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'[PIC] Anyone using C Compiler for critical applica'
2008\04\15@100220 by Rafael Vidal Aroca

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   Hi,

   i was reading MikroC user's guide, and there is a note that they do
not take any responsability for any C code written for criticial
applications.

   My question is if anyone is using Microchip C18 or any other C
compiler for PICs in critical applications such as flight control
systems, automotive ones, or other applications that needs high reliability.

thanks

Rafael

2008\04\15@102459 by Walter Banks

picon face
You will find that the microprocessors are also
documented as not for use in life critical devices.

FDA have rules for testing and releasing
software for life critical applications. Several
government agencies regulate automotive
software.

Over time the issue has become application
testing and not the tools application developers
use. Companies that implement high reliability
are required to satisfy the regulatory agencies
and their customers that they have followed
good practices.

Regards,

--
Walter Banks
Byte Craft Limited
1 (519) 888-6911
http://www.bytecraft.com
spam_OUTwalterTakeThisOuTspambytecraft.com




Rafael Vidal Aroca wrote:

{Quote hidden}

> -

2008\04\15@103011 by Brendan Gillatt

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Rafael Vidal Aroca wrote:
>     Hi,
>
>     i was reading MikroC user's guide, and there is a note that they do
> not take any responsability for any C code written for criticial
> applications.
>
>     My question is if anyone is using Microchip C18 or any other C
> compiler for PICs in critical applications such as flight control
> systems, automotive ones, or other applications that needs high reliability.

Believe me, I would not rely on mikroc for anything close to reliable!
It's one of the worst compilers I have ever seen and, looking at the way
the assembly is created, it is constructed pretty much as a basic
compiler adjusted to look like C. It's not where close to ANSI meaning
porting code is a no-no.


- --
Brendan Gillatt | GPG Key: 0xBF6A0D94
brendan {a} brendangillatt (dot) co (dot) uk
http://www.brendangillatt.co.uk
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2008\04\15@103532 by John Ferrell

face picon face
I don't think anyone accepts any liability for such applications.

John Ferrell    W8CCW

"All that is necessary for the triumph of evil is for good men to do
nothing." -- Edmund Burke
http://DixieNC.US

{Original Message removed}

2008\04\15@105113 by Mohit Mahajan (Lists)

picon face
I am sure if you read the fine print, somewhere in Microchip's (and in
other manufacturers) documentation you'll find similar warnings too.

I remember coming across an application guide from TI where they had
given a description on how to go about designing an ECG (and other
medical equipment) using their parts. Then right on the very last page
in small print they write that their parts are not meant for critical
applications unless the designers have necessary expertise and have some
written agreement on it.

So you can use any tool/component for any application, if you are
competent enough to design for it - which, please note, also means that
you should also be competent enough to decide whether the application
specs are inside the tool/component specs.

And at the end of the day, its the testing of the designed product that
indicates the reliability of the system... You may use a million dollar
tool that may be used by NASA in all their spacecrafts, but unless
you've designed and tested it properly, it really doesn't matter to the
reliability.

Remember, its not the machine but the man behind the machine!

But also please don't use no-name Chinese batteries in any kind of
product whether safety-critical or not, despite whatever the
manufacturer specs state. :-)


Rafael Vidal Aroca wrote:
{Quote hidden}

2008\04\15@115304 by Bob Axtell

face picon face
Rafael Vidal Aroca wrote:
> Hi,
>
>     i was reading MikroC user's guide, and there is a note that they do
> not take any responsability for any C code written for criticial
> applications.
>
>     My question is if anyone is using Microchip C18 or any other C
> compiler for PICs in critical applications such as flight control
> systems, automotive ones, or other applications that needs high reliability.
>
> thanks
>
> Rafael
>  
That's not what they mean. They mean "time-critical" applications. Their
stuff works fine anywhere
you'd like to use it.

--Bob Axtell

2008\04\15@115359 by Funny NYPD

picon face
We have used both PICC and PICC18 "old" versions and still using the "old" version as possible for automotive, truck and marine products. They works great.

The new V9.xx really sucks, you can use bit variable without declaration (powerful but wrong!). Things like that really worries me if I have to use it for new released chips.

Personally I don't think the new V9.xx(s) are fully tested. It is a pain of "on-time release first, fix it later" issue from those "smart" MBAs.

Funny N.
Au Group Electronics, New Bedford, MA, http://www.AuElectronics.com

{Original Message removed}

2008\04\16@090331 by Alan B. Pearce

face picon face
>I am sure if you read the fine print, somewhere in Microchip's (and in
>other manufacturers) documentation you'll find similar warnings too.

I remember that National Semiconductor has had, for far more years than I
can remember, a disclaimer in their data books and data sheets that their
products are not for use in life support products or other critical
applications, without written consent from National Semiconductor. I suspect
they were setting out to head off any possible law suit due to a medical
instrument malfunctioning, causing death.

2008\04\16@091921 by Walter Banks

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"Alan B. Pearce" wrote:

> >I am sure if you read the fine print, somewhere in Microchip's (and in
> >other manufacturers) documentation you'll find similar warnings too.
>
> I remember that National Semiconductor has had, for far more years than I
> can remember, a disclaimer in their data books and data sheets that their
> products are not for use in life support products or other critical
> applications, without written consent from National Semiconductor. I suspect
> they were setting out to head off any possible law suit due to a medical
> instrument malfunctioning, causing death.

That is a part of the reason. The FDA has specific rules for approving
devices that contain unapproved parts. Essentially a different testing
requirement kicks in. By saying that they specifically are saying they
haven't tested according to FDA requirements headed off some nasty
potential liability issues (US 1% rule) and forced there customers
to add more testing.

For the average PIC (small microprocessor of any stripe) be glad they
have this disclaimer because potential life threatening liability would
add a significant amount to a sub $1.00 part.


w..



2008\04\16@093102 by Tamas Rudnai

face picon face
I guess noone makes a really extensive unit test except for critical
applications where they can supply components fully tested and possibly even
under rated to achieve better reliability. For development tools could be
done the same with special libraries that have run-time range checking or
more rigid compile time validators. As far as I know currently only Ada
supports that, but I my wrong on this.

Tamas


On Wed, Apr 16, 2008 at 2:01 PM, Alan B. Pearce <.....A.B.PearceKILLspamspam@spam@rl.ac.uk> wrote:

{Quote hidden}

> -

2008\04\16@105040 by Ariel Rocholl

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I am not sure what initial post means by "critical", if that means
"safety critical" then this is to be expected. Industry standards for
safety critical systems are much higher than consumer products can
achieve. For instance, SIL4 rail systems have requirements that cannot
be fulfilled by standard hardware components, designs nor languages
like C. Thinks like a pointer, a "void" variable and many other things
are very flexible but unsafe,  you are right  ADA is the language of
choice in most cases.

Now this is completely different  story if "critical"  means "mission
critical" or "time critical", etc

My  2 cents

2008/4/16, Tamas Rudnai <tamas.rudnaispamKILLspamgmail.com>:
{Quote hidden}

2008\04\16@180602 by M. Adam Davis

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In the automotive industry you'll find that they pay for the very
expensive compilers, and they follow a set of rules for coding in C
called MISRA that disallow many common practices for reasons of "C"
safety.

They then test to the umpteenth degree.

Then they have backups and backups of the backups in really critical
cases, and often the backups are mechanical linkages that prevent
certain things from happening.

This is the major reason why we don't have, for instance, drive by
wire for steering, brakes, and only recently have introduced
electronic throttle control.

Even if every ECU in the car stopped (say, through an EMP pulse) the
car wouldn't explode, and it would still be steerable and brakeable.
When any major ECUs do shut down, typically the car enters a "limp"
mode, where it turns off all but critical systems, and automatically
turns on the headlights and windshield wipers in case it happens at
night, in the rain, or both.  This allows you to drive it to the shop.

So if your windshield wipers turned on at any odd time by themselves,
it usually means a fairly major ECU had a hiccup...

:-D

But yes, PICs are used in automotive modules (not often, but they are
there) and so are C compilers.  When a consumer sues the auto company,
the auto company tries to pin it on the supplier, who tries to pin it
on the compiler maker, who tries to pin it on the chip.  At the end of
the day the insurance for the companies go up, the lawyers buy new
yachts, everyone is under a gag order, and the supplier has to work
harder bidding on the next contract to prove that it won't happen
again even though it may have been the car company's fault.  Usually
this means another rule or so added to the great book of "lessons
learned."

-Adam

On Tue, Apr 15, 2008 at 10:03 AM, Rafael Vidal Aroca <EraseMErafaelspam_OUTspamTakeThisOuTagx.com.br> wrote:
{Quote hidden}

> -

2008\04\17@052826 by Michael Rigby-Jones

picon face


> -----Original Message-----
> From: piclist-bouncesspamspam_OUTmit.edu [@spam@piclist-bouncesKILLspamspammit.edu] On
Behalf
{Quote hidden}

We are almost there though.  Many cars can apply the brakes without the
driver touching the brake pedal for stability control, and the BWM
system will even adjust the steering angle, again without the driver
commanding it.

Mike

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2008\04\17@064247 by Gerhard Fiedler

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Michael Rigby-Jones wrote:

>> From: M. Adam Davis This is the major reason why we don't have, for
>> instance, drive by wire for steering, brakes, and only recently have
>> introduced electronic throttle control.
>
> We are almost there though.  Many cars can apply the brakes without the
> driver touching the brake pedal for stability control, and the BWM
> system will even adjust the steering angle, again without the driver
> commanding it.

You have to somehow transmit brake, steering and accelerator commands from
the driver to the executing device. As long as electronics were/are far
more unreliable than mechanics, drive by wire was a no-no. But the moment
that reliability relation changes, they become an option.

Gerhard

2008\04\17@065429 by Tamas Rudnai

face picon face
> drive by wire was a no-no. But the moment
> that reliability relation changes, they become an option.

That's interesting as many small airplanes use wires for the rudder. Is it
because with planes they have a more strict test virtually every time before
flying? Or they think that if rudder gone they can still do something with
aileron+elevator?

Tamas


On Thu, Apr 17, 2008 at 11:42 AM, Gerhard Fiedler <
KILLspamlistsKILLspamspamconnectionbrazil.com> wrote:

{Quote hidden}

> -

2008\04\17@075332 by Rafael Vidal Aroca

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M. Adam Davis wrote:
> This is the major reason why we don't have, for instance, drive by
> wire for steering, brakes, and only recently have introduced
> electronic throttle control.
>
>  


   Adam, i agree with you, but just to mention, SMART (a Swiss "mini"
car for 2 passengers) uses CAN bus to control the steering and gas. Only
the brakes are mechanical.

   It's even possible to implement a DIY autopilot for this car,
sending CAN commands to the steering system and to the gas pedal.

Rafael

2008\04\17@083302 by Jake Anderson

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drive by wire means using electronics not mechanical control wires/lines.

many new large aircraft and most modern fighters have no mechanical link
from the stick to the control surfaces and in some cases are actually
impossible to fly without the aid of a computer.

Tamas Rudnai wrote:
{Quote hidden}

>> --

2008\04\17@084801 by M. Adam Davis

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On 4/17/08, Tamas Rudnai <spamBeGonetamas.rudnaispamBeGonespamgmail.com> wrote:
> That's interesting as many small airplanes use wires for the rudder. Is it
> because with planes they have a more strict test virtually every time before
> flying? Or they think that if rudder gone they can still do something with
> aileron+elevator?

Well you have to take into account all the factors.  In cars weight is
a factor, but it's effect on the overall equation is low.

In aircraft weight has a much greater effect on the decision to use
fly by wire.  Further, that mechanical linkage is much longer,
heavier, more complex, and expensive to manufacture and assemble than
any of the mechanical linkages in a car.

Lastly, while you want to avoid it, you _can_ fly and control many
(most?) airplanes even if all the the tail linkages fail, though you
certainly don't want to.  So it's not as safety critical as, say, the
wing surfaces.

But even given all that, it's not like brakes where human strength can
be expected to control the surfaces of a large plane - so there are
backup systems to power the hydraulics, etc, and for all intents and
purposes there's no direct link between the control stil and the
rudders on many aircraft - it has to go through a few transitions
(mechanical solids to mechanical liquids to torque multipliers, etc)
which require power of some sort to function.

So the move to electricity performing some of that linkage is not as
big a jump as it is on a car.

Besides, if we started using aircraft fly by wire in cars we'd have to
eliminate cell phone use in the vehicle, right?

;-)

-Adam

2008\04\17@085301 by M. Adam Davis

face picon face
On 4/17/08, Rafael Vidal Aroca <TakeThisOuTrafaelEraseMEspamspam_OUTagx.com.br> wrote:
> M. Adam Davis wrote:
> > This is the major reason why we don't have, for instance, drive by
> > wire for steering, brakes, and only recently have introduced
> > electronic throttle control.
>
>    Adam, i agree with you, but just to mention, SMART (a Swiss "mini"
> car for 2 passengers) uses CAN bus to control the steering and gas. Only
> the brakes are mechanical.
>
>    It's even possible to implement a DIY autopilot for this car,
> sending CAN commands to the steering system and to the gas pedal.

That's very cool.  I know there are steer by wire vehicles available
now, but it's technology that's not widely used.

Keep in mind, though, that even though liability is a factor,
eventually cost becomes the overriding consideration.

If a supplier could make a steering system, including all the
electronic and mechanical components required, for 10-50% of the cost
of existing systems and demonstrated equivilant reliability then you'd
find the auto companies working with their lawyers and insurers to get
that into the car.  It would improve the weight and maintainability of
the car significantly as well.

-Adam

2008\04\17@091611 by Tamas Rudnai

face picon face
> drive by wire means using electronics not mechanical control wires/lines.

Oh, I mixed up with the "fly by cable" then... For some reason I thought
that the claim is that the mechanical pull-pull system is more vulnerable
than any other push rod style control system. My bad.

Cheers,
Tamas



On Thu, Apr 17, 2008 at 1:32 PM, Jake Anderson <RemoveMEjakespamTakeThisOuTvapourforge.com> wrote:

{Quote hidden}

2008\04\17@092107 by Walter Banks

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Jake Anderson wrote:

> > That's interesting as many small airplanes use wires for the rudder. Is it
> > because with planes they have a more strict test virtually every time before
> > flying? Or they think that if rudder gone they can still do something with
> > aileron+elevator?
> >

The mechanical systems have a different kind  reliability problems as well.
I know of  three cases of elevator reversal after maintenance and one of
rudder reversal that were not caught before flight.

One of the elevator reversals resulted in a fatality.

Many years ago I was a passenger in the right seat in a plane with
one of the old VOR and wing leveller type auto pilots, about 20 minutes
after we got underway still climbing out the pilot slid his seat back to take
off his shoes when auto pilot locked up. The controls were out of
his reach. (It's amazing how fast you can find the master switch)
It is these old horror stories that fly by wire systems are still viewed
with suspicion.

w..


2008\04\17@092111 by Apptech

face
flavicon
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>> drive by wire was a no-no. But the moment
>> that reliability relation changes, they become an option.

> That's interesting as many small airplanes use wires for
> the rudder. Is it
> because with planes they have a more strict test virtually
> every time before
> flying? Or they think that if rudder gone they can still
> do something with
> aileron+elevator?

Drive-by-wire means electrical control via "wiring" - not
mechanical cables. The changes being talked about are to put
electrical control into braking and steering circuits. Don't
buy one for the first 10 years and don't travel in one for
the first 3 :-).





       Russell

2008\04\17@094637 by Apptech

face
flavicon
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>    It's even possible to implement a DIY autopilot for
> this car,
> sending CAN commands to the steering system and to the gas
> pedal.

Hmm. A car that can be accelerated and steered by remote
control, but not braked. I wonder what use that could
possibly be?


       R :-) :-(

2008\04\17@102939 by Roger, in Bangkok

face
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Running revenuer barricades ... yeehaaaa!

Okay, okay I'm settled down now ... I promise uh-huh ...

RiB

On Thu, Apr 17, 2008 at 8:25 PM, Apptech <EraseMEapptechspamparadise.net.nz> wrote:

{Quote hidden}

2008\04\17@104711 by Apptech

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> ... and one of rudder reversal that were not caught before
> flight.

Old pilots and checklist-careless pilots but no ...

Rudder reversal MIGHT be bearable albeit very hard on the
brain.


   R

2008\04\17@112943 by Peter Todd

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On Thu, Apr 17, 2008 at 08:47:59AM -0400, M. Adam Davis wrote:
{Quote hidden}

For resistance to combat damage the longer attribute can be a big
problem, just that much more stuff that can be hit by shrapnel. At the
extreme take a look at an old Vietnam era OH13 Bell 'sioux' choppers.
The control cables going to the tail rotor on them are completely
exposed to fire, sitting right out in the open on a space frame
construction tail. Lots of them got shot down by just small arms fire
that cut cables.

Now if there were reliable fly-by-wire systems on the other hand it'd be
dead simple to get, say, four data cables, hide them in the struts of
the tail, and setup a redundent comm protocol where by the time you've
lost communication your tail has fallen off anyway. In the context of
Vietnam, even a not all that reliable fly-by-wire system implementable
with current, cheap, digital technology would probably have failed less
often than the fly-by-cable system they had to use.

Not that I'd be inclinded to sign up for anything more intense than
rear-base mechanic. :)

- --
peter[:-1]@petertodd.org http://petertodd.org
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2008\04\17@115011 by John Gardner

picon face
It continues to happen - A couple three years ago in Kansas (I think)
a relatively well-known experimental aircraft guy was killed on take-off
by aileron linkage reversal.

Low & slow, with the AC rolling the wrong way, even a very experienced
pilot could'nt realize & react in time... Murphy rules.

On 4/17/08, Apptech <RemoveMEapptechspam_OUTspamKILLspamparadise.net.nz> wrote:
{Quote hidden}

> -

2008\04\17@115639 by Apptech

face
flavicon
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> For resistance to combat damage ...
... big interesting aero/combat snip ...

>> Right, well in that case I for one vote to change [EE] to
>> [EESM]..

Don't know if you subscribe to [OT].
If not you may, or may not wish to Gargoyle up the correctly
tagged response


       R

2008\04\17@120812 by Forums

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Russell Wrote:
>Rudder reversal MIGHT be bearable albeit very hard on the
>brain.

On landing, unless you were equipped with differential breaking to steer
once you've hit the tarmac you could have problems. Some aircraft have
nose-wheel steering connected to the rudder pedals. If only one aspect of
the rudder control (the rudder itself) were reversed and the nose-wheel
wasn't this could get extremely tricky... first with the rudder having more
impact to your direction, then as you slow, the nose-wheel having more
impact.

Aside from that, I think yes, after a few minutes most pilots could handle
the reversal - or just decide to trim the rudder to center and fly without
it.

I bet it's possible to configure a rudder reversal on an aircraft (rather
than just rudder *control* reversal) and simulate that in FS2004/FSX and see
how messy the landing became. Would be interesting.

Adam Davis wrote:
>Lastly, while you want to avoid it, you _can_ fly and control many
>(most?) airplanes even if all the the tail linkages fail, though you
>certainly don't want to.  So it's not as safety critical as, say, the
>wing surfaces.

Losing the rudder is one thing, but control loss of the horizontal
stabilizers on the tail has been a factor in a number of MD-80 and DC-9
crashes. Of course, the design of the aicraft (the MD-80/90 and DC-9 are
similar) and the nature of the failure will either doom you or not.

en.wikipedia.org/wiki/Alaska_Airlines_Flight_261
en.wikipedia.org/wiki/Aeromexico_Flight_498
http://en.wikipedia.org/wiki/Continental_Express_Flight_2574

The tail fin itself is also critical:
http://en.wikipedia.org/wiki/American_Airlines_Flight_587

Andy.

2008\04\17@120844 by Tamas Rudnai

face picon face
In airplane modelling actually some of us practising what to do if control
surface is reversed - as it happens from time to time. It can be learned,
but extremely difficult, especially when you least expect it. Most probably
it is even harder if not impossible when you panic while saving your life.

Tamas


On Thu, Apr 17, 2008 at 4:49 PM, John Gardner <RemoveMEgoflo3TakeThisOuTspamspamgmail.com> wrote:

{Quote hidden}

2008\04\17@120905 by Michael Rigby-Jones

picon face


> -----Original Message-----
> From: RemoveMEpiclist-bouncesKILLspamspammit.edu [piclist-bouncesSTOPspamspamspam_OUTmit.edu] On
Behalf
> Of Peter Todd
> Sent: 17 April 2008 16:19
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] Anyone using C Compiler for critical applications
>
> Now if there were reliable fly-by-wire systems on the other hand it'd
be
> dead simple to get, say, four data cables, hide them in the struts of
> the tail, and setup a redundent comm protocol where by the time you've
> lost communication your tail has fallen off anyway. In the context of
> Vietnam, even a not all that reliable fly-by-wire system implementable
> with current, cheap, digital technology would probably have failed
less
> often than the fly-by-cable system they had to use.

Getting data to the actuators intact is a relatively simple task
compared to maintaining the power source to the actuators (probably
hydraulic on a heli or fixed wing craft).

FWIW the Typhoon uses an optical network to reduce susceptibility to EMI
weapons; "fly by light".

Mike

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2008\04\17@122148 by Robert Ammerman

picon face
I have developed quite a bit of code that one might consider critical.
Although not involving a risk to life or limb, a failure could end up in
$millions of damage to hydroelectric generators.

The largest such system runs on embedded x86 hardware. We use the Microsoft
C++ compiler, and a proprietary operating system kernel that I developed
that emulates enough of the Win32 environment to allow a single standard
Windows executable to run.

Basically, we protect ourselves in several ways:

1) Watch dog timers
2) Redundant systems
3) Careful, well reviewed, design
4) Testing
5) Testing
6) Testing
7) Testing
....
n) Testing

--- Bob Ammerman
RAm Systems


{Original Message removed}

2008\04\17@122324 by David VanHorn

picon face
On Thu, Apr 17, 2008 at 11:49 AM, John Gardner <spamBeGonegoflo3STOPspamspamEraseMEgmail.com> wrote:
> It continues to happen - A couple three years ago in Kansas (I think)
> a relatively well-known experimental aircraft guy was killed on take-off
> by aileron linkage reversal.


Too many people do their checks by "yeah, it wiggles", instead of  "It
actually moves the right direction for the control input".

2008\04\17@124008 by Peter Todd

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On Thu, Apr 17, 2008 at 05:05:20PM +0100, Michael Rigby-Jones wrote:
{Quote hidden}

Well in the original 'sioux' the power source is the cables themselves,
one set for clockwise, another for anti-clockwise. These rotated a pully
on the tail rotor to change the rotor pitch. To be exact, the sioux I've
seen in person had *8* control cables, two sets of four. If this was for
redundency, or some other reason, (tensioning? maximum pully diameter?
common parts requirements?) I don't know, but they were spaced close
together enough that a single piece of shrapnel would take them all out
at once if your luck wasn't holding up.

You are of course right, but given the probably low power requirements
of that particular chopper, a electric servo motor, powered by wires
running along-side the data cables should be fine. Usual redundency
engineering challenge to take four power sources and make something
reliable in the face of shorts and the like. Point being, the full
solution could still conceivably weigh less, and still be more reliable
than the alternative even with corners cut in the use of relatively off
the shelf parts.

All that said, I don't see a good electronic replacement for that single
half inch and vulnerable drive shaft powering the back rotor...

- --
peter[:-1]@petertodd.org http://petertodd.org
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2008\04\17@130944 by Forums

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Peter Todd wrote:
>All that said, I don't see a good electronic replacement for that single
>half inch and vulnerable drive shaft powering the back rotor...

Good point... hmm, completely redesign it then, and dump the tail rotor....
;-)

http://en.wikipedia.org/wiki/NOTAR

Andy.

2008\04\17@134724 by James Salisbury

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Hi all,

My Vauxhall / GM  Astra has an electrical power steering pump, lose that
and I can't turn the wheel.... Is that counted as drive by wire?

2008\04\17@144225 by M. Adam Davis

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On 4/17/08, James Salisbury <KILLspampiclistspamBeGonespamjsalisbury.clara.co.uk> wrote:
> Hi all,
>
> My Vauxhall / GM  Astra has an electrical power steering pump, lose that
> and I can't turn the wheel.... Is that counted as drive by wire?

Are you sure you can't?  The power steering system is designed to
assist the driver by boosting your effort.  If it's a typical power
steering in every other way, then you should be able to steer even
when the pump is off.

-Adam

--
EARTH DAY 2008
Tuesday April 22
Save Money * Save Oil * Save Lives * Save the Planet
http://www.driveslowly.org

2008\04\17@150235 by peter green

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>     Adam, i agree with you, but just to mention, SMART (a Swiss "mini"
> car for 2 passengers) uses CAN bus to control the steering and gas.
Are you sure it is true drive by wire (no mechanical link at all) and
not just electric power steering (electric systems replace hydraulic
systems but mechanical links remain)


2008\04\17@193246 by James Newton

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Aircraft fly by wire systems are not (as far as I know) PIC related.

Please change the topic tag to EE.

--
James.

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