Toyota Investigating Hovercars

cartechboy writes: Remember back in the day when we all thought we'd be driving flying cars in the future? Well that clearly didn't happen, though it still might in the future. But somewhere inside Toyota there's a team of engineers who think hover cars might be a thing, and apparently there's a project underway at one of Toyota's "most advanced" research and development areas. We aren't talking Jetson's flying car, more like a car that merely hovers "a little bit away" from the road. Probably a few inches, with the aim to reduce road friction. With no wings or ridiculous speed, this is probably no simple process. No one really knows how long Toyota has been working on the idea, or how far along it is. Basically, don't expect flying Priuses any time soon...

Comments

aka

[GoddersUK]

small hovercraft.

this is probably no simple process

Surely the underlying technology required is essentially what's already been developed for hovercraft, which already come in car sized variants. Don't get me wrong, I'm not saying it would be easy to stick a car body on them, develop intuitive controls and stick them on public roads; I'm just not sure the technology is as novel and underdeveloped as the summary makes out.

Re:aka

[CastrTroy]

I'm not sure why a person would want a hovercraft for general use. It's way more efficient to just have car that rolls on wheels. Lifting the entire car off the ground with a cushion of air is terribly inefficient. Not that there aren't any uses at all, but as a general purpose vehicle on public roadways, it seems like a terrible idea.

Re:aka

[Tx]

The trouble with those car-sized hovercraft is the turning and braking profile, which is nowhere near good enough for public roads designed for cars. Now a design something like the Aero-X hoverbike might be able to improve on that - by hovering a bit higher and tilting the entire craft, you could effectively vector a large proportion of the lift airflow for turning force, as opposed to redirecting a bit of the horizontal thrust only with a fin as with conventional hovercraft. Aerofex don't seem to make any such claims about their design though, they seem to be targeting off-road use only, and I guess turning that way might present problems for other road users/pedestrians getting hit by the airflow.

Re: aka

[Viol8]

Given 95% of resistance at motorway speeds is air resistance, not rolling resistance I'm not entirely sure how having a massive fan to create the lift and another to propel the car is going to improve fuel efficiency given how inefficient propellers are to start with.

Re: aka

[rmdingler]

Yes.

Unless and until technology emerges that makes defying gravity much more efficient, there is no advantage (outside of the WOW factor) for using these vehicles on the highway.

Off-road applications are a different matter.

Re: aka

[Rei]

That's not true. It varies from vehicle to vehicle and between driving profiles, but it's usually 50-75% of the resistance at highway speed coming from aero drag - not 95%. Rolling drag remains a significant loss factor at all speeds.

That said, this doesn't sound to me like the most logical approach to tackle rolling drag - wheels are more efficient than hover as-is in most general-use cases, and I can easily envision a lot more that could be done. For example, you could use very high pressure (120+ psi) tires with a hard, thin central tread, relying on automatic camber to a thick, sticky side tread during accel, braking, cornering, or when traction control kicks in (the additional vibrational load from cruising on high PSI tires could be canceled with, for example, a cable vibration isolation system or active vibration cancellation). Such a system should be able to approach the rolling coefficients of hard steel wheels (a tenth that of traditional car pneumatic tires - effectively rendering rolling losses irrelevant). Heck, if you're going to that extent, it's not much further to go all the way to completely solid wheels (though you'd want foam-core carbon fiber or similar to keep the weight and in particular unsprung mass down, not solid steel) and not even have to deal with tire inflation or puncture risk. So long as you have a way to automatically shift to a thick, sticky tread as needed based on current traction conditions and have a mechanism to soak up the higher vibrational loads to maintain ride quality, you're fine.

Is that a pretty huge deviation from standard practice? Yeah, by no small amount, it's literally reinventing the wheel. But you know what, it's also a pretty huge deviation to have cars outright hover on the highway. ;)

But yeah, you're right in that rolling losses aren't the *primary* loss mechanism on the highway. A lot more has to be done to tackle aero drag, and that's trickier - not least of which because the optimal shape varies based on speed and things like crosswinds (and the more you optimize your shape, the bigger of an issue this becomes). One of the more clever ideas I've seen - I don't know how it'd play out in the real world, mind you - was Aptera's plan to take a page from Gerald Bull's playbook and fill in the low pressure wake with air ducted in through the cabin. There's also a fair bit of research designed for aircraft (where aero drag is an even bigger issue) that could translate to cars, for example, skin textures or microstructures designed to maintain laminar flow or reduce surface drag. One of the more exotic variants of that which I've seen is a taut film outer-layer over a microscopic layer. The film vibrates in the wind between its ridges, setting up standing waves which separate the laminar flow from the surface, reducing the flow speed in contact with the surface and thus reducing direct surface drag. There've been peer-reviewed papers on it, and one of the researchers founded a company that now makes kits to reskin a variety of small aircraft (not very many thusfar, the skin has to be custom designed for each model). That's of course just one example among many, it's a very active field of research, as even a fraction of a percent reduced aero drag on a commercial airplane results in massive fuel savings.

Honestly, I'll be happy if we can just get people's style preferences to shift away from naturally high-drag forms like those ridiculous oversized front-end things where you can barely see over the hood. I know I'm out of the mainstream, but I love the look of aerodyamics. Real aerodynamics, not counterproductive curvy features that a lot of people think are "aerodynamic" but actually raise your drag. I want my car to look like a wingless plane, a car that cuts through the air like a knife rather than a clobbering oaf shoving it all around as it drives by ("Excuse me air, coming through, excuse me, sorry there!"). I want a rounded front end and a rear end that tapers vertically down with as long of a t

I get enough flying priuses already.

[nimbius]

call me a fogey but we cant handle flying cars and we certainly cant begin to handle hovering ones either.

Here in america you need look no further than your local road to confirm my assertion. just drive to lunch today and count how many people change lanes without a signal, make an illegal left across two lanes of opposing traffic, run red lights, cut eachother off, and tailgate. We're a fucking mess. On the highways every single vehicle routinely travels 15 miles or more above the speed limit, even though we've had reliable cruise control thats far superior to our own clumsy right foot for more than 3 decades. Drivers are glued to their phones or face down in the texting position for the majority of their commute. We're horrible at looking ahead and predicting when traffic will stop, instead choosing to slam on our brakes and let the other guy do his best to stop. Although every drivers manual reads we should slow down if someone wants to merge into our lane, we instinctually speed up or ignore them. Try an experiment: go the speed limit in the center lane of the highway and see how many furious drivers pound their horns and flash their headlights. Better yet, try driving in the left lane on a road that isnt limited access, a speed limit something around 35mph, and see how many people completely lose their minds despite the fact that what youre doing is entirely legal. And speed? The only time speed factors into any collision in america is when its fatal, and even then its only if the wreckage is catastrophic or the occupant a celebrity. We wrecklessly whip across 3 lanes of traffic and insist on maintaining our lead regardless of how congested the roads are. We categorically ignore speed limits in a construction zone despite a quad-damage boost to any citation received. We race along at all hours of day and in all seasons as if a collision would have no consequences to us, because we're all we think of.

The best innovation in automobiles has been to autonomize them, but compared to things like rail even an autonomous car is laughably inefficient and merely perpetuates a host of systemic and unsustainable problems related to automobiles nonetheleast of which is climate change.

Re:I get enough flying priuses already.

[Viol8]

"Try an experiment: go the speed limit in the center lane of the highway and see how many furious drivers pound their horns and flash their headlights"

Yeah , I wonder why that could be. Perhaps because some arrogant ass is blocking the lane when he's supposed to move over if the nearside lane is clear. If you want to play traffic cop go sign up and do the 2 years training, otherwise get out the fecking way.

Re:I get enough flying priuses already.

[JimFive]

Better yet, try driving in the left lane on a road that isnt limited access, a speed limit something around 35mph, and see how many people completely lose their minds despite the fact that what youre doing is entirely legal.

No, it isn't legal. Look up Impeding Traffic. You aren't allowed to impede the normal flow of traffic, even if that traffic is violating the law.
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JimFive