1. Attachments are working again! Check out this thread for more details and to report any other bugs.

July 2006 Scientific American - A New Take on Hybrids

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by walt, Jul 16, 2006.

Page 1 of 4
  1. walt

    walt New Member

    Joined:
    Jan 14, 2006
    195
    1
    0
    Location:
    Bel Air, MD, USA -=- Blair, Merlin, Merka
    Vehicle:
    2006 Prius
    Found this in the current issue of Scientific American (July 2006).
    Definitely from the perspective of the "big iron" automible manufacturers.

    Walt

    ====================

    A New Take on Hybrids - Former Skeptics Develop an Alternative Hybrid System
    By Steven Ashley

    Toyota’s flagship gas-electric hybrid sedan Prius represents the epitome of the emerging “green car†category in the mind of the buying public. Although hybrids are still only a blip on the automobile sales charts, the market-leading model has been the most effective tool in the car industry’s effort to wrap itself in an eco-friendly cloak. But even with the success of this niche market, General Motors, DaimlerChrysler and BMW have mostly remained on the sidelines, unconvinced of the hybrid’s practicality and marketability. (They shied away from having to swallow the added cost of the hybrid’s extra electric motors, batteries and so forth— the “hybrid premium†that has thus far failed to fully appear in sticker prices.)

    But that view seems to have changed. A consortium of the three firms is working on an alternative technology called a two-mode hybrid to challenge Toyota’s supremacy.

    As in most hybrids, the two-mode system marries a gasoline engine with electric motors. And it recaptures braking energy as battery power, shuts down the engine at stops and can operate at slow vehicle speeds on electricity alone. Unlike Toyota’s single mode Hybrid Synergy Drive, however, the two-mode offers enhanced fuel efficiency not only in stop-and-go traffic but also on the highway, producing a 25 percent improvement in combined mileage over standard models. In addition, the new design can accommodate vehicles large and small as well as rear-, front- or all-wheel-drive models.

    In a typical single-mode hybrid, engine power drives a planetary gear set (which multiplies the torque from the power source) that splits the power between the drive axle and an electric motor. The system’s first electric motor operates as a generator, converting that mechanical rotation into electric current, which can then either recharge the battery or power a second electric motor that produces drive-axle torque, depending on the driving conditions.

    In contrast, the two-mode system contains two electric motors sandwiching two planetary gear sets, which are separated by two electronic clutches that together form a pair of electric continuously variable transmissions. The system can thus deliver a continuous spectrum of gear ratios that overlays four fixed gears sized to provide operating “sweet spots†at which the engine can achieve enhanced fuel economy or traction power for rapid acceleration, hill climbing or trailer pulling. “It switches between modes seamlessly, without the driver realizing it,†explains GM’s Larry Nitz.

    Single-mode systems are efficient at low speeds mainly because they can propel the car without the engine. At higher velocities, when engine power is required, however, running the electric motors yields less benefit because transmitting power through the motors and a variable transmission is nearly 25 percent less efficient than sending it through a mechanical path that uses gears, Nitz says. At high speeds, the two-mode system improves fuel mileage by relying on electric-motor assist and cylinder deactivation—shutting down part of the engine when extra power is not required. Real-time computer controls match the most favorable operating configuration to each driving situation to optimize power and torque as needed.

    The two-mode’s mechanical components are cheap and reliable, whereas the single mode’s electric motors and power electronics tend to be more costly and tricky to run, says Andreas Truckenbrodt of DaimlerChrysler. The new system also avoids the big, heavy electric motors that a single-mode vehicle needs to accelerate to top speed and to compensate for its lack of gearing.

    GM’s Chevrolet Tahoe and DaimlerChrysler’s Dodge Durango SUVs will receive the two-mode in late 2007 and early 2008, respectively. Although BMW has not yet revealed its plans, the German car maker’s Wolfgang Epple confirms that each company will adapt the system to its own engines and brand—for instance, a two-mode in a BMW X5 sport wagon would perform differently from one in a Tahoe or a Durango.

    GREEN OR GREENWASHING?

    Honda was the first to introduce a fuel-sipping, lower-emission hybrid into the American market (the two-door Insight). Toyota currently sells more hybrid vehicles than its competitors combined. It even licenses hybrid patents to Ford and supplies components to Nissan. Hybrids have enabled car makers to project the image of being green, even while purveying fleets of gas guzzling but high-profit pickup trucks and sport utility vehicles—a public relations strategy critics call “greenwashing.†They also help the companies meet federal Corporate Average Fuel Economy (CAFE) standards.

    BIG, HIGH-POWERED VEHICLES, such as this GMC Graphyte concept SUV, will be targeted for the two-mode hybrid system, because boosting mileage ratings will save more fuel than using the same technology in smaller cars and trucks.
     
    #1 walt, Jul 16, 2006
  2. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,041
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    Ehh, anything that helps. But I will be surprised if a drive train with two gear sets and two clutches proves to be as reliable as HSD.
     
    #2 richard schumacher, Jul 16, 2006
  3. jbarnhart

    jbarnhart New Member

    Joined:
    Jan 3, 2004
    629
    1
    0
    Location:
    Santa Clara, CA
    My simple mind gets so confused....

    It has TWO planetary gear sets plus clutches, it still has two motor/generators and associated controls and batteries, it has an ICE with cylinder-deactivation, yet it avoids the complexity of the single-mode system??

    I really must need a brain upgrade to follow GM's logic.
     
    #3 jbarnhart, Jul 16, 2006
  4. BobZ

    BobZ New Member

    Joined:
    May 11, 2006
    323
    0
    0
    Location:
    Long Island, NY
    <div class='quotetop'>QUOTE(jbarnhart @ Jul 16 2006, 08:53 PM) [snapback]287321[/snapback]</div>
    You can say that again! :mellow:
     
    #4 BobZ, Jul 16, 2006
  5. wstander

    wstander New Member

    Joined:
    Jul 16, 2005
    982
    1
    0
    <div class='quotetop'>QUOTE(jbarnhart @ Jul 16 2006, 05:53 PM) [snapback]287321[/snapback]</div>

    Not just GM, but also Daimler-Chrysler and BMW are all in this consortium, no doubt led by Rube Goldberg :)
     
    #5 wstander, Jul 16, 2006
  6. Godiva

    Godiva AmeriKan Citizen

    Joined:
    Apr 8, 2005
    10,339
    14
    0
    Location:
    San Diego, CA
    Vehicle:
    2005 Prius
    Please provide a link to the origin of the article.

    And please copy/paste only a portion. Copy/pasting the entire article violates copyright and forum guidelines.
     
    #6 Godiva, Jul 16, 2006
  7. VaPrius

    VaPrius New Member

    Joined:
    Nov 2, 2005
    150
    0
    0
    Location:
    Virginia Beach
    Vehicle:
    2005 Prius
    These are the same car companies that said the Prius couldn't be very efficient because of all that extra weight from the electric motors and batteries. Now they are saying we need to double up on everything! All for a 25% gain on combined MPG? The Prius gets 33% better MPG combined. 33 is better than 25 right? :)
     
    #7 VaPrius, Jul 17, 2006
  8. john1701a

    john1701a Prius Guru

    Joined:
    Jan 6, 2004
    12,769
    5,252
    57
    Location:
    Minnesota
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    When you dig deep, you discover that the two-mode system won't actually be able to be used as competition with Prius. It is specifically designed for the really large vehicles.

    And to make their "lots of talk, little action" behavior even more pronounced, you'll eventually discover that all 3 combined (GM, DC, and BMW) only plan to build 83,000 vehicles by 2010. So even among the large vehicles, they aren't planning to deliver much.

    It's good to hear that they intend to get in the "full" hybrid game, but the clutches and additional PSD make you wonder what the heck the cost & efficiency numbers will really be.


    .
    That's because part of the benefit comes from cylinder-deactivation... which isn't possible with a 4-cylinder engine... hence the inability for this system to compete with vehicles like Prius.

    Also, the scam of "save more fuel" is starting to get really annoying. It's a great example greenwashing, because they're still using more fuel. But you tend to overlook that reality by the way they present the info. It's a trick they use to keep promoting the use of BIG, HIGH-POWERED VEHICLES.
     
    #8 john1701a, Jul 17, 2006
  9. Jonnycat26

    Jonnycat26 New Member

    Joined:
    Mar 14, 2004
    1,748
    1
    0
    Location:
    New Brunswick, NJ
    Vehicle:
    2004 Prius
    <div class='quotetop'>QUOTE(john1701a @ Jul 17 2006, 09:07 AM) [snapback]287495[/snapback]</div>
    The Civic used (and may still use) cylinder deactivation, and last I checked, that was a 4 cylinder engine.
     
    #9 Jonnycat26, Jul 17, 2006
  10. sharkmeister

    sharkmeister Junior Member

    Joined:
    Apr 13, 2006
    56
    0
    0
    I'm skeptical about the reliability of their system. I would not buy first generation new technology from any of those firms.
     
    #10 sharkmeister, Jul 17, 2006
  11. wstander

    wstander New Member

    Joined:
    Jul 16, 2005
    982
    1
    0
    <div class='quotetop'>QUOTE(john1701a @ Jul 17 2006, 06:07 AM) [snapback]287495[/snapback]</div>

    Which, if you happened to look, are exactly the vehicle that bring the stuff of commerce; last I looked, I cannot get 170, 2x12s into my Prius.

    My Highlander Hybrid won't carry 2,000lbs of building brick

    That lexus 400h just won't tow a 9,000lb power utility unit to a remote building site

    There are places in the world and in everyday life that require powerful vehicles to get thing delivered and done. Why 'dis' an attempt by those who build the "BIG, HIGH-POWERED VEHICLES" to reduce their fuel usage too? That is what GM and its ilk do best; build powerful vehicles. If those vehicles can improve their usage of fuel, more power to them

    In all of my years, I can never recall a vehicle built by any of those 'big guys' that was ever an economy car; the few that were, came from captive imports and rebadged (Suzuki cum GEO, Toyota cum Prism, etc.)

    Clydesdales don't win the Kentucky Derby, but Secretariat never pulled a draught wagon, either.

    Everyone with a doctorate does not perform surgery, why does a car company have to succeed at every level?

    Hey, if we all look RREEEEEEEEAAAALLLL hard and honestly, we Prius drivers waste a lot of fuel just tooling about with one person burning fossil fuel too. If we really cared about these things, we would all get on public transit, buy and drive electric golf-carts, or better yet walk. But noooo, we need the ego of having a 3,000lbs status symbol that might, 2 or three times a year, carry 4 people, pampered in air conditioned comfort, to run errands or go to work. I have NEVER seen a Prius with more than one person in the car. Ever. I have seen dozens of them in my commute, but never with 2+ people. I have seen several VanPool 15 passenger vans that were full of people.
     
    #11 wstander, Jul 17, 2006
  12. clett

    clett New Member

    Joined:
    Jul 15, 2005
    537
    19
    0
    Location:
    Scotland
    Vehicle:
    Other Non-Hybrid
    One reason why Honda uses IMA, and DC/GM uses 2-mode is because these companies are too proud (or concerned about pricing) to license the HSD patents from Toyota.

    Ford did their research into hybrids and came up with what they thought was the best overall design, but soon realised that it was basically the same as the Prius set up. So, rather than cobble together a different, but likely less efficient, system to get around the patents (like GM etc are trying to do), they swallowed their pride and licensed certain parts of the technology from Toyota.

    There is another way around the whole hybrid patent mess, and that's to go series-hybrid. No patents holding back this setup, so whoever does it first will be a big winner. The question is who has the resources to start a big manufacturing drive in large, efficient battery packs and decent power electronics?
     
    #12 clett, Jul 17, 2006
  13. Jonnycat26

    Jonnycat26 New Member

    Joined:
    Mar 14, 2004
    1,748
    1
    0
    Location:
    New Brunswick, NJ
    Vehicle:
    2004 Prius
    <div class='quotetop'>QUOTE(clett @ Jul 17 2006, 10:45 AM) [snapback]287531[/snapback]</div>
    That's close, but not quite. Ford developed their system independently, realized it was close to Toyota, and did a patent swap to avoid trouble (which is why Lexus diesels have Ford technology in them).
     
    #13 Jonnycat26, Jul 17, 2006
  14. finman

    finman Senior Member

    Joined:
    Apr 9, 2004
    1,287
    111
    0
    Location:
    Albany, OR
    Vehicle:
    2014 Nissan LEAF
    Lexus has a diesel? Over here? Who in the Lexus crowd wants a diesel? Never heard of that.

    It'd be nice to say that GM's in the game but right now I'm doubtful. All signs point to a cheaper, less fullfilling system than HSD.

    Well, here's your chance GM, prove me wrong and get a competitive hybrid car that will make me WANT to move "up" from a Prius...

    Cheers,

    Curt.
     
    #14 finman, Jul 17, 2006
  15. Jonnycat26

    Jonnycat26 New Member

    Joined:
    Mar 14, 2004
    1,748
    1
    0
    Location:
    New Brunswick, NJ
    Vehicle:
    2004 Prius
    <div class='quotetop'>QUOTE(finman @ Jul 17 2006, 11:22 AM) [snapback]287540[/snapback]</div>
    They have many... not over here, but in Europe. They need them to sell cars over there, given that Europeans seem to prefer diesels. :)
     
    #15 Jonnycat26, Jul 17, 2006
  16. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,041
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    One of largest wheeled vehicles, if not the largest, the Komatsu 930E 300-ton mining truck, is a series hybrid using a 2 MW electric motor. No clutches and variable-geared mechancial transmissions for them.

    Considering another approach: does anyone know why it is said to be difficult to scale up Toyota's HSD to much greater torques and powers?
     
    #16 richard schumacher, Jul 17, 2006
  17. wstander

    wstander New Member

    Joined:
    Jul 16, 2005
    982
    1
    0
    <div class='quotetop'>QUOTE(finman @ Jul 17 2006, 08:22 AM) [snapback]287540[/snapback]</div>
    I don't think, based upon the supplied article, that GM, et al, want to take you away from the Prius. What the GM/D-C/BMW consortium seem to be developing is for trucks and SUVs, not mid-size passenger cars.


    <div class='quotetop'>QUOTE(richard schumacher @ Jul 17 2006, 08:35 AM) [snapback]287554[/snapback]</div>
    Money and weight, probably. Just a guess though. Does the Komatsu 930E use a large array of batteries, or is it a fixed speed diesel driving a large generator?
     
    #17 wstander, Jul 17, 2006
  18. clett

    clett New Member

    Joined:
    Jul 15, 2005
    537
    19
    0
    Location:
    Scotland
    Vehicle:
    Other Non-Hybrid
    <div class='quotetop'>QUOTE(richard schumacher @ Jul 17 2006, 11:35 AM) [snapback]287554[/snapback]</div>
    Razertec have a motor the same size as the Prius main motor in HSD that puts out 500 horse-power (was recently shown in Monaco in an electric F1-style car).

    500-horsepower in a Prius would provide adequate performance.
     
    #18 clett, Jul 17, 2006
  19. Ron Dupuy

    Ron Dupuy New Member

    Joined:
    Nov 12, 2004
    112
    0
    0
    Location:
    Fortuna, CA
    Vehicle:
    2005 Prius
    I don't think anyone ( maybe the really Green Weinies) is critcizing GM, et al, for making really large trucks for really large jobs. The problem is the Mountain of Metal and the Behemoth that is being used to transport one person to the neighborhood grocery store.
     
    #19 Ron Dupuy, Jul 17, 2006
  20. wstander

    wstander New Member

    Joined:
    Jul 16, 2005
    982
    1
    0
    <div class='quotetop'>QUOTE(Ron Dupuy @ Jul 17 2006, 09:36 AM) [snapback]287573[/snapback]</div>

    I understand this idea. Frankly, on a percentage basis, I have never seen any more than one person guzzling their way along in a Prius, either.

    Right now, across the street from my house, the neighbor has about 20 guys working on some concrete project. There are 4 large pickups and one is towing a mixer trailer and another has a generator set.

    Of course, I live in rural horse country, so trucks full of contractors and hands are normal.

    Another idea: How many vehicle do you own? I have only the one: a Prius. My neighbor has 4: a small 2-seat Mercedes, a Lincoln SUV to tow their boat/camp trailer, a small truck her husband uses for work, and a 4X4 Dodge that is for sale (replaced by the little truck, I guess).

    If they could only afford one vehicle, which do you suppose that they would NEED to keep?
     
    #20 wstander, Jul 17, 2006
(You must log in or sign up to post here.)
Page 1 of 4