the aircraft cabin, and in small aircraft it is more remarkable. The weight and geometry configuration of a traditional aircraft stabilize the flight after it has been perturbated, without touching the command.

    Very different are the unstable aircraft, that show the instability characteristic in pitch control. However, imagine for the yaw control to move the fin from the rear fuselage to the front: in that case you will have to continuosly and very rapidly operate with the rudder, also in very quiet weather condition, impossible to do with human control... well it depend on the degree of instability.

    I mean that control law techniques today are very elaborate and accurate, and I think they can solve the kite flght.

    Just to be precise: the "autopilot", in the aeronautical jargon, is the system that authomatically follows a route or keeps some flight parameters as the speed, the altitude ecc. Whereas, in our case, the flight control system is the correct name. The difference is remakable: in the automotive situation the autopilot could be the constant speed device, whereas a sort of drive control system could have been the active shock absorbers.

    Group: AirborneWindEnergy Message: 2872 From: harry valentine Date: 1/9/2011
    Subject: Re: Kitegen Carousel - Russian research precedent
     Many years ago, a Russian research team proposed a very large VERTICAL-Axis wind turbine . . . . . they proposed to build a circular railway track with wheels on tracks to carry horizontal and vertical loads. Each railway car was to carry an airfoil.
     
     
    Perhaps there may be a way to combine the Russian circular railway track proposal with Kitegen's airborne multiple kite system . . . . with axle-mounted electrical generators producing the power. A large diameter path could provide for more space between much larger kites.
     
     
    Let us hope that the research team in Torino, Italy will be able to solve the control requirements of the multi-kite concept.
     
     
    Harry

     



    Group: AirborneWindEnergy Message: 2873 From: dave santos Date: 1/10/2011
    Subject: Re: Reliable Kite Auto-Pilots
    Massimo,
     
    Allow me to assert that we are not actually debating, just clarifying details, as i greatly admire your work & consider us to share core AWE design philosophy.
     
    "Autopilot" is traditional nomanclature & still covers the subject we are discussing (fully autonomous flight, including take-off & landing). "Flight controls" is the superset (including engine controls, control surfaces & linkages, etc.). I come from both a robotics & aviation background & will continue to use "autopilot" as a proper term for any autonomous flight controller. Perhaps you mean that a kite is not an aircraft, which was the FAA default postion, but we know it is, & the FAA is now ready to agree-
     

    Aircraft flight control system - Wikipedia, the free encyclopedia

    Turbulence is not a trivial aviation issue. It continues to drive flight procedures & pilot training, & cause accidents. In particular CAT (Clear Air Turbulence) is an issue for visual piloting, as it can occur unexpectedly & invisibly. Avoidance is the primary strategy & few are aware how often modern aircraft still change airspeed, altitude, or course, to stay in smoother air. Our challenge is to fly 7/24 in the inherently turbulent Boundary Layer that most aircraft avoid. A dedicated kite flyer soon learns turbulence is a real challenge.
     
    A note to Stefano about Big Dog on ice: Yes, ice is a non-linear trigger (stick & slip physics). Marc's early robots where single legged pogo-sticks & would fail the ice test, but a four-legged robot is far more robust, due to the redundant legs. This effect is not a breakthrough in advanced controls; a centipede, after all, would do even better on ice. Similarly, kites teamed together in trains & arches exhibit what KiteLab calls Aggregate Stability, where the local chaos of a single kite is cancelled out by the overall stability. This is a great illustration-
     
     
    daveS
     
     
    PS let me know if these links are breaking when pasted
     

    Group: AirborneWindEnergy Message: 2874 From: Pierre Benhaiem Date: 1/10/2011
    Subject: Re: Welcome Dave North
    Hi DanP,

    Thank for the information.I am looking after stepper motors but it seems
    that rpm is too low for my use (+ -150 rpm for a printer);my motors are
    too quick (12 V for 12000 rpm);I look after a light 12 V, 2 to 5
    A,DC,for between 3000 and 7000 rpm.

    PierreB

    --- In AirborneWindEnergy@yahoogroups.com, Dan Parker
    <spiralairfoil@... brushed motor speed 600 9,6 V (195 g,no gear,max.efficiency as motor =
    75 %,as generator the same);Master propeller 9x4 or Graupner super nylon
    9x4,8x4,7x4 on Graupner speed 500 (158 g, max.efficiency = 67 % and much
    less from 6 or 7 V); Master propeller 16x10 on speed 600 FG3 (gear =
    3:1).Efficiency of propellers (reverse position as wind turbine):from 40
    to 50 % Betz limit in the good range of use (from 12 m/s to 30 m/s).
    the moment I have a linear regulator for 6 V with 55 % efficiency,and a
    switching regulator with only 45 % efficiency.My motors-generators make
    6 V but I would prefer a 12 V generator (with low value of A).
    wrote:
    kite so much that I suggested to three high school students that I am
    mentoring that they try to duplicate it as their technical school
    project. They decided to take on the challenge and have also decided to
    design and build the kite with radio control (kind of like what Makani
    and Joby are doing, but on a $150 budget). Our first tests will be more
    like yours with two-line, manually controlled kites.
    motors? What did you use? I know there are several suppliers out there,
    but most seem to be moving over to brushless. We bought a few E-Flite
    motors and gear boxes, but they are cheap quality can-type motors with
    really bad efficiency. Also, any suggestions on off-the-shelf props that
    can be used (backwards) as turbines without too much loss. Not wanting
    to have the students design their own turbines, as this could be a whole
    other project.
    pierre.benhaiem@ wrote:
    Group: AirborneWindEnergy Message: 2875 From: dave santos Date: 1/10/2011
    Subject: Carousel & Kite Control Notes

    Some of these notes are in the spirit of Diehl's famous AWE Conjectures; some are review-

     

    ======================

     

    Its harder to fly a kite from a carousel wheel (especially lots of kites doing the Tango) than from a fixed anchor. The quantity of kite is directly limited by carousel diameter.

     

    A nice option is to operate kites next to the wheel, rather than crowd kites on it The carousel can then be far smaller & operate as a pure generator cranked up to TGV speeds. Kite failures remain isolated away from the wheel. This carousel variant can be built with less material, lower capital cost, & less operational risk. It can even be roofed, with all kite-power cableways to the crank buried.

     

    =======================

     

    Useful actuation-bandwidth for a "servo-kite" is its ability to act faster than a disturbance. While a large kite has a slower control-rate, based on its lower fundamantal harmonic, a micro-meteorological disturbance still propagates across any size kite at the same speed. Therefore one must move the control line just about as fast (m/sec), especially to prevent common luff/collapse. A high-speed winching capability is needed, but this trades against high-power winching.

     

    A solution is to "punch turn" the kite, where the "outside" line is simply loosed & plays-out by kite pull, which makes for fast turns with little or no actuator power. One must have some line on the reel (or some give to a steering boom) like money in the bank.

     

    =======================

     

    A "killable" kite like the stem uses does not need super-strong actuation, unlike a non-killable kite, which must be hauled in powerfully in rising wind. Still, the prototype stem's powerful steering servos will serve longer. accept larger kites & enable experiments with non-killable kite rigs.

     

    ========================

     

    Aircraft Re grows faster by size than it diminishes by lower dimensionless velocity (?).

     

    ========================

     

    "Flight-Controller" may be used interchangeably with "Autopilot". "Controller" is common usage in embedded controls & robotics.


    Group: AirborneWindEnergy Message: 2876 From: harry valentine Date: 1/10/2011
    Subject: Re: Kite Control Notes

    The reel-in, reel-out kite control concept can be adapted to drive a lever-and-crank mechanism
     . . . .  i.e: the control line pulls against a lever that pushes a cohnecting rod to drive a vertical crankshaft. Using geometry, it is possible for a lever pulled over an arc of 45-degrees to drive a crank beyond 180--degrees . . . . 2-kites pulling on levers that drive cranks could maintain positive torque on the crankshaft through 360-degrees of rotation. The crankshaft may also drive a flywheel to maintain inertia.
     
     
    While the carousel concept allows for the use of multiple kites, there would be possible application for 1-kite and 2-kite power generation installations.
     
     
     
    Harry
     
     
     
     

    Group: AirborneWindEnergy Message: 2877 From: Pierre BENHAIEM Date: 1/10/2011
    Subject: Re: Carousel & Kite Control Notes

    DavesS,

    "A nice option is to operate kites next to the wheel, rather than crowd kites on it The carousel can then be far smaller & operate as a pure generator cranked up to TGV speeds."

    Carousel diameter (it is the same thing for OrthoKite and generally) is the result of radial velocity (lever) or tip speed (ring) and the torque.So its diameter is the result of chosen trajectories of kites and the length of tethers,according to the wanted power of kites,according to wanted altitudes.With a smaller diameter and identical trajectories you cannot obtain the same power:trajectories are the same while trajectory of ring descreases,so its tip speed.Following it with no diameter kites are towing without operate any powerful conversion.

    A question:is the kite pilot (maybe terms of "lifter kite" are better) an example of autopilot for "passive control" of a kite system like,for example the "tripod" configuration? 

    PierreB 



    Group: AirborneWindEnergy Message: 2878 From: dave santos Date: 1/10/2011
    Subject: Re: Carousel & Kite Control Notes
    Pierre,
     
    You are right; the single-line kite (pilot-kite) is truly Autopiloted. This is what Sir Clarke meant when he asserted "any sufficiently advanced technology is indistingishable from magic". Paleo-tech's cybernetic flight capability for AWE is far in advance of anything even NASA has going (Mark Moore proposes triple-redundant electronic flight controls). The classic kite's "passive-aggressive" control ;^) is quantum-phononic field-computing. Its far cheaper & more robust than conventional aerospace controls; a child can make & deploy it. But there is always a control cost-to-performance, whatever method chosen, as predicted by Information Theory & Thermodynamics Law.
     
    daveS
     

     

    Group: AirborneWindEnergy Message: 2879 From: christopher carlin Date: 1/10/2011
    Subject: Re: Reliable Kite Auto-Pilots
    I don't disagree that very difficult control challenges can be fixed with sophisticated control systems. However the control systems designer has a responsibility to push back  hard against aerodynamics and performance people who want to squeeze the last small percentage of performance out of a system and in the process create something that requires a sophisticated control system to operate. Developing the sophisticated control system including certification and providing redundancy if it's flight critical is almost certain to be expensive, time consuming, and heavier than might otherwise be the case. Bottom line select a kite system concept which is simple and stable. Figure out its performance. Then compare other more complex concepts to it. In order to select a more complex concept you must demonstrate that the net economic benefit including realistic control system development and hardware costs is really there. 

    It is the nature of the of the aerospace business to create complex high performance systems. As evidenced by the A 380 and the Boeing 787 they tend to have schedule delays because each piece of the system is stretching the state of the art to the maximum to gain a competitive advantage. I could site many examples of military programs with similar problems and also some wave power generation systems which have had inordinate delays. I can also site two of the greatest development efforts in terms of getting a new technology into production quickly. One is George Stephenson's invention of the locomotive and railway system. The other is Bill Gate's introduction of software for PCs. Both initial deployments were far less than optimal but they got to market first and became commercially successful as a result. In Stephenson's case Brunel's competitive broad gauge system sank only to reborn almost 150 years later in the TGV. In Gate's case Apple's superior product was almost sunk by Microsofts lower acquisition cost although it is now doing well.

    My point is forget fancy concepts. Go with something easy and relatively inexpensive to build, deploy and control. Wherever possible use existing hardware. I agree with the definition of autopilots and flight control/stability augmentation systems. Ideally you want a kite system which if it needs control at all only needs an autopilot. The basic system needs to be inherently stable and able to ride through turbulence on it's on. 

    Chris    
    On Jan 9, 2011, at 9:45 PM, mmarchitti wrote:


    Group: AirborneWindEnergy Message: 2880 From: Dave Lang Date: 1/10/2011
    Subject: Re: Carousel & Kite Control Notes

    Group: AirborneWindEnergy Message: 2881 From: dave santos Date: 1/10/2011
    Subject: Re: Kite Control Notes
    DaveL,
     
    Sorry for the rant, Pierre pushed my button. I have not been the same since learning the Patent System drove Doug to sell speakers from a van.
     
    No, i did not think of the tether as a passive control, but it does after all regulate altitude, so thanks for the hint. Pitch, roll, & yaw of a single-line kite are controlled by true feedback loops created by mere bridling, tails, dihedral, etc. The toy kite is a perfect example of situated embodied logic & high integration. Its important to note this stick & fabric flying robot is even self-powered.
     
    What do you have against field-computing (except that nobody cares about it)? I know you prefer stress-wave view in place of phonon view, but the list of cool phonon interpretations is growing, including quantum behaviours possible in large scale string networks (more ranting). 
     
    So here is an attempted wave conjecture, that aeromechanical AWE is best created as a wind-induced transverse wave train in a wing structure that is optimally converted into longitudinal waves on the tether, & converted back into a transverse standing wave on the generator shaft. I am trying to design suitable low-loss (T<=
     
    daveS
     
     
     
     

    From: Dave Lang <SeattleDL@comcast.net
     


     

    Group: AirborneWindEnergy Message: 2882 From: Pierre BENHAIEM Date: 1/11/2011
    Subject: Re: Carousel & Kite Control Notes
    DaveS,

    See p.4 an other example of "pilot-kite" Kite Power Generation but for stabilization.
    It seems (at least) difficult to see an application of "pilot-kite" for systems like Carousel of Stem and others.

    "Pilot-kite" can be a good (small and quickly available in model airplane market) system for static AWECS where it becomes "kite lifter" of "lifter kite" (my english language!).

    For model airplane market you have a good example on KiteLab ,I have another example on Optimization of AWECS of type flygen (video Manual Flygen ).If theese products are successful,an acceleration of the development of great systems can be accelerated with the only possibility for numerous persons to see existing (even small) AWECS and also with description and annoncement of technological revolution,following it the description of some great AWECS in the packet.

    Note:it seems KiteGen aleady replied to Cristopher Carlin for some points:Bill Gates towards Stem;Apple towards Carousel.

    Other:the document from Dr Fort Felker  Dr. Fort Felker - Engineering Challenges of Airborne Wind ... is essential for procedures towards acceptability in regard to reliability of system.

    PierreB



    Group: AirborneWindEnergy Message: 2883 From: Dan Parker Date: 1/11/2011
    Subject: Re: Welcome Dave North
     
     Salute PierreB,
     
                        Stepper and Servo motors are wonderful, they produce hi voltage and low amperage, they will take whatever rmp you want to throw at them. Pierre, keep in mind there are much bigger stepper and servo motors then are found in printers, if you do a google you will find many go suppliers out there. Do understand that withing a stepper and servo are many alternating fields in most I believe 200 magnetic poles. The great thing about them is they will send down the line a very high frequency ac current which in AWE terms is a good thing as you can transmit high voltage ac on a very long skinny lightweight wire setup.
     
                                        http://www.mpja.com/products.asp?dept=101
     
     
                           I hope this helps Pierre, I send my best.                                                 Dan'l

    To: AirborneWindEnergy@yahoogroups.com
    From: pierre.benhaiem@orange.fr
    Date: Mon, 10 Jan 2011 21:43:35 +0000
    Subject: [AWECS] Re: Welcome Dave North

     


    Hi DanP,

    Thank for the information.I am looking after stepper motors but it seems
    that rpm is too low for my use (+ -150 rpm for a printer);my motors are
    too quick (12 V for 12000 rpm);I look after a light 12 V, 2 to 5
    A,DC,for between 3000 and 7000 rpm.

    PierreB

    --- In AirborneWindEnergy@yahoogroups.com, Dan Parker
    <spiralairfoil@...
    Group: AirborneWindEnergy Message: 2884 From: Doug Date: 1/11/2011
    Subject: Re: Kite Control Notes
    --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...
    Group: AirborneWindEnergy Message: 2885 From: dave santos Date: 1/11/2011
    Subject: Re: Carousel & Kite Control Notes
    Pierre,
     
    Its true that a classic pilot-kite is not suited to ride a carousel; its hard for any kite. But a carousel can be easily driven from fixed-anchor kite-cells around it. Then pilot-kites can be utilized with great results. In particular, one can suspend sweeping kites under them with all the passive stability benifits (& none of the major active-control negatives).
     
    Note that many Pumping Laddermill ideas, like the vari-Dragon kite & Pocock's never yet surpassed two-kite system, have inherent flight stability & can drive pulsed lines feeding a high-speed energy-carousel ( an ultra-high diameter, low RPM generator)
     
    The emerging picture, which Chris Carlin so ably painted, is that AWE systems with inherent flight stability are very highly favored. We now have a plausible end-to-end low-complexity conceptual solutions, maybe not performance-optimal, but ready to test against "fancy" concepts.
     
    daveS
     
     

    From: Pierre BENHAIEM <pierre.benhaiem@orange.fr
     

    DaveS,

    See p.4 an other example of "pilot-kite" Kite Power Generation but for stabilization.
    It seems (at least) difficult to see an application of "pilot-kite" for systems like Carousel of Stem and others.

    "Pilot-kite" can be a good (small and quickly available in model airplane market) system for static AWECS where it becomes "kite lifter" of "lifter kite" (my english language!).

    For model airplane market you have a good example on KiteLab ,I have another example on Optimization of AWECS of type flygen (video Manual Flygen ).If theese products are successful,an acceleration of the development of great systems can be accelerated with the only possibility for numerous persons to see existing (even small) AWECS and also with description and annoncement of technological revolution,following it the description of some great AWECS in the packet.

    Note:it seems KiteGen aleady replied to Cristopher Carlin for some points:Bill Gates towards Stem;Apple towards Carousel.

    Other:the document from Dr Fort Felker  Dr. Fort Felker - Engineering Challenges of Airborne Wind ... is essential for procedures towards acceptability in regard to reliability of system.

    PierreB