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Some cars have an active suspension: that is, instead of just having springs and dashpots, they have motors which actively work to smooth out the ride. These motors are driven by a system which senses the motion of the car/tires/etc and tries to cancel them.
Presumably, however, even this can't
smooth out all bumps. (I'm not actually sure whether I've ridden in a car with an active suspension.) Most driver-hours are spent driving a few routes over and over again --- eg, a daily commute. So, if the active suspension were coupled with a GPS receiver and a memory, it could remember where all the bumps are on your route and exactly how high they are, enabling it to smooth them out perfectly. (GPS probably isn't of fine enough resolution, so throw in a hidden-Markov-model, Kalman filter, or the like to allow the suspension to use the remembered & perceived road surface to fine-tune its notion of its location.)
Advantage: a nice smooth ride, and another excuse to use GPS and HMMs.
Disadvantages: Well, if a pothole were repaired, your car wouldn't learn of this until you had driven over it a few times. So you'd have a faint "afterimage" of the pothole for a few days.
Also, the rich would all have predictive suspensions, and would not feel flaws in the road surface and would see no need to have the government spend money repairing the roads. The roads would deteriorate into impassable ridges and ruts, and civilization would collapse, and all die. O, the embarrassment.
The six-wheeled car
http://www.halfbake...20six-wheeled_20car
tangentially related... [hippo, Oct 04 2004, last modified Oct 05 2004]
[link]
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<rant>Shame this wasn't around 2 days ago in the form of compensating for lack of 4-point contact with road surface - My Fiancees Nephew, His Girlfriend and their 6 Month Old Baby were in a Ford Bronco travelling to spend Christmas with the Grandmother and Us. The Passenger Side Rear Wheel came off the hub completely and as a result the Bronco rolled 4 times. The Baby was strapped in and received very minor abrasions. The Mother of the child has a broken thumb, a broken angle and is bruised over half her body. The Father - I will see in 18 hours - he got the worst of it. He had bought the now demolished vehicle 2 weeks ago, and had new tires put on just 1 week prior to accident. Great Job Installers. Hopefully next time, they'll remember to tighten all 4 of the wheels.</rant> |
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Just strap lasers or radars to the front bumpers and measure the distance to the ground every few milliseconds. Use a computer to move the wheels up and down with the road to maintain a constant average altitude AGL. This eliminate the (re)learning curve, doesn't rely on predictive data and doesn't rely on an outside system to function. |
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One downside would be that fender benders would be astronomically expensive. |
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[thumbwax] I hope everything works out for your fiancees nephew. I'm glad his girlfriend and baby are all right. |
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My uncle was in a LandRover station wagon one night, footling along the Flinders highway and hit a pothole. The front driver's side wheel came off and went bush. He described the car as "standing gently on its nose, doing several pirouettes and coming to rest with a very large clatter, most of which was spanners and tools hitting the back of my head". |
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He walked away from the accident unscathed, as he had many times previously. A terrible driver with a worse than average record on the road. |
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My uncle was in a LandRover station wagon one night, footling along the Flinders highway and hit a pothole. The front driver's side wheel came off and went bush. He described the car as "standing gently on its nose, doing several pirouettes and coming to rest with an enormous clatter, most of which was spanners and tools hitting the back of my head". |
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He walked away from the accident unscathed, as he had many times previously. A terrible driver with a worse than average record on the road. |
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This sort of thing may have helped, but the vehicle was worth less than a weeks wages. |
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The same wheel had come off the vehicle at much lower speed several weeks earlier, whilst a dog was chasing the old 'Rover. The dog followed the errant wheel for about 200 feet before it came to rest against a fence, pissed on it then trotted home, rather proud that it had finally caught and conquered the object of its frustration. |
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It's a shame the uncle has died, he was quite a character. |
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Every time UnaBubba tells that story, it gets stuff added to it.
Sorry the Earth lost such a character, let alone the fact he was kin, UB.
Broken Tailbone on Nephew - They had gotten married 2 days prior, and Bronco was uninsured. I got to play psychochiatneuroliagecounselmediatravelagentyer for a few days - what a Christmas for these folks. |
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I didn't say he was a nice man. He died of a heart attack at 2 am one Christmas morning. Completely stuffed up an otherwise perfectly good Christmas. He was the only one who knew where the chairs, tables, marquee (tent) and food were coming from. We figured it out eventually, but lunch was 3 pm by that stage. |
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He may have been a character, but he was the rudest bastard I've met, by a long shot. |
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Thumberg, Goldwax, Thumbwaxstein and Waxociates, LLC
The Thumphew is retaining services of a highly profitable and contagious litiganthill. It is expected to be just plain lawful.
Wax N. Stein |
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Have open content sharing of topographic data between cars. This way with a few thousand such cars in regular use it should be possible to make a very detailed and up-to-date picture of road surfaces for miles around. Perhaps the data exchanges could take place in parking lots. |
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Download the data in burst transmissions to selected roadside furniture articles, networked together. |
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Eventually, a database of info would be shared with each node, weighted towards nodes in the immediate vicinity, transmitting back to vehicles in burst uploads as they approach the area of road overseen by each node. |
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A central monitor could be used to alert Flocking Road Cones to converge on those areas in need of repair. |
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True, this would work well if integrated with the FRCs. |
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One problem with the shared database idea: malicious users (eg hackers). I could sit somewhere with a fake transmitter, repeatedly broadcasting news of a nonexistent pothole, and chuckling as everyone's suspensions go crazy anticipating it. |
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Public key crypto could prevent that. Send a signature along with the transmitted data, and if it doesn't match the signature of the appropriate government department (stored within the receiving car somewhere), ignore it. |
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Lackey: Captain, I have just received an encrypted message for you from the Department of Flocking Road Cones. |
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Captain: Oh really, what does it say? |
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Lackey: "aj6b d45df2ee j5ls jh jh2ggsa w8iw9
la lm3 ml, jh a kdn5s9dw ", then it ends with "710 77345" |
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Captain: 710 77345? Are you sure? Is that a message from [lewisgirl] ? |
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Nah, it's an idea by [cryo]. |
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[cp]: thought of that. PK crypto won't
help if the idea is that cars can share
road-surface information. All I have to
do is impersonate a car (or a series of cars)
going over the nonexistent pothole and "warning" others about it.
Yes, yes, you can get all fancy and add tamper-resistant modules, traffic analysis,
reputation systems, trusted third parties, etc., but then it's no fun any more. I'll just take my plain ol' non-distributed predictive suspension. |
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Yes man: Sir, the car ahead of us is spewing out paragraphs on end about potholes, and we can't work out who it is. |
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Boss: Does it sound like a harebrained scheme for solving suspension problems for once and for all? Lots of pseudo-science and a disclaimer that it was written 15 years ago, but would still work if only he can get his car to defy gravity? |
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Yes man: <consults printout> Er, yes, how did you know, sir? |
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Boss: It's Vernon. He must have got that grant from MSRC after all. |
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------[return to normality]------ |
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[wiml] Yes, that's true. I think it would work if the suspension information wasn't transmitted from car to car, but instead from some device on the side of the road; that wouldn't be as nifty as having cars cooperate, though. |
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Cadillac already has a similar suspension but to replace each strut costs around 700.00. Most owners swap in a custom passive strut system. |
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Actually F1 used laser ride height and suspension control over 11 years ago. In addition, Nissan's 300ZX from almost 20 years ago had laser controlled suspension in a prototype. |
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