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Toyota invests $394m in Joby Aviation's flying taxis

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Re: Toyota invests $394m in Joby Aviation's flying taxis

#31

Post by OnlineGladiator »

smattiso wrote: post #17
OnlineGladiator wrote: post #15

Earlier quoted context omitted.

Sure, they're trying to make it cheaper. But all of the eVTOL designs I've seen can't autorotate, making them much less safe (contrary to your implication about redundancy). Everything I've seen about this space is people with big checks trying to cut corners to enter a new market, and it seems ripe to fail much like the 737-MAX. https://www.forbes.com/sites/jeremybogaisky/2019/12/01/insid... And that's ignoring all…

The likelihood of failure is much lower with an eVTOL than a conventional helicopter. Additionally a BRS chute could work with eVTOLs in a way it couldn't with a normal heli.

> The likelihood of failure is much lower with an eVTOL than a conventional helicopter.

You're basing this on a myriad of assumptions as eVTOL designs are barely at the prototype stage right now. Helicopters have been in use for decades, so we know how safe they are.

If they truly prove to be safer then that's awesome, but based on everything I've seen I don't believe that to be true.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#32

Post by kgilpin »

If an aircraft can’t glide or autorotate then I don’t understand how it can be safe at low altitudes. Because whole plane parachutes (BRS) have a minimum altitude required to open successfully, and that altitude is a lot higher than anyone would care to drop.

Airplanes have energy from their forward motion. Helicopters have energy in their rotor blades. This energy can be used to soften a crash landing. Without this available energy, and without a parachute, then how do you soften a crash and survive?

People say that electric motors are so reliable... But batteries can spontaneously combust.

I would like to know how these aircraft are safe enough to be treated the same as a taxi ride.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#33

Post by rorykoehler »

kgilpin wrote: post #32

If an aircraft can’t glide or autorotate then I don’t understand how it can be safe at low altitudes. Because whole plane parachutes (BRS) have a minimum altitude required to open successfully, and that altitude is a lot higher than anyone would care to drop. Airplanes have energy from their forward motion. Helicopters have energy in their rotor blades. This energy can be used to soften a crash landing. Without this…

Perhaps we could borrow ideas from bicycle helmets and airbags to create an emergency mechanism which absorbs most of the impact?

Re: Toyota invests $394m in Joby Aviation's flying taxis

#34

Post by awb »

JohnJamesRambo wrote: post #19
the_duke wrote: post #2

There are a lot of companies working on "flying taxis". All of those seem to have a large footprint with lots of rotors, meaning they will need dedicated landing/take off zones. This seems to limit their usability a lot, turning them more into a short range point to point helicopter service. Not to mention the noise pollution. Those things are all loud. Combine that with limited speed and range, and I just don't see…

Wheels are really awesome at fighting gravity when the engine dies so I’m not sure I ever see a time people are flying around in personal aircraft en masse. I’ve seen enough try to drive on the ground.

Planes and drones are getting pretty good at autonomous flight. You might not need pilots by the time this tech is mature.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#35

Post by dmitrygr »

awb wrote: post #34
JohnJamesRambo wrote: post #19

Earlier quoted context omitted.

Wheels are really awesome at fighting gravity when the engine dies so I’m not sure I ever see a time people are flying around in personal aircraft en masse. I’ve seen enough try to drive on the ground.

Planes and drones are getting pretty good at autonomous flight. You might not need pilots by the time this tech is mature.

They said the same about doctors, and yet heart surgery is done by real people.

All your NNs are entirely completely utterly pointless when faced with inputs they have never been trained on. They always suck at extrapolating, and almost always suck at interpolating as well. So when an unexpected emergency happens, what exactly are they going to do?

And outside of NNs, The only thing we have are autopilots. They sometimes fail, and that is why real pilots mainly just babysit them as their main job.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#36

Post by elamje »

JohnJamesRambo wrote: post #19
the_duke wrote: post #2

There are a lot of companies working on "flying taxis". All of those seem to have a large footprint with lots of rotors, meaning they will need dedicated landing/take off zones. This seems to limit their usability a lot, turning them more into a short range point to point helicopter service. Not to mention the noise pollution. Those things are all loud. Combine that with limited speed and range, and I just don't see…

Wheels are really awesome at fighting gravity when the engine dies so I’m not sure I ever see a time people are flying around in personal aircraft en masse. I’ve seen enough try to drive on the ground.

Additionally, people forget the extra energy cost of fighting gravity. It takes a lot more energy to use a motor and prop to directly resist gravity, rather than using a static object like a wheel. Energy loss fighting gravity with a propeller >> energy loss fighting wheel friction.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#37

Post by xingyzt »

ianai wrote: post #30
hndamien wrote: post #18

This makes a lot of sense for Toyota. Their hydrogen fuel cells probably make a lot more sense in this context.

How would hydrogen make more sense?

Hydrogen fuel cells are much more energy-dense compared to Li-ion batteries.

Re: Toyota invests $394m in Joby Aviation's flying taxis

#38

Post by squeakynick »

the_duke wrote: post #2

There are a lot of companies working on "flying taxis". All of those seem to have a large footprint with lots of rotors, meaning they will need dedicated landing/take off zones. This seems to limit their usability a lot, turning them more into a short range point to point helicopter service. Not to mention the noise pollution. Those things are all loud. Combine that with limited speed and range, and I just don't see…

Half of these designs are simply scaled up drones which, according to simple physics and engineering, is the wrong direction.

Details: http://datagenetics.com/blog/february62019/index.html

How can organisations this large get it so wrong? When is someone going to tell them that the Emperor is not wearing any clothes?

Re: Toyota invests $394m in Joby Aviation's flying taxis

#39

Post by godelski »

JohnJamesRambo wrote: post #19
the_duke wrote: post #2

There are a lot of companies working on "flying taxis". All of those seem to have a large footprint with lots of rotors, meaning they will need dedicated landing/take off zones. This seems to limit their usability a lot, turning them more into a short range point to point helicopter service. Not to mention the noise pollution. Those things are all loud. Combine that with limited speed and range, and I just don't see…

Wheels are really awesome at fighting gravity when the engine dies so I’m not sure I ever see a time people are flying around in personal aircraft en masse. I’ve seen enough try to drive on the ground.

Just an FYI, helicopters can land without engine power by autorotation. I'm assuming these things, if you're putting people in them, would do the same.

Additionally, autonomous flight is fairly common right now. There's less going on in the air than on the ground (or rather less surprises with small response time and high consequences). Planes even land and take off by themselves. The first plane to actually be certified to autoland was in 1968[0]. The tech has been around for awhile and been making serious development this entire time.

[0] https://en.wikipedia.org/wiki/Autoland

Re: Toyota invests $394m in Joby Aviation's flying taxis

#40

Post by godelski »

dmitrygr wrote: post #35
awb wrote: post #34

Earlier quoted context omitted.

Planes and drones are getting pretty good at autonomous flight. You might not need pilots by the time this tech is mature.

They said the same about doctors, and yet heart surgery is done by real people. All your NNs are entirely completely utterly pointless when faced with inputs they have never been trained on. They always suck at extrapolating, and almost always suck at interpolating as well. So when an unexpected emergency happens, what exactly are they going to do? And outside of NNs, The only thing we have are autopilots. They somet…

Just an FYI, planes already regularly fly by themselves. Auto landing has even been around since the late 60's.
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