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This is really weird, I thought it was established that the Toyota acceleration WAS a phenomenon brought on by faulty microprocessor design: http://www.edn.com

This is really weird, I thought it was established that the Toyota acceleration WAS a phenomenon brought on by faulty microprocessor design: http://www.edn.com/design/automotive/4423428/Toyota-s-killer-firmware--Bad-design-and-its-consequences http://www.edn.com/design/automotive/4423428/Toyota-s-killer... Toyota's problem wasn't that they shouldn't have blamed the customer when it was the customer's fault, their problem was that they shouldn't have blamed the customer when it was Toyota's fault.

deleted 12y ago
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lambdaelite 12y ago
Toyota released an independent analysis of their electronic throttle system through their press website: http://toyotanews.pressroom.toyota.com/article_display.cfm?article_id=3593 http://toyotanews.pressroom.toyota.com/article_display.cfm?a... It's a fascinating report that includes a code review with PolySpace and hardware-in-the-loop testing. TL;dr, Exponent didn't find any hardware or software design defects that could cause "uncommanded acceleration". Barr's analysis in the linked article sounds like he found problems that should have been caught by their coding standards and design reviews, but it doesn't sound like he found or could suggest a specific event sequence that could lead to an UA.
- TwoBit 12y ago
  If Toyota had anything to do with that analysis then it wasn't independent. My recollection of the Barr analysis is that a particular failure case was in fact described which occurs during certain conditions of memory exhaustion: http://embeddedgurus.com/barr-code/2013/10/an-update-on-toyota-and-unintended-acceleration/ http://embeddedgurus.com/barr-code/2013/10/an-update-on-toyo... "the team led by Barr Group found what the NASA team sought but couldn’t find: 'a systematic software malfunction in the Main CPU that opens the throttle without operator action and continues to properly control fuel injection and ignition' that is not reliably detected by any fail-safe."
  - kabouseng 12y ago
    As far as I followed the story, the BARR group only found it was possible, but couldn't replicate the condition. I would also be careful in stating who is independant. Mr Barr also have an incentive to claim the code is terrible since he sells static code analysis software and embedded programming bootcamps. That's great advertising for his business. Would your code stand up to the rigours of a Barr analysis? Would any automotive code from any other manufacturer stand up to Barr analysis? Would any other industry stand up to Barr analysis? We don't know the answers to these questions...It is for instance well known that if your code is squeeky clean according to one static analysis package, just running another static analyser will raise a host of other warnings.
  - lambdaelite 12y ago
    I don't see why an independent analysis commissioned by Toyota would be any more or less credible because Toyota paid for it than an analysis by an expert witness paid for by a plaintiff in a civil suit. I should think they deserve equal scrutiny. Reading the transcript of the court proceedings, it sounded like Barr Group were able to induce a fault that could lead to an unintended acceleration, but the evidence that this fault actually happened was circumstantial. Also, I don't find the jury's decision against Toyota to be relevant, given that there are so many other elements that figure into the calculus of a jury decision. I can't fault Barr Group for trumpeting that they were a key expert witness in a successful trial of this magnitude—it's phenomenal advertising—but I don't see how it follows that their failure proposal is actually what happened (nor do I think that the Barr Group would say with certainty that it did happen).
    - tunesmith 12y ago
      How would it be anything other than circumstantial that it "actually happened"? Those cars crashed and people died. You could make the same case about any bug; "I duplicated the behavior, but that doesn't mean it actually happened in the original bug report". That kind of developer comment would raise eyebrows. Toyota's original defense was that it was user error because unintended acceleration couldn't happen; they blamed it entirely on driver error. They were making a "forall" argument, and all Barr had to do was show an "exists". He did. Toyota was completely wrong.

deleted 12y ago

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lambdaelite 12y ago

Toyota released an independent analysis of their electronic throttle system through their press website: http://toyotanews.pressroom.toyota.com/article_display.cfm?article_id=3593 http://toyotanews.pressroom.toyota.com/article_display.cfm?a... It's a fascinating report that includes a code review with PolySpace and hardware-in-the-loop testing. TL;dr, Exponent didn't find any hardware or software design defects that could cause "uncommanded acceleration". Barr's analysis in the linked article sounds like he found problems that should have been caught by their coding standards and design reviews, but it doesn't sound like he found or could suggest a specific event sequence that could lead to an UA.

TwoBit 12y ago
If Toyota had anything to do with that analysis then it wasn't independent. My recollection of the Barr analysis is that a particular failure case was in fact described which occurs during certain conditions of memory exhaustion: http://embeddedgurus.com/barr-code/2013/10/an-update-on-toyota-and-unintended-acceleration/ http://embeddedgurus.com/barr-code/2013/10/an-update-on-toyo... "the team led by Barr Group found what the NASA team sought but couldn’t find: 'a systematic software malfunction in the Main CPU that opens the throttle without operator action and continues to properly control fuel injection and ignition' that is not reliably detected by any fail-safe."
- kabouseng 12y ago
  As far as I followed the story, the BARR group only found it was possible, but couldn't replicate the condition. I would also be careful in stating who is independant. Mr Barr also have an incentive to claim the code is terrible since he sells static code analysis software and embedded programming bootcamps. That's great advertising for his business. Would your code stand up to the rigours of a Barr analysis? Would any automotive code from any other manufacturer stand up to Barr analysis? Would any other industry stand up to Barr analysis? We don't know the answers to these questions...It is for instance well known that if your code is squeeky clean according to one static analysis package, just running another static analyser will raise a host of other warnings.
- lambdaelite 12y ago
  I don't see why an independent analysis commissioned by Toyota would be any more or less credible because Toyota paid for it than an analysis by an expert witness paid for by a plaintiff in a civil suit. I should think they deserve equal scrutiny. Reading the transcript of the court proceedings, it sounded like Barr Group were able to induce a fault that could lead to an unintended acceleration, but the evidence that this fault actually happened was circumstantial. Also, I don't find the jury's decision against Toyota to be relevant, given that there are so many other elements that figure into the calculus of a jury decision. I can't fault Barr Group for trumpeting that they were a key expert witness in a successful trial of this magnitude—it's phenomenal advertising—but I don't see how it follows that their failure proposal is actually what happened (nor do I think that the Barr Group would say with certainty that it did happen).
  - tunesmith 12y ago
    How would it be anything other than circumstantial that it "actually happened"? Those cars crashed and people died. You could make the same case about any bug; "I duplicated the behavior, but that doesn't mean it actually happened in the original bug report". That kind of developer comment would raise eyebrows. Toyota's original defense was that it was user error because unintended acceleration couldn't happen; they blamed it entirely on driver error. They were making a "forall" argument, and all Barr had to do was show an "exists". He did. Toyota was completely wrong.