Human-Powered Helicopter Wins the $250,000 Sikorsky Prize
popularmechanics.com
popularmechanics.com
Interesting tidbit:
"The pedaling of the pilot pulls on and reels in four Vectran cords, which are pre-spooled onto each of the four rotor hubs. The action of unspooling the cord and pulling on the rotor hub drives each rotor to overcome the drag force."
Empty Weight: 55.1 kg All-Up Weight: 130.1 kg Flight Power (0.5 m): 450 W Flight Power (3 m): 750 W
I wonder if those wattage numbers are estimates or measurements.
About 1kw for the first 12 secs, then settling down to 600w for most of remainder. That's a boss ride, especially for a 70kg rider. Dude's a monster.
To put that into perspective, that's a chart[1] that some exercise scientists have put together that shows what power cyclists of varying levels tend to be able to produce. The data in the spreadsheet gives an average power of 708W for a minute, which equates to 10.1W/kg at 70kg, which puts him at the level of a category 1 racer or domestic pro.
Keep in mind that the ~1000W spike for 10s at the start of the ride probably harms the overall average, as a more constant power output generally leads to a higher overall average (or, higher power outputs are disproportionally harder).
Edit: according to the photo gallery in the article, Reichert is a nationally ranked speed skater in Canada, which is another one of the "big quads" sports.
1. https://s3.amazonaws.com/cyclinganalytics/static/cycling-pow...
Edit: spelling
These guys are lifting 130kg with ~750W...
[1]: 6.6Ahr battery @ ~14.4V, 95Whr of power. It'll go through that in slightly under half an hour, so it's pulling ~200W in hover. Small scale multirotors aren't very efficient. http://www.mikrokopter.de/ucwiki/FlugZeit#MikroKopter_als_He...
Whilst that may be true, don't forget that the energy output is in kinetic form, so for comparison you'd need to factor in the weight of motors, and for a "permanent" presence, some form of energy storage for night time use (and batteries are far from light!)
1 sq meter of monocrystalline cells (approximately 2kg) deriving about 166W/hr over a 6 hr solar "day" (1000 W.hrs) stored in LiFePo batteries (about 1kG/100 W.hrs) so 10kg of betteries, with .5 kg of electronics (battery charger) and wires, delivered over 24hrs or 12.5kg/41watts continuous. Human athelete lets call it 165 lbs, so 75kg, or 6 * 12.5 or 246 continuous watts over a 24hr period, or a total of just over 5.9Kwh per 24hr period.
So basically anything a human can power, an equivalent mass of solar power infrastructure can power. The interesting bit is of course that you can use it all at once (like a human sprint) or spread it out over time. It will have more surface area however which often limits the ability to just swap solar cells for other forms of power.
Bottom line connecting the human energy to motion is different but from a weight/volume standpoint similar in both cases.
Your batteries have to provide 600W continuous for 18 hours (actually more as that was the power needed for a controlled decent), and your solar panels have to provide that same energy in your 6 hour 'solar day'. In addition, the solar panels would need to provide another 600W for 6 hours in order to run the motors whilst charging the batteries.
So that's 10.8KWhrs of batteries, and 2400W/hr or 14.5sq m of solar panels.
That translates to 108KG of batteries and 29KG of solar panels using your weight to power ratios - 137KG in total, compared to the rider at 75KW, so your 24 hour solar bird is a sadly flightless before even adding motors, gearboxes electronics and cabling.
https://dl.dropboxusercontent.com/u/5093348/Draft%20Atlas%20...
More considerations are the additional power needed for control inputs and to resist wind, and to compensate for thinner air at altitude, and the weight of a craft strong anough to operate outdoors.
You could use low powered propellers (like a blimp), and take advantage of weather patterns (like Google's Loon project) in order to maintain position or to slowly travel.
I'm always surprised that these teams never seemed to try and recruit pro athletes for this kind of thing. I've got a friend who's a professional cyclist and his 30 second power rating is something like 1100 watts and I'm sure at a minute it's only degraded by 50-100 watts.
It's better to have an amateur who is 80-90% as good as a real pro, but is genuinely interested in the project and would be more dedicated than a hired pro.
If they have downtime I don't see why you couldn't find a pro that is genuinely interested in what you're doing.
But that's a very good point you've made. I obviously didn't even factor in price.
Also, how is powering the first human powers flying machine not good for a professional athlete's career?
Pros take risks, but I'd theorise that a part of the career would be managing those risks, to maximise the career. It would be very cool to power the first human powered helicopter, but I suspect we are not typical, in that the typical punter cares more about sport than a helicopter. From a professional point of view, the fame and returns from piloting a helicopter are negligible compared to the rewards of improving in the Tour or the Giro.
I'm descending into hot air production here, since I have no real evidence on which to base it!
"This attempt was made in accordance with the regulations of the FAI Sporting Code including the provisions of 5.2.2.3 on Unsporting Behavior."
and googling for that reveals:
'5.2.2.3 reads: "Unsporting Behaviour. Cheating or unsporting behaviour, including deliberate attempts to deceive or mislead officials, wilful interference with other competitors, falsification of documents, use of forbidden equipment or prohibited drugs, violations of airspace, or repeated serious infringements of rules should, as a guide, result in disqualification from the sporting event."'
So I'd guess for official World Record attempts (and probably for the prize rules) doping is out. (Sounds like the pilot has enough other sporting pastimes that he'd be unlikely to dope just for this project too…)
Shane Perkins, and Aussie track rider who is probably the strongest cyclist in the world in terms of pure brute strength, has a maximum output of 2500 watts (my guess is that is a ten second effort, they don't give it, but his 60 second effort is certainly higher than 1100 watts).
The more reliable measure is w/kg. Pros tend to range anywhere from high 4s (low-level sprinters or rouleurs) to mid 6s (world class TT'ers or climbers), with most being somewhere in the 5s. If la gazzetta's numbers are right, and if we believe Tony Martin's posted weight of 75kg, his 480 watts puts him at 6.4 w/kg.
Don't get me wrong, I'm nitpicking here, I was just noting those numbers feel slightly low.
On individual rides (e.g. http://app.strava.com/activities/66583736 ) there's a chart below the map which you can switch to show "Performance", check the "Power" checkbox and you'll see his watt output. Looks like today he cracked 1kw momentarily about ten times, and for an hour starting around ~1h30 in he never went below 200w.
I'd like to point out the distinction from professionally paid road racers and olympic-level track (velodrome) riders. Road riders are always travelling, generally pretty busy and would probably be hard to get for a project like this, but more to the point, don't train for this kind of maximal wattage output.
But in fact, the world record for the 1km time trial is right below 1 minute right now (58.875).... I read somewhere on the internet that world class kilo riders are doing <900 avg. watts to do a kilo. Not to mention the fact that these guys aren't really bothered by much outside an olympic year.
otoh, canada doesn't have any of these caliber of riders, afaik.
to me, the history of materials improvements is the history of materials characterization techniques.
so much of materials science is just trying to figure out the right lever to pull to control some property, and modern tools like electron microscopy, tga/dsc, xps, afm, bet, etc. all provide amazing insight that was simply unavailable 150 years ago.
but also, 150 years is a really long time frame. people were only just beginning to study material fatigue in the mid 1800s.
Exciting times to be a human.
On a similar note, for those of you who may not be aware, there has also been a human-powered airplane: http://en.wikipedia.org/wiki/Gossamer_Albatross
I am totally amazed by the Gossamer Albatross. It was made in 1979. And here's the most awesome part - a cyclist flew it across the English Channel!
'With the pilot using both hands and feet to power the aircraft, UMD faced a challenge developing a control system for the Gamera II. But an attempt to clarify the rule prohibiting energy-storage devices inadvertently opened the door to electronic controls being used on both the Gamera II and Upturn II.
AHS has closed the loophole, but both teams have until July to attempt winning the prize under previous rules.[0]
0: http://www.aviationweek.com/Article/PrintArticle.aspx?id=/ar...
Hopefully, the same people who are causing the accidents in cars won't be able to directly control the helicopter.
A car wreck slowing traffic down to 10% on a freeway is preferable to death looming from the sky because someone really needs to check twitter right now.
That said, gyro-copters have excellent fail safe properties (then can autorotate/glide to a landing without power) when controlled by someone, or something, committed to operating them safely.
Autogyros fly in constant autorotation (hence the name), the main rotor being unpowered.
Imagine the commuting public of the New York City region, all in the air above Manhattan.
Scheduled commercial airline flights are quite safe, which makes people think "flying is safe", but general aviation, which lacks many of the strong controls that scheduled airlines have, is much worse[1]. I would expect flying cars under manual control of typical drivers over a crowded city to be much, much worse still.
Batteries are pretty heavy, Solar panels might be too.
I don't think we'll be seeing electric helicopters with any practicality until battery tech gets much, much better. I can't really even think about possibilities unless it gets at least 5x better with 10x being more interesting.
Nobody literally goes over a pre-drive checklist before driving down to the grocery store.
If you built electric motors for a chopper you could theoretically design so that it had 8 motor any one or two or three of which could fail and still fly. Make several different independent battery packs and you enjoy more robustness. If you engineered it right you could make the case to the FAA that the helicopter doesn't need any expensive preventative maintenance on the motors or batteries, just on the drivetrain. Which would save a lot of money.
EDIT: "most helicopters" to "most big helicopters"
Edit: Corrected typo noted below - "skull" to "scull" - oops.
http://rowingbike.com/site/EN/ shows a bike operated using a rowing motion. That machine is competitive with 'normal' recumbent bikes, except in climbs. The main parts also could be fitted on that Decavitator. I would expect similar speeds.
Cycling is, among many things, very smooth, which helps when dealing with such delicate machines.
Source: Powerlifting cyclist here. :)
As one of the people that donated to the Kickstarter this make me very happy!
[1] http://www.aerovelo.com/2013/07/11/aerovelo-officially-award...
- former HPH member
I suspect there are (other) people out there now thinking things along the lines on "Hmmm, made from balsa and foam covered in poly film, prepreg carbon tube, kevlar tow, epoxy and cyano. All pretty common high-end but regularly homebuilt model plane techniques. 10m long rotor blades are big - but only 2 or 3 times longer than pretty common competition rc glider wings. There's a very reasonable chance that the right group of comp rc glider builders and quad rotor hobbyists could build something that weighs maybe only twice what this does, and has 5 or 10 times as much power available - probably for a budget of not much more that $10k."
I don't think "hardcore hobbyists" will be pedaling one of these anytime soon, but flying something similar electrically is certainly not an impossibility.
What's next? Lighter materials? I'd love to play around with something like this and not have to be a world class cyclist.