I was out in the surf off the NSW coast today, and it was scary as hell. Massive waves that suck you in and spin you around like a washing machine, coupled with a strong current pulling you out to deep water.
I definitely would have felt safer knowing there was a drone in the sky above me, ready to drop a flotation device on me. Our lifesavers do a great job, but it's a long, long way from the beach out to a drowning swimmer.
>I definitely would have felt safer knowing there was a drone
The presence of drones will likely encourage people to take more risks in rough surf. The same thing happened with car air bags-- when they were introduced, people with airbags drove more aggressively, negating the safety benefit.
That was a conversation we were just having today. We definitely went out further than was safe, simply because there were lifeguards on the beach. I've been to plenty of beaches without lifeguards and been far more risk-averse.
It wasn't a conscious choice. It was only something I became aware of once I'd had that dangerous experience in the water.
You could tow a floatation device anyway, then the drone doesn't even need to work.
It's there a "pocket-sized" buoyancy aid that locks into a small canister you can strap to your wrist/ankle? I'd guess not due to insurance liabilities.
Casey Neistat worked with a team to create a drone capable of lifting him and his snowboard in heavy ski gear/boots. I bet you could make something like this to lift a drowning swimmer to the beach.
One of the hurdles is that the traditional multi-rotor design doesn't scale up well. The blades just gain too much mass to be quickly sped up and slowed down. As the craft gets bigger to hold bigger payloads, more energy has to be devoted to fighting rotor momentum, making them less efficient.
It's why most multirotors over a certain size use variable pitch rotors, like a helicopter. And at some point, the complexity of managing multiple variable-pitch rotors just makes the single rotor design of a helicopter more efficient; especially when it can be powered by a gas engine.
Of course, a normal helicopter can be run remotely just as effectively as a multi-rotor.
When you say 'gain more mass,' do you mean the inertia from the rotor speed? I would think the more rotors you have, the slower each can spin? Is it possible there is an efficient design we havent yet tried involving self-stabilizing bearings or ball detents?
Intertia from both mass and speed (larger props tend to spin more slowly, at least in part to keep the tips sub-sonic).
Traditional multi-rotors, like the one featured in this article, maneuver by quickly changing the speed of the props with respect to the other props to change the attitude of the craft. The larger the prop, and thus the greater the inertia, the harder it is to quickly change the rotational velocity of those rotors.
Which is why helicopters tend to use variable pitch props, since they can alter the lift (and rotational force) generated by the prop without having to change the velocity. Well, that and variable pitch props let you create differential lift (such as tilting the helicopter into forward flight) with a single rotor as well. :)
However, many (probably all, but I don't know for sure) heavy lift or rescue helicopters are multi-engine. For example, the Westland Sea King (Powerplant: 2 × Rolls-Royce Gnome H1400-2 turboshafts, 1,660 shp (1,238 kW) each)[1] or a newer Sikorsky S-92 (Powerplant: 2 × General Electric CT7-8A turboshaft, 2,520 shp (1,879 kW) each).[2]
Here's a document from the Civil Aviation Safety Authority (CASA) in Australia, concerning performance standards for multi-engine helicopters. It provides a pretty good overview of what they need to be able to do with one engine inoperative (OEI).[2]
I'm not sure I need another threat to my life whizzing toward me, when my life is already in danger. He's drowning! Lets sent an airborn quisinart chopper at him at high speed!
Multi-rotors of that size can handle some pretty serious winds (10-15 ish MPH+, more if you're willing to potentially lose it to save a life). And since the craft itself isn't in the water, it doesn't have to deal with the seas.
I'd imagine a drone that size can handle 25-30+ MPH.
I routinely fly my DJI Mavic in 20MPH winds and it handles fine. You have to be mindful of how long it'll take to fly back upwind, but actually keeping it in the air is a piece of cake.
There's a huge difference in stability between sub-$100 throwaway drones many of us have played with and "serious" units in the $1,000+ range. Even on sport mode, you'd have to work pretty hard to crash a mavic in an open field (i.e., short of flying it sideways into a tree). I'm sure commercial, life-saving drones that cost 2 orders of magnitude more are on yet another level still.
Indeed. But from the picture on the site, it looks like they were about 150 feet above the average sea level. It would take quite the rogue wave to hit the drone at that altitude.
Sea spray (fine droplets of salt water) would indeed have an effect, but more over the long term than immediate problems since the motors are brushless. Brushless motors are not terribly susceptible to shorts from water, and the only other vulnerable component - the battery - would be hard to short out by sea spray alone.
Drone flying towards drowning person is one issue, but how accurately can it drop that "inflattable rescue device" ? It would be a real bummer if the drone made its way to a victim only to miss it by 50 yards.
Well, thankfully an uninflated raft will have a rather low surface area, meaning you can drop it with reasonable accuracy even in strong winds. I'd also hope the teams deploying these rafts are practicing in real conditions, and have backup teams on ski-dos ready to roll.
> To get an idea of just how quiet and undramatic from the surface drowning can be, consider this: It is the No. 2 cause of accidental death in children, ages 15 and under (just behind vehicle accidents)—of the approximately 750 children who will drown next year, about 375 of them will do so within 25 yards of a parent or other adult.
> 375 of them will do so within 25 yards of a parent or other adult.
This stat always rubs me the wrong way. It paints the image of a parent watching their child drown, but I imagine it's pretty easy to be within 25 yards of the pool and have no visibility to the pool.
I don’t think it is meant to imply parents purposefully watch their kids drown. It is more of a warning that drowning isn’t obvious and can be silent. You might lay next to the pool and think you could rescue your kid at anytime, it is just a couple of meters away. But your kid may never shout for help because it is struggling to breath and stay afloat.
I watched a video of a life guard jumping into a large crowded pool, swimming towards a certain location. Even though I knew somebody is drowning there, my untrained eyes couldn’t spot the drowning person until the life guard almost reached the child. Everyone next to the child was completely oblivious and looked funny at the lifeguard wondering why he is swimming towards them.
I'm glad the boys are safe! This is something that was bound to happen eventually and we've seen recent videos of this use and many others in advertising. I think dropping floats from a some is a natural use but it will be interesting to see if some of the other ideas survive.
Yes, I've seen the video where Casey Neistat hangs off a drone in ski gear. But to attempt a rescue, the drone is pulling against somebody who isn't trained (more movement means harder to stabilize). You're also fighting against the ocean, so you're going to need extra power to pull the person against the waves, at least until you get them plucked out.
As mentioned elsewhere in this thread, the drone will need to operate quite a bit higher up to stay safely clear of water and heavy spray, so the person would be at the end of a much longer rope, and a longer rope means the system is a longer "pendulum", which again means it'll take more energy to stabilize it.
An ocean rescue is going to happen on a warm day, whereas the Casey Neistat video was done in cold, dense air where drones are more efficient.
I would not be surprised if it takes an order of magnitude more energy, at the drone, to pull a person out of the ocean that it takes to lift a calm person on dry land. That's a big hill to climb.
Is a terrific idea in paper, but there are serious obstacles to solve. There is a potential problem in using a long swinging rope attached to a powefull engine in a beach with thousands of people looking. Ropes at high speed can cut the skin. Even worse, you do not need to apply a lot of force to suffocate or break the nek of a children.
In case of severe bad weather could work, sometimes. Ropes attached to a heavy engine that could crash and sink in seconds can be very dangerous in water.
I definitely would have felt safer knowing there was a drone in the sky above me, ready to drop a flotation device on me. Our lifesavers do a great job, but it's a long, long way from the beach out to a drowning swimmer.