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Transportation Power Technology

MIT Team Creates Shock That Recharges Your Car 281

Posted by samzenpus
from the power-up dept.
An anonymous reader writes "If you had a GenShock, you may not mind those potholes in the road any longer because this new prototype shock actually harvests energy from bumps in the road to save on fuel. A team of students at MIT have invented a shock absorber that harnesses energy from small bumps in the road, generating electricity while it smooths the ride more effectively than conventional shocks. Senior Shakeel Avadhany and his teammates say they can produce up to a 10 percent improvement in overall vehicle fuel efficiency by using the regenerative shock absorbers. They also already have a lot of interest in their design, specifically the company that builds Humvees for the army are already planning to install them in its next version of the Humvee."
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MIT Team Creates Shock That Recharges Your Car

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  • by feedayeen (1322473) on Thursday February 12, 2009 @08:59AM (#26826057)
    Looks like MIT just gave us a little picklet, will we repair our roads or use the potholes to power our cars?
    • by daniorerio (1070048) on Thursday February 12, 2009 @09:03AM (#26826091)
      I wonder if the 10% improvement in fuel efficiency only counts for roads in Boston, how about cities with decent roads?
      • Re: (Score:2, Interesting)

        No, I'm pretty sure they'd work in Detroit, too. Especially since I grew up there and drove on those roads for almost 35 years. Let me tell you: if this works half as well as they say in Boston, it'll probably cut your hybrid gas mileage in half.

        Okay, maybe that's an exaggeration. But it makes a good glass of lemonade!

        Now in the Tampa Bay area where I live now? Probably not so good. Every now and then I hit a pothole and I'm *shocked*.

        • Note they say "upto" 10 percent. Which means it might only be 1 percent in the real world. The regenerative braking in my Honda Insight is supposed to do "upto 30%" according to Honda's engineers, but in my experience on I-95 it's more like 1/2 percent. If that. The energy recovered represents maybe 1/1000th the amount of energy contained in each gallon of gasoline.* It's small and not significant.

          *
          * From 60 to 0, an Insight regen braking fills 80 D-zized batteries by 1/10th their capacity. That's 80

          • by virtue3 (888450) on Thursday February 12, 2009 @08:04PM (#26836605)
            ... regenerative braking only matters in city situations. As, well, quite obviously, IT ONLY POWERS UP YOUR CAR WHEN YOU BRAKE.

            Crappy highway conditions aside, you aren't pulling up to a stopsign/red light that often on the highway. THUS, the regenerative braking can't work.

            bottom line, if we keep making little features that add up, we can make an extremely efficient vehicle. Braking and shock absorption have always been energy transfer mechanisms that have just turned energy into waste heat before, now, we can do something with that energy and that is amazing!

      • will be on the lookout for new shocking disc-recoveries?

      • by TheKidWho (705796)

        It *should* work on a large portion of roads, and it also comes into affect during acceleration/decceleration.

        It's kinda interesting because I'm working on the same exact project at a different university in NY, we are actually just about to start manufacturing our prototype regenerative shock absorber...

        Our basic design is similiar to a 2-phase Linear motor, but obviously designed to fit onto a vehicle and provide sufficient damping.

      • by Rei (128717)

        No kidding. Since when is 10% of a vehicle's energy lost through the suspension? I doubt it's even that high on 4WD trails, what with all the accel/decel/low speeds/etc burning power.

        • by TheKidWho (705796)

          It's true! I don't have any papers on hand, but I can link to you some research papers later after I get out of work. There are NHTSA studies on it too.

      • by WMD_88 (843388)
        Ever been to Chicago? If this doesn't work there, it won't work anywhere. :o
        This probably won't work at all in Florida, anywhere. The roads are all too new, and the conditions that make potholes don't exist.
    • by txoof (553270)

      Don't let New Orleans hear about this! It will just give the city another reason to ignore the 6" wide pothole on my street.

    • by DG (989) on Thursday February 12, 2009 @10:54AM (#26827359) Homepage Journal

      I did a ton of shock development as part of my race car engineering job.

      We had sensors on the suspension to directly measure suspension travel, with a view towards measuring suspension velocity as part of shock development.

      Even on what feels like a perfectly smooth track, there's still a lot of humping and bumping going on.

      See http://farnorthracing.com/autocross_secrets6.html [farnorthracing.com] for example graphs of suspension velocity pulled right off the car.

      DG

      • Even on what feels like a perfectly smooth track, there's still a lot of humping and bumping going on.

        And even in what feels like a car that stands still (such as parked in a lonely forest parking lot), there's still a lot of humping and bumping going on...

    • by JonTurner (178845) on Thursday February 12, 2009 @10:54AM (#26827361) Journal

      OTOH, if you're running low on fuel/power, just cruise up onto the sidewalk and mow down a few unsuspecting pedestrians. *KaThumpKaThump* *KaThumpKaThump* Presto! Enough juice to make it home (after a quick run through the carwash, of course). Thanks, MIT!!

    • I suspect the first use won't be for cars. I suspect the first non-governmental use will be in the RV industry: Just think, put these shock absorbers on your boat trailer, and your electric boat will be charged and ready to go when you hit the lake. Put them on your (very heavy) Class C RV Bus (all 10 wheels) and you'll have 10kw of energy generation to recharge those batteries in between campgrounds.

  • by Anonymous Coward on Thursday February 12, 2009 @08:59AM (#26826059)

    Is this actually legal since it hurts the oil industry ?

  • by Anonymous Coward on Thursday February 12, 2009 @09:03AM (#26826087)

    I hope you are being silly. The most efficient way to travel would be a perfectly smooth road, one that didn't suck energy out of the vehicle, in the form of a bump, in the first place.

    To truly express the dilemma, you have to weigh the amount of energy used to maintain a smooth road versus the new found energy return from these shocks.

    • by oneiros27 (46144) on Thursday February 12, 2009 @09:11AM (#26826177) Homepage

      Which is why this makes sense for off-road vehicles, such as military hummers.

      But I agree that poor road maintenance is not just a suck on fuel efficiency, but results in increased costs on the upkeep of vehicles as a whole. (and it takes energy to make and ship those new sway-bar struts that I had to have replaced because of hitting too many bumps)

      • by Ogive17 (691899) on Thursday February 12, 2009 @09:23AM (#26826279)
        I take it you don't live in a cold weather climate or in a large city. Snow/ice + salt + plows = pot holes. Large cities have notoriously bad roads, it's too hard to repair them with so much traffic.

        And it's not just bumpy roads that shocks help with. Every time you turn a corner the shocks are used to keep the car stable.

        Personally, I think it's a brilliant idea. The easiest way to become more efficient is to turn the wasted energy into something useful.
        • by sumdumass (711423) on Thursday February 12, 2009 @10:17AM (#26826813) Journal

          You do realize that this will only effect hybrid or electric cars right?

          Here is some things to consider, in 2006 [bts.gov]there were a little over 135 million registered passenger cars in the US. Now that's not counting pickup trucks that had to be registered as commercial vehicles but are still used as personal vehicles. Since 2000, not more then 2.5-3 percent of new car registrations have been to hybrid vehicles or electric vehicles until 2007 which saw around 5%. This means that this can effect less then 10% of the passenger vehicles on the road and more likely that number is much lower.

          The second thing is, if these shocks produce a gain of around 10% in energy recovered, then we can do some math on the economics of it. If a hybrid electric car gets 60 MPH, Some say on 40, and they travel an average of 1500 miles a month, then we can find how much 10% is worth. So 1500/60 and 1500/40 respectivly come out to 25 and 37.5 gallons of fuel. At $2.00 a gallon, that would be about $50 a month for the 60MPH and $75 a month for the 40MPG. A 10% savings of them would be $5 and $7.50 per month savings. Regular shocks wear out after about 5 years or so of driving, some last around 10 years before they are noticeably shot. So $5 * 12 months * 10 years means this device would only save about $600 and $900 over ten years. That's the price point they have to beat in order for there to be a savings. If they can't get the cost of this stuff under those dollar figures, then they are probably costing more then any savings.

          My guess is that their effectiveness is going to go as the shock absorption abilities go and will only be effective for that typical 5 years then severely degrade after that like regular shocks and struts seem to do. The concept doesn't seem to be much different then a wave generator but applied to an existing gas or oil filled cylinder instead of hydraulic pistons connecting floats. This means that they will have to create a valve system and generator and a way to connect it to the cars power inputs. They might be able to do that for less then $6-900 every ten years. But I doubt it.

          • by suggsjc (726146)
            You and your facts and figures. Please don't let sumdumass talk to some dumb ass in Congress else this will never get gov't funding!
            • by sumdumass (711423)

              Lol.. You think it needs government funding? I would figure if it actually was efficient as in saved more money they it costs, then there would be a market for it and people would be begging to have it.

              Here is the problem with government funding for crap like this. Now keep in mind, I say crap not because it is, but because you assume I think it is. I wasn't attempting to talk anyone out of it, I was attempting to show the practical savings of it. Anyways, if it exists only because of the government funneli

          • by Firethorn (177587) on Thursday February 12, 2009 @11:05AM (#26827553) Homepage Journal

            You do realize that this will only effect hybrid or electric cars right?

            Given the specific mention of military hummers, which are most certainly NOT hybrids or electic, it must have some benefit for non-hybrids.

            Then again, how difficult would it be to replace the starter and alternator with a motor/generator capable of putting power to the drivetrain? Even if it's only a 5hp sustained, that'd be more than enough to take the 1kw each of the six shocks is capable of putting out(1hp=746W). Switch out the lead battery for a LiIon/NiMH of substantially more capacity. Increased cost, but probably actually lighter than traditional systems. For cold areas, there are LiIon that perform *as rated* at -40C. Not the 'put a bigger battery than you could possibly need in warm weather so you still have enough power to start when the oil is like jelly and the battery has 10% capacity left'.

            You'd end up with a mild hybrid that can do stuff like shut off the engine at stops. Oh and stick the energy gained from the shocks back into moving the vehicle.

            If they can't get the cost of this stuff under those dollar figures, then they are probably costing more then any savings.

            The only problem I see with your figures is that they're explicity talking about trucks and other heavy vehicles. So you might want to redo your figures for 12-20 mpg ranges. Their test mule was a heavy truck with six shocks. Indeed, they also mention that it provides a better ride than traditional shocks, so there's a possible selling point there.
            20 mpg/15,000 miles=750 gallons. Save 75 gallons a year(10%), that'd be $150@$2 gas, $300@$4 gas. Ten year timeframe? Could save them $3k, more if they've got a really heavy truck or are driving on particularly bumpy roads.

            Then again, I've said numerous times that it makes more sense to make trucks and SUVs hybrid before you start making sub-compact hybrids. More fuel to save, more room to put the components, components end up being a lower percentage of the cost of the vehicle, etc...

            I mean, look at the typical UPS/FEDEX panel van. Consider it's usage - stop and go traffic all day in the city for most of them. Right now they have a diesel engine that doesn't get turned off when they stop. How much fuel can be saved if you turn the truck into a hybrid? As a bonus, the heavy battery pack in the bottom of the vehicle would help mitigate the tipping hazards of a tall vehicle like that.

            My guess is that their effectiveness is going to go as the shock absorption abilities go and will only be effective for that typical 5 years then severely degrade after that like regular shocks and struts seem to do.

            Might last longer due to the nature of the energy absorbtion, but you're right. A lot of cost and durability issues need to be resolved.

            • Re: (Score:2, Interesting)

              by maxume (22995)

              The military is all about electric drivetrains. Stuff isn't necessarily deployed, but they burn a lot of diesel and carry around generators, so they are very interested in things that save diesel or put a generator in every truck.

            • Re: (Score:3, Insightful)

              by mdielmann (514750)

              Might last longer due to the nature of the energy absorbtion, but you're right. A lot of cost and durability issues need to be resolved.

              Think along the lines of the shake-charged flashlights. The only things added to a regular shock are a coil and a magnet. The magnet isn't going to wear out in any reasonable time-frame, and a properly insulated and protected coil won't either (unless the temperature starts to affect the insulator - unlikely, and can be mitigated with engineering). I suspect they would last about as long as regular shocks unless they completely replace the standard shock-absorption part. That seems unlikely - a wire bre

            • by MrTester (860336)

              Given the specific mention of military hummers, which are most certainly NOT hybrids or electic, it must have some benefit for non-hybrids.

              Au contraire

              hybrid HMMWV research right here:

              http://www.sae.org/technical/papers/2008-01-0775 [sae.org]

          • by inKubus (199753)

            I can see what's next: Regenerative bumpers that recharge your car whenever you get in a wreck. GET ON IT MIT!

          • by justthinkit (954982) <floyd@just-think-it.com> on Thursday February 12, 2009 @11:32AM (#26828037) Homepage Journal
            Let's respond point by point.

            You do realize that this will only effect hybrid or electric cars right?

            Yes. This will only affect some present and most future cars. Sorry to have disturbed you with it.

            ...your 2nd paragraph yields number of cars affected...

            Ok, let's agree on less than 10% of passenger cars today. I can add that it affects zero% of my car(s) -- an equally irrelevant fact.

            The second thing is, if these shocks produce a gain of around 10% in energy recovered, then we can do some math on the economics of it.

            We sure can, and the bottom line is that for 5% of the cost of a $20K car, you can get 10% better fuel economy. [2.5% of a $40K car, 1% of a $100K car, 0.1% of one of these [wikipedia.org]] This "spend 5%, get 10%" thing should already be a clue but here is a back-of-the-envelope calculation anyway: over 150,000 miles, a 25mpg car will use 6,000 gallons of fuel. 10% of that is 600 gallons. At today's price, that is about $1,200, FTW. 5 or 10 years from now it will be higher.

            Also, 10% more energy translates to a savings in weight somewhere else. For example, the batteries can be 10% smaller, and a 10% battery weight savings could lead to a further 10% gain. Yes, adding a small "Shock Energy Recovery System" to each wheel would add weight, but most likely not equal to 10% of 68KG [eaa-phev.org]. And those 68KG only take a Prius for about 5 miles (currently). The next gen is going for 11 miles of electric-only range, so scale the battery weight accordingly. And that is the point -- if you scale the battery range to 50 miles for example, the weight goes to 680KG, and the SERS savings becomes 68KG since it is not necessary to scale the size/weight/cost of the SERS system.

            My guess is that their effectiveness is going to go as the shock absorption abilities go and will only be effective for that typical 5 years then severely degrade after that like regular shocks and struts seem to do.

            Bad guess -- electrical systems last vastly longer than purely mechanical systems like a shock absorber. SERS could be an induced system, without physical contact, and thus without wear.

            And how about just having an extended vehicle range? If you live 5.5 miles from work, your present day Prius will still have to fire up its gas engine. Add SERS and you don't need the gas. If you presently change the oil every 6 months, now you change it every 6.6 months. And unlike engines, and batteries, the SERS can be designed to not wear out at all -- so you extend the total life of your car, bringing further savings.

            I think I'd like to let the marketplace decide, rather than choosing to not offer this product because it might just break even in some initial/present day cases. If SERS causes excitement and optimism, people will want to move toward electric and electric/hybrid systems even more -- and that would bring lower prices and more savings.

            The future is in plastics, and SERS-like systems. I find your post well reasoned...for a 1900s buggy whip manufacturer.
            • We sure can, and the bottom line is that for 5% of the cost of a $20K car, you can get 10% better fuel economy. [2.5% of a $40K car, 1% of a $100K car, 0.1% of one of these [wikipedia.org]] This "spend 5%, get 10%" thing should already be a clue but here is a back-of-the-envelope calculation anyway: over 150,000 miles, a 25mpg car will use 6,000 gallons of fuel. 10% of that is 600 gallons. At today's price, that is about $1,200, FTW. 5 or 10 years from now it will be higher.

              So, for an extra $1000 in cost o

          • by Spoke (6112)

            You do realize that this will only effect hybrid or electric cars right?

            Actually, you'd be surprised at how much electricity a modern vehicle draws at highway speeds. And as more and more parts move to electric power from engine power to facility things like auto-start-stop without compromising functionality, those power draws will only go up.

            For example, a typical car today will draw about 50-60 amps cruising on the highway. At 14.4v, that's over 700 watts.

            Now, lets put make the AC compressor, coolant pu

          • There are a whole lot of components that could be replaced on a non-hybrid vehicle that would save fuel. The alternator being the main one. It runs off a belt off the engine. Use the energy from the shocks to run the electrical system and keep the battery charged. The A/C compressor is another one. Make it run off the electricity generated by the shocks. You might need a different battery system, but it could be done, and it would definitely increase fuel economy.
        • I am going to guess that in the future, these will use perm mags, rather than a small turbine. When that occurs, I think that we will see the upfront costs be a bit more, but they will last for several 100K of miles, rather than just a 100K miles.
        • by rickb928 (945187)

          "In this house we are subject to the laws of thermodynamic..."

          Fixed that for ya...

      • by El Torico (732160)

        Which is why this makes sense for off-road vehicles, such as military hummers.

        Not exactly, military vehicles need to be robust and should be capable of being rapidly serviced. This applies to ground vehicles more than aircraft. The US military has lot of current equipment that is unnecessarily complicated or poorly modified (such as the up-armored HUMVEE).
        However, I didn't RTA, so I don't know how complicated the system is.

        • Re: (Score:3, Insightful)

          by DrgnDancer (137700)

          I'll take the "poorly modified" up-armored vehicles over a canvas passenger compartment on my patrol of Baghdad any day. When we were in Iraq in 2004-5 my brigade lost a few soldiers, but at least as many and probably more were saved by vehicle armor as were lost. The armor provided some maintenance headaches for sure, but I'd rather (and the mechanics, would rather, especially since they ran in the same vehicles when they went outside) the mechanics have to work a bit harder than having the fatality rate

    • by tecker (793737)
      Apparently you have never driven an interstate highway or local road in Kansas (or the Midwest in general). You would easily get some power just on a drive around town or to the next.
    • by clickety6 (141178)

      Rubbish, the most efficient way to travel would be a perfectly smooth road going downhill so that we can utilise the power of gravity.

      That is why the government should insist that all hills are built downhill and in those states that are flat, convenient hills should be built.

  • by Carewolf (581105) on Thursday February 12, 2009 @09:04AM (#26826107) Homepage

    Recharging the batteries using movement of the shock absorbers is ingenious!

    That they would smooth the ride more than conventional shock-absorbers is bullshit. You can get all kinds of traditional shock-absorbers. American ones for instance are typically softer than European which leads to poor handling and increased fuel consumptions. European ones are harder, and sports-models even harder yet, given the cars better handling at the expense of ride comfort.

    If the new absorbers are smoother than traditional ones, it just means the car can't corner, and rides like a pimp car.

    • by drinkypoo (153816)

      European ones are harder, and sports-models even harder yet, given the cars better handling at the expense of ride comfort.

      The firmness of the ride is not the only story in ride comfort. I have a 1982 300SD, my last car was a 1983 Impreza LS with WRX wheels, before that a 1981 300SD. :) The 300SD is a hundred times more rigid up top. Meanwhile my pop used to have a 1991 (I think) Mercury Grand Marquis. Just as heavy as the 300SD and even bigger, but with a significantly inferior ride. Over the super-bumpy road I live on, the Mercedes is substantially more pleasant to drive than the Marquis, probably because it has a fully indep

    • Would not having smoother roads do more to benefit economy as well as reduce maintenance costs?

      Besides you have to evaluate the whole of the suspension system to get an accurate measure of how well it rides and handles. Shocks used to be a bigger part of it ages ago, today they are just one component in many that determines how a car rides. If anything you can cause more issue by just having too much air pressure in the tires.

    • by dwandy (907337) on Thursday February 12, 2009 @09:16AM (#26826223) Homepage Journal

      If the new absorbers are smoother than traditional ones, it just means the car can't corner, and rides like a pimp car.

      "handling" and "softride" are not a zero-sum game. Suspension can be both better handling and softer than conventional systems.
      being a good /.-er I did not rtfa, but I assume their suspension is active [wikipedia.org].

      • by Carewolf (581105)

        Sure it is not a zero-sum, but if it is active suspension it is softer by being active, not by being a hybrid-suspension. They could also be using decoupled suspension like everybody outside Detroit does, but that is still just another standard trick, and nothing new or special.

        Btw. If I remember correctly, active suspension primarily improves comfort during cornering by eliminating body-roll. This makes the driver _feel_ turning is easier, but it doesn't improve the turning performance. No race-cars use th

        • Re: (Score:3, Informative)

          by KowShak (470768)

          Some forms of active suspension mean your car can have suspension matched to the weight of the car and its loads, you can have suspension matched to an empty car when its empty and matched to a fully laden car when its loaded up instead of having a compromise setup thats matched to neither laden or unladen. How many times have you seen a car where the rear is low because of the load of the passengers or the trailer its towing?

          Other forms of active suspension means you can have soft suspension when you're dr

    • So thats why Europeans are so snotty, their asses are so sore.
      On a more serious note.
      I think it is the size of the cars more then the suspension that really accounts for the difference in fuel. Sometimes things are different because of personal preferences, and one is not necessary better then the other. One could argue the extra comfort of driving will allow the driver to use the highway without stopping more often thus maximizing the efficiency of the car. Vs. A car with poor suspension where people will

    • by Ed Avis (5917)

      They might be smoother yet not softer. That is essentially the art of making suspension: anyone can make a car which gives a smooth ride but wallows round corners, or one which handles well but rattles your bones. Hydraulic shock absorbers are often thought to give a smoother ride than springs but with just as good handling: look at the hydropneumatic suspension traditionally used by Citroen (and licensed by some other manufacturers).

  • Once the team found the wasted energy, they were focused on harnessing the loss energy. Their prototype shock absorbers use a hydraulic system that forces fluid through a turbine attached to a generator. The system is controlled by an active electronic system that optimizes the damping, providing a smoother ride than conventional shocks while generating electricity to recharge the batteries or operate electrical equipment.

    In other words, this would be a useful retrofit for existing vehicles, but it will never happen; And instead of continuing to build lots of big heavy vehicles we need to be making smaller, more efficient vehicles which will not only lose less energy during damping due to reduced mass but also where the shock absorber generator system's additional weight will be a significant drawback. Finally, the incredible added complexity as compared to an ordinary shock damper means that such a system will have incredib

    • by Locklin (1074657) on Thursday February 12, 2009 @09:50AM (#26826521) Homepage

      I wouldn't be surprised to see tractor-trailers going hybrid soon. Fuel economy is a HUGE factor for trucking, and they require large engines to maintain speed up large inclines. Additionally, all that weight is very hard to slow down on declines -producing a lot of wear on brakes and power-train (engine breaks). Trains already do it, trucks are next.

      • by drinkypoo (153816)

        Trains already do it, trucks are next.

        I'm actually not sure why they haven't done this already... Perhaps the cost of the motor/generator? Certainly it would actually reduce the parts count and could make the vehicle more reliable overall.

        The only problem is that if you don't have batteries you have to use the power on-demand, and so far tests of battery-equipped hybrids of that size have been failures, although perhaps there's something I don't know about coming up in trucking. They haven't been able to make a power system useful for a locomot

        • Re: (Score:2, Informative)

          by Tiber (613512)

          (My father in law drove an 18 wheeler at one point).

          So much of the 18 wheeler relies on moving air around pneumatically. The two basic forces in an 18 wheeler are positive pressure and vacuum. If you do away with the engine (or otherwise turn it off), you lose the boost/vacuum economy which makes those accessories work. While you could probably come up with some weird stopgap - they already use compressed air tanks as a backup - the retrofit to make it work with existing trailers would far outweigh the savi

          • by drinkypoo (153816)

            Guess what? There's no vacuum in a turbo diesel; you can make some on the intake side of the turbo but you have to restrict the intake significantly, causing problems feeding the engine with air. But anyway we're not talking about having an electric 18-wheeler. We're talking about having a series hybrid tractor, which would eliminate the transmission in favor of a motor-generator pair just as they do with diesel locomotives today. The most logical engine to couple to it would probably still be a turbo diese

          • by Firethorn (177587)

            Add to this that the truckers rent or own their own cabs as part of the business and there's little incentive for anyone to innovate or upgrade in a direction that would hurt their prospects for hauling.

            Conservive I can understand. However, there are large fleets out there, and as the parent mentioned, a 10% savings in fuel costs is substantial. New car every year type substantial.

            Now, as for the pneumatics, that's easily handled with a couple electric pumps. Still, I don't think anybody's talking about making semis anything other than weak hybrids. Or killing their transmission in favor of a smaller version of the generator-motor system used in trains because it's actually more efficient than a mechan

            • by drinkypoo (153816)

              Still, I don't think anybody's talking about making semis anything other than weak hybrids.

              What is a "weak hybrid"? That doesn't mean anything that I know of, and the word "weak" is entirely unclear in this context.

              Or killing their transmission in favor of a smaller version of the generator-motor system used in trains because it's actually more efficient than a mechanical transmission.

              From your sentence fragment it is unclear whether you advocate this approach or not, but it is probably a fantastic idea. The problem is that it would best be applied to every wheel on the vehicle (including on the trailer.) Perhaps the approach would be better applied first to the lowly box truck.

              Arguably if we as a nation were to spend money on transportation it would better be spent

        • by DemiKnute (237008)

          The reason they haven't done it is weight. Trucks are legally limited to 40 tons in most places in the US. All those batteries are heavy, which cuts down on the cargo you can haul, which cuts down on your pay, which cancels out the money you save on fuel.

          Do expect to see hybrids popping up in local delivery trucks. Driving in the city with lots of starts and stops and usually at less than maximum load really helps the hybrid economics work out.

      • Batteries will only make it worse.

      • by Spoke (6112)

        The biggest problem with hybrid trucks is that power demands of trucks are HUGE when compared to a typical vehicle.

        For example, if we take your example of trying to slow down a truck on a long grade, the batteries would need to be huge to absorb all that power. Also, hybrids tend to be most effective in start-stop type driving. On long hauls diesels, a hybrid system typically won't improve fuel economy much. (Note: it does work effectively on gas hybrids where you are able to run the engine on the atkinso

    • That truck has an alternator that probably puts out 55A peak at 12V, most likely only 30A for long periods.

      More likely that the truck has at least a 90 amp alternator that could go as high as 150 amps depending on usage. For example, a fully loaded 4 wheel drive truck with lift kit and multiple shocks, plus multiple-off road lights would use a minimum of a 120 amp alternator just to handle the lighting load.

      In a commercial truck (class 6-8) the minimum alternator is 90 ampps for class 6 (3 axles) with the class 8 (Heavy Semis) having anything between 110 to 180 amps. This is due to not only the lighting loads of

    • They say they're getting up to 1kW per shock off a six-shock truck. That truck has an alternator that probably puts out 55A peak at 12V, most likely only 30A for long periods. That's only 660 watts! You can't even USE this much electricity without a hybrid vehicle. So this is only going to be useful for very heavy electric or hybrid vehicles. Who's going to make use of this again?

      Design a system to regulate the power from those shocks. If it is deliverying 1kW/shock that's great. Once you get the vehicle

  • Bad summary (Score:4, Insightful)

    by Nimey (114278) on Thursday February 12, 2009 @09:12AM (#26826199) Homepage Journal

    should s/shock/shock absorber/ so we know WTF you're talking about right away.

  • by argent (18001) <peter.slashdot@2006@taronga@com> on Thursday February 12, 2009 @09:22AM (#26826269) Homepage Journal

    This is pretty good.

    In their testing so far, the students found that in a 6-shock heavy truck, each shock absorber could generate up to an average of 1 kW on a standard road.

    The total insolation at the equator is about 1kW per square meter, so if your solar cells are 20% efficient that's the equivalent of 30 square meters of solar panels.

    ("up to an average", though... wtf does that actually mean? Oh well, your solar cells only get "up to an average" of 1kW too...)

    • Shocks generate that 1kW only at peak actuation, whereas solar is continuous. I would find it hard to believe that even a heavy truck would have the ability to generate a continuous 9HP (about 6kW) on shock alone, unless it were in some off road condition.

  • by courteaudotbiz (1191083) on Thursday February 12, 2009 @09:27AM (#26826309) Homepage
    I've been saying for 5 years now that we should use all the available energy to power electric cars. Shock absorbers are one step, but combining it with solar cells, small wind generators deployed while coasting, regenerative braking, coupled with supercapacitors and a plug to recharge when necessary, that would be truly innovative.

    I think that this is the way of the future, and MIT did one step.
    • by drinkypoo (153816) <martin.espinoza@gmail.com> on Thursday February 12, 2009 @10:10AM (#26826737) Homepage Journal

      I've been saying for 5 years now that we should use all the available energy to power electric cars.

      I've been saying it for ten! Where the fuck have you been?

      I think that this is the way of the future, and MIT did one step.

      Now if they take one step back, and one step forward, and one step back... they're doing the cha-cha.

    • by Culture20 (968837)

      small wind generators deployed while coasting, regenerative braking,

      Small wind generators are a form of regenerative (air)breaking.

  • by jellomizer (103300) on Thursday February 12, 2009 @09:36AM (#26826393)

    Cars are brought back to their parents on prom night with a full tank of gas.

  • So we'll know when California is about to experience 'the big one' as the pre-shocks will overcharge the batteries and everyone will be diving for cover amidst assploding vehicles?

  • washboard road. That's where these shocks could generate some serious juice.

    Or for fun test these shocks on the corduroy roads [wikipedia.org] this country had as an early form of paving.

  • That is one company that is BEGGING to be let go from GM. It is wasted there. I am not a real fan of hybrids, but it has its uses. It would be good in cross-country trucks and vehicles like the Hummer. This is the PERFECT place to put a serial hybrid. A hummer with electric drive, batteries for 5 miles and 2 small motor/generators would be a winning vehicle.

    I still feel that the best way out for the car companies is to break them up for those that accept fed. money. Otherwise, you have the same idiots in
    • Re: (Score:3, Interesting)

      by Andy Dodd (701)

      http://en.wikipedia.org/wiki/Joint_Light_Tactical_Vehicle [wikipedia.org]

      The next military truck might not even be from the company that makes the HMMWV. BTW, most of the JLTV entrants (if not all? It might be a program requirement...) are hybrids. The military wants increased fuel efficiency for logistical purposes.

      • If EESTOR was real, this would be the place to be bidding. Assuming that they are real, I can understand their wanting to keep quiet while working with manufacturers. Otherwise, it would cause TOTAL ECONOMIC CHAOS. But I do not see them in this. Though their Military partner is L-Mart and I see that they are on the final 2 list.
  • Let's do the math (Score:3, Informative)

    by Ancient_Hacker (751168) on Thursday February 12, 2009 @09:57AM (#26826605)

    At first glance this sounds like a good idea, but let's do the math.

    Assume you're driving over an evenly and heavily potholed road, such that all four wheels are rising and falling four inches four times a second. That's a very generous assumption. And assume a rather pudgy 400 pounds of unsprung weight. To move that stuff 1.33 feet per second takes 900 ft-lbs.sec of power, about 1.5 horsepower. But you don't want to absorb all that power or the whole point of a flexible suspension is lost. Let's guess we want a Q-factor of about 3, that is, we absorb 1/3 of the energy per cycle. We're down to 0.5 horsepower, and that is under optimally bumpy conditions. And small random jiggles are hard to capture as electricity. Overall it does not seem to be worth harvesting.

    If one is going to be driving on such surfaces a lot, it makes a whole lot more sense to fit the vehicle with larger flotation-type tires. Those tend to flex and span potholes, so the car and passengers don't jiggle at all.

  • $@#%@$%@#$^@%&#%....Stupid....MIT....STOLE MY IDEA....now......I have to keep working for a living.......OH WHY DIDN'T I patent it when I thought of it!!!...KAAAAAAHN

  • They're called "dampers" or "shock dampers", not "shock absorbers". The springs on a vehicle are absorbing the shock, and the dampers have the job of damping the resulting oscillation of the sprung mass. In a way, the job the dampers do is almost opposite that of shock absorption.
  • "a shock absorber that harnesses energy from small bumps in the road"
    It doesn't create energy, it only recovers a certain percentage that would have been lost otherwise.

    As such, it'll only be practical on rough terrain, poor quality roads, or when you intentionally drive over potholes . . .

    • Re: (Score:3, Funny)

      by GameMaster (148118)

      As such, it'll only be practical on rough terrain, poor quality roads, or when you intentionally drive over potholes . . .

      Or people, don't forget people.

  • Parking (Score:2, Redundant)

    So when I am parking with my girlfriend the car is charging up? Wow.

  • Could the shock absorbers themselves (which are presumably more expensive than regular shock absorbers), plus the cost of installing them, plus whatever additional electronics are needed for them, actually have a chance of paying for themselves? They said it would be an increase in mileage of 10%, but a lot of cars on the road right now could realize 10% or better just by getting a tune up and checking their tires.
  • Faraday anyone? (Score:2, Interesting)

    by DrWatson333 (1362277)
    What about cutting out the hydraulic middle man and just have a coil of wire on the shock moving through a magnetic field?
  • Yes, thats same Bose who invented the namesake sound system. I think his was based on magnetic levitation. [wired.com]
  • planning to install them in its next version of the Humvee.

    Cuz with these things fitted, an IED going off underneath you should just about fill your battery!

  • Now if they can make something that captures energy from wiggly little kids, we're set forever.

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