From: Brimstone on
"Mrcheerful" <nbkm57(a)hotmail.co.uk> wrote in message
news:dXNKn.101968$Lg1.49883(a)newsfe17.ams2...
> Brimstone wrote:
>> "Doug" <jagmad(a)riseup.net> wrote in message
>> news:0fac0491-913a-439e-90e3-4726e85d066c(a)y12g2000vbr.googlegroups.com...
>>
>>> A wake up call eh? Not overly concerned but a little concerned maybe?
>>> I know I would be very concerned if my life depended on a computer
>>> working 100% properly throughout its useful lifetime.
>>
>> What makes you think that the computer in a car is the same as the
>> one on your desk Doug?
>>
>>> Thes researchers have proved conclusively that the car computer can
>>> cause the engine and brakes to malfunction, thus putting road users
>>> at risk.
>>
>> Only when interfered with by an external computer.
>>
>>> Whether the computer will actually malfunction in this way
>>> remains a moot point but should be a matter of serious concern to
>>> anyone who cares about road safety, which apparently excludes most of
>>> the motorists who post here.
>>>
>> It also excludes you Doug, because if you had any understanding you
>> would realise that there is no point in jumping up and down and
>> getting excited.
>> The only result from this research for the future is that car
>> designers need to make sure that new designs cannot be interfered
>> with by those with evil intent.
>
> I worry far more about the nut behind the wheel (or the handlebars)
Indeed, a factor which passes Doug by, unless he chooses to collide with it,
which he seems to do more often than anyone else.


From: Ian Jackson on
In message <htgkio$6k4$1(a)speranza.aioe.org>, boltar2003(a)boltar.world
writes
>On Tue, 25 May 2010 06:20:47 -0700 (PDT)
>"Man at B&Q" <manatbandq(a)hotmail.com> wrote:
>>> Yes, thanks for the heads up, but I work in software development and
>>
>>Then you only have one viewpoint. Designing safety critical systems is
>>as much about the hardware and *system* design than it is about
>>software. Again. don't expect to understand if you can't grasp that
>>point.
>
>The hardware will generally be stock microcontrollers probably running
>an ARM core which is a proven design. The peripheral circuitry will obviously
>be bespoke for a given task but the software will be a lot more complicated
>than any of the hardware.
>
>>> written realtime systems so don't try and tell me my job. Unless some
>>> software has been formally proved which is VERY time consuming and expens=
>>ive to
>>> do and VERY rare then there will almost always be some bugs lurking somew=
>>here
>>> that only come to light in exceptional and unexpected combination or sequ=
>>ence
>>> of events.
>>
>>The *system* is designed to fail safe in that eventuality.
>
>Tell that to the people who died in the air france crash. Whatever fail safe
>there was for when the pitot tubes fucked up clearly didn't work or didn't
>even exist.
>
>Fail safes are only as good as the people who designed them are smart.
>
And one of the absolute essentials is for the fail-safe system to 'know'
that it has failed. If (for whatever reason) it is fooled into believing
that it is still working OK, it won't default to the fail-safe mode. It
may therefore continue happily working in a dangerous mode.
--
Ian
From: Mrcheerful on
Doug wrote:
> On 24 May, 11:50, Adrian <toomany2...(a)gmail.com> wrote:
>> Doug <jag...(a)riseup.net> gurgled happily, sounding much like they
>> were saying:
>>
>>>>>> The other thing to consider is the major difference between
>>>>>> dedicated embedded computers and generic PCs. PCs mostly crash
>>>>>> due to user error, primarily in the installation (often
>>>>>> unintentional) of poor-quality software. With embedded systems,
>>>>>> that's not an option - when did your washing machine, fridge or
>>>>>> freeview box last crash?
>>>>> Freeview boxes quite often.
>>>> Really? If so, then I suspect it's an aged one that's experiencing
>>>> hardware issues.
>>> Yes everything becomes aged with time, including car computers. You
>>> never can tell when they might pack up. At least with a Freeview
>>> box it doesn't happen when you are doing 70 or more on a motorway.
>>
>> Of course, that ignores (what a surprise...) the very different
>> standards of hardware build quality for a controller intended for a
>> 10-20yr service life in a hostile environment and a disposable bit
>> of cheap consumer tat.
>>
>> Anyway, even if it does, you'll just glide gently to a halt safely
>> on the hard shoulder.
>>
> Despite being in the fast lane


Please can you read the Highway Code, there is no such thing as a 'fast
lane' .

Hundreds, possibly thousands of cars on UK roads run out of fuel every day
and manage to coast to a halt on the hard shoulder. Even with the engine
stopped the brakes still work, as does the steering, as does the indicators,
lights etc.

Just think Doug, your chain might suddenly jump off the sprockets and lock
the wheel hurling you into a bus queue, or your spokes break, or any one of
a million things CAN happen, but that is life, you can't legislate away
every possibility, you can plan sensibly and drive sensibly. Lets face it,
people drop dead walking on the street, should they be forced to stay
indoors , just in case?


From: cupra on


"Adrian" <toomany2cvs(a)gmail.com> wrote in message
news:86180eFkj2U4(a)mid.individual.net...
> Doug <jagmad(a)riseup.net> gurgled happily, sounding much like they were
> saying:
>
>>> > Yes everything becomes aged with time, including car computers. You
>>> > never can tell when they might pack up. At least with a Freeview box
>>> > it doesn't happen when you are doing 70 or more on a motorway.
>
>>> Of course, that ignores (what a surprise...) the very different
>>> standards of hardware build quality for a controller intended for a
>>> 10-20yr service life in a hostile environment and a disposable bit of
>>> cheap consumer tat.
>>>
>>> Anyway, even if it does, you'll just glide gently to a halt safely on
>>> the hard shoulder.
>
>> Despite being in the fast lane and having to cross over in heavy traffic
>> with no brakes and no engine?
>
> Yup.
>
> It's really not that complicated.
>
>>> >> > and my little fridge is not computer controlled.
>>> >> Then it'll be ancient and hugely inefficient.
>
>>> > No its quite recent and efficient and only needs a thermostat and not
>>> > a computer.
>
>>> Then it will most certainly have embedded control electronics.
>
>> What for? It only needs the thermostat to switch the motor on and off?
>
> You don't have the first clue, do you?

lol... points Doug to "PI loop"....


From: cupra on


"Brimstone" <brimstone(a)hotmail.com> wrote in message
news:BPKdnSUJc4qt-2bWnZ2dnUVZ8nSdnZ2d(a)bt.com...
> "Doug" <jagmad(a)riseup.net> wrote in message
> news:cda489cc-8685-4ee5-8176-5441f49463b3(a)e28g2000vbd.googlegroups.com...
>
>> So the engine can stop and the brakes fail if the computer
>> malfunctions.
>
> No Doug, only when it is interfered with by an external computer which has
> been plugged in to the car's system.

Could happen... only today on the M5 someone pulled alongside me and tried
to hurl a comms cable though my closed window - lord only knows what could
have happened if he'd hit the port!