Recent Engineering Debacles 7

[hidalgoe]

HellO:

What have been the results of recent engineering debacles, like Boston's Big Dig concrete section that fell and killed some folks in a car or Katrina meant for PE's as far as liability and ethics are concerned?

 

[brandoncdg]

macguyvers2000: travanx is my handle everywhere. Actually if you search stolen porsche 993, you will find what I really think about people. UGH!

From the current discussion it sounds as people should drive a manual car! Problem so solved. Every single time I see Toyota mentioned in the last week or so, I think what is the Ferrari 458 Italia thinking!!! Supposedly the car is only auto because the computer is so sophisticated that a manual is not possible.

Does a smart person only have to come out with secure wifi car ECU updating program now?? When I mention an invention so far it has been made within 3 years.

Civil Development Group, LLC
Los Angeles Civil Engineering specializing in Hillside Grading

http://civildevelopmentgroup.com

http://civildevelopmentgroup.com/blog

 

[drawoh]

...

From the current discussion it sounds as people should drive a manual car!

...

I think manual transmissions are safer because manual transmission drivers are better. In parking lots and on narrow roads with children playing, you can drive in first or second gear and rely on the engine noise to tell you how fast you are doing. There is no need to glance away from the road to scan your instruments. On the other hand, I would guess that most of the cars on this website have manual transmissions.

One of my understandings about all this is that the engine and automatic transmission have not been made that can overpower your brakes, if you have applied them. A car is a piece of heavy machinery which must be treated with respect. The least reliable component is the nut that holds the wheel.

JHG

 

[unclesyd]

An interesting article from Dvorak.

http://www.marketwatch.com/story/your-car-computer-may-kill-you-2010-02-05

 

[drawoh]

unclesyd,

That article was interesting, especially the stuff about drive-by-wire.

Modern fighter aircraft are inherently unstable, and are human controllable because a computer automatically provides rapid control corrections. Some aircraft are huge. How feasible would it be for a person of average size and build to manually control a Boeing _747 or an Airbus_A380? These aircraft at the very least, have massively power assisted controls.

What problem would drive by wire solve? Are most accidents caused by people unable to master complex control movement?

I was on a bus a few years ago that was headed down a snowy, slippery road. The driver decided he was losing control, so he put the thing in the ditch. The alternative was to slide down a hill and somehow recover control and avoid a lake.

Would a drive by wire bus have allowed him to do this?

JHG

 

[KENAT]

Well, depending how it's implemented I suspect 'throttle by wire' might allow improvements in efficiency, at least isn't this one of the reasons for FADEC on aircraft engines?

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[IRstuff]

I think the older planes were fly by hydraulics, not wire, e.g., DC-10.

FBW for fighters is not because the computer is faster, per se, but because the stability equations are not solvable by the pilot, even if he had more time.

TTFN

FAQ731-376

 

[GregLocock]

Throttle by wire is cheaper, more reliable, marginally better for crash, quieter, lighter and offers easier implementation of features than a cable operated throttle.

You have to look at these things from a system perspective.

Cheers

Greg Locock


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[bpattengale]

Greg,
Just a question, but where is the cost savings in throttle by wire? It just seems counter intuitive to me. I'd think some cabling vs a bunch of computers would be cheaper. I'm sure you're right but could you elborate? I'm sure there is something I'm overlooking, but it isn't obvious to me.

 

[IRstuff]

For airplanes, it's not about cost, per se. Weight of hydraulics, elimination of handling costs of noxious fluids, ability to have redundancy, ability implement high-performance stability algorithms, ability to distribute processors and sensors.

Note that that cabling is often already present for the sensors, so a slight addition to the existing harness in some cases, and simplification of the harness in others, results in substantially higher performance.

TTFN

FAQ731-376

 

[MikeHalloran]

There's already a throttle position sensor, so the ECU can know the demand.
There's already a throttle actuator, for cruise control, or at least a snap-shut damper or burp valve.
There's already computing power available, for 'free'.
So removing the mechanical linkage or cable provides a cost savings.
... which is mitigated by the risk and cost of litigation or legislation over the reliability of the computer code.
... which is always postponed and politicized and rushed, and is one of the most expensive components of computerized systems.




Mike Halloran
Pembroke Pines, FL, USA

 

[drawoh]

GregLocock,

Throttle by wire does not bother me. The throttle system is one system that can malfunction, whether it is mechanical, electronic, or computer controlled. You still have the gearshift and the brakes, and some of us have clutches.

I was more concerned about the entirely driven by wire cars described in Dvorak's article. Now you have the possibility of a central malfunction that cannot be overridden. There are a lot more cars on the road than there are fighter planes and airliners. They are not as well maintained, and the stuff happening around them is a lot less predictable.

JHG

 

[PeterStock]

I would have no problem traveling by cars controlled by computers. It's the transition where there are some controlled by computers and some by people that has me scared.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net

 

[MacGyverS2000]

What about computer-controlled steering? Steering racks don't exist in all vehicles (electric steering), so what happens as we move forward in technology and a computer error decides to turn us left instead of right?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[unclesyd]

Not really but.

http://www.businessweek.com/news/20...haft-said-to-be-recalled-by-dana-holding.html

 

[GregLocock]

drawoh- I didn't read the Dvorak article as I usually find old gum wrappers are more sensible, he's mostly a troll. OK, that article wasn't too bad.

"I was more concerned about the entirely driven by wire cars described in Dvorak's article. Now you have the possibility of a central malfunction that cannot be overridden."

Yup, that's how it'll pan out. So the question is, is there a net cost benefit to society in an Everything By Wire car? I don't know. I have seen a presentation intimating that the technology will be deployable by 2020, and I imagine there are a lot more people thinking this through than there were.

I suppose one bright spot is that by and large we have managed to get ABS and ESC introduced without causing too many accidents caused by system failures.

Cheers

Greg Locock


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[MikeHalloran]

The thing that worries me about doing anything important by wire is ... not the wire, but the connectors, which are the least reliable part of any competently designed electronic device today.

They may be getting worse. I submit that we are starting to reap the fruit of the RoHS initiative in that respect.



Mike Halloran
Pembroke Pines, FL, USA

 

[CajunCenturion]

With respect to the recent death of Georgian luger Nodar Kumaritashvili, is their a track engineering component to the accident?


Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein

 

[unclesyd]

It has been said to be so.
There have been complaints that the track is too fast, fastest in the world. There is also some discussion about the inspection committee's recommendation for higher guard rails. The part that I hears mentioned a wooden fence to keep people on the track which specifically mentioned the area where he went over.
The politics are so thick around the games i don't think you will ever hear anything about whys and wherefores.

I think a wooden fence or a small mesh net would be better that a steel support column.

 

[unclesyd]

The plot thickens!

http://www.businessweek.com/news/20...y-toyota-helped-halt-acceleration-probes.html

 

[philipoakley]

Perhaps look at the more mundane "The Design of Everyday Things", Donald Norman and similar ideas.


Would a Toaster be allowed if it were a new design (you do remember when you used a knife to extricate the burnt bread when it was still on ;-) - safe as houses, wouldn't be without it.

Philip