Google's delivery drones combine a multirotor design with fixed-wings. It seems like an eminently sensible design to me; fixed-wing operation will be quieter and more power-efficient, allowing longer travel distances (unlike the early Amazon Prime Air videos [1]), while hover capability avoids the need to parachute the load (unlike the current Zipline drones [2]) and provides a hover-and-land-almost-anywhere capability I imagine is useful.
Presumably the winch-down-the-load design reduces the risk of a user putting their hands into the blades - not to mention reducing the risk from customers choosing an inappropriate landing location; I imagine the drone can also jettison the winch cord if it gets caught on anything. It precludes delivering directly to apartment windows - but AFAIK no-one else is trying that either.
It's a pity they haven't released clear info on these drones' range, round-trip time and weight carrying capacity. Which are of course critical to working out the profitability of a citywide coffee delivery service.
Mount Tennent in the centre background at 0:10 in the video. Tidbinbilla Deep Space tracking station is a bit off to the right (and behind a range of hills).
I'm frankly surprised that they've chosen Canberra (the nation's capital) as a launch city. The degree of nimbyism in Canberra would be very high with a lot of people who are very good at lobbying and political action (it's their job). In the case of this particular project I see that as a good thing. I think delivering coffees by a noisy drone that overflies urban areas is an incredibly stupid enterprise.
They probably chose Canberra as it has no state government, which is an entire monolith of bureaucracy to avoid, and in the NT they'd probably just shoot at them ;-)
Easy layout, yes. Fairly flat? No. Adelaide, Melbourne and Perth are far flatter.
Canberra is situated in a horst and graben [1] landscape with multiple prominent ridges separating the various urban 'valley' sections of the city.
Don't get me wrong, I can see some of the reasons why they may have picked Canberra. Generally a population with a high percentage of early tech adopters. Houses set back from the road with easy landing driveways at front. Power lines run along the back of property lines, not along the street. Etc, etc. Just I think they underestimated the resistance they are very likely to experience and also underestimated the danger of annoying the actual lawmakers who live there.
It's to keep the drone as far away from landing hazards as possible - you don't want someone accidentally losing a finger to a rotor or the drone crashing through someone's window or landing in a location it's likely to get stuck.
Yup it's a pretty good idea too. Pets, odd structures, children, terrain type, puddles, water run off areas.
Not to mention you need to account for the wind. Drones can actually fly really well in wind, and while obviously they won't be flying in strong winds, you never know if there'll be a gust.
In rural/suburban/residential districts the airspace is pretty darn clear above the treeline/buildings. Assuming you aren't next to a large airport, there is little to no air traffic, there's more wind but there's plenty of room, etc.
I couldn't tell from the video, but I'd assume they drop the entire string to prevent it from being snagged.
I saw the winch in the video and thought "what if someone grabbed the rope and used it to pull the drone to the ground", but then I saw the comment speculating that the drone could jettison the winch.
I predict that when drone delivery services are commonplace, there will be a community of drone hunting enthusiasts.
Delivery trucks are hard to transport and store once they're reported stolen. It'd be more sensible to just steal the packages on the truck.
The drone is "small", can be transported and stored without it being visible, so it get's lots of points there. Also I'd be concerned about stupid people/assholes and the shiny new drone.
That said, Cameras+GPS, not to mention you don't want to steal the drone if it's delivering to you because it'd be kinda obvious.
A better example could be electric scooters, which are indeed stolen sometimes, but apparently not enough to kill the various operator businesses (lime etc).
You know, I thought of a bunch of reasons why drones would be more likely to be stolen, but it never occurred to me that delivery trucks are accompanied by people.
> Is it possible to use a drone with a balloon on top to help it lift more?
That's essentially a blimp. Due to square/cube scaling, blimps have less lift and more drag relative to their size at small scales than large ones. The extra power needed to overcome the drag would by far negate the power savings from reduced lifting requirements.
Also, helium is for all practical purposes a nonrenewable resource. One drone wouldn't use a lot, but a few million refilling every day would put a dent in the world's helium supply.
I think having what essentially would be small robot controlled fire-bombs flying through the skies would be a tough sell. Even if you managed to make them as safe as possible it's not exactly the kind of thing people would be eager to approve.
It's worth noting that hydrogen is orders of magnitude more energy-dense, by mass, than lithium-ion batteries.
As a benchmark: the DJI Phantom weighs roughly 1kg, and its battery can store about 80kJ of electrical energy. I found a NASA study [1] which estimated that the energy released when a li-ion battery combusts is roughly 2x the usable energy capacity. So let's say that a battery fire would release 160kJ of energy.
In contrast, a balloon capable of lifting a 1kg drone would need about 830 liters of hydrogen, with a mass of 75 grams. That amount of hydrogen, if burned in room-temperature air, would release about 9MJ -- roughly 50x as much energy as a battery failure.
(Of course, most of the hydrogen would burn itself up quickly and harmlessly, assuming the balloon isn't flying near any flammable objects.)
Plus assuming the drone is above the tree line and not next to a tall structure, the actual "fireball" should move fairly skyward and not pose much of a fire threat? I'd be more concerned about the falling drone/battery.
It's not only direct contact with the fireball you have to worry about, a large amount of the energy in the explosion would be coupled into a pressure wave and infrared radiation.
What do you think gasoline powered drones are? Agreed that hydrogen is perceived as being much more dangerous than it is because of the Hindenburg disaster.
But (and I have no reason to think that this is true) if it turned out to be commercially viable, I'm sure that perception could be changed.
Agreed. But there's a perception issue that arises from flammability that requires political skills I don't have. So hydrogen feels like a difficult solution to me. Example headline: "Flying Bombs, Oh My!"
If there were a mini-compressor-pump aboard the drone, is it possible that it could inflate/evacuate a balloon on demand during hover mode? Is the economics of such a thing
even possible?
Assuming there weren't already problems with the balloon idea, what you'd have then is a pressurized vessel, the pump, and of all the compressed helium weighing you down for 99% of your trip just to save a tiny bit of energy (and I'm assuming a day with zero wind here) during the offloading procedure which probably doesn't even last long enough for the balloon to fully inflate.
Also, as far as I know, the cheapest/lightest material to make the balloon out of would be mylar, which is conductive and not something you want around powerlines.
You'll experience the same scaling issues with whatever it is you expect to inflate with. You're going to have a lot of volume dedicated to the pressure vessel and not so much in the pressure vessel, because of scaling issues.
And I'm discarding the pump to put it back, assuming we're just going to vent to the atmosphere when we're done. Things get worse if you want to pump it back in.
No that doesn't really work. High pressure helium pumps are expensive, heavy, and require a lot of maintenance. Plus they require a lot of power to operate. And they produce a lot of waste heat.
Not saying this idea is worth the complexity (sounds over-engineered), but I am pretty sure you could make like a 1"x2" can of compressed helium attached to a 3' balloon with a simple valve to pop open and inflate the balloon. Think of those little air cans that you use for refilling bike tires on the go. Only weigh a few grams, holds a lot of air.
Hadn't heard of Zipline. And when I read it I imagined a simple cableway with small autonomous cars zipping along the line, possibly with branching points. I suspect it would be way cheaper to set up as an infrastructure and much more reliable than drones.
We're talking about drones which can serve an area of 7800 sq miles (20000 km²), going at over 60mph (100km/h), across rivers and mountains inaccessible by vehicles.
I don't think there's any way you could even install enough poles and cables to cover such an extension, let alone keeping them functioning without permanent maintenance teams trekking across the peaks. Plus all that would fail exactly when you need it the most: after a big storm, when the roads are impassable and even walking is difficult.
Yes, I was thinking more of an urban context, there are surely places and situations where a real flying drone (basically a model airplane in this case) works better.
I was merely trying to suggest that maybe we are too dazzled by the technology (flying! straight to your garden!) to see simpler and more effective solutions.
Drones don't really require infrastructure though? They don't require any setup at the physical locations, and they have a pretty obstacle free path above the trees.
Zipline would require infrastructure setup on the scale of roads/telephone lines to be useful wouldn't it?
Yep. But it seems it would be rather cheap to set up an infrastructure made principally of steel towers and (thin) cables, and there shouldn't be many technological challenges. It would be probably faster, more reliable and energy efficient than drones, allowing for heavier packages. Of course at the cost of having to build an infrastructure, and maybe of a smaller, fixed number of delivery points.
> But it seems it would be rather cheap to set up an infrastructure made principally of steel towers and (thin) cables, and there shouldn't be many technological challenges.
Just huge logistical challenges with right-of-way, construction labour, tearing up and making good the {sidewalks,lawns,gardens,driveways,etc}, actual acquisition of poles, ongoing maintenance and trimming duties, etc.
Greenfield installation of infrastructure in public areas is incredibly complex.
Yes, and I imagine it would be really difficult, for good reasons (mostly esthetical), to convince a city to install poles and cables for package delivery. At the same time, we've seen drone trials going on for some time, and the idea of having expensive, autonomous flying machines, on a very limited battery life, carrying weights over our heads and delivering them possibly without even landing but just hovering and lowering a winch, well it seems pretty implausible.
A Google wing drone probably costs a few thousands, can deliver two cups of coffee on range of about 1.5km, in extremely controlled conditions, for 100 suburban homes. And has already pissed off people in the neighborhood. Imagine how it would work inside a city center, and how it would scale. And how would you adapt it to homes and buildings that have no garden and no roof terrace?
I actually have a drone I fly around freestyle for fun, after seeing how truly versatile they are, not to mention how cheap, I'm really not sold on constructing more towers.
The EMax Hawk 5 is 250$ and while I don't know how much it can lift, it's actually a VERY decent amount, if we're just talking about a single person's mcdonalds then no problem. The expenses come from making it more robust, making sure it has signal, etc. But those issues are mostly already solved, especially with a winch the drone can stay above the tree line, a single radio tower would have incredible range - or they might be able to get away with existing 4G towers.
Now you're just down to battery life, and noise. The hybrid fixed wing/multirotor system seems to at least partially address both.
Battery life. And noise. And carrying anything substantial. And adding all the safety mechanisms that prevent it from killing someone in case of malfunction. And mechanisms to prevent it from being stolen or damaged. And autonomous navigation in case of unforseen obstacles (a construction crane?). And the ability to either land or negotiate a delivery point (imagine an urban road, with tall builings, walkways and traffic). And the ability to coordinate with other autonomous drones (avoid collisions, etc.).
I do fly a drone for fun as well. Last Christmas I had the idea of flying it over the frozen surface of a mountain lake, not far from my hometown. Well, about 30 seconds in, a pretty angry buzzard made a straight line for it and crashed it. It weighs about 2.5kg, it crashed on the ice from about 10m. No major damage, but retrieving it from there was, well, tricky :)
Google's delivery drones combine a multirotor design with fixed-wings. It seems like an eminently sensible design to me; fixed-wing operation will be quieter and more power-efficient, allowing longer travel distances (unlike the early Amazon Prime Air videos [1]), while hover capability avoids the need to parachute the load (unlike the current Zipline drones [2]) and provides a hover-and-land-almost-anywhere capability I imagine is useful.
Presumably the winch-down-the-load design reduces the risk of a user putting their hands into the blades - not to mention reducing the risk from customers choosing an inappropriate landing location; I imagine the drone can also jettison the winch cord if it gets caught on anything. It precludes delivering directly to apartment windows - but AFAIK no-one else is trying that either.
It's a pity they haven't released clear info on these drones' range, round-trip time and weight carrying capacity. Which are of course critical to working out the profitability of a citywide coffee delivery service.
[1] https://www.youtube.com/watch?v=MR9PoBAssw0 [2] https://www.youtube.com/watch?v=bnoUBfLxZz0