Volocopter – The world’s first green helicopter | Hacker News Reader

Volocopter – The world’s first green helicopter

e-volo.com

33 pointssasvari51 comments

Cool stuff. However, the first thing I wondered was "does it use variable pitch props so I can get it to autorotate?"

    Our volocopters are fitted with a rescue system in the form of
    a parachute which safely lets the entire aircraft sink to the ground
    in the case of an emergency. At helicopters in contrast, is the main
    rotor in the way.

-- http://www.e-volo.com/information/safety-concept

This (combined with an emergency back-up battery) is probably better than a traditional helicopter for low-altitude power failures, but worse for higher-altitude. With a main engine failure at sufficient altitude, a helicopter pilot can reverse the pitch of the main rotor so that it builds momentum while the craft falls. During the decent the pilot also has control over the craft, so he/she can hopefully avoid trees, power lines, etc. Finally, at the end of the decent the pilot is able to reverse the pitch of the blades again, turning the stored momentum back into downward thrust, safely landing the craft.

I think lack of autorotation would make this idea dead in the water. Very low altitude failures would also be dangerous, as parachutes are hard to deploy without a few hundred feet to spare. Also currently, all single engine helicopters must be able to complete an autorotation to get certified. I'm not sure where this would stand though, since it may end up as an experimental category aircraft.

A clarification for those who haven't seen one, an autorotation is less about falling than gliding. You have very good control, though you do only get one shot at the landing. A quick search brought up this video with a few landings: http://www.youtube.com/watch?v=E2a9H8Xw8Mo

Yes. Also, Smarter Every Day's Helicopter Physics series on YouTube had one of the best explanations of autorotation I've seen: http://www.youtube.com/watch?v=k7u8m0Qpn38

Didn't I just see a story about quadcopter design, and how helicopters were actually more efficient due to the single large rotor?

Here it is: http://www.geek.com/science/weve-been-designing-quadcopters-...

Traditional helicopters are also far more efficient in normal cruising forward flight. They can glide quite well, which is how you can safely land in the case of engine failure [0]

[0] http://en.wikipedia.org/wiki/Autorotation_(helicopter)

I wonder if, at larger scales like this, electric motors and batteries are unable to efficiently power a tradition helicopter design (one main rotor and a small tail rotor).

Batteries are less energy dense (J/kg) than fossil fuels at any scale. For flight applications this makes batteries not so great because reducing weight is so critical. This becomes especially pronounced for larger aircraft sizes. You also don't get the weight reduction as you burn off fuel. For tiny RC aircraft the short flight times are fine, you can use cheap electric motors and they're safer. Larger RC aircraft are gas powered though.

the advantage here is the ability to have several (like 8-16 motors) so the failure of one motor isn't leading to a crash). It is the same paradigm shift as when horizontally scaled commodity hardware systems with expected multiple points of failure have almost everywhere replaced the highly-reliable Big Iron systems.

Another advantage is the possibility to have the propellers in ducts/shrouds (eVolo didn't do it, yet nothing prevents it) that is not doable for one big helicopter's propeller, thus such machine can fly near buildings/trees/etc... where helicopter can't. There is also issue of control in tight quarters where air flow is hard to predict and is affected by near by objects - multiple electric motors are much more flexible and faster reacting than one big engine+propeller.

Like with electric cars, the main issue is "range". It is solvable by having a series hybrid drive (especially once new gas engines specifically developed for series hybrids - ie. higher efficiency and lighter weight at the cost of power band - come to market). While such system willn't beat efficiency of 787 or fly transatlantic, it would be unbeatable for Santa Cruz to Mountain View commute.

Helicopters are pretty crash proof - the autorotation system is simple and very effective.

the autorotation requires a highly trained pilot and it is an emergency situation. Failure of 1 motor/propeller out of 16 is like a "low gas" warning, time to think about where to conveniently and casually land, instead of immediately autorotating down to whatever lake or heavy forested mountain you happened to be flying over.

I suspect it is more the availability of motors. Bigger than that and you are going to want to build them yourself because the price will be astronomical and nearly everything you will be able to get will be for the marine industry and weigh a ton.

http://www.yasamotors.com and similars. 75kw/27kg

Exactly what I thought of the moment I saw this.

Not only that, but the range for a battery-powered helicopter is going to be severely limited.

Green? Because it runs off batteries? Is that all it takes.

OK, but didn't we just have a discussion on hacker news showing that helicopters with one large blade are more efficient than ones with many smaller blades?

It's easy to ignore where your power's coming from when your vehicle's not burning fuel-- in the US, ~40% from coal and ~30% natural gas.

Morality fades away when the results occur at a distance. Compare plugging into a socket to pumping gas, or buying cuts of meat to slaughtering an animal.

Centralizing power production, even in a coal-burning plant, is better for the environment than burning fuel locally (and extremely inefficiently) in a helicopter.

So just ignore the "emission- free" quote on their home page.

The helicopter is emission-free. How you power it is up to you. You have the option of using an emission-free source, which is not an option with normal helicopters.

20 minutes flight time, constrained by battery technology. They say it's 'conceivable' that there could be a considerable improvement in battery technology over the next few years to allow up to an hour of flight.

I hope so - both for cars and for mobile devices a 3x improvement in battery capacity per unit weight would be transformative. Imagine an iPad air at half the weight again, or a Tesla Roadster with a 750 mile range.

Just came across this article http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem... about an advance in silicon microparticle anodes for lithium ion batteries which claims a capacity of 3000 mA h/g, and retaining similar performance (~2000 mA h/g) over 100 discharge cycles. They don't mention the voltage, so it's a bit hard to compare energy density; at the 3.2 volts common to lithium ion batteries, that's 6400 watt hours per kilogram, but taking a look at some of the charts available (I can't look at the article itself due to the paywall) it looks like it may actually be .5 volts, which means 1000 watt hours per kilogram. Compare to Tesla's batteries, probably the best in the business, which give you ~130 watt hours per kilogram, and this could be a pretty big game changer. Obviously, they will have to improve past 100 discharge cycles, but it looks like substantial gains in battery technology may be coming within the next decade.

You mean, imagine an iPad too hot to touch.

Because we always optimize for performance, keeping battery on the bare acceptable minimum. With the newest trend to also seal the batteries to ensure that the device has a limited useful life.

While I often cringe at how terrible batteries are, the alternative wouldn't be that attractive for mobile devices either. Because we wouldn't have had the same focus on low power if we had decent batteries.

Do you seriously think that sealed batteries are designed to shorten the life of devices?

No, but there aren't any less pathetic reasons for it.

So you were being deliberately misleading in your earlier comment.

Wasn't meant to be taken seriously.

Just as I don't imagine that apple would create an iPad that was too hot for touch...

The gist, and my point is that it is easy to imagine an alternative universe with, for instance, much better battery tech, without considering how our bad batteries have influenced our.

Our batteries have forced us to focus on low power designs. Designs that also benefits from low heat output which also benefits from cheaper, smaller and quieter cooling.

That seems like a strange universe. I don't see why designers would suddenly disregard heat output or noise just because batteries were able to provide more power. Apple doesn't disregard these factors in their AC powered computers, so why would they do so in mobile computers?

Apple don't have much to say about these factors in their AC powered computers. They just buy whatever is on the market.

And that's exactly what the market did just a few years ago, "ignored" (in favor for performance) heat output - until it became a big enough problem.

http://www.extremetech.com/wp-content/uploads/2012/02/CPU-Sc...

Just before 2005 power consumption suddenly became a top priority (well, ok, earlier than that but it was around then the results were showing in consumer products across the board).

One can argue the same even with modern macbooks that get extremely hot when pressed. That's favoring performance over heat output. In a world were batteries were even worse that would not have been acceptable, now we live on the edge on how much heat we can tolerate.

Many of todays phones do get quite hot when gaming and with better batteries I'm sure it wouldn't exactly be less of a problem. Now we are saved by the fact that a battery time of 60 minutes wouldn't be acceptable in a phone and the goal is to get as much performance out of a device that has decent battery life. When battery performance goes up so does the performance of the phone - but not the battery life.

What are you talking about? Apple are renowned for striving to make quiet computers. And your comment about hot MacBooks directly contradicts your claim that heat would be ignored as a factor.

Really? MacBooks have never been quiet, apple don't want to pay the premium for low power chips so even if they tried they would fail (exception: MacBook Air).

Of course you have to take heat into account, but it's not like it takes priority.

Exception: the most carefully engineered and popular computer in Apple's history, regarded by many reviewers as the best laptop ever designed.

If you consider the MacBook Air to be an 'exception' then there is nothing to discuss. I can't really respond to comments that are in blatant disregard of the evidence.

The only, ehm, evidence you've put forward is claiming to the authority of "reviewers". I guess that works for you.

So you no longer consider the MacBook Air to be an exception?

Even the DoE is trying to help battery technology along with $120 million in research funding.

http://www.extremetech.com/computing/142155-doe-calls-for-a-...

Well, as research goes, $ does not guarantee to reach a specific outcome (it does help tremendously, though).

But there is a lot work done nowadays when it comes to batteries, fuel cell membranes and solar cells - so let us hope something will come out of it.

First time I read this I honestly thought they were talking about a helicopter painted green...

I wonder if this can allow for bigger sizes. The most common use cases for helicopters (transporting people like for medivac) can't seem to be filled by this. I did hear once about IBM using a helicopter to fly in a technician to some server farm to fill in a "on site in 60-minutes" contractual clause with a client.

From a quick look at it, it seems they are just fishing for investors. They have a cool looking prototype and use "green" in their marketing a bit too much. I couldn't find any studies or more detailed explanation justifying their design vs the traditional one.

These are the advantages and disadvantages I can think of:

Pros

* Probably much cheaper than a traditional helicopter - you don't need any complicated mechanical components like swash plates. * Increased redundancy would be much easier - you can wire up batteries in parallel, and it can no doubt fly with a significant number of broken propellers. The only other component is the microcontroller, which is cheap enough that you could have multiple copies of it. * Looks like you could fly it indoors fairly safely (in large buildings). With minor modifications it could be flown closer to buildings more safely than a traditional helicopter. * Easy to remote control, as already demonstrated in the video! This could make a great medical evacuation helicopter. * Should be virtually maintenance-free. The only thing I can think that you'd need to do is replace the battery.

Cons:

* Undoubtedly has a much shorter flight time than non-electric helicopters. * Lower capacity than (most) traditional helicopters. * Can't autogyro, so running out of fuel is much more serious! * Possibly costs more to run when you consider the cost of replacement batteries. Hard to say for sure.

It's certainly not a worthless design.

What's the point of flying it indoors!? And how many buildings you know are suitable, not to mention need, such an apparatus?

"However, a considerable advancement in battery technology is conceivable during the next few years, so that a multiplication of the energy capacity will occur within a short period of time. At present a battery flight time of 20 minutes is possible, but in the near future this will be extended to one hour or more."

What companies / people are working on new technology to make this true? We hear this with every new project, but it doesn't seem like enough people are choosing that as their goal.

There have been quite a few developments in battery and ultracap technology that seem pretty promising in the last few years, but it is one thing to have something up and running in the lab and quite another to bet on a particular technology and then industrialise the production process for global mass production. Luckily there is now money being waved around by the car industry that should see at least some of the developments enter the marketplace, which is what more specialist companies like this one are banking on, as they don't have enough money themselves to wave around.

I don't really agree with the 'green' hype, and banking on battery improvements etc. However, I think designs like this will become useful along with other forms of drone technology. This helicopter actually looks fairly cheap to manufacture and maintain, and a 10 minute flight can easily be, for example, a hop across a river or over dense traffic as part of a daily commute, and it can stand and charge at each end.

As most rc hobbyists know today, you can make just about anything fly by festooning it with little propellors. Flying well on the other hand...

Ah interesting.

I don't understand much about efficiency, but after reading http://www.geek.com/science/weve-been-designing-quadcopters-... I thought that a big rotor was inherently more efficient, so how can this design be more "green"?

I am not into flying, but last time I was a passenger I remember that a helicopter engine needs a certain cooldown time after landing which could be around 30 minutes. In this time the engine needs continue running. My guess is that the electric motors in the Volocopters do not have this requirement.

But again, I am not a helicopter specialist.

It is "green" because the emissions are out of sight out of mind..

Just ignore the coal plant in the background.

To be fair, people who get involved in developing green tech these days are fairly likely to have bought solar panels, especially given the price of them.

More videos on YouTube while their side is hammered: http://www.youtube.com/user/forschungsbuero

With what looks like a collection of interesting new-technology and innovation it's kind of sad to see them marketing it as

  It's electric. Greeeeeeeeeeeen.

A plane is much greener

ROFLcopter was first - it runs on plain text :-)

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