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Old 28th April 2011, 12:56   #31
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Default Re: Camless and electronic timing : The future?

@tsk1979 interesting topic. I think R&D is more tilting towards Electric Vehicles and with the advancement of Nano batteries, EV will become more practical. Almost all major manufactures is into it. This could be one of the reason for limited information on this topic.

@vina - Some awesome information shared .
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Old 28th April 2011, 13:07   #32
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Originally Posted by tsk1979 View Post
I was simply referring to articles which said high speed applications have trouble with electronic valve timing.
Low speed engine do not have those problems.

That said, won't using electromagnets solve the rare earth problem to a degree?

About reliability of electronics, I would disagree. Its more of a QC issue than a design issue. Military grade electronics and chips are still manufactured and can run in adverse conditions.
Even normal chips are taped out with an aim of 125-130 degree operational parameters. However to cut costs the casings are cheap quality which cannot withstand those temperatures.
In an expensive automobile a few dollars/chip will be acceptable.

Already we have components like cam sensor and sensors in the exhaust circuit. Exhaust circuit sensors run at much higher temperatures.

The biggest drawback i could see is the magnetic valves, as you mentioned. I am not well versed with electrical engineering, so you are right, there may be many problems in those areas. However, as far as ICs are concerned, its easy in current tech to manufacture chips which can survive 200 degree C temperatures without skipping a heartbeat.
Even consumer grade hardware like GPUs touches 100-110 degree C before thermal shutdown algos kick in.
Tanveer

I saw your profile - we are in the same business buddy !

Coming back to the topic:

Electromagnets would require a significant DC current to hold the magnetisation and double the size (you need a moving coil and a static coil) not really a good solution, but may be workable. However all said and done this may eliminate almost all advantages that you mentioned (lesser components ...)

You can disagree about what I said about the reliability, but I'll stand my ground. The tape our of 125C is for junction temperature - not ambient. Even good packages cause a difference of at least 30C between outside and inside temperature. 200C of operation is not going to happen with CMOS or CMOS like technologies - (sorry to everyone who doesn't have a background in semiconductors) every one of the reversed biased diodes will leak so heavily, it'll be a short for all practical purposes. On top of that thermal stresses (SiO2 and Si do not expand at the same rate, neither does SiNx) will be a problem within the chip and on the board.

Military grade and Military are not the same thing. Automotive temperature range includes 125C - but those are chips that go in music systems in cars (even car music systems are more reliable than what you get for home use). Military grade has more specs that I'm sure you would have never simulated. e.g. What happen if temperature increase by 100C in 3 seconds (chips used in rocket controls), what happens if the chip is going through a shock of 10g (almost all aircraft), a shock of 50g (even industrial sensors need that).

Exhaust circuit sensors are not ICs that you refer to, they are sensors - they give you a weak electrical (usually current) signal. Thermocouples tolerate thousands of degrees C but they do not do any signal procession whatsoever. And semiconductor doesn't mean silicon. Long before there was silicon there were other materials (I'm not talking about Germaniumor GaAs - CdS, Zinc Blende and stuff was what caused semiconductors to be initially discovered and used - a lot of them are still in use, though not in ICs, in sensors, displays and what not) however these other materials are no good for signal processing and controls - which is what you need here.

Regarding your comment on GPUs, imagine the scenario that you are playing NASCAR 2011 on your xbox, trying to overtake on the game and the GPU overheats - all hell breaks lose your computer shuts down you lose to your buddy for the first time in months !

Now imagine the same experience on a highway at a modest speed of 80kmph while trying to overtake a truck. GPUs have zero reliability if you use the lingo of Automobile designers (whose stuff has zero reliability if you talk to military types).

And you haven't even consider soft error rate (I mentioned it by its real effects - alpha particle strikes) which can play havoc with any and every algorithm you can consider.


And we haven't even started discussing what happens after you make a chip.


And all this for what? Even assuming that all this were possible for $1, what exactly do you gain? Can the transmission take the higher rpm? how about flame front inside the cylinder, heat and mass flow ...

The technology will take immense investment to develop (if it is possible which is not obvious to me) for gains which are debatable do a good extent, and there are many other (better) uses the investment money can be put - look at Tesla.
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Old 28th April 2011, 13:21   #33
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Default Re: Camless and electronic timing : The future?

@vina, you do not need to put the control circuit in the engine, it can sit with the ECU. All you need to is have sensors there.
That said, back in 2005-2007 timeframe there was a lot of research going on in this, but details are sketchy. Maybe you are right.
Focus is now on EVs and all, and this project has been abandoned.
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Old 28th April 2011, 13:33   #34
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Default Re: Camless and electronic timing : The future?

Tanveer since we are talking of the future we should possibly consider completely dispensing with the traditional IC engine ! In any case its a highly inefficient energy converter. So much gets wasted as heat !

Why not tiny nuclear reactors that generate electricity to drive your car? Or a hydrogen fuel cell system that generates electricity.

I think the future of cars is electric and the very latest in brushless motors etc and advances in battery technology.

The IC engine will one day remain history in my opinion

Last edited by DKG : 28th April 2011 at 13:35.
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Old 28th April 2011, 14:07   #35
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Default Re: Camless and electronic timing : The future?

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Why not tiny nuclear reactors that generate electricity to drive your car? Or a hydrogen fuel cell system that generates electricity.
So, every car we will see on road is actually nuclear bomb and it can explode during crash. How Fukushima nuclear plant exploded after those tremors in Japan.

Nuclear option would never be used in public utilities as outcome of which are unknown during adverse condition.

Electronics has been developed leaps and bound and during the last 20 - 30 years time frame, we saw many ground breaking products in market containing electronics. I feel something new will come soon in a decade regarding engine and energy efficient subject.

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Old 28th April 2011, 14:31   #36
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How Fukushima nuclear plant exploded after those tremors in Japan.
Wow! did it explode. Can you post some pictures of the mushroom cloud?
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Old 28th April 2011, 14:54   #37
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Originally Posted by tsk1979 View Post
@vina, you do not need to put the control circuit in the engine, it can sit with the ECU. All you need to is have sensors there.
That said, back in 2005-2007 timeframe there was a lot of research going on in this, but details are sketchy. Maybe you are right.
Focus is now on EVs and all, and this project has been abandoned.
I knew you would say that - that is why I mentioned in my original post the stuff about inductances and bandwidth. If you have long leads (which you'll need if the controller, or at least the driver of the solenoids, is not in the engine bay) those leads will have huge inductance. That is a problem due to multiple reasons:
  1. Fast change in current is harder (if possible - depends on how fast you need) so turning on and off fast may not be easy.
  2. Large switching currents on long cable will almost certainly fail EMI requirements all over the globe given the frequencies involved.
  3. Long leads = delay. Delay can be a problem in control-loop stability (goes out of you phase margin)
  4. ...
Overall you must think about it this way - let us say the valve train losses account for 1% of the total power delivered - this I believe may be an underestimate (if it is not ), our engine design friends may help with this. Now for a Swift engine, that comes to 500W at peak power (engine does over 50kW) - that is how much your valves are eating.

If you do it electronically you'll need much more than this (alternator efficiency is close to 50% on good ones, solenoids less than that, and then there are controller losses) - say you lose 2kW.

So unless you somehow gain 1.5kW by doing all this, there is no advantage. However I think you believe gains will be at least 10% if not more, then this still makes sense.

So now let's go to cost - assuming valves take 500W, solenoids will take at least 1kW. This means you would be driving 1kW power into audio-band frequencies with good quality waveforms. You can go to the market and inquire how much that kind of a music amplifier costs (you'll need an amplifier that can do 10kW PMPO and 1kW sustained) - this is more than most heavy duty loud speakers you'll see on streets.

Now take that price and multiply that at least 5 fold (longivity, reliability etc. doesn't come cheap in the realms of power electronics) and you'll get a ballpark estimate of what the driver will cost you. Controller will actually be (most likely) pretty cheap.

On top of this you'll practically need one more (bigger) alternator - the 50A 14V alternator barely generates 700W and you need much more than that just for the valvetrain. This is also the reason why the AC couples directly to the shaft (not an electric motor).

And you also need to cool down all the electronics involved (if you have an inverter at home you'll know what I mean - in fact go around the neighborhood asking for how many people had zero trouble with their inverters and you'll know a little more about electronics reliability)


Now the calculations above may be off the mark (to some extent) but you can see why I don't think this obviously is better.
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Old 28th April 2011, 15:04   #38
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Default Re: Camless and electronic timing : The future?

I think manufacturers might have been working less on electronic valve controls. They might be concentrating on electric drive and the only problem now would be storage. Fuel cells have an advantage over batteries.

This requires cheaper and greener energy generation in general to provide the hydrogen needed for fuel cells. So now everything is linked and energy generation is a generic problem that needs to be dealt with .
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Old 28th April 2011, 15:22   #39
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Default Re: Camless and electronic timing : The future?

Quote:
Originally Posted by DKG View Post
In any case its a highly inefficient energy converter. So much gets wasted as heat !
Agreed.

Why not tiny nuclear reactors that generate electricity to drive your car?
For various reasons, we'll let the SF writers deal with this.

Or a hydrogen fuel cell system that generates electricity.
Fuel Cells distinct possibility.

I think the future of cars is electric and the very latest in brushless motors etc and advances in battery technology.
Agreed. Advances in batteries really.

The IC engine will one day remain history in my opinion
Agreed. When is the question. Till such time we have the pleasure of playing with the throttle, something no electric motor can duplicate.
@Vina,
Again too much to discuss. So let me narrow it down to points where I have significant differences with your views.

I don't think processing power is a problem. Once the decision to operate (open/ close/ hold) a valve is taken, its actions will be determined by the mechanical (in the larger sense of the term) parameters. It will not be very much more computationally intensive than say multi injection in a modern diesel. And there are a vast number of tricks available to lessen even that computational load. (Crude eg. Think of Sine wave generation techniques in inverters before DSPs took over.)

The maximum source of unreliability is where the form of 'energy' changes:- actuators and transducers. (Power electronics falls in the category of actuator, in my view). After that will come the more common ones like power supplies, interconnections, mechanical switches etc. Chip level failure will be way down the list.

One thing you have not mentioned is handling all the electrical noise (EMI/ RFI/ Power line) which will be generated by the operation of so many highpower solenoids. This will play more havoc than alpha particle radiation.

One very minor point. Are Ne magnets temp stable?

Anyway, great posts. Keep them coming. A pleasure reading them. And a pleasure interacting.

Regards
Sutripta
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Old 28th April 2011, 15:58   #40
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Default Re: Camless and electronic timing : The future?

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Originally Posted by pranavt View Post
I believe the working prototypes involved moving the mains up/down depending on what you wanted to do to the compression. Mains meaning the main bearing supports on which the crank rotates.
IIRC, it was a hinged cylinder assembly (block and head). Of course seen from the reference of the cylinders, it was the crankcase which was hinged.

@SS.
What have you done to your signature. I referred to it in one of my posts!

Regards
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Old 28th April 2011, 16:44   #41
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Originally Posted by tsk1979 View Post
Wow! did it explode. Can you post some pictures of the mushroom cloud?


Here you can see "Hybrid" mushroom cloud.
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Old 28th April 2011, 17:24   #42
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Default Re: Camless and electronic timing : The future?

Fantastic topic and discussion.

Quote:
Originally Posted by tsk1979 View Post
... high speed applications have trouble with electronic valve timing. ...
The control (and device) techniques at 18-20K rpm are completely different. At that rpm getting reliable inputs is more of a hassle than the actual control. Even the algorithms are different. Injection control for such duty has been around for 20 years now (F1 and such engines) - the architecture is completely different. Valve Control is less of a problem - one doesn't need to make corrections for every cylinder cycle.

Quote:
Originally Posted by tsk1979 View Post
... About reliability of electronics, ... more of a QC issue than a design issue. ...
Absolutely. Keeping temperature under control is an engineering issue, and it is the sensors - not digital electronics - that one needs to look at. Digital electronics usually works in snug comfort away from the engine.

Quote:
Originally Posted by vina View Post
... Electromagnets would require a significant DC current to hold the magnetisation and double the size ...
DC? Double the size? Why 'hold the magnetization'?

Quote:
Originally Posted by vina View Post
... 200C of operation is not going to happen with CMOS or CMOS like technologies ...
CMOS is the most suitable material technology at high temp - getting it work reliably would be a matter of material science, not empirical thought. We are not talking of current tech state, are we?

Anyhow, the chips that you are talking about work in a well-protected environment - perhaps you are completely discounting the engineering practice of cooling (both natural and forced)?

Quote:
Originally Posted by vina View Post
... What happen if temperature increase by 100C in 3 seconds (chips used in rocket controls), what happens if the chip is going through a shock of 10g (almost all aircraft), a shock of 50g (even industrial sensors need that). ...
One can write off the main equipment, let alone the electronics, when such rapid change happens. For example, in rockets 100degC temperature change in 3s would mean the rocket has disintegrated, or the satellite has broken up. Otherwise, the electronics would still be protected from exposure.

Quote:
Originally Posted by vina View Post
... And you haven't even consider soft error rate (I mentioned it by its real effects - alpha particle strikes) which can play havoc with any and every algorithm you can consider. ...
One normally uses a. radiation hardening, and b. robust algorithms. These techniques have been around 30 years at least - since TTL and SSI days! Doesn't normally appear in college text books though.

Quote:
Originally Posted by vina View Post
... And all this for what? ... gains which are debatable do a good extent, ...
Absolutely agree. If the objective is set after checking the quantum of gain then material science, technology and engineering will follow as always. One can look at the large investment needed in a different way - it is a business / economic opportunity that one can't pass over. No?

Quote:
Originally Posted by vina View Post
... assuming valves take 500W, solenoids will take at least 1kW. This means you would be driving 1kW power into audio-band frequencies with good quality waveforms. ...
Why would a valve take 500W to open and shut? You are assuming current tech again, right? What happens if one does away with the spring (which is used to hold the valve shut - and naturally is a hindrance to opening)? What if one uses a positioner instead of a solenoid? What happens if you get a different seat material? The possibilities are, if not endless, numerous enough. And one builds products by looking at possibilities, and not being deterred by constraints.

Quote:
Originally Posted by Sutripta View Post
... One thing you have not mentioned is handling all the electrical noise (EMI/ RFI/ Power line) which will be generated by the operation of so many highpower solenoids. This will play more havoc than alpha particle radiation. ...
Even the alternator throws out a significant amount of power in RF range - enough to possibly cause EMI disturbance. The engine bay is 5 sides shielded, so you cause minimal disturbance outside the car. The car electronics is 6 sides shielded, so it is not affected. Old tech - good electrical practices like grounding.

Last edited by DerAlte : 28th April 2011 at 18:31. Reason: Removed extra smiley :p
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Old 28th April 2011, 18:15   #43
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Default Re: Camless and electronic timing : The future?

Fascinating insight in to topics and engineering thoughts continue. Hats off to the "guru's" for a lovely discussion. And again Tanveer thanks for touching this topic.
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Old 28th April 2011, 20:20   #44
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One thought: what is the temperature of the exhaust gas at the exhaust valve (and valve stem)? My guess would be, not less than 1000-1200*C even after the engine oil cools it down, but please correct me if I am wrong. What kind of electronics (i.e. the materials that make up the solenoid, chip etc.) is expected to tolerate that sort of temperature (although, @vina, you did talk about temperatures of 200*C)? And what would be the cost implications of such materials?

Also, the higher the rpm of an IC engine, the greater would be the exhaust gas temp anyway, so that might nullify the possibility of a camless engine managing to rev higher (as Tanveer suggested).
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@SS.
What have you done to your signature. I referred to it in one of my posts
Saw that reference too! It's still the same, and is an appropriate one for some of our interesting discussions on this thread and elsewhere, isn't it?
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Old 28th April 2011, 20:37   #45
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Thanks to all for the contribution to the subject.

As stated earlier I am sailing on such camless engine powered ships. I find the electronics talk quite amazing. I mean in our day to day life on-board, we rarely give a thought to details like power drawn by solenoids et all.

Coming back to the topic, yes I overwhelmingly agree that marine engines and automotive engines are mighty different.

The whole view point of discussing these marine engines on automotive forum was to let people know that these camless engines are very much here and in existence hence there is no arm-chair professoring about it.

Any new technology that is introduced in shipping is obviously first developed ashore and tried out. Since marine engines market sizewise is very very small, there are pretty high chances that these technologies were developed for some different intentions (read automotive) and later found their way into shipping.

As regards CPU and other electonics not sustaining environmental tortures, I strongly feel that todays electronics hardware is pretty strong to these external factors.

The engines that I am sailing on has duplicated EICUs(Engine Interface Control Unit) that modifies the speed set point by protective ALGORITHMS (in earlier post logarithms was typo error, apologies), then sets command for ECU which is duplicated- one serving as hot stand-by, which it-turn sets command for CCU (cyliner control unit: one per cylinder).

All these cards known as MPC (Multi-purpose controllers - meaning same card can be used as EICU, ECU or CCU) are located in engine room which is analogous to placing them under the hood of ones car.

They have their own cabinets but no ventillation/cooling. Few fuel pipes carrying fuel at 145 deg C are passing close to it. The whole area is god damn hot and in areas like persian gulf is just unbearable but still this electronics is going strong, add to that the vibrations, humidity and dust. In a nutshell electronic components are pretty tough nowdays.

As far as ships being nuclear powered is concerned, it is a complete gossip. There are definitely naval vessels nuclear powered but for merchant vessels to be nuclear powered, there isn't even a design code yet made. Imagine a vessel picking up some radium/thorium whatever fuel it is, at singapore or Suez Canal or panama canal. Add to that the lack of marine engineers with nuclear power experience and hell lot of legal / logistics / safety issues i don't think merchant vessels would ever be nuclear powered.

Anyways, these camless engines offer a true flexibility to me. As some one menitoned about altering compression ratios, it is a kids play on these engines. just few clicks on screen and one can vary compression ration, expansion ratio etc. This comes very handy for me as for power balacning of cylinder. For earlier engines with cams, I was required to dismantle fuel pump adjust shims etc. On few engines one has to turn the cam through certain degrees which means minimum 6 hrs layoff. Now with these engines i can adjust all these variables with eninge running.

Also some times in emergency we need to cut off one cylinder firing. If not electronically controlled eninge, one needs to stop engine, lift the roller up lock it in position and then resume which costs about 3-4 hours of delay. ,With electronically controlled engines, it is just a click away.

Apart from these advantages, what I feel the biggest advantage is that the injection pressure remains constant over all operating RPM ranges resulting in much better and uniform combustion and smoke less exhaust. This obviously results higer fuel efficincy (SFOC in marine parlance)

Though all this talk is so specific to marine engines I feel the technology would sure unleash even more potential benefits to automotive engines. Any thoughts?
I think there is enough steam left in IC engine technology to be easily wiped-off by EV.

Anyways hope this tread lives long so that I can get more insight abt that dreaded mysterious box containing some complex electronic card whic made my life so simple.

Rgds to all.
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