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Electromagnetic Automobile Suspension Demonstrated
cylonlover writes "Last December at the Future of Electric Vehicles conference in San Jose, a representative from The Netherlands' Eindhoven University of Technology presented research that his institution had been doing into a novel type of electromagnetic vehicle suspension. Now that a test car equipped with the suspension is about to appear at the AutoRAI exhibition in Amsterdam, the university has released some more details about the technology. For starters, it is not only electromagnetic but also active, meaning that it doesn't just mechanically respond to bumps in the road, but is controlled by an onboard computer. It is claimed to improve the overall ride quality of cars by 60 percent." That seems an awfully exact figure — I'm not sure any two people would ever agree even about the exact same car's "overall ride quality."
The first thought that came to my mind when reading this post were hovercraft over water and maglev trains.... No give me a power source that has nothing to do with fossil fuels and you might have a winner!
I'm pretty sure Bose did this at least 4 years ago: http://www.bose.com/controller?url=/automotive/bose_suspension/index.jsp
That seems an awfully exact figure — I'm not sure any two people would ever agree even about the exact same car's "overall ride quality."
Dutch people have the rough analogue to "perfect pitch" for ride quality. I'm guessing they got to about three significant figures in the study but rounded it off to sound a bit more plausible to the rest of the world. No serious studies have to be done on why exactly Dutch people have this ability, but the current predominant theory among many is that it has something to do with putting mayonnaise on french fries.
Working...
http://www.bose.com/controller?url=/automotive/bose_suspension/index.jsp
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Even cars such as my VW Scirocco GT have similar systems (VW calls it Adaptive Chassis Control), it's not the preserve of supercars anymore. However according to the article, existing systems use hydraulic actuators, this system is apparently electromagnetic only, reacts faster and uses less power. Yes, I know, it's almost cheating to RTFA.
Oh no... it's the future.
That's what the spring is for. An electromagnetic "shock absorber" dampens oscillations by collecting the energy as electricity. It is essentially a linear motor run as a generator.
According to TFA, the system actually draws less power than hydraulic shock systems:
With a peak consumption of 500 watts, the suspension uses about a quarter of the power of hydraulic systems. It also stretches its battery life by using road vibrations to generate electricity. The designers believe that with refinements, the suspension's energy-efficiency could be improved even further.
rage, rage against the dying of the light
I worked for Bose back in 2005 and they were researching something like this. They were partnering with GM at the time but I think it fell out because the system was too heavy. There's a video floating around on YouTube of a car jumping over a bump using the Bose system.
Negative. This is not that system. There are a number of cars that let you adjust the shock absorbers on the fly: at the entry level, this involves servos adjusting the shock valving; at the high end (such as the F599) they use electromagnets to adjust the viscosity of the fluid in the shocks, which can be done much faster.
This system is altogether different: there is no shock absorber. They have a linear motor in its place. This gives advanced capabilities that adjustable shocks cannot.
For instance, say you turn hard left. The car wants to lean right. Soft springs are good for comfort, but allow the car to tilt more. This system lets you use soft springs, and then actively counter the body roll by pushing on one side and pulling on the other. The net result is you have the best of both worlds: the smooth ride of a luxury car's soft springs combined with the fast response and stiff anti-roll characteristics of a sports car.
You need a very strong linear actuator to make a meaningful improvement, but those are expensive and require a hefty electrical system to power them, further increasing the price. Bose did some fantastic demos of these some years back, but I don't think they managed to get any manufacturers interested, probably due to cost. Hopefully these guys have improved in that regard.
The Citroen Xantia Activa used a pair of hydraulic rams to counteract roll forces, as well as the four hydraulic rams that comprise the normal suspension. Apparently they maintain grip to 0.98G lateral force - they certainly can be flung round tight corners much faster than anything with those obsolete old sofa springs at the corners.
They are probably talking about pressurised hydraulic systems. You'd be surprised how much the coffee mug sized hydraulic pump on a hydropneumatic Citroen takes to run - possibly as much as 2hp with a heavy demand on the hydraulics. That said, most of the demand is from the power steering; the brakes use about a tablespoon of fluid every time you press the pedal and once the car is up to normal ride height it only takes a little trickle of fluid to keep it there (usually it'll take two hours for it to settle back to the ground).
The cost-reduced version of the Citroen hydraulics used on Rolls-Royce and Bentley cars uses a slightly different design of pump, but they have a bit more power to drive it...
Not true. As cars have gotten more complex, they've also gotten more reliable because electronics allow greater precision and control. Problems per mile has been going down for the entire industry, and the most complex cars (hybrids) are among the most reliable.
Remember carburetors? Mechanical throttle cables? Tune-ups every 3K? Automotive electronics before body computers?
--srj/mmv
Actually us pavement engineer types do this all the time. Basically the input to the function is the profile of the pavement measured by a pavement profilometer which essentially captures pavement elevation about every 6 in or so. (http://www.dynatest.com/functional-rsp.php) Then this profile is fed through an algorithm that models the response of a hypothetical "quarter car" (basically a spring above a tire to simulate the amount of movement experienced by something on the axle). This measurement is called the International Roughness Index and it has been correlated to "Ride Quality" perceived by highway users. It is not a perfect measurement but it is used quite frequently to help decide pavement projects. if you are more interested.... http://en.wikipedia.org/wiki/International_Roughness_Index http://www.umtri.umich.edu/content/LittleBook98R.pdf So for this thing they would need some other model to calculate the "movement" induced by road profile on the vehicle much like IRI. Once you have that you could correlate it to Ride Quality, have they done that? That is the question...
Mechanical throttle cables?
Yeah, I remember them. When you tap the accelerator, the engine revs in time, with no delay due to slow actuators on the low-mid range end of the market. Our Toyota Matrix pisses me off with this delay. How someone designed this and deemed it acceptable, I do not know.
Friends tell me that their cars (higher end cars) do not have a delay, but without trying it for myself, I can only give them the benefit of the doubt. Give me a throttle cable ANY DAY.
Oh and on topic. Didn't Bose (yes, the speaker people) already do this before?
Tom...
But isn't the Bose system that came out years ago fully electromagnetic? http://www.bose.com/controller?url=/automotive/bose_suspension/index.jsp
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
Sounds like a cool system, but it is limited to modulating the dampening, and the springs are still just passively pushing on the road, not knowing if they ought to be pulling to suck up a bump or pushing to counter body roll.
The average desktop computer is an unwieldy behemoth compared to a sleek laptop.
A desktop computer can use standard parts because the specs rarely change. Drives will be 3.5" wide, regardless if its cd/dvd/bluray/hdd. Even SDD, which most adhere to the 2.5" laptop size, will come with railings to get into the 3.5" space. You can dedicate space for the PSU, and the motherboard is usally ATX. You need to keep space free for any cards and for air circulation. A functional case from the late 90s won't be much different than a case today, except IDE cables turned into SATA.
OTOH, Vehicles have the same needs as notebooks. To compete on looks and a premium on space. They can't keep standards on things for 20+ years. Apple even designs their own motherboards and I guess the other manufacturer do as well. They can't agree on the standard, because advances make the minimum size a shifting target so shapes have to change. Notebooks and cars usually also need the exact same part in order to make repairs, so modularity, a strength of the PC, is out.
It would be interesting to have a car platform based on PC philosophy. Modularity and whatnot. I'd imagine it would be an electrically driven vehicle that can accept input from a variety of battery or generation from a fueled engine. It's body replaceable to perform a variety of tasks. I believe ford was working on such a future platform but cannot find it.
Mechanical throttle cables?
Yeah, I remember them. When you tap the accelerator, the engine revs in time, with no delay due to slow actuators on the low-mid range end of the market.
You're ignoring the down side to those same cables. Flooding of the carb, back fires, carb damage, excessive gas being dumped and flowing out the exhaust resulting in much more exhaust waste, cooling of the catalytic convertor preventing proper operation. Not to mention, on a lot of vehicles, the inline actuator is part of a safety system which reduces throttle when traction or control is lost. Thusly, for most drivers, direct cable is far more dangerous to everyone.
Basically, it was more reactive because it was so wasteful. Now throttle response follows a consumption and efficiency curve rather than a dump, waste, and foul curve.
If you want a more responsive throttle, simply changing out your air filter can make a big difference; as well as making sure it remains clean. Something like a K&N filter can make for big differences. As can a new exhaust pipe. Basically, on many small displacement engines (really, many engines but especially so on small displacement ICE), their intake and exhaust are artificially restricted; with the intake much more commonly so by the air filter. Remove your air filter and conduct some quick throttle response tests. For many economy cars the difference in throttle response is noteworthy. If this is true for your vehicle, a K&N (or any other high flow filter) can make a big difference.
I really like how nobody bothered to RTFA, which is not unusual, but which addresses this point. If the power goes out it still damps, it just doesn't have variable damping.
I understand not reading the fine article before making a comment about something related, but actually bitching about something that ain't even true and which is covered in the article is kneejerk slashbotism.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Good for, you've got an anecdote. Go back through the years of statistics that the NHTSA maintained on recalls and incidents; Toyota's trouble stirred much of this to the surface and it's easy to find. Note how high SUA issues and recalls were.
You're driving the wrong cars, then. Electronic throttles have been well worked out on, well, just about everything from supercars on down. You'd think that, if mechnical throttles were better that someone---Ferrari, BMW, whomever---would be using them. They're not.
Again, I point to the recent Toyota SUA incidents as a counterpoint. It was proven that most people don't step on the brakes hard enough to overcome the engine, or that they pump the brakes, or that they do something similarly stupid. SUA rates were quite low for cars with brake/throttle override. It's actually a very simple, very elegant idea that works for most people. Oh, sure, it makes heel/toe and left-foot braking harder, but outside of rally drivers that sort of behaviour is asking for trouble.
You're under the impression most people drive on a racetrack. Most people don't.
Yes, that's true. And the "interference with driver decisions" is why road accident and fatality rates are at their lowest ever, despite there being more cars on the road than ever. Half the people on the road are, by default, below average. Most aren't all that skilled. Personally, I'd like to avoid getting hurt because someone isn't 31337 enough to induce just the right amount of wheel lockup to not skid into me, or apply just the perfect amount of opposite-lock.
But they work well for most people under most conditions, allowing them to retain steering control (for ABS) or skidding uncontrollably (ESC). Yes, if you're a rally-racer they should be disabled. Most people aren't. You seem to miss that point
My, aren't we elitist? Look, good for you that you can drive your home-built Caterham at 10/10s on the track and can tear down and rebuild and engine in two hours. I'm glad for you. But you need to realize that most people are not you, and never, ever will be you. So just keep sneering to yourself.
But don't assume that electronics don't make cars more reliable, more efficient, safer, cleaner and faster for 99% of the people out there who don't give a shit about throttle oversteer or adjusting camber between laps. The facts are a) cars have more electronics, and b) those cars are thusly better in every way for everyone who isn't a gearhead.
This thread started because someone offered the usual "Oh noes, more stuff to break!" fallacy which has been proven, time and again, to be utter crap. It wasn't started as debate on automotive purity.
--srj/mmv
Several comments:
Fuck You. The notion that somebody would reply so rudely astounds me.
Raw fuel heats a catalytic converter. When catalytic converters were first put on carbureted engines, this was a common failure point. The fuel ignites in the converter, sometimes melting the catalyst. Some of the early converters used beads as the catalyst. These beads conducted heat poorly to neighboring beads, so they would heat very quickly, melting and eventually plugging the converter. Converters are more robust today, and engines much more tightly managed, so this particular failure mode is much less common.
The real-world results to which you are referring are so small, and at such a high throttle, that they're useless to 99% of the driving public. At best, a high-flow air filter moves the point at which the air flow chokes back to some other point, such as the throttle body, the intake manifold, the head (or heads) or the valves. In many instances, the air filter isn't even the restriction that chokes the intake as a system. I handled one of your closing sentences obliquely, but I'll address it out-of-order here: Of course restricted air flow reduces the potential of an engine. Perhaps you should learn to parse what you read properly, then come back and notice that my assertion is that there are bigger gains to be made elsewhere.
The comment to which you first replied was made by somebody driving a Toyota Matrix. This is not a performance-oriented car, so he's probably bothered about low-end throttle response. At the low end, a high-performance filter is not going to change anything. By necessity, the air flow will not be choked by a clean air filter at low engine speeds. A performance air filter CANNOT make any difference at the engine speeds that Tom17 is probably driving.
I didn't say "all", I only used the plural. In your original reply, you mentioned both an air filter and exhaust, hence my plural usage. As to idiots on slashdot, I was just now asking the same question.
Really, you little shit-tard, you know nothing about me. I've been repairing and improving cars since I was 14, for close to 30 years now. I was a mechanic for ten, until I finished an undergraduate degree in Mechanical Engineering. I'm quite aware that such experience doesn't necessarily make me smart, but your assumption that I'm stupid may be misplaced in the face of your demonstrated ignorance of air flow basics. Your continued, and false, assertion that hot catalytic converters cool with the introduction of raw fuel similarly betrays your ignorance. What's most disturbing to me is your bravado. You sound to me like some young little shit trying to cover his ignorance with bravado. I strongly doubt you would talk to me this way if you saw my time slips at the track. Have a good day: I've wasted too much time on you already.