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Old 4th February 2010, 20:56   #106
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Electro magnetic interference (EMI) and electronics

Here's yet another can of worms opening right after the Prius report

Quote:

Toyota Recall: Did Toyota Hide Life-Saving Information? - ABC News

Some experts believe there is a software glitch or that the computer is susceptible to electromagnetic waves. "It's the electronics, it's not the pedal," said Keith Armstrong, an an electromagnetic interference expert who was interviewed just this week as part of the new federal safety probe of Toyota.

Toyota's top executives have repeatedly denied there is any electronic problem that could cause their cars to speed out of control.
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Old 5th February 2010, 00:03   #107
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Originally Posted by RX135 View Post
But, I am sure that Toyota would bounce back soon enough.
But now the US DT will analyze each consumer complaint more thoroughly which will make Toyota's life harder in US. We could expect many more recalls in the near future by Toyota. This will give enough time to GM / Ford to bounce back.
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Old 5th February 2010, 09:35   #108
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Originally Posted by teamveevee View Post
But now the US DT will analyze each consumer complaint more thoroughly which will make Toyota's life harder in US. We could expect many more recalls in the near future by Toyota. This will give enough time to GM / Ford to bounce back.
Well I am not sure of that, particularly because today's news talks of Ford agreeing to address problems with its hybrids in the US like the Fusion---don't remember the other name.

We should have more news hopefully by tomorrow.
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Old 5th February 2010, 13:07   #109
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Originally Posted by R2D2 View Post
a) Electronics, specially computers, operate on the boolean principle. When they operate well, they work well but they can FAIL and that too completely. The danger comes in trusting high tech electronics with your life and to perform critical operations based on algorithms programmed into the chip. Remember, a computer programme burned into your car's EPROM ECU is only as good as the programmer(s) that wrote it.
Agreed about software being as good as a programmer, but then what is the guarantee that the same human brain would make better judgment in split second under pressure? At least, greater chances are that, the software design would be well though out, reviewed and tested several times before getting deployed.

I agree that, mechanical components are much less susceptible to failure compared to electronic components. But, in most cases, there are mechanical overrides provided to account for failure. e.g. if EPS fails due to electronics, there will still be regular manual steering, though harder to steer. Or. manual braking in case of ABS failure.

In case of Toyota, as I understand it, they did not provide mechanical override, which several other car manufacturers seem to provide. So, when it failed, there was no way to control it.

IMHO, having electronics is great addition as long as we can successfully fail over to mechanical components.
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Old 5th February 2010, 13:35   #110
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Here's another recall...

Delayed braking problem forces Toyota to recall Prius
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Old 5th February 2010, 13:48   #111
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If you look at this mats fiasco, something astounding strikes us. In India how many cars have a so called "locking mechanism" on the floor to hold the mats down? Going by that logic each and every car here probably is a candidate for recall as the mat can slip under the accelerator or the brake at any point in time!!! Then again maybe not because very few cars here, if any, really come with the floor mats on. They are always extra accessories that you pay for separately and get them on.
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Old 5th February 2010, 13:58   #112
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Here's another reason that I can think of - Buy the cars that are 'General'ly available

Last edited by aargee : 5th February 2010 at 14:00.
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Old 5th February 2010, 14:07   #113
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Originally Posted by mohan41 View Post
Toyota recall and apology come too late for Redwood City man and San Jose family - San Jose Mercury News

I dont understand why the car could not be stopped by shutting off the engine and applying brakes
everything is drive by wire. The brakes were not effective due to some reason. And some of the affected cars were turned on/off by a button, not with a key as most of us do. The procedure involved pressing and holding the engine start button for three seconds.
Think you've got time for that when your car is accelerating out of control ?
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Old 5th February 2010, 14:15   #114
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Looks like more and more software in the cars is making them more and more un-reliable.
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Old 5th February 2010, 15:02   #115
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Originally Posted by aargee View Post
Here's another reason that I can think of - Buy the cars that are 'General'ly available
I've a feeling Toyota won't roll over if the US Government tries anything like that. The problem is real. Its not a conspiracy. But then again, we never really know, do we?
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Old 5th February 2010, 15:23   #116
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Quote:
Originally Posted by RX135 View Post
Agreed about software being as good as a programmer, but then what is the guarantee that the same human brain would make better judgment in split second under pressure? At least, greater chances are that, the software design would be well though out, reviewed and tested several times before getting deployed.

I agree that, mechanical components are much less susceptible to failure compared to electronic components. But, in most cases, there are mechanical overrides provided to account for failure. e.g. if EPS fails due to electronics, there will still be regular manual steering, though harder to steer. Or. manual braking in case of ABS failure.

In case of Toyota, as I understand it, they did not provide mechanical override, which several other car manufacturers seem to provide. So, when it failed, there was no way to control it.

IMHO, having electronics is great addition as long as we can successfully fail over to mechanical components.
Agree with the failover to mechanical controls. Also, there's only so much of redundancy you can build into the vehicle. Aircraft have 3 operating computers including the primary, and they still crash. When a human operates the control, he may be comparatively slow to react but there is still something called 'seat of the pants driving/flying' that makes the difference. A human being receives inputs from eyes/ears/skin/nose that no car ECU can ever compete with.
It is fuzzy logic.

And yes, electronic controls give a driver a "Gee whiz this IS a high tech machine" feeling. But then electronics have their limitations

You may remember that people dont like EPS for the simple reason it feels like a game steering wheel without much feedback being provided to the driver. What do I prefer, an electronic or manual accelerator? Give me the manual anytime and it has nothing to do with the recall. I simply like the additional 'notches' of control that a manual throttle gives me. I can 'feather' the throttle as I like. Similarly I prefer a manual to auto tranny.

In the end I say, full control to the human being in the driving seat without a bunch of electronic circuits acting as brokers to the primary inputs of steering/accelerator/brakes. They should supplement and assist the driver, without the capability of overriding his decisions.

Cheers!

Last edited by R2D2 : 5th February 2010 at 15:29. Reason: Added a sentence.
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Old 5th February 2010, 15:34   #117
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Quote:
Originally Posted by Zappo View Post
If you look at this mats fiasco, something astounding strikes us. In India how many cars have a so called "locking mechanism" on the floor to hold the mats down? Going by that logic each and every car here probably is a candidate for recall as the mat can slip under the accelerator or the brake at any point in time!!!
Believe it or not my car came with Toyota mats as add ons and no Toyota didnt supply me with clips to hold the mat in place. Every car is a potential candidate for this problem.

Hey, what's next? A recall coz a bunch of drivers get their shoelaces caught in the accelerator?

Cheers!
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Old 5th February 2010, 15:44   #118
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Exactly.

I am all for electronic displays which give real time feedback/statistics etc, based on which let the driver take the decision. While electronic assists do make the job easier of novice/firsttime driver or non-Auto enthusiasts, this also tends to give a false assurance that everything can be controlled at the last moment. If this electronic/software assisted driving is deemed a must have, then for each such decision made by the electronics system should have a upper limit restriction..

As a programmer, I know the limits a decision engine can have within a given set of parameters. Similarly, if the vehicle is making a judgement, it should be equipped to warn/halt or completely shut itself off and pass over to manual control, in case, any one of the parameters needed to safely come to a judgement fails.

Over and above eveything else, a proper training/education should be provided to the users so that no false assumptions are made, and people are aware of the limitations.

All said and done, methinks, going by the rate of failure/fatalaties compared to the number of vehicles on road, it seems to me these discussions are basically futile. Until you are the one of the unfortunate one. That's why, I say, let the decision be with the driver..no one else can be blamed then;-}

Last edited by sanjayc : 5th February 2010 at 15:46.
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Old 5th February 2010, 17:18   #119
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Not sure if this is posted earlier or not, but thought it was worth posting it here.

I am shocked to see this. First gas pedal issue, which is more than just the gas pedal issue. A few links were posted by me about questions asked by some media. Toyota did respond to that in a particular day, but somehow, I get a feeling that Toyota has tried to hide some facts. Gas pedal issue is not just 2 months old, but older than that IIRC. And now Pruis brakes issue that is there since 2007.
And now this allegation.

Source : Toyota confirms Prius had brake design problems

Article :

Quote:
The news just keeps getting worse and worse for Toyota.

Now, the storied Japanese automaker has had to admit there have been problems with the anti-lock braking system on the celebrated Toyota Prius hybrid model.

The company has received about 180 complaints from Prius owners in both the U.S. and Japan about unresponsive brakes. The flaw is due to the dual nature of the gasoline-electric hybrid Prius - the brakes may become momentarily ineffective as the vehicle switches between the hydraulic brakes and the electronically controlled braking system. The brake system flaw requires a software reprogramming to fix.

Toyota has said it has fixed the problem in its Prius production but has not yet decided whether to issue a recall for Prius models which were delivered to customers before the fix in late January. The brake problem in the Prius dates back to 2007.

Toyota has recently had to recall about 4.5 million vehicles worldwide due to a gas-pedal flaw which can cause the accelerator to stick. The company estimates the cost of the recall to be about $2 billion, including a loss of sales. Toyota's stock value has fallen about 22 percent since the recall was announced on the 21st of January.
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Old 6th February 2010, 08:56   #120
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Quote:
Originally Posted by Zappo View Post
If you look at this mats fiasco, something astounding strikes us. In India how many cars have a so called "locking mechanism" on the floor to hold the mats down? Going by that logic each and every car here probably is a candidate for recall as the mat can slip under the accelerator or the brake at any point in time!!! Then again maybe not because very few cars here, if any, really come with the floor mats on. They are always extra accessories that you pay for separately and get them on.
Zappo, the same thought struck me as soon as I saw news about it on TV. But today's edition on The Washington Post carries pictures and more details about all 3 issues of Toyota.

The issue with the mats is not related to mats slipping under the throttle pedal, but due to slipping at it and depressing it: this is due to minimal clearance between the floor of the car and the accelerator pedal.

The remedy by Toyota involves lowering the floor or clipping the bottom of the pedal to get more clearance.

I wanted to scan the article, but the newpaper is far bigger than the scanner we have with us, and I am a technically challenged person

Quote:
Originally Posted by aaggoswami View Post
Not sure if this is posted earlier or not, but thought it was worth posting it here.

I am shocked to see this. First gas pedal issue, which is more than just the gas pedal issue. A few links were posted by me about questions asked by some media. Toyota did respond to that in a particular day, but somehow, I get a feeling that Toyota has tried to hide some facts. Gas pedal issue is not just 2 months old, but older than that IIRC. And now Pruis brakes issue that is there since 2007.
And now this allegation.

Source : Toyota confirms Prius had brake design problems

Article :
I have another colleauge hear who owns a Prius, and he told me about this issue with brakes a week ago. It appears that in the hybrid, energy from braking forces is sent to the battery to get better FE, but there is some flaw there causing momentary loss of braking, especially on uneven surfaces.

Last edited by vnabhi : 6th February 2010 at 08:57.
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