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Comments: 144 +- Technology: Appeal For Commuter GPS Logs To Aid Electric Cars on Sunday November 01, @03:42PM
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holy_calamity writes "A team at Carnegie Mellon University has begun a project seeking to design a kit to cheaply convert secondhand cars into cheap, electric ones suitable for commuting, if little else. They hope to rely heavily on smart management software to extract as much efficiency as possible from regenerative braking, and knowledge of terrain from GPS tracking. But they are hampered by a lack of public data on how commuters actually drive. Their solution is to appeal to GPS users to upload .gpx log files of their commute to the team's site. The data is plugged into a simulator that reveals how much cheaper an electric car could do your journey, and an anonymized public dataset will be created. A programming contest will award a production electric car to the coder who designs the best management algorithm using it."
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Regenerative breaking? (Score:5, Funny)
I am Car of Borg. You will be assimilated.
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Is that where they break, and then fix themselves?
No, it is a series of electricity saving dance steps from the streets.
Regenerative Breaking 2 - Electric Boogaloo.
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While you were jesting, you actually aren't too far from the truth. To over simplify what it does, all of that excess energy created while braking, it dumps that energy back into the battery (or fuel storage device) to help keep it charged. I honestly don't know how much of an effect it has on the batteries to help keeping them charged, but it does do a little charging. I guess the more efficient the system, the more impact it has.
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In a NiMH hybrid, it regens about 1/3rd of the energy. On a li-ion EV, it's about 2/3rds.
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TomTom (Score:2, Informative)
TomTom has been collecting this data for years for their IQ Routes:
http://www.tomtom.com/page/iq-routes
Did CMU ask them ?
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It's probably a lot more sensible to use the data over at OpenStreetMap, actually...
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exactly. http://www.openstreetmap.org/ [openstreetmap.org] project has massive amounts of gpx tracks uploaded from all over the world, and i think that would be a wonderful source of information for these people.
My experience (Score:4, Insightful)
From what I see here in rush hour, you only need boolean control: Full throttle or hard braking. When I coast towards a red light, there'll always be someone next to me who steps on it and cuts in front of me.
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Yeah I wrote travel time algorithms for freeway travel in my last job. The travel time was pretty much directly related to the length of the queue at the end of the freeway.
Re:My experience (Score:4, Funny)
Yeah I wrote time travel algorithms for freeway travel in my last job. The queue travel was pretty much directly related to the length of the freeway at the end of time.
Parent
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I love the people who tailgate using boolean throttle techniques; they constantly alternate between slamming on the accelerator then the brakes to maintain a constant average speed. It's only slightly better than driving at a constant speed while simultaneously applying the brakes and the accelerator but it clearly projects to drivers around them that they're morons...which I assume is the idea because I can think of no other reason why they do it.
I think every new car should have a system that calculates h
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Braking (Score:5, Informative)
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I wonder if electric cars will start to sacrifice power to brake without using friction. The benefit would be longer service intervals, at the cost of some power. I wouldn't be surprised if electric cars in a decade or so have a single friction brake for emergencies and parking with brake pads which last the life of the car.
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Another nice feature of the Tesla is that the regen is triggered merely by lifting off the accelerator, so you can
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That's why the friction brakes on my Tesla still squeak; because the regenerative deceleration is enough 98% of the time, and I rarely need to use the friction brakes.
I think his point is if you actively burned battery power you could probably eliminate that last 2%, making for an even lighter, faster, higher performance car. I've got years of experience driving a hybrid with regen braking, and it is not nearly powerful enough to trigger the anti-lock brakes. Perhaps a Tesla can regen brake hard enough to feel it in your eyeballs, don't know, would be fun to find out...
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Re:Braking (Score:5, Interesting)
What do you mean sacrifice power? The prius' regenerative braking already has this kind of effect. It doesn't completely eliminate pad wear, but it fantastically extends the life of the pads. There are ones out there with over 100k miles still using the factory pads.
Parent
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I mean don't (or hardly use) brakes at all. Have a simple brake which can stop you in an emergency and keep you parked. Use the traction motor to bring the car to a stop.
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If I understand you correctly, the Prius has done this for a decade. One of my Priuses is at well over 100,000 miles, and still has its original brake pads. The only time the Prius' friction braking system is activated is during very slow speed stops (when there's not enough counter EMF from the generator to get significant regenerative braking), and during emergency stops (when maximum deceleration is requested by the driver). The rest of the time the car uses regenerative braking.
What do you mean by sa
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The only time the Prius' friction braking system is activated
When the car is completely quiet (no ventilation, no screaming kids, no music) I can hear them activate, if I'm actively listening for it an paying attention. Not even a sound so much as a change in road feel as the friction kicks in. Now the anti-lock, that is a different issue and its impressively loud.
What do you mean by sacrificing power? Regenerative braking returns some of the vehicle's kinetic energy to the battery, making the car more efficient.
Think slamming it in reverse at full throttle instantaneously, up to and including breaking the tires loose and smoking them. With current technology (electric "current" get it?) that would probably roas
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Exactly right.
?? I don't understand your point. What does slamming it in reverse at full throttle have to do with rege
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Think slamming it in reverse at full throttle instantaneously, up to and including breaking the tires loose and smoking them. With current technology (electric "current" get it?) that would probably roast the controller and the motor.
Current regenerative braking systems are far more advanced than this.
Today's electric cars use AC induction motors driven by variable frequency inverters. Throttling the motor from acceleration to deceleration is done by varying the motor's drive frequency from slightly higher then the motor's speed (positive slip) to slightly lower (negative slip). This speed/frequency difference can be controlled very precisely, thereby controlling the amount of torque and power into or out of the motor. So, like accelera
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What do you mean by sacrificing power?
I mean that instead of using the brakes at very low speeds where regenerative braking doesn't work it will just run the traction motor backwards. You lose power that way but you lose complexity as well, and save on maintenance. I can imagine cheap cars being totally fly by wire with more electrical and electronic components. Maybe shock absorbers will be electric. Steering may be totally fly by wire. At most they may have a one shot last ditch friction brake.
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The friction brakes on my Tesla still squeak after 12,000 miles of driving.
I find the brakes on my Tesla Roadster also squeak - mostly due to non-use. The brake dust gathers on the rotor and doesn't get wiped away since I mostly use regen to slow the car. This causes the brakes to squeak when I do try and use them. When this happens, I can make the squeak go away by braking hard once to remove the brake dust. I find an empty residential street and bring the car up to 15 or 20 miles per hour, and then stomp hard on the brakes to come to a complete stop. No more squeak for anoth
Anonymized Travel Data (Score:3, Insightful)
Ok, so maybe someone can help me out here, but how exactly do you anonymize travel data?
I mean sure, psuedo anonymized could be fairly easily done, just take the raw data, match with topographical data, and output the combined result devoid of geographic representations.
But even that wouldn't be anonymized to anyone who's looking for info on a specific area, since the data would all be similar and it wouldn't be hard to detect a route that goes through a given set of terrain, especially if the start or stop points (someone's house/parking garage) is known.
So someone who's more in-the-know with anonymizing data sets of this or similar nature able to shed some light on this?
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I think they answer this on their site: http://chargecar.org/privacy [chargecar.org]
Two passages jump out:
"To further ensure your privacy, the first and last tenth of a mile of every commute is automatically removed before it is saved to our servers, and no data from those omitted portions is retained."
and
"ChargeCar will also not disclose your position data to anyone and it will be used strictly for research purposes. Search capabilities are only as low as the city level. The only information that ChargeCar will share are
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*remove the end points of the journey and use the data between the end points.
*separate the movement data from other data; they don't need to connect a car to its data as it probably isn't needed to determine general commuter habits. If they somehow need to connect a car to its journey they can generalize to its model or assign a randomised alphanumerical tag to it instead of someone's name etc..
Re:Anonymized Travel Data (Score:4, Insightful)
Ok, so maybe someone can help me out here, but how exactly do you anonymize travel data?
You have a table of GPS tracks. And you have a table of cars. And the two tables have no columns in-common that could be used to join the data.
Parent
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And here we see a completely anonymous GPS track starting at 47 Washington Ave, Charleston, California*, stopping for 30 minutes just outside "Bobbie's Big Bargain Bisexual Brothel" before continuing to parking space 15 at the Word Of God radio station. We have no idea what car it was.
(P.S. others have pointed that this scenario will not happen, because they delete the first and last .1 mile of the trip.)
* All parts of this address except 'California' were made up by me. Any resemblance to the address of an
Re:Anonymized Travel Data (Score:4, Interesting)
So someone who's more in-the-know with anonymizing data sets of this or similar nature able to shed some light on this?
Much like social networking sites, the best solution is not to upload anything you don't want your name on. Since they're trying to build a "commuter car" as opposed to a "adult video shopping excursion car", the best solution is to only upload the drive to and from work, unless your work happens to be "professional adult video shopper".
Parent
Wow, look at that: (Score:4, Insightful)
Do they really expect anyone who isn't already driving a hybrid or electric and/or driving super-energy conscious will be interested in helping a project like this and send in Data? How people really commute: They drive 10-20 miles over the speed limit on highways, and 5-15 miles over the speed limit on city streets. They speed up to get in front of a slower (but still over the speed limit) car, just in time to brake hard for the stoplight. The data they collect will say regenerative braking is pointless, but the common-knowledge data will say that regenerative braking is the bee's knees.
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So data that runs counter to 'what everyone knows' is pointless? It seems the rejection of science that so many characterize as being typical of America has at last come to Slashdot.
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Complete off-topic for the original story but this is exactly why I'm hoping more cars get CVTs as the technology matures. I have a Subaru Legacy with a CVT and it is great for MPG. The car can always run the engine at the optimal RPM for the combination of speed, load and acceleration demand. When cruising on the highway its fun to watch the RPMs vary slightly to compensate for hills but having the speed never budge. I think in this case the Legacy with the CVT gets ~5mpg better than the same care with an
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Slightly related, open source electric cars (Score:3, Interesting)
I've been following the progress of a Finnish electric car project:
Quote:
"we are offering the open source blueprints of the electric conversion kits globally and leave the manufacturing of the kits to the markets"
http://www.sahkoautot.fi/eng [sahkoautot.fi]
http://ecars-now.wikidot.com/ [wikidot.com]
Requires Cheap Batteries First (Score:5, Interesting)
According to http://www.sahkoautot.fi/eng:faq#toc3 [sahkoautot.fi], lithium batteries will last for about 125,000 miles. What nobody wants to talk about is the price of replacing them. They just want to talk about how "cheap" it is to charge them. Articles just assume that by the time you need to replace them, surely cheaper and better batteries will be available. I've heard estimates of about $10,000 for replacing the batteries in an electric vehicle. So that's 8 cents per mile times 30 miles per gallon that conventional engines get for the same size vehicle which is $2.40. So pretty much zero savings.
My Versa gets around 36mpg which bumps the cost per gallon of the electric up to $2.88 which is about 30 cents more than fuel in my area. And that doesn't include the cost of electricity needed to charge the batteries.
Electric cars simply cannot beat the economics of a small commuter car. Until they get the price and performance of rechargeable batteries well below the cost of regular gas there's no financial incentive to buy an electric car. They need to do far better than 8 cents per mile for electric. I'm not going to spend $20,000+ on a car just to have electric when I'm saving no money per mile and could have spent $10,000 less on standard car AND saved money on getting where I want to go.
The part of the story you're missing... (Score:2)
If you've got a halfway modern Garmin GPS, you have already been collecting the very data that this project is working for. What? Your GPS is logging you without permission? Yes. (Garmin probably got some legalese somewhere to cover their tracks.)
The Garmin GPS has a facility to show/hide your 'trail' (which is based on a time/location log of your travel). I believe it also has an option to reset that log. (Or, at the very least, you could USB mount its storage device and clean out the log file.) But even i
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I would suspect that this varies depending on the model. My Garmin 60csx has the ability to disable track logging. There have been numerous times where I've wanted it to record the track, but it had turned off track logging... Sounds like a good time to say "YMMV". :^)
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Ah, truth, justice and the american way. How refreshing
Damn straight. If you are so hot to trot for people to work for free, then you should work for free for me.
Re:CMU can pay for it. (Score:4, Insightful)
Well, once would have to wonder if CMU produces any IP as a result of this free data, would they release all copyrights and patents for free?
Or is that different?
Parent
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and the whole electric drive-train, is going to be cheaper than paying for gas?
Hell, wouldn't it be cheaper to buy a new electric than to retrofit it?
I know you're just trolling, but its an interesting topic anyway.
Most conversion stories seem to begin with "remove burned out IC engine and leaky transmission". You'd be surprised how expensive a new gas drivetrain plus installation costs compared to the new parts for a small electric drivetrain. So, drivetrain is usually mentally justified as a repair cost.
Then justify the purchase price of just enough small lead acid deep cycle batteries to just barely work, because you've got leftover money from the d
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I'm thinking we're looking at 6+ years to break even
There's a few electric conversion cars in my neighbourhood - A minivan, an old Ford Fiesta etc. For most of the guys who have done this it's not for the cost savings (although here in BC with cheap hydro there is certainly a piece of that) - It's largely a hobby for them, in the same way some people like playing around with computers, messing about with toy trains or 'tuning' their Hondas. To be honest, this sort of project appeals to me as a hobby pro
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What's wrong with six years to break even, with the money spent raising the value of the vehicle?
If you were given an low-risk option for your 401k wherein you'd earn the amount of money you put into the fund in only six years, and continue earning from there on out, wouldn't you leap at the opportunity? That's a 12% rate of return.
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First, lets see any domestic car manufacturer make any car of any technology with those specs:
35+ mph ... 10+ year lifespan ... under $10K.
I mean before going all star trek with complicated stuff, can they even build a "model T" or VW-bug-alike that meets just those basic specs, even if it only seats one and gets two miles per gallon, etc, before trying to install new high tech with amazing performance (and probably, amazing costs)?
the buyer will buy the amount of kwh in batteries they feel they need
I do agree that "marketing-miles" will become the new "cupholder count" in car advertising. Perhaps, instead of advertis