This link has a design for a car with a tilting body. It’s supposedly allows for a much smaller vehicle that can corner safely or some such. The inventor claims it’s a revolutionary concept, but I am POSITIVE I’ve seen it before and it was many years ago. I once read a book on ‘concept cars’ and this design (3 wheels, tilting body) was def. there.
What I can’t remember is who made the darn thing. I THINK it was Chrysler but not sure at all.
Can anyone knowledgable in concept cars or american car co. history provide any details?
The comments mention a Dutch co. called Carver has a similar design and another person mentions Mercedes as having come up with something similar several years ago, but I read the book in the early 90s and it was already an old book, so I figure what Im thinking of predates both those comments. No I don’t remember the name of the book or else I’d go look.
Anyone?
I seem to recall that this was a feature of The Dale (sorry my googlefu is weak this AM, no linky) a 3 wheeled “safety” car of the late 70’s early 80s.
The kicker was that the creator of The Dale was a transvestite, and the entire project was a scam. Defrauded a bunch of people, and the creator went to jail IIRC.
Other than that, I don’t recall any car with a leaning body.
Well it’s not so much a revolutionary concept because it’s so obvious, not because there’s prior art.
It’s not like nobody else in the world ever thought “Gee, let’s make a car tilt to help handling”. I bet every engineering student thinks this but most have the presence of mind to realize it’s not very practical and implementing it puts limitations on the vehicle nobody wants to have.
Detroit (Big Auto in the article) doesn’t make one passenger, three-wheeled cycle thingies. I don’t get the straight-up comparison.
“Active Suspension” has been employeed to keep cars level thru a turn, which is essentially leaning the vehicle, although the lean is not so pronounced as to show the vehicle tilting in the complete opposite direction that inertia would cause.
In other words, in a typical car inertia would cause a car to roll over on its suspension to the left during a right hand turn/curve. With active suspension, a car is tilted into the turn, to the right, with the resulting profile of the car being one the is somewhat horizontal.
Anti-sway bars, a common feature of most modern vehicles, also work to offset the lean (or sway) generated by cornering. It’s not quite like leaning into the turn, but it’s an entirely passive system that points to that strategy.
Mercedes also had a similar concept car: the F300 Life Jet.
There are also human-powered leaning trikes in production: the Stites Chameleon is probably the most successful (or at least held in highest regard). It’s reportedly much more stable than other trikes of similar height and width, because the leaning seat moves the center of mass to the inside of the turn. The Tripendo looks more striking but not very successful.
As I understand it, the difficulty with leaning vehicles is that the relationship between steering angle and optimal lean angle is not constant. It depends on speed. So the choices are:
[ul]
[li]Tie the leaning mechanism to the steering mechanism, and live with non-optimal lean angles (it leans too much at low speed and too little at high speed).[/li][li]Vehicle is free to lean either way. That means the driver/rider must actively balance the vehicle, as you would a normal motorcycle. But if you put springs and dampers in the lean mechanism, it will be a little easier to balance than a 2-wheeler.[/li][li]Computer-controlled lean mechanism that controls lean angle based on speed and steering angle. The Mercedes Lifejet took this approach.[/li][/ul]
“Big Auto can’t even ‘grasp the technical fundamentals’ he’s embedded in his prototype…” Please! The handling and dynamic behavior of two-, three-, and four-wheeled vehicles is well understood by the engineers of “Big Auto”. See this book for a fairly comprehensive discussion of both traditional and closed-loop feedback suspension designs. Virtually all modern cars incorporate some kind of anti-sway mechanisms to combat the natural body roll of the chassis, and many upper-tier (and even more moderately priced) vehicles now utilize active control systems to minimize roll and underable dynamic response.
I can’t tell what is supposed to be unique about his concept (his “patent” is actually a patent application and gives only vague information on the workings of the vehicle) but I’ll note that the system requires the rider and engine to sit low to the ground, which makes the vehicle longer and increases the turning radius over a motorcycle…perhaps quite significantly, considering the narrow wheelbase. Such a narrow wheelbase probably creates a high Ackermann error, which I explain in [post=6512613]this post[/post]. Also, scaling it up to passenger /cargo vehicle size and placing a protective faring would most likely encounter the same problems as Buckminster Fuller’s Dymaxion Car.
As far as “chang[ing] the face of motoring”…the damned truth is that consumers for the most part don’t want something new and different, and that “Big Auto” produces suboptimum designs (solid rear “live” axle, semi-trailing arms or leaf spring suspension, body-on-frame construction, et cetera) not because they don’t know better but because the tooling and experience makes it cheap and low-risk, and consumers don’t know any better. Most car buyers place more emphasis on how they car fits their creature needs and transportation/cargo requirements than the performance or handling, and on that account this tri-bike doesn’t fit the bill for most drivers. It’s a neat alternative to a motorbike and it might have a niche market (once he adds on all the safety features and amenities to make it legally roadworthy) but it’s as doubtful that it will revolutionize auto transportation as the Segway is to cause people to rebuild cities to accommodate it. The hyperbole regarding it’s technical superiority is just marketing hype.
I seem to recall having read an article once in one of the big car magazines where they were doing a road test of a car with a fully active suspension system. It mentioned that the engineers had once programmed it so that the car leaned into the corners (instead of the usual behaviour of leaning outwards), but everyone who drove it got motion-sick. Seemed to work best to program it so the car remained flat during cornering.
active suspension was used in F1 (or was it indy?) at least for awhile, and I remember seeing cars that leaned into turns on discovery like 10 years ago.
this guy is talking out his ass.
Honda (at least I think it was Honda) sold a combination trike/moped back in the Eighties. The two rear wheels turned as the vehicle banked into a turn.
The reason you haven’t seen leaning motorized 2+ wheel vehicles in the US has mainly to do with product liability. For a leaning system to be easy-to-use, it has to be totally automatic and speed-sensitive as well, which means only computer control can do it properly–but if the leaning mechanism malfunctioned, it could mean very dire consequences for the people inside at high speeds.
Some research models in the past (such as the GM Lean Machine) had a steering wheel that controlled the steering wheels but had separate foot-pedals so that you could manually control the amount of body lean. The problem with not using automatic computer control is that operator error can easily make the vehicle unstable. And then you’re back to product liability lawsuits again.
You can’t use a mechanical system because for best performance, the lean angle has to be to different degrees at different speeds, for the same turn radii. And anyway, linking the lean angle mechanically to the front-wheel steering angle in any way causes the inherent stability of the front-wheel-steering to be lost. There is no way to do it, and have it work well at high speeds/in poor traction.
There’s lots of people making these vehicles and it works just fine as they test it, so they assume that it works perfect, but lacks true inherent stability that a typical non-leaning front-wheel-steer setup does. There’s lots of people who build recumbent tricycles with the lean angle linked to the steering angle, and they test it at low speeds and announce that it works great, but it really doesn’t overall. Particularly in bicycles, linking the center of mass to the steering input usually results in a rear-wheel-steer vehicle, handy for a forklift but not known for their high-speed usefulness. And this is why no motorcycle company in the whole world will build such vehicles.
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This is apparently a big problem with active suspension. The british Advanced Passenger Train (aka ‘tilting train’) of the seventies had the same problem. They engineered it so that it cancelled perfectly the lateral forces of taking a bend at high speed, with the result that anyone inside saw the horizon swinging back and forth with no lateral sensations at all. :Insert barf smiley here:
That, along with the fact that the systems broke down frequently so it did not ‘untilt’ coming out of a corner resulted in the whole project being flushed. The italians finally made it all work.