After the Chevy Volt has been driven 40 miles on electricity, the gas-powered generator turns on supplying electricity along with a buffer in the battery that the electric motor needs for continued operation. Though GM has been developing this function for a while they have not shown it publicly.
I had a chance to discuss this extremely important and unique mode of Volt operation with Volt executive Tony Posawatz who explains what functions GM still has to work on.
When the generator goes on will it come on gradually?
We’re still playing with it. The initial transition we like very much, it is almost imperceptible. We want to tune it and exercise it more for production readiness, but we have an algorithm of software that feathers it in so that its almost imperceptible.
To many people it is imperceptible, to those that are a little bit more tuned in…Frank (Weber) says its not quite perfect, he wants it so that no one can hear it.
That transition isn’t handled in most hybrids that well, particularly when you stop at a light an the engine shuts off and you get that shudder. We have this benchmark we set, that we’re going to blow them away.
By the way, our motor is so much bigger than theirs, the power output of the electric motor, that effectively is the starter. We’re in the point of tuning it and it’s a very very complicated tuning exercise if you want to make it perfect.
It’s a balance equation. Here lies the challenge. You will get some feedback from the car about its environment, or the road load. You’re demanding so much power from the car, and you will get some feedback. That’s one input that you have to be able to respond to to deliver the right amount of power. The other aspect that we have to play with is this area of OK when I respond to it, the engine generator will run in different modes or RPMs. How do I transition from mode to mode, a timing issue, do I smooth it, do I try to react immediately to that response? If I act immediately to that response how will customers receive that? such as a wild of swing of RPMs?
There’s the responding to the car’s demands based on the loads number one, then there’s the affect on the customer, we want that to be really pleasant. The transition to charge sustaining, we’ve got that down, it’s the operating in the very different modes we’ve got to figure out. The next leg is making sure the engine is running the most efficiently that it can.
Generators are typically run at a sweet spot that’s very efficient. We could do that. The question is, does the amount of output of power that results from that manage or balance with what the car needs?…hmm how do you do that? That’s another reason we have this battery buffer reserve.
How often do you turn the engine off and on is another question. These are the factors that have to be balanced.
People ask why can’t you show it to me? Because we want it just right.
This requires a lot software. The other interesting challenge is the regulatory issues. Theoretically you could run the engine enough to build a surplus of energy. The regulatory guys are not going to let us do that, it’s a five legged stool.
Is the EPA sitting on a committee while you engineer the car?
This is more CARB than it is EPA. EPA is interested from the perspective that they need to understand how to label it. CARB really doesn’t want you to burn fuel if you don’t have to.
The message on charge sustaining mode is we’ve got a good beat on it, its the four or five things that have to be balanced together and the team needs time to work.
Will the engine rev higher when you step on the accelerator?
Yes, but the question is, if I have a little battery reserve at that time, do I turn the engine on right away to follow that or is it a smoothing function?
Also lets say you just went up a monster hill and the engine feathered up a little to support you and you get to the top of the hill and hit a light. Should the engine keep on running to allow you to recover or do you turn off the engine because the customer expects it too because they’re stopped at a light?
Technically are these difficult challenges? No. Its hard development work balancing the calibration of a lot of software.
This entry was posted on Monday, August 17th, 2009 at 6:44 am and is filed under Engineering, Generator. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
+8
Aug 17th, 2009 (6:51 am)I have been in a Prius when the ICE turned on.
It was blatantly obvious. I will be nice to have a silent mode on the Volt.
And being in IT, the more software code the more chances for bugs. It should be interesting.
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+10
Aug 17th, 2009 (6:51 am)As an engineer I appreciate the complexity of the systems engineering going into this car. But as someone who’s been following the volt for a while and who currently drives a prius I’d be more concerned with operating at the sweet spots and trying to achieve the best MPG’s possible while still having a smooth ride. I don’t think they should kill themselves to make it “SOUND” like an EV all the time. Let the engine do what it needs to do to get us above 50 MPG in RE mode. I think that should be the goal.
BTW – Absolutely awesome article Lyle. This is what keeps me coming to the site
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+1
Aug 17th, 2009 (6:56 am)It’s interesting that so much time is being spent making the RE experience as similar to current ICE responses as possible.
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+4
Aug 17th, 2009 (7:00 am)I concur. I hope that this level of refinement and attention to the details will distinguish the Volt from the knock-offs ( especially those from China) that are sure to follow.
Also, it makes me wonder how Fisker is approaching it, given that their timetable seems more agressive than GM’s.
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+4
Aug 17th, 2009 (7:02 am)GM…do not forget the KISS rule of engineering.
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+2
Aug 17th, 2009 (7:06 am)My 03 HCHI has the shudder and very limited start-stop capability. Going through a drive through, the engine may shut off once then keep running after the restart. Have to shut it off and restart with the key it if I want the silent feature, which is a nuisance.
Guess if I have a choice I’d have to agree with CARB. Using as little gasoline as possible would be my goal too.
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+2
Aug 17th, 2009 (7:11 am)During acceleration from a stop, yes.
During other times, often you can’t.
Owners connect aftermarket devices (like ScanGuageII) because they can’t always detect when the engine is starting/stopping. Seeing the RPM reveals more than you can perceive by feel or sound… especially for the 2010.
It’s not a crude startup like with traditional vehicles. The generator motor is enormous compared to a starter. So when it spins the engine, the RPM is all the way up to idle speed and is held there until oil pressure is established before injection & spark. The result is a much smoother start.
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+3
Aug 17th, 2009 (7:14 am)Yes, it is obvious, but it doesn’t matter that much. My friends that own Prii both get mileage in the mid to high 40’s, and getting off of oil is the point for many of us. I think Weber is letting perfect be the enemy of very good. Obviously, if you start the generator at a low RPM it will be very hard to tell that it is on. Just program the generator to increase from set point 1, i.e. 1200 rpm, to set point 2 at 2400 rpm, 5 or 10 seconds after the battery hits the customer depletion point so that there is no sudden increase in the background noise. And I really hate that term, customer depletion point… But my point is, allow the generator to slowly ramp up rpm, and ramp down when the car is at a stop, but don’t shut it off until the battery is the customer depletion point plus 5%. Then the car goes back to all electric mode for 3 or 4 miles, then the cycle starts all over again. Unless of course you are climbing Pikes Peak, or driving down I-95 at 90 mph.
I think GM is being tone deaf on two points, the generator mode is not going to be used that often by most drivers, and only the anal retentives are going to fault them for having an IVer that allows you to hear the generator, as long as it is programmed to follow driving cues, i.e. the generator slows at times the car is stopped. Second, they should have stressed the formula in the 230 mpge pitch, because they allowed the anti-Volt crew to pitch it as a GM lie, when in point of fact it is what the Volt will get using the EPA’s test cycle.
Those two points irritate me, but what I think GM really needs to do is get a dozen or so of these pre-production but post-IVer quality Volts out to people that blog about cars and/or the environment. If Lyle can get an electric Mini this year, he should be able to get a Volt by April of next year. Hundreds of thousands of people read this site, and hearing a real world evaluation of the Volt from someone who has built real world credibility would do GM a world of good. And by waiting til April GM would avoid the cold weather drop in efficiency up north.
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+1
Aug 17th, 2009 (7:15 am)On this we can agree. Even if the operation of automatic transmissions seem beyond your ken.
Moving parts and software too? That must have you running off screaming.
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+5
Aug 17th, 2009 (7:20 am)Well, that is one of the most candid interviews I’ve read about the Volt in a long time…if not ever. Excellent job Lyle and thanks to Tony for taking the time to explain the challenges. I would have to imagine the “tuning” aspect is doable but challenging and time consuming. I am glad to hear they are striving to make it perfect.
Maybe that test drive Statik requested just isn’t ready yet.
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+3
Aug 17th, 2009 (7:20 am)My ‘01 Prius is terrible at shutting down and starting. I can’t wait to try the Volt and the better system.
Zel
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+1
Aug 17th, 2009 (7:21 am)This is an interesting issue now they’ve made clear the ICE switches on at 30%. It does make one wonder when the ICE shuts off again. Does it cycle up to a certain point above 30% then shut off again?
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Aug 17th, 2009 (7:23 am)Only stuff that breaks when it shouldn’t.
And automatics aren’t beyond me.
I’m just not the lazy type.
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+7
Aug 17th, 2009 (7:24 am)And I really hate that term, customer depletion point
_____________________
That’s not an official term. So, just stop using it. These are what SAE has defined:
CD – Charge Depleting
CS – Charge Sustaining
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+8
Aug 17th, 2009 (7:27 am)John, I like your (SAE) answer better than Weber’s so I will adopt it in the future. Thank you!
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+1
Aug 17th, 2009 (7:30 am)Why not always start the ICE running at 2200 rpm for 10 seconds? Then measure demand to find the sweet spot. Perform this simple measure/adjust function each few minutes. Add a default of 1200 rpm when the car pauses for more than 10 seconds. With a full stop of the ICE at a 20 second pause.
=D~
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+5
Aug 17th, 2009 (7:30 am)______________________________________________________
I agree w/ #2 Gsned57.
Optimize MPG, KISS everything else…it’s about max MPG.
______________________________________________________
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-5
Aug 17th, 2009 (7:31 am)“The message on charge sustaining mode is we’ve got a good beat on it, its the four or five things that have to be balanced together and the team needs time to work.”
___________
This response shocks me a bit, this late in the game. These “four or five things” have always been the real barriers to weather series EREV would work or would not work. The charge sustaining mode was the primary thing in question about the volt’s viability, right from the start.
This is one of the first times we’ve seen a GM rep really stay on the subject for any length of time and all he can do is raise the same questions that everyone’s been asking since this project’s inception.
These are the questions that you’d want answered in computer simulation, on the test stand, and in a mule before you ever green light any production.
(especially when you’re out of money already)
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+7
Aug 17th, 2009 (7:31 am)Why not let the driver decide? The Volt could offer two different modes of operation for the gasoline engine. The standard mode, which GM seems to be favoring, would emphasize transition smoothness and responsiveness similar to a regular car. The second mode would favor running the engine at its sweet spot as much as possible, even if that means a driving experience unfamiliar to the average driver.
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-2
Aug 17th, 2009 (7:36 am)Ooooh how fun! A list of things that break when they should.
Number 1 explosive bolts on aircraft canopies during the ejection sequence.
That was a a pretty lazy critique of the G6 in the previous thread even if I was never very fond of Pontiacs.
You are free to love a stick (well not LOVE a stick). Just don’t pretend it’s character-building.
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-3
Aug 17th, 2009 (7:39 am)I wasn’t pretending anything.
You are really an A$$.
I am surprised by that because you have always seemed like a good bloke.
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Aug 17th, 2009 (7:44 am)Yes that concerns me a bit. One would think the IVERs would be used to optimize production techniques and final parts. But perhaps they are taking the opportunity to tweak the software because they still can?
Definitely job one for the mules at least.
Guess we just cross our fingers and hope it turns out.
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+11
Aug 17th, 2009 (7:45 am)“We have this benchmark we set, that we’re going to blow them away”
———————————————–
I love it! these guys are doing it right.
And Frank Weber is TOTALLY RIGHT to insist, as the article puts it, “its not quite perfect, he wants it so that no one can hear it.”
Go Frank! Make it the best in the world! That is the ONLY way to go.
GO GM
GO VOLT!
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+3
Aug 17th, 2009 (7:51 am)I don’t agree with CARB and others that the ultimate goal for the Volt is to use the least amount of gasoline. That will only lead to the failure of the Volt program. This car must differentiate itself from all other hybrids available today. It must elevate the playing field about what makes up an acceptable American hybrid automobile. If GM was simply satisfied with the Prius “bump” drive characteristics, why wouldn’t you just buy a Prius?
I’m not saying that extreme MPG isn’t one of the goals; it is and should be, but there isn’t just a single goal. The volt is a GM product and it had better feel like one; pull like a Camaro, ride and sound like a Buick or Cadillac, and carry passengers and gear like a GMC. Nothing else will BE the game changer that they need!
Show a little patience. Let the GM folks finish the job. The Volt team has already demonstrated that they have the right stuff. In the mean time, keep saving your pennies so that, when the time comes, you can put your money where your mouth is!
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+1
Aug 17th, 2009 (7:54 am)I agree with James, give two or three modes to the driver.
-Efficient mode – Run the engine when it makes the most sense for fuel efficiency
-Comfort Mode – Hide the engine from me so I can impress the passenger
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+5
Aug 17th, 2009 (7:57 am)I’ve been a bit hard on you and that is the truth. My hope was that your subsequent comments would be more considered and well thought out. So I will apologize for calling you an idiot since I knew that would likely negate the educational value.
I’ve always found your other comments very insightful and interesting and was a bit shocked when you penned your judgment on the G6.
Especially when there are so many genuine quality issues with rides other than the G6.
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+7
Aug 17th, 2009 (8:00 am)Yeah, when I go out for my walks during my lunch hour it amazes me how every Prius I see on the slow side streets (there a lots of them in this “look how green I am” neighborhood) has its gas engine running.
I have never heard one go by in electric only mode, although maybe the newest ones are better. I haven’t seen one drive by where I walk yet.
It just brings home the point that the Prius is basically a gas engine car with an electric assist. The Volt, however, will be electric drive at all times.
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+3
Aug 17th, 2009 (8:04 am)“The regulatory guys are not going to let us do that,”
Thank goodness the boys and girls of CARB are putting demands on GM to make this thing work they way those bureaucrats think it should. We would not want GM to be free to just optimize the car as their engineers see fit.
Bigwigs on county and state boards always know better than some nitwit engineer.
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+1
Aug 17th, 2009 (8:08 am)That’s what i was going to type. If they have the initial starting of the engine already nailed, so that its inperceptable to the driver, I think that would be mission accomplished. The engine starting for the first time would be unexpected by the operator, unless they are constantly monitoring their battery to hit 30%. Now on the other hand, if i mash the gas pedal, i’m going to expect to hear some noise. So don’t worry about trying to feather the RPM’s up on the engine. Just let it go. KISS.
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+11
Aug 17th, 2009 (8:08 am)Much of this has been done before with cruise control. Cruise control requires input from the environment – uphill / downhill / headwind / tailwind – and so forth.
At least from the interview, it is clear that GM is asking the right questions. Fortunately, GM is also making 80+ production accurate vehicles to use as test platforms, so there will be no shortage of vehicles needed to sort all this out.
As an aside, Lyle, if you wrote this article, would you mind attaching your name to it? I am no longer certain whether it is you are statik writing these articles.
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Aug 17th, 2009 (8:12 am)Yes if gas consumption were the over arching concern it would be pulsing like a squid looking for the earliest opportunity to shut down.
My assumption though was that in charge sustaining mode the ICE was splitting the power between the generator/battery pack and sending current directly to the wheel motors. Is this not the case?
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+3
Aug 17th, 2009 (8:13 am)I think the Mules and any simulations, including the accelerated testing on the batteries, was to prove function. What Tony is talking about now, is perfecting the driving experiece. The function of the EREV technology, i believe has already been proven.
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+1
Aug 17th, 2009 (8:17 am)Remeber you also have different modes for the regenerative braking. Sometimes too many choices for controls is a bad thing. But maybe this would work. People could play w/the combinations of how they want their ICE to run and how they want their regenerative brakes to work. As long as its simple enough so that most people understand it.
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+1
Aug 17th, 2009 (8:23 am)I hope so! I drive across I-81 in PA once or twice a year and I hope the down hill portion will be EV mode and will build up extra reserve above the 30% rather than to waste it.
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+10
Aug 17th, 2009 (8:23 am)Schmeltz and ziv
I agree that this was the best, most candid interview we’ve been treated to in a very long time. Maybe the best to date! Thanks Lyle.
Ziv, you say anal retentive like it’s a bad thing (g). Almost all engineers are in that mode because they HAVE to be, to be great engineers!. It’s not OK if the bridge meets in the middle and is “almost perfect”. Things have to be “just right” – and that’s a GOOD thing. It also ratchets up the internal pressure (like there wasn’t enough external pressure), which makes the process even tougher.
These people are trying to please about 4 different masters (not counting themseves). Keep the mileage UP. Keep the noise DOWN. Keep the customer HAPPY. Keep the critics at bay (by definition you won’t please them). On and on it goes.
This interview goes a long way to adding to my patience in waiting for a preproduction volt to be pranced about in front of the media in charge sustaining mode.
All the “solutions” floated here have one thing in common – we don’t have all the facts. “For every complex problem there is always a simple solution, which is almost inevitably wrong”
Best of luck to all the conscientious GM engineers!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (8:23 am)I hope and actually expect that they will do this. Of course, the EPA rating will be on the worst setting.
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+7
Aug 17th, 2009 (8:24 am)Truce then, my friend.
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+1
Aug 17th, 2009 (8:28 am)My hope is the tweeking process never ends and I will be receiving updates via lone star for the life of the car.
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Aug 17th, 2009 (8:32 am)I totally agree with this approach. After about two weeks the “second mode” will become familiar, and for me it won’t be objectionable. I look forward to experiencing that mode.
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Aug 17th, 2009 (8:32 am)I still want updates for the life of the car BUT, I would like to be able to select the second mode because I would willing sacrafice a bit of engine noise for better MPG and the car slipping back into EV mode for ANY ADDITIONAL miles of EV mode.
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+2
Aug 17th, 2009 (8:34 am)“The charge sustaining mode was the primary thing in question about the volt’s viability, right from the start.”
This is so wrong.. there was never any doubt GM could build a genset and stick it in an electric car, this is trivially easy.
The Volt’s viability (in the long term, 1st couple of years will sell out) is the total cost and warranty issues with the battery.. its a race between mass production lowering the cost and the public losing interest.
BTW, engineers will always tweak software until the last minute.
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+1
Aug 17th, 2009 (8:35 am)Lone Star being the bigger, bolder, and Texan version of on-star?
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+5
Aug 17th, 2009 (8:38 am)Agreed. Moving silently but not wordlessly forward into the VoltAGE!
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Aug 17th, 2009 (8:41 am)A bit off topic but looks like the Gen 5 Fuel Cell fits in an I-4 space:
http://green.autoblog.com/2009/08/17/honey-i-shrunk-the-fuel-cell-next-gen-gm-hydrogen-stack-gets-s/#comments
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+1
Aug 17th, 2009 (8:43 am)Great article Lyle.
It clearly shows the complexity involved in the development of a quality vehicle and why you can’t just slap some parts together and start selling it. I am sure the software algorithm will be a continuing refinement for the entire life cycle of the Volt platform. It sounds like they could put it out right now and most people would be happy with the results compared to current hybrids. That means there is little schedule risk associated with this issue. That is good news.
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+2
Aug 17th, 2009 (8:44 am)Dang!! I should never try to think after drinking the night before!
Maybe Lone star is a place to eat. So my excuse is I was hungry, not hung over!
THATS IT, FORGET THE DRINKING PART, AND NO THE CAPTAIN WAS NOT THERE!!!
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+7
Aug 17th, 2009 (8:51 am)I love it when people “play nice” (g).
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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+4
Aug 17th, 2009 (8:54 am)I agree with Gsned57 that maximum MPG should be a primary consideration and queitness as a secondary or better yet have it as an option, two different programs the customer can toggle between, IE quiet mode or MPG mode with the press of a button. Surely there is enough memory to hold both programs and or subroutines. Use quiet mode to impress your friends then MPG mode while commuting.
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Aug 17th, 2009 (9:01 am)old man,
I’m on I-80 in PA but 90 miles west of I-81. I-81 has some huge hills, most of which are missing on I-80 (E/W).
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (9:04 am)kdawg,
If you mash the pedal from a dead stop don’t you want all the instant torque from all electric?
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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+3
Aug 17th, 2009 (9:05 am)I think they should make it as quiet and smooth as possible for the masses. There are always the tinkerers and hackers that are going to immediately start tweaking the software to get more MPG, which is us hardcore people that will be visiting the owners forums many times daily, neglecting our health, jobs, loved ones to eek out another mpg. =)
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+4
Aug 17th, 2009 (9:12 am)Kdawg,
That’s my take as well. They have the piano built, it just needs to be tuned.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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-19
Aug 17th, 2009 (9:14 am)(click to show comment)
+1
Aug 17th, 2009 (9:14 am)Herm,
These issues sure didn’t sound “trivial”. JMO.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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+1
Aug 17th, 2009 (9:15 am)“Is the EPA sitting on a committee while you engineer the car?
This is more CARB than it is EPA. EPA is interested from the perspective that they need to understand how to label it. CARB really doesn’t want you to burn fuel if you don’t have t”
—————————————–
Since the Volt will be in short supply anyway, maybe it should be designed to be sold outside the CARB zone and without their supervision. Sounds like it would be a better car. (smile)
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+5
Aug 17th, 2009 (9:15 am)In case none of you have done it yet… go to your Ford Dealership and test drive the 2010 Fusion Hybrid. I have had mine a month (tomorrow) and am just loving this car.. as for the trasition from ICE to EV… it is flawless..Most times you have to be watching the instrument panel to see the switch over. As for mileage … it blows the Prius and the Camry out of the water.. Lifetime average so far is down to 5.5 L / 100 KMS (51.4 MPG Canadian). and it is still going down..
I was expecting to be close to the EPA standards of 5.4 L / 100 in town and 6.1 L / 100 KM on the highway. But I have run difffernt trips of varining lenghts and can acheive super MPG numbers…
Best so far 2.1 L / 100 KM and worst was 7.9 L / 100 KM.
The car does run for a couple of minutes most mornings about a minute after ignition is on.. I think it has something to do with a “systems check” and making sure the battery is up to speed.
I am not filling up often and am acheiving well over 1100 KMs per tank (66 L).
It’s bigger than the Volt…costs well under the $40 K mark and seats 5. I still want a Volt when they get here but I will be keeping the Fusion for the Family trips..
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Aug 17th, 2009 (9:16 am)James,
I like the idea of being able to choose, but which does the EPA test for the plethora of #’s on the window sticker?
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (9:17 am)“By the way, our motor is so much bigger than theirs, the power output of the electric motor, that effectively is the starter.”
——————
Do you think this means there is not a normal starter for the ICE?
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Aug 17th, 2009 (9:23 am)kdawg,
And when you found a favorite combination, you could press a button oin the fob to remember the combo, so two drivers could have different setting in their own fob – a little like my seat has 2 memory settings – for my (short) wife and for my (taller) self.
But again, what does the EPA use for it’s testing? An average? Shrug.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (9:24 am)That’s good news. I’d avoided the Fusion because, well, it seemed like false advertising. Nice to see they’ve put something interesting under the hood. (Still holding out hope for the Mr. Fusion version)
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Aug 17th, 2009 (9:24 am)GM is over designing this. Please remember KISS. Forget the idea that when driver push the accelerator down that they should hear some increase of generator like an ICE. DO NOT try to copy an ICE experience. This is an EV based vehicle and people will get us to it. Focus on smooth transitions and take advantage of the buffer energy in the battery. Maximize the MPG with smooth transitions, and only go to higher RPM after longer period of high demand. Do not have the generator always responding to the ups and downs of energy needs. It is better to have a larger battery buffer amount then to have the generator changing modes and speeds frequently.
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Aug 17th, 2009 (9:28 am)nuclearboy,
Aren’t these regulators the national EPA Guys? Or are you talking about CARBI agree that the engineers should be in the rivers seat and present the vehicle that they decide is best, but they have to be shooting for the highest mpg too. What a challenge!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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+2
Aug 17th, 2009 (9:38 am)I suggest… “The Art of Electronics” … good book.
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Aug 17th, 2009 (9:39 am)They would test the standard mode, which would be the worst of the two. Nobody is going to argue with a second option that gives them better mileage than can be advertised.
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Aug 17th, 2009 (9:41 am)Back from Vacation…
While I don’t disagree with you about multiple modes it still means the Volt team needs to finish their tuning of the ‘quiet mode’.
If the Volt drives ‘weird’ Aunt Molly isn’t going to like the car.
THAT would be a disaster for a car destined for the mass market.
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+3
Aug 17th, 2009 (9:44 am)“trivially easy” — now there’s a description that’s so wrong I don’t even know where to start typing. (I’ve got a feeling weber and crew would take my side on this one)
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+2
Aug 17th, 2009 (9:46 am)Agreed.
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+1
Aug 17th, 2009 (9:55 am)I would like to add a “vote” for a driver selectable mileage or comfort mode. This would be similar in operation to the regenerative brake modes previously revealed by Lyle in his April ‘09 mule test drive:
“The braking had a customary feel. Regenerative braking was of course in effect, and every downhill grade and coast charged the pack. GM had cleverly built in two driving configuration options called D and L. Both gave the same acceleration, but when you step off the accelerator you get strong regenerative drag if in L and coast in D, the former being best for city driving. As Greg said this could allow you to drive with one foot.”
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Aug 17th, 2009 (9:58 am)I’m guessing it will take about two weeks for someone to hack the Volt software. Since all of this, the duration of EV, the SOC level, generator kick in, RPM’s and duration is controlled by software the adventurous Volt owner who doesn’t care about voiding their warranty will be able to modify and tweak their Volt however they want. Personally I would be interested in expanding the window of ‘usable’ battery from 8kwh to 10 or 12 kwh. Of course tinkering around with it could end in disaster but for the tech savvy the possibilities are all there.
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+7
Aug 17th, 2009 (10:07 am)Same here. Bugs will be found and hopefully, dealt with correctly and quickly. Just don’t let Microsoft anywhere near the project.
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+1
Aug 17th, 2009 (10:09 am)I am not sure who exaclty is interfering. I was just responding the to article where the guy said that they could not run the gen set in a specific way because “The regulatory guys are not going to let us do that,” (referring to CARB).
I have always thought that it might make sense to run the Generator at some max efficiency point and charge the battery up a little and then shut down when you reached some magical level (say 35%). This way, if the engine and generator are running, they will run at optimal efficiency. Running at optimal efficiency on the engine would seem like a good idea even if you are charging the battery a little.. This overcharging of the battery past 30% seems to be what they don’t want.
My concern is that low level bureaucrats on some panel or board are putting obstacles in the way of GM exploring various ICE/GEN algoritm concepts for the car.
If the approach they are blocking is no good for VOLT, GM would figure this out and the CARB nitwits should have stayed out of the process and let GM get the job done.
If the approach they are blocking is more efficient for VOLT, the CARB nitwits should have stayed out of the process and let GM get the job done.
Either way, I see CARB intervention as a drag on productivity. Interfacing with the Govt is a waste of resources for a company…. Unless maybe you are a company like GM and the Govt has just bailed you out.
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-1
Aug 17th, 2009 (10:13 am)I don’t have any real problem with the term, it simply gives reference to when the switch occurs.
Using “Customer” DOES make sense since the drivers habits and patterns determine when transition occurs.
I have used the term “depletion point” in the past and am comfortable with that. All it means is the point in time (and charge) where the battery charge finishes depleting and the Volt starts sustaining said charge level.
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+1
Aug 17th, 2009 (10:15 am)My (limited) experience confirms what you’re saying. If you’re not accelerating it’s hard to know when the motor has come on. It’s an almost seamless transition.
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Aug 17th, 2009 (10:15 am)I just got something in mind:
When generator kicks in, it will be aimed to keep the battery SOC around 30% (which is the initial full customer depletion point). But we all know there will be a delay between instance power needed for the driver (pushing down accelerator pedal straight) and the power that will be supplied in response. It’s clear that the instant power will be supplied from the battery, and generator will slightly increase power generation in order to bring SOC back to 30% in a short (and smooth) delay. The same occurs with regen-braking, effecting the generator will simply go in a lower power state.
If this mechanism sounds logical, the battery, at 30% SOC (user depletion) will experience frequent “yo-yo” charge/discharge rate. Will this have some negative effect on it? (battery lifetime, power)
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+1
Aug 17th, 2009 (10:16 am)Yes i would, plus rev the ICE if needed. Dont worry about noise when i mash the peddle. I’d be more concerned/upset about a lag in the engine response. If i step on the gas peddle and 3 seconds later the enginer revs up, that would bother me more than instantaneoulsy reving it.
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Aug 17th, 2009 (10:16 am)Yes, it was confirmed in a chat that the generator acts as the starter, there is no standard 12v starter.
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-4
Aug 17th, 2009 (10:20 am)Volt Bugs will abound. The question is how quickly can GM fix them. We don’t need the infamous Microsoft Patch Tuesday Crapola.
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Aug 17th, 2009 (10:21 am)James,
GM would argue with it, if it’s not the lowest #!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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+4
Aug 17th, 2009 (10:22 am)Agree 100 Percent, this is so important it bears repeating.
DON’T LET MICROSOFT ANYWHERE NEAR THE VOLT !.
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Aug 17th, 2009 (10:24 am)It’s interesting that so many fh owners are beating EPA numbers. I attribute this largely to the engauging Eco display?
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+4
Aug 17th, 2009 (10:25 am)Your last paragraph said it all very correctly. The Prius is not an electric car. It just has an electric assist motor. But, over all the Prius is a great car accomplishing very well what Toyota designed it to do.
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+2
Aug 17th, 2009 (10:25 am)nuclearboy,
Well put. Uncontested.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (10:26 am)That’s what i thought. There’s no 12V starter. Wasnt this discussed in detail recently?
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Aug 17th, 2009 (10:27 am)I guess I was thinking that the all electric torque has been described as 100% instantly, that the engine would just slow it down! (g).
JMO,
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (10:28 am)A larger buffer zone woud be preferable, but puts more strain on the battery. as long as the buffer is large enough to power a decent overtake at motorway speeds(~38kw for a minute/90 seconds) before you throttle back to 70 (~26kw) then it’ll be fine. if you ran the genset at 27kw output for the whole time while doing 70, you’d build enough buffer in the battery to do this, without being obvious to the driver.
I’m just hopeful that it’s easy to hack the 100mph limit, we now know the battery can handle the full 112kw load of the motor, so with the 53kw genset assisting you could go for 43 miles at a constant 120 before the battery was empty. you could even go 21 miles at 145! maybe the Ampera will have the option of their 1.9cdti diesel lump, and an uprated genset, for a higher sustained top speed….
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+2
Aug 17th, 2009 (10:29 am)Keep in mind that there is still more than a year before the first cars are released. There is still plenty of time for this type of fine tuning. (And if this is perceived as a big issue then from an engineering standpoint the development team is in very good shape). As for the timing of the test drives, a roll out has a certain pace to it. You want to space the PR and then accelerate it towards the roll out date, so there doesn’t seem to be any advantage to having the media test drive the cars now rather than five months from now.
If they didn’t have the time then we’d have a different situation. The reality is that the more time used in development the better the product, it’s just usually that you make the big strides early on and it takes more and more time for smaller benefits. But it is an important component of the operation so I’d encourage them to keep at it.
As for the 230 mpg number being seized on, that’s to be expected. What’s funny is that you don’t see the same attack on Nissan’s much larger number which AFAIK is far less defensible. Basically there is a negative perception of GM in some quarters and this gets expressed from time to time. But it does have a good side. Given that the Volt is really something of a “halo” vehicle, without a need to dispel some negative perceptions — perceptions which “pissed off” Bob Lutz and probably a lot of other people at GM as well — I’m not sure GM would seen the need to bring the Volt to market.
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-1
Aug 17th, 2009 (10:29 am)For best code I would suggest they Open Source it. All the experts now agree that the OSS model results in the safest and most efficient software in the industry.
BTW, what happens in closed source systems (ala Microsoft) is that poorly written code modules tend to be completely re-written many times from the ground-up because of lack of peer review and following best practices. A good example would be MS TCP/IP stack which has been totally rewritten at least five times because it has been a poster for how-not-to-write-c-code !
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+1
Aug 17th, 2009 (10:31 am)I ‘think’ what Herm means that it’s easy to add a range extender to an electric car, it happens all the time with people sticking a generator on a utility trailer and dragging it behind their home built electric.
I bet many people on this board could do that… I could.
What is HARD and why the Volt is taking so long is getting it to work as a system, reliably, smoothy, and truly efficently.
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Aug 17th, 2009 (10:34 am)OK, found the posting. It was from Cab Driver
———————-
Cab Driver Reply:
August 14th, 2009 at 7:12 am
By the way, did you see my thread from a couple days ago ( http://gm-volt.com/forum/showthread.php?t=3218 ) reporting that when I asked Frank Weber if the 12 volt battery could start the ICE he said no, since there’s no 12 volt starter motor?
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+1
Aug 17th, 2009 (10:35 am)Cool information. a fuel cell powered genIII volt..suh…weet.
Thanks for the link
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Aug 17th, 2009 (10:36 am)Remember the Volt is designed to be a World Car, sold in many other countries. Most likely the majority of Volt sales will be outside the U.S. once production cranks up in Europe and China. The Volt will remain a niche product in America for the foreseeable future. So it has to meet the strict EU standards on emissions, while Chinese version will have much less emission components.
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+1
Aug 17th, 2009 (10:39 am)Sigh…
Just when I thought I had found a forum where people didn’t feel the need to bash Microsoft (While turning a blind eye to Apple) at every turn…
Oh No! Spaceballs… There goes the planet…
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Aug 17th, 2009 (10:39 am)Super interview Lyle. Congrats on a very nice exclusive.
I will say that Tony Posawatz (and Greg Ceisel) are great interviews. The passion and dedication show through — though they are very down to earth — and they are very technically knowledgeable so they give out great information. (We don’t see much of Jon Bereisa and that’s unfortunate).
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Aug 17th, 2009 (10:41 am)Muddyrover,
Welcome back!
I think by the time Aunt Molly can get her HANDS on a Volt, it will have been polished to the point were she won’t notice the different modes. I’m just saying that the Gen I’s will be awfully scarce and snatched up by the rich and the lunatic, er I mean fanatically intense.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (10:41 am)What we really need to know is, what is the MPG in generator mode? The 230 number is fine for publicity, but what is the real MPG of the Volt?
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Aug 17th, 2009 (10:42 am)I hope there will be some “intelligence” in the software. It has to recognize different traffic situations. It would be awful, if the ICE turned on and off every half a minute in an everyday stop-and-go / jam situation.
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Aug 17th, 2009 (10:42 am)Also here:
Live Chat with Frank Weber, 10 August 2009
5:47
[Comment From CaptJackSparrow]
no 12volt starter motor? Then what turns over the ICE to start it?
5:48
Frank Weber: The generator within the electric drive unit, which is directly coupled to the engine.
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+2
Aug 17th, 2009 (10:46 am)This is going to be a selling point. Not just the ICE integration but the perfection of the car. At 32.5K I want a car that is perfect in every possible way. Word of mouth is very powerful. If word gets out that yes the car is expensive, but look at what a great perfect car you get, then GM will have a winner. They really can’t push that pricetag up. They are on the line now. So they must make up for that with extreme quality. I think they will surpass everyone but Chevy haters expectations.
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Aug 17th, 2009 (10:50 am)Johann,
i agree with you about “as quiet and smooth as possible” as this will lessen any stress in starting and stopping. I trust GM to do this part of the software correctly. The pre-production vehicles in consumer hands will be monitored and the data used to determine the proper settings, at the same time letting the public see and ask questions of these lucky ones driving these vehicles.
As far as people messing with the software to tweak out another mpg, this would invalidate the car warranty, especially the battery warranty. This is not something that you want to mess with. Let Toyota and the others mess with it.
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Aug 17th, 2009 (10:52 am)Re Post #5 Fellow engineer #5 makes sense. The driving situations Lyle envisions gots to be routine stuff for GM. That said, for openers priority must be given to balancing hill climbing. Even a 3% grade doubles (x2) (or more depending on load) the power demand. A 5% grade, such as going over the Sierras right here in Northern Cal. could quintuple (x5) power demand. In short, hill climbing wipes out the battery. Which raises a question: When enabled can Volt’s ER hold battery drain to x1 load? The corollary question: What’s Volt’s ER potential? The answer to this yields comparative mph. How far (at x mph at y time) + battery range = total range. Imagine a fuel tank size giving 1000 miles range.
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Aug 17th, 2009 (10:52 am)It was my impression from previous comments from GM that there would possibly be an “Eco” mode and a power mode. Some of the buttons we saw on the original pictures of the console seemed to imply this also although those buttons were never described by a GM official. But having two modes does make sense to most people.
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-3
Aug 17th, 2009 (10:54 am)That is a useless question to 80% of the driving public.. similar to asking how many 4×8 plywood sheets it can carry.. the answer would be interesting but only useful in a handful of cases..
If you USUALLY drive more than 50 miles a day, please dont get a Volt.
GM should offer the genset as an option on the Volt.. that MAY finally make people understand that it is an electric car.
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Aug 17th, 2009 (10:56 am)I predict that the generator mode will evolve after a significant number units get into the hands of customers. Opinions will vary greatly due to different wants and needs. While the software algorithm should the best…some things should be left until customer feedback is possible.
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Aug 17th, 2009 (10:58 am)The devil is in the software details.
I remember about a year ago some self proclaimed software engineer posting how easy the software would be. No challenge at all. What a tool.
A positive thing is that the software can be updated after the car hits the road. Just go to your local GM dealer and get the latest software update. The bad thing is that things could get unpredictable. Let’s hope for bulletproof software.
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Aug 17th, 2009 (11:01 am)As I already predicted, this 50 mpg in normal highway driving will not be achievable (due to efficiency issues). Soon we will see.
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+1
Aug 17th, 2009 (11:08 am)For the people who post here, I am sure that the VOLT, like the new 2010 Camaro, will convince the trolls that GM finally gets it and is working on the best built Chevys ever made.
That being said, I wish that process didn’t involve so much ‘overkill’. But I guess perfection comes at a price.
Why does the ICE Gen need to be “imperceptable”? I’m sure VOLT owners aren’t stupid. I’m sure there will be a SOC guage on the dash right next to the Gen Fuel Level guage. I would bet that those huge LED screens are chock full of colorful displays that will show exactly when you’re gonna run out of pure electric power, and when the gas engine is on, and at what power output level.
Personally, I think it would be cool if the display said, “generator ignition in three… two… one…” when it’s about to start up.
I’ve driven and sold several Tahoe Hybrids this year, great truck but expensive, and the “shudder” when the ICE starts and stops at a light or in the parking lot is NOT objectionable. It is barely noticable. I have to tell many customers on test drives that it has even happened. And even if I did not, the ‘oil pressure’ guage tells them it is on.
The same thing can be done for VOLT. All of this ‘extra development’ to make something as simple as engine start unnoticed is just another reason this car will be $40k. And in the same breath, another reason people should compare it to Lexus or Mercedes rather than a buzzy little Prius.
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+3
Aug 17th, 2009 (11:08 am)Truth!
However, the media is set to pounce.
The Volt HAS to be right or it will get shredded by short sighted opportunists. Headlines sell papers and get web hits not facts. I think this is why they are playing the extended range experience close to the vest. A report of a ’slight’ unpleasantry would result in a flurry of “The Volt Sucks” stories here and elsewhere.
It’s DEFINATELY “Danger Will Robinson!”
Frank and team have their work cut out to avoid the bad headlines.
This is a difficult situation where a Gen 1 product (The Volt) really has to be close to perfect to just get a passing grade.
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+1
Aug 17th, 2009 (11:08 am)a 2-3% oscillation around the 30% charge point of the battery wont hurt anything. Note that even at the 30% point the battery still contains 4.8kwh of juice, lots more than a Prius battery.
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+25
Aug 17th, 2009 (11:11 am)>> As an aside, Lyle, if you wrote this article, would you mind
>> attaching your name to it?
Second that. Please +1 my post if you agree.
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Aug 17th, 2009 (11:14 am)I love the idea of the Volt with a generator to recharge the battery when it gets low. I would plan to use this car for everything including long trips.
One question that puzzles me is why did Chevy not put a motor in each wheel ( like the design from Siemens ). That design would do away with the weight of a drive train, steering gear etc and would make the car a perfect 4 wheel drive for superb control in all climates. The car would be a real drive by wire future car. I would think the price might be a little less.
DOES anyone have insight if this idea was considered and if so why was it not used. ie what are the flaws. Thanks in advance for replies.
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+2
Aug 17th, 2009 (11:15 am)and what about the poor sob that buys this Volt used?.. yeah the previous owner restored the original code but the damage has been done. I sure hope GM uses big holographic tamper-proof stickers on all the data ports.
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-12
Aug 17th, 2009 (11:16 am)(click to show comment)
Aug 17th, 2009 (11:16 am)Brings a ‘lil tear to your eye, don’t it? *sniff*
Wistfulness aside, we have bigger fish to fry, don’t we? Onward and upward!
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Aug 17th, 2009 (11:16 am)The CARB involvement in this is very disturbing. Could it be that we will wind up with a less than optimal product because some idiot bureaucrat at CARB had control over this. CARB had better wake up and remember that if this product doesn’t sell then they are back to gas guzzling engines and even comparatively inefficient hybrids.
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Aug 17th, 2009 (11:17 am)Ya, and have the freaking thing reboot when I’m not looking
or in this case, driving.
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+1
Aug 17th, 2009 (11:18 am)They seem to have done OK with Ford’s Sync system. *dons flame-resistant suit*
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+3
Aug 17th, 2009 (11:19 am)I chuckle at “customer depletion point” also.
That term best describes the dealers lot about 4:00 pm on a Monday when the game is about to start.
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Aug 17th, 2009 (11:20 am)Muddyrover,
Wow you are far too (uncomfortably) close to reality, so I’ll run away now (with Will Robinson). Seriously, I fear that you are right and that the Volt will be micro-analyzed right out of the chute. Then again, I guess that’s what he was talking about in the interview. SIGH – I really hate this reality stuff. It’s much more pleasant in my world. (g)
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (11:22 am)I think the source code & algorithms are probaby 50% of the propriotory Voltec technology. I dont see GM sharing this w/anyone. I know of lots of problems w/PC software, but have not run across too many in a car’s computer. Maybe Dan Petit can chime in.
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+4
Aug 17th, 2009 (11:23 am)texas.. I agree with 95% of your comments, but not this one.
Here is why:
Cruze has a 1.4L ICE @ 39 mpg
The Cruze will not have a 400 lb battery like the Volt. But, it will have more transmission weight and a bigger fuel tank. The Cruze will use the standard method of burning gas to move pistons which rotate gears which rotate rubber wheels. The Cruze will require about 3000 rpm to achieve 70mph.
The Volt has a 1.4L ICE @ 56 mpg
The Volt ICE rotates a generator. Which, we both agree, is less of a load than the old way of firing pistons then gears then rubber wheels. The Volt ICE will send generated electricity to an electric motor. It will not race to 5000 rpm on hills (smell the coolant overflow?). The Volt ICE should easily average 2800 rpm. True, we won’t know until we own a Volt.
50 mpg is a certainty. With 56 being a very solid high end guesstimate.
=D~
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Aug 17th, 2009 (11:23 am)Perhaps I missed something, but this answer seems exactly the same as offered months ago. As Statik would translate, “we ah are not going to tell you.” Something that could be defined to the engineering/management decision point in a matter of weeks, using simulation plus IVER’s for validation, is being characterized as a year long project. My lollapalooza meter is pegged.
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+1
Aug 17th, 2009 (11:23 am)Lone Star used to be a good beer. First one for me was that.
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+1
Aug 17th, 2009 (11:24 am)Mike-O
ABSOLUTELY! Onward and upward….. To infinity and BEYOND!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (11:24 am)i’m sure there would a deadband in there.
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Aug 17th, 2009 (11:25 am)I think GM has thought of that. If not with such a minor detail, GM is in deeep trouble.
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Aug 17th, 2009 (11:26 am)If I remember correctly, the answer is no.
The ICE does not charge the battery.
At least, that is how I understand it.
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+2
Aug 17th, 2009 (11:27 am)RE: Gsned57 “I don’t think they should kill themselves to make it “SOUND” like an EV all the time.”
From my perspective, it seems like they’re killing themselves to make sure it sounds like a gasoline-driven car. What with comments about raising the engine RPM to match how hard you’re pushing the “gas” pedal.
As a friend once pointed out about meat-simulating vegetarian products: “Why put so much effort into recreating what you’ve voluntarily avoided? Do monks have sex dolls?”
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Aug 17th, 2009 (11:27 am)There was an article in R&T or C&D a while back about a Mini Cooper that had hub motors placed in all 4 wheels. Incredible power and performance, But it would not pass federal safety guidelines beacause there was no emergency or backup braking system. Nowhere to put it.
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Aug 17th, 2009 (11:27 am)I’m sorry, but I totally disagree with that. This car should be able to make -40Miles AND +40Miles daily commuters happy. Otherwise, there is no reason to put so many effort in designing and fine tuning the genset the way GM does. If you say that this car is basically for -40Miles commuters, simply put a V6 engine as genset and don’t bother more. We will still get our “triple digit mpg” (which is a true false statement, imo).
I’m unfortunately not a 40Miles commuter. I get to work using public transportation. I do use my car on week-ends for about a 150 miles away trip.
On a additional note, the E-REV concept itself is all about remove the link between an ICE and the wheels. You create a whole new space for ICE power efficiency improvements. This is what I’m mostly interested, and this is the second key information we are missing at the moment.
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+2
Aug 17th, 2009 (11:28 am)This interview goes a long way to adding to my patience in waiting for a preproduction volt to be pranced about in front of the media in charge sustaining mode.
All the “solutions” floated here have one thing in common – we don’t have all the facts. “For every complex problem there is always a simple solution, which is almost inevitably wrong”
________________________
Thank you Tag. That is exactly what I think about when people complain GM is not being forthcoming and transparent, or everything should be done now and people should have Volts for unlimited test drives.
Personally I am not engineering, nor co-engineering, nor back seat engineering nor Tuesday morning quarterbacking the Volt engineering groups. That’s not on my resume; and I get pretty tired of people pronouncing GM should start acting like a Microsoft clone and just put their cards on the table ready or not.
Many go on to state with absolute certainty that unless GM follows their advice they’re doomed. I’m not an expert but I think when the car is released, people outside GM will drive it.
And not only that but GM will put out documentation called an owners manual, will have staff available to answer questions from the press, and will even train some of the dealers sales staff to answer questions from the public.
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Aug 17th, 2009 (11:30 am)From ShockMe: “My assumption though was that in charge sustaining mode the ICE was splitting the power between the generator/battery pack and sending current directly to the wheel motors. Is this not the case?”
Is the ICE storing energy or supplying power to the wheels? – or both?
Does anyone know this??
Thanks for the reminder if already discussed.
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Aug 17th, 2009 (11:32 am)A button can be re-purposed at any time. What the heck is a “hold” button, anyway?
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Aug 17th, 2009 (11:33 am)The law regarding braking systems is simple. The law states there must be friction type brakes on all wheels of the vehicle. If this helps.
=D~
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Aug 17th, 2009 (11:33 am)I would think (hope?) that the NAV system would be linked into the control software. In this way the car would KNOW what the road ahead has in store so it can optimise the trip efficency.
I don’t see this as being a huge inconvenience, my $100 Tom Tom remembers quite a few destinations, so it’s as easy as clicking ‘home’ and it has all the info it needs.
I’m buying the loaded one, I guess the entry model would have to do without that sort of integration.
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Aug 17th, 2009 (11:35 am)Superb! Now off to the lab, where I’ll build myself a completely leakproof, crashproof, lunchbox-sized, 50,000 PSI H2 tank.
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Aug 17th, 2009 (11:35 am)That’s a really good idea, I like it.
And I’m sure if we go through about 3 million lines of now discarded code, we could determine the point where GM engineers liked it too.
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Aug 17th, 2009 (11:36 am)Amendment: I did see that ABG article and the size/volume reduction between gen4 and gen5 is astounding. So is the reduction in platinum use, apparently with more improvement to come in that department.
I surely didn’t mean to belittle the achievement… It’s just that I get depressed thinking about H2 storage and supply/transport issues.
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+1
Aug 17th, 2009 (11:38 am)It is trivial.. here let me give you the secret formula they could use.. for free.
1. Driver is happily motoring about, he has gone about 60 miles and at that time the computer determines that the battery has reached the 30% point (actually this can be hard to do).. it starts the genset slowly, over 15 secs it ramps up to the desired power output point, again determined from data the computer has been collecting for the past few minutes.. the computer tries to match the output to the AVERAGE power demands of the driver. This can be achieved by varying the ICE throttle, timing or field excitation of the generator.. this will be computer controlled to meet pollution and MPG requirements. The driver suddenly steps on the gas when he reaches a zone with no speed limits.. after a set time the computer increases power output to match the new demands.. but that reaction time may be slow since it has such a huge buffer battery and quick reaction is not needed.
2. the driver severely steps on the brakes or comes to stop.. the computer immediately slows down the engine to idle or maybe even stops it.. but if the computer detects the radio is playing at a sufficient volume it may elect to keep the engine running, but only for a limited time. Go back to step one.. change the program if the driver selected a different mode and so on.
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+3
Aug 17th, 2009 (11:41 am)I can easily understand why GM is not giving much details about the ICE sustaining mode.Let GM get it perfected first and keep the competition guessing. Then, next year, show the world. By that time, it’ll be too late for the competition to copy from it.
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Aug 17th, 2009 (11:41 am)Right you are Mike.
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+1
Aug 17th, 2009 (11:46 am)The genset can charge/return the battery to the depletion point if it goes below under severe usage.
However under normal steady state operation the genset power would go directly to the drive motor. This could be common on a flat freeway but I bet the battery will be ‘buffering’ driving variations (start/stop) the rest of the time.
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+1
Aug 17th, 2009 (11:47 am)They are many drawbacks with having the motor in each wheel. Weight is one. Having all that extra weight going up and down for each bump would take a toll. Another, is the harsh environment of dirt, water,ETC.
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Aug 17th, 2009 (11:49 am)>> Imagine a fuel tank size giving 1000 miles range.
Now imagine a Beowulf Cluster of these!
D’oh!!… sorry, thought I was on Slashdot for a second, there.
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+3
Aug 17th, 2009 (11:49 am)“If you USUALLY drive more than 50 miles a day, please dont get a Volt.”
This argument is totally circular. If you drive UNDER 50 miles, why would you consider the Volt, and not a BEV. It seems ardent Volt supports say they will never use the extended range, so why not just get a BEV with a 100 mile range?
On the other hand, I drive over 50 miles a day, therefore am the perfect candidate for a Volt. I will utilize the range extender, which is the main selling point of the Volt.
Therefore I want to know the MPG!
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Aug 17th, 2009 (11:50 am)” I think GM is being tone deaf on two points, the generator mode is not going to be used that often by most drivers, and only the anal retentives are going to fault them for having an IVer that allows you to hear the generator, as long as it is programmed to follow driving cues, i.e. the generator slows at times the car is stopped. ”
I think you are describing the reviewers that will comb the car for nits to put in their articles… also, the people that will test drive these cars prior to buying them will be attentive to anything unusual.. and any sound will be unusual in a whisper quiet Volt.. even normal tire noise may be too much for some.
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Aug 17th, 2009 (11:53 am)Also, increased unsprung weight is the enemy of good suspension & handling. And I gotta believe four small motors are less efficient than one or two bigger ones. Experts, chime in please!
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Aug 17th, 2009 (11:53 am)Pretty sure they don’t. Excellent point
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Aug 17th, 2009 (11:54 am)You do make me laugh No Name…
At least you should be out of the rain under the bridge…
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Aug 17th, 2009 (11:54 am)I’m sure the “tweaking “or refinement and advancement of the propulsion system will continue as long as EREV exists. There will be plenty of aha moments, breakthroughs, man that’s obvious why didn’t any one else think of that type of ideas. The ICE has been developed for over a hundred years and people are still trying new ideas.
Henry Ford probably had an idea for HCCI and never built it because he could never prioritize the two or three hours he guessed it would take to design it. It’s a fact though that Edison never made a long range electric car, even though for most of his life he thought he only needed “a couple more months” to build a better battery that would make it possible!
(Side side note, Tesla claimed that despite despite Edison’s capacity for invention he was ignorant of science and engineering, so maybe Edison just didn’t have the perspective to know the job was impossible, again. Will we know were the next breakthrough comes from?)
The one sure thing is the development will continue, the Voltec system is not a perfected piece suitable for framing in museums, yet.
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Aug 17th, 2009 (11:58 am)You bring up an interesting question. As a prospective customer, how do you experience Charge Sustaining mode? Most test drives aren’t very long and my guess is that the car will be fully charged when you go out because what you really want to experience is the EV drive.
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Aug 17th, 2009 (11:58 am)Answered my own question… The answer is both…
from an earlier post: http://gm-volt.com/2008/09/27/how-charging-of-the-battery-works-in-the-chevy-volt/
Thanks All.
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Aug 17th, 2009 (12:01 pm)This to me is somewhat puzzling. The mass would be similar whether in the wheel or suspended above it. Would not having some of that weight directly on the road surface put less pressure on the suspension given that it is not….suspended?
I should think that damage to the motors would be the primary concern. The potential for all wheel steering would have been cool though.
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Aug 17th, 2009 (12:10 pm)I think I’ll go with Texas on this one. GM has said the computer model predicts 50 MPG. The models are always overly optimistic so you’d normally expect a bit lower MPG. Also, my guess would be that GM will sacrifice some efficiency for what it deems a better user interaction (though I think we could adapt better than they seem to think). So my wild guess is 45 MPG.
But does it really matter? Seems to me that opportunistic charging will be much more important. For example, take Rashiid’s hundred mile commute, which is quite a long one. For him charging at work will be far better than getting 55 MPG rather than 45 MPG. Not only is the EV mode vastly more cost efficient — and more fun! — getting 45 MPG rather than 55 MPG doesn’t involve all that much of a fuel penalty. Over 5000 miles we’re only talking about 20 gallons of gas.
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Aug 17th, 2009 (12:11 pm)Yes I agree 100%.
I think the only things that needs to be done is a way to left the driver know why thier car is acting “strange”.
I favour an “Electric Boost” Bar right next to the Speedometer. When that bar is “low”, the engine will need to run at say a stop light. But at the stop light you can clearly see -why- its running.
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Aug 17th, 2009 (12:12 pm)So when it’s really cold and the genset kiscks on the very first thing. Is it still “CD” or “CS”? Hmmm…….
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Aug 17th, 2009 (12:15 pm)Good one! I’m not a monk so I can’t answer the sex doll question!!!
But your point is well taken. Remember all those (horrible) user interfaces for the early software programs that tried to make the program look like an office with desks and filing cabinets? Ugh! People are very adaptable IF they want to adapt. A slightly different experience seems like a small price to pay for greater efficiency.
In this regard, the lack of a true “freewheeling” mode seems like another pox visited on us by the perceived need to make driving the Volt similar to a conventional car.
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Aug 17th, 2009 (12:17 pm)I don’t think we have anything to worry about in the sense of “Noticing” the genset kicks on.
IMHO, who cares. It’s on it’s on, it’s off it’s off.
If the beers cold, do you complain?
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Aug 17th, 2009 (12:17 pm)I drove the 2010 last week. Engine start/stop is practically undetectable. It’s very quiet even under full acceleration.
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Aug 17th, 2009 (12:22 pm)ziv: “I think Weber is letting perfect be the enemy of very good.”
Well, he knows what he’s doing. This must be important or the effects are more severe than they’re letting on.
What concerns me a little, is how they’re going about the “tuning.”
If they’re adjusting parameters or modifying easily debugged subroutines (or objects, as we’re in the 21st century, now), then the overall quality of the code at launch should be as good as can be expected and testing today is almost perfectly relevant to what will be in Customer Vehicle 1.
However, if they’re rewriting entire collections of objects, changing calling interfaces and overall flow of engine management code, then the code for Customer Vehicle 1 will be pretty fresh and bugs are much more likely.
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Aug 17th, 2009 (12:23 pm)IMHO, hearing/feeling the car is how many troubleshoot a car. If I never notice the genset kicks on/off then I’ll never know if it supposed to under any conditions.
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Aug 17th, 2009 (12:31 pm)I bet they are playing with electronic compression release valves and big ignition timing swings.
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Aug 17th, 2009 (12:38 pm)What about Linux which is open source? Homany differen’t variations are there? What kernel is being used? What GUI is used? How does one get a specific kernel to run an rpm file for install? Why does one command work on one version but not the other partys?
Perfect example of no control or consistency or STANDARDIZATION.
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Aug 17th, 2009 (1:00 pm)Just curious, what’s an “inefficient hybrids.” and who makes it/them?
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Aug 17th, 2009 (1:02 pm)…and warm with his sheep!
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Aug 17th, 2009 (1:07 pm)You must have missed his name at the very bottom, after the related links list. Statik’s name was on his post, too.
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Aug 17th, 2009 (1:07 pm)Citing to Beowulf is cryptic enough. Beowulf Cluster is more so. Never been on slashdot. So few understand and even fewer get it. My ‘in-cheek’ comment, notwithstanding GM’s 230 claims, intend to spur thinking. With your conclusive ‘D’oh!!’ — that was missed. Happily I explain.
Take a level trial speed – 40 mph. Battery propulsion first – 40 miles or 1 hour. With ER enabled and no intermittent (or overnight) charge — how long will the EV run on ER? That will determine total range. If 1 gal. goes 40 miles – 20 gal. + the battery totals 1040 miles. Now how close are we to that. Pretty close. For example, the Smart Car .7 L turbo gas (premium) at 45 kW is a very good reference. Let’s say we double our assumptions (and thereby assume 90 kW) – that’s a 40 gal. tank. And you know what – I have a 31 gal tank (GMC 1987 – 311,000 original miles) and its compact enough I can hold it in my hands.
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Aug 17th, 2009 (1:12 pm)So if there is no 12V starter (thank you for the links), does that mean that the Volt cannot be jump started from another car?
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Aug 17th, 2009 (1:14 pm)Also lets say you just went up a monster hill and the engine feathered up a little to support you and you get to the top of the hill and hit a light. Should the engine keep on running to allow you to recover or do you turn off the engine because the customer expects it too because they’re stopped at a light?
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You should let the engine keep on running. That is the same thing that happens now if the engine idles-up because of the air conditioning, for example So long as the car does not pull against the brakes, soon you don’t even notice.
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Aug 17th, 2009 (1:15 pm)or Iced Tea
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Aug 17th, 2009 (1:23 pm)A fair and interesting question!
I don’t have a good answer there.
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Aug 17th, 2009 (1:27 pm)I like the “driver-controlled” scenario where I can choose when it comes on and at what power. Just imagine being at a stoplight and kicking on the genset at 4000 RPM !!! You could scare the beejeeezuss out of those unsuspecting blind people at the crosswalk! Or, grit your teeth and hunch your shoulders and pretend you’re going really fast while the guy next to you looks on!
(Nah. I’m just kidding. I don’t know how they’re gonna fix that.)
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Aug 17th, 2009 (1:29 pm)You just had to pull out a Back to the Future reference, didn’t you? Good work.
We’re down to the nuts and bolts – of getting butts in Volts (see what I did there?)
And yes, I intentionally posted as the tenth sub-post so that noone could reply to this. Feels strangely like an accomplishment (kinda like the old “first!” posts, but different).
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Aug 17th, 2009 (1:31 pm)Good point! I wonder if there will be a feature on the Volt that will allow you to run it in charge sustaining mode when there is still significant charge left. If so, then you could try it out during a test drive to see what the charge sustaining mode is like.
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Aug 17th, 2009 (1:32 pm)>> However, if they’re rewriting entire collections of objects, changing
>> calling interfaces and overall flow of engine management code
I doubt that’s the case. I’m sure they have internal methodologies and have established code libraries that they’re using. No reason to reinvent the wheel for R&D that’s already been done.
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Aug 17th, 2009 (1:33 pm)That is an interesting question!
I can’t help but think that the software would start the genset well before the pack got to that point and would bring the battery pack back to minimum charge.
If the pack DID get to zero charge you have bigger problems that a boost just isn’t going to fix.
I would think at that point a ride on the hook back for repairs would be in order.
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Aug 17th, 2009 (1:34 pm)jeffhre,
Thanks for the kind words.
I don’t know what’s wrong with your resume’, but mine has ALL those titles (g). Talk about multiple personalities (lol).
I’m of the sort that actually does read the manual, but until one is available, this site is the absolute next best thing.
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
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Aug 17th, 2009 (1:35 pm)I’m skeptical that is possible to code one solution for every scenario. Sounds like maybe they need a toggle setting so the driver can choose between “performance” and “luxury” modes.
In luxury mode, the ICE and electric motor transitions could be as buttery smooth and imperceptible as possible. In performance mode, the transitions could be more abrupt so as to immediately match the power needs of the driver.
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Aug 17th, 2009 (1:36 pm)Yes, I agree. Good idea – hope GM is listening.
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Aug 17th, 2009 (1:38 pm)>> I’m not a monk so I can’t answer the sex doll question!!!
I missed whatever led to you saying this… but I believe I’ll elect NOT to read backwards to find it
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