5 ms·

> All of the flying car concepts, which are like drones big enough to hold humans, promise to be better than helicopters. Helicopters are expensive to maintain,

> All of the flying car concepts, which are like drones big enough to hold humans, promise to be better than helicopters. Helicopters are expensive to maintain, noisy to fly and require trained pilots. They forgot to add helicopters can also auto-gyrate in the event of engine failure. Quad-copter drones probably just crash.

JKCalhoun 7y ago
Almost certainly if the blades cannot vary pitch.
prawn 7y ago
Most drones can compensate to account for issues. My drone has hit a tree a few times, self-balanced and continued flight. It's flown fine through heavy wind/rain with cracked propellers (that I've replaced after noticing). There's a video out there of someone throwing cushions at, or suspending weights from, a consumer drone and it takes the hits and re-stabilises. High-end drones have battery redundancy, six props to account for failures, parachute systems, etc.
- sschueller 7y ago
  From what I have read and seen a drone with only 4 props has almost no chance of recovery if one prop fails. This is also why drones for high end expensive video have six or eight props to prevent a catastrophic failure resulting in loss of equipment.
  - satori99 7y ago
    There are algorithmic solutions to maintaining some semblance of flight with a damaged quad copter, even down to one remaining prop, however it involves spinning the entire air-frame to stay aloft -- which means it is probably not suitable for a human passenger drone https://newatlas.com/quadcopter-failure-algorithm/30031/ https://newatlas.com/quadcopter-failure-algorithm/30031/
- nosianu 7y ago
  Scale matters. Compare a small animal falling and a large animal falling (i.e. compare what happens when they hit the ground). A "drone" large enough to carry a human or two will be much more heavily damaged by an impact that appears to be similar to one that leaves a much smaller drone intact. A parachute system only helps if you are high enough. Looks like the flying thingys we are talking about here will be close to obstacles a lot and not very high up much of the time given how they are to be used. Battery redundancy: The scale argument again. This is an order of magnitude harder to achieve on a much larger man-carrying "drone".
  - Erlich_Bachman 7y ago
    > Battery redundancy: The scale argument again. This is an order of magnitude harder to achieve on a much larger man-carrying "drone". Isn't it much easier because you have capacity (weight carrying ability) for many more cells, and the chances too many of them fail is much lower? If you have 3 cells, 1 of them can fail at any given time, and you're left with 66% of power, but if you have 200 cells, and 1 or 2 of them fail, you don't even notice. How do you mean that it's harder? Electric cars certainly don't seem to have any problems with this and their batteries are much more reliable than the ones available for drone usage. Also with big size/capacity you can easily include additional systems like temperature control which increase reliability because they don't weigh as much in relationship to the whole vechicle.
    - nosianu 7y ago
      > Isn't it much easier because you have place for many more cells Don't think space (not the biggest issue here as you say), think weight, power and the ratio.
      - Erlich_Bachman 7y ago
        Yes, of course. I was using "space" as a more general term, as in "capacity". Should have been more clear.
  - prawn 7y ago
Aozi 7y ago
>Helicopters are expensive to maintain, noisy to fly and require trained pilots. This part really puzzles me, I mean I guess they're better than helicopters but all those thing apply to flying cars as well, just to a lesser degree. Getting some flying cars won't be cheap, maintaining them might be cheaper than a chopper but still not very cheap. And if you're going to pilot one of these, and carry people around I guarantee you will have to be licensed and trained in piloting one. The regulations won't be as loose as with drones. As for the noise, well this isn't exactly quiet.... https://youtu.be/cmdilp9LM0E?t=67 https://youtu.be/cmdilp9LM0E?t=67 Sure it might not be as bad as a helicopter but you also rarely have two dozen helicopters zipping around near ground level. While the whole plan is to have these zipping around everywhere.
- condercet 7y ago
  I imagine a ridesharing / uber-like model will be dominant compared to private ownership and personal piloting. But these things are going to be incredibly annoying and disruptive -- the various drone delivery efforts already seem loud and stress-inducing. I imagine airspace restrictions on these are going to become common in the near-ish future.
- dgzl 7y ago
  >As for the noise, well this isn't exactly quiet.... I remember listening to Elon Musk dismissing flying cars for this reason.
  - yoz-y 7y ago
    I wonder if asymmetric blades like in fans could work and if they would be any good for reducing the noise.
    - fooker 7y ago
      Also reduces thrust.
    - mannykannot 7y ago
      There has been a good deal of economic incentive for finding ways to reduce the noise of the fans in turbofans for a long time. the relatively recent introduction of chevrons on the exit end of fan nacelles shows how even minor improvements are pursued. It is unlikely that an opportunity for significant improvement has been overlooked.
Erlich_Bachman 7y ago
That's why this design is not a quadcopter, it is technically an octocopter.
kalleboo 7y ago
One thing I've always wondered is why is it so hard to make a self-flying helicopter? Helicopters already exist, can carry much heavier weights than most multirotors, and have other pro's (like being able to auto-gyrate). Is there some reason we haven't automated the flying of those and are instead going for multirotors? Or do they exist but just aren't sexy enough to make headlines?
- satori99 7y ago
  They do exist for military purposes; https://en.wikipedia.org/wiki/Northrop_Grumman_MQ-8_Fire_Scout https://en.wikipedia.org/wiki/Northrop_Grumman_MQ-8_Fire_Sco... https://www.engadget.com/2019/07/09/us-navy-mq-8c-fire-scout-drone/ https://www.engadget.com/2019/07/09/us-navy-mq-8c-fire-scout...
- deleted 7y ago
  [deleted]

JKCalhoun 7y ago

Almost certainly if the blades cannot vary pitch.

prawn 7y ago

Most drones can compensate to account for issues. My drone has hit a tree a few times, self-balanced and continued flight. It's flown fine through heavy wind/rain with cracked propellers (that I've replaced after noticing). There's a video out there of someone throwing cushions at, or suspending weights from, a consumer drone and it takes the hits and re-stabilises. High-end drones have battery redundancy, six props to account for failures, parachute systems, etc.

sschueller 7y ago
From what I have read and seen a drone with only 4 props has almost no chance of recovery if one prop fails. This is also why drones for high end expensive video have six or eight props to prevent a catastrophic failure resulting in loss of equipment.
- satori99 7y ago
  There are algorithmic solutions to maintaining some semblance of flight with a damaged quad copter, even down to one remaining prop, however it involves spinning the entire air-frame to stay aloft -- which means it is probably not suitable for a human passenger drone https://newatlas.com/quadcopter-failure-algorithm/30031/ https://newatlas.com/quadcopter-failure-algorithm/30031/
nosianu 7y ago
Scale matters. Compare a small animal falling and a large animal falling (i.e. compare what happens when they hit the ground). A "drone" large enough to carry a human or two will be much more heavily damaged by an impact that appears to be similar to one that leaves a much smaller drone intact. A parachute system only helps if you are high enough. Looks like the flying thingys we are talking about here will be close to obstacles a lot and not very high up much of the time given how they are to be used. Battery redundancy: The scale argument again. This is an order of magnitude harder to achieve on a much larger man-carrying "drone".
- Erlich_Bachman 7y ago
  > Battery redundancy: The scale argument again. This is an order of magnitude harder to achieve on a much larger man-carrying "drone". Isn't it much easier because you have capacity (weight carrying ability) for many more cells, and the chances too many of them fail is much lower? If you have 3 cells, 1 of them can fail at any given time, and you're left with 66% of power, but if you have 200 cells, and 1 or 2 of them fail, you don't even notice. How do you mean that it's harder? Electric cars certainly don't seem to have any problems with this and their batteries are much more reliable than the ones available for drone usage. Also with big size/capacity you can easily include additional systems like temperature control which increase reliability because they don't weigh as much in relationship to the whole vechicle.
  - nosianu 7y ago
    > Isn't it much easier because you have place for many more cells Don't think space (not the biggest issue here as you say), think weight, power and the ratio.
    - Erlich_Bachman 7y ago
      Yes, of course. I was using "space" as a more general term, as in "capacity". Should have been more clear.
- prawn 7y ago

Aozi 7y ago

>Helicopters are expensive to maintain, noisy to fly and require trained pilots. This part really puzzles me, I mean I guess they're better than helicopters but all those thing apply to flying cars as well, just to a lesser degree. Getting some flying cars won't be cheap, maintaining them might be cheaper than a chopper but still not very cheap. And if you're going to pilot one of these, and carry people around I guarantee you will have to be licensed and trained in piloting one. The regulations won't be as loose as with drones. As for the noise, well this isn't exactly quiet.... https://youtu.be/cmdilp9LM0E?t=67 https://youtu.be/cmdilp9LM0E?t=67 Sure it might not be as bad as a helicopter but you also rarely have two dozen helicopters zipping around near ground level. While the whole plan is to have these zipping around everywhere.

condercet 7y ago
I imagine a ridesharing / uber-like model will be dominant compared to private ownership and personal piloting. But these things are going to be incredibly annoying and disruptive -- the various drone delivery efforts already seem loud and stress-inducing. I imagine airspace restrictions on these are going to become common in the near-ish future.
dgzl 7y ago
>As for the noise, well this isn't exactly quiet.... I remember listening to Elon Musk dismissing flying cars for this reason.
- yoz-y 7y ago
  I wonder if asymmetric blades like in fans could work and if they would be any good for reducing the noise.
  - fooker 7y ago
    Also reduces thrust.
  - mannykannot 7y ago
    There has been a good deal of economic incentive for finding ways to reduce the noise of the fans in turbofans for a long time. the relatively recent introduction of chevrons on the exit end of fan nacelles shows how even minor improvements are pursued. It is unlikely that an opportunity for significant improvement has been overlooked.

Erlich_Bachman 7y ago

That's why this design is not a quadcopter, it is technically an octocopter.

kalleboo 7y ago

One thing I've always wondered is why is it so hard to make a self-flying helicopter? Helicopters already exist, can carry much heavier weights than most multirotors, and have other pro's (like being able to auto-gyrate). Is there some reason we haven't automated the flying of those and are instead going for multirotors? Or do they exist but just aren't sexy enough to make headlines?

satori99 7y ago
They do exist for military purposes; https://en.wikipedia.org/wiki/Northrop_Grumman_MQ-8_Fire_Scout https://en.wikipedia.org/wiki/Northrop_Grumman_MQ-8_Fire_Sco... https://www.engadget.com/2019/07/09/us-navy-mq-8c-fire-scout-drone/ https://www.engadget.com/2019/07/09/us-navy-mq-8c-fire-scout...
deleted 7y ago
[deleted]