HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Page 1/7  >  >>
GlennA
User Rank
Gold
vs. learning how to drive ?
GlennA   5/9/2012 9:49:08 AM
In the old days of a cable linkage between the accelerator pedal and the carburetor, my brother had the experience of the return spring breaking.  He turned off the ignition and the car stopped.  Another option is to put the gear selector in Neutral.  If you are truly concerned that the car won't stop, I don't think you will be worried that the engine will overspeed and throw a connecting rod.  But then that would stop the engine.  I do agree with having an interlock between the brake pedal and the electronic throttle control, but technology can't replace good driving skills.

tekochip
User Rank
Platinum
Driver Panic
tekochip   5/9/2012 11:14:02 AM
NO RATINGS
It seems somewhat unfair that Toyota's acceleration problem got so much press when it was first examined, but when the cause was not found to be a software or electrical issue the media was mute. If the driver doesn't panic there are plenty of methods to disengage power by shifting into neutral or turning the car off. Adding this additional method to cut power in drive by wire systems wouldn't add any additional hardware, and would remove power even if the driver panics.


bdcst
User Rank
Platinum
Re: vs. learning how to drive ?
bdcst   5/9/2012 1:24:36 PM
NO RATINGS
Yes but..good driving skills may include keeping the brake pedal depressed while giving the vehicle some gas when starting up on a steep hill so it won't roll backwards.  Thus, the interlock firmware needs to be intelligent and not override the throttle the instant both both pedals are activated.

GlennA
User Rank
Gold
Re: vs. learning how to drive ?
GlennA   5/9/2012 4:05:54 PM
NO RATINGS
bdcst;  Some vehicles have 'hill start assist' that maintains braking for a short time to allow time to press the accelerator.  Rolling backward was more of an issue when the clutch pedal was also present.  Some drivers have the (bad habit) of 'two-foot' driving;  one foot on the accelerator and one foot on the brake;  poor mileage, poor acceleration, brake pads wear out quickly, the driver following can't tell riding the brake pedal from actual braking.

Beth Stackpole
User Rank
Blogger
Re: Driver Panic
Beth Stackpole   5/9/2012 4:31:55 PM
NO RATINGS
From what Chuck describes, it also sounds pretty painless for the automotive makers to incorporate so why wouldn't they. As someone else pointed out, it could also provide some legal protection.

cookiejar
User Rank
Gold
Just One Minute!
cookiejar   5/9/2012 4:42:17 PM
NO RATINGS
I wish to express my outrage at the lies contained in this report!

In its investigation NASA found examples of throttle sensors that had grown Tin wiskers that shorted out the pot's leads effectively indicating a full throttle command.   The web link to the NASA paper is here:
http://nepp.nasa.gov/whisker/reference/tech_papers/2011-NASA-GSFC-whisker-failure-app-sensor.pdf

This is an example of an undesirable side effect typical of every human endeavor.   In this case the desire to eliminate lead from solder has resulted in a proliferation of tin wiskers causing no end of trouble in electronic circuitry.

I would question the use of carbon potentiometers for this critical throttle control application.  D.C. voltage applied to a carbon pot makes it go noisy rather quickly .  I'm not aware of a single carbon volume control pot, which by the way is normally only subject to A.C., that I've owned that hasn't got noisy within 10 years of use.  We're talking about blow your speakers type noisy.

In one report on the Audi runaway problem, the engineer was able to readily reproduce the runaway problem caused by alternator noise wreaking havoc with the controller CPU when the battery's impedance rose at high temperature extremes.

It's obvious to me that both of your mentioned reports were written by the industry friendly mandarins of NHTSA and NASA.  These do a major disservice to the hard work of some honest engineers, who take due diligence seriously, especially when people's lives are at risk. 

SHAME! SHAME!


tekochip
User Rank
Platinum
Re: Just One Minute!
tekochip   5/9/2012 5:03:48 PM
NO RATINGS
You are correct, the report clearly finds a tin whisker as the failure cause.  Why does the article state otherwise?

Charles Murray
User Rank
Blogger
Re: Just One Minute!
Charles Murray   5/9/2012 7:12:32 PM
NO RATINGS
Lighten up, "cookiejar." Your indignation about this matter is very selective. On one hand you refer to the "industry friendly mandarins of NHTSA and NASA." On the other, you cite a NASA pdf file to make your point about tin whiskers. The fact is, NHTSA's final report cited tin whiskers on pages 46, 48, 69 and 74 (those are the pdf page numbers), proving that it was aware of the issue. In the end, though, the report concluded that the tin whisker effect is not dangerous. Its conclusion was that it would have been impossible for tin whiskers to cause the Toyota vehicles to accelerate out of control. As I noted in the story, the Secretary of Transportation emphatically stated that the verdict was in: "There's no electronic-based cause for unintended high-speed acceleration in Toyotas. Period," he said. For this story, we also talked to the Center for Automotive Research and Consumer Reports. Reports by the National Academy of Sciences and by Edmunds.com have reached similar conclusions. If you can demonstrate that tin whiskers were the cause, I strongly suggest you call Edmunds, which offered a prize of $1 million to anyone who could demonstrate "a novel cause for unintended acceleration." If all these people are in on some kind of conspiracy, it must be a whopper.

To see NHTSA's final report, go to the following page and click on the link that says "NHTSA Full Report":

http://www.nhtsa.gov/UA

naperlou
User Rank
Blogger
Re: vs. learning how to drive ?
naperlou   5/9/2012 7:28:58 PM
NO RATINGS
bdcst, this really only applies to manual transmission cars.  I wonder how this drive by wire works for them?

Charles Murray
User Rank
Blogger
Re: Driver Panic
Charles Murray   5/9/2012 7:46:35 PM
NO RATINGS
I agree with you, tekochip. Although there was a fair amount of media coverage when the Secretary of Transportation made his pronouncement, it paled by comparison to the amount of coverage the story got when it orginally broke.  

Page 1/7  >  >>


Partner Zone
Latest Analysis
Last year you helped Design News and Allied Electronics crown its first-ever Gadget Freak of the Year, and we need your help again. Vote in round 2 of our second-annual contest.
The key to autonomous driving is not to forget about the driver, and to remember that passengers want a sense of control, as opposed to being utterly passive backseat drivers.
HP revealed more of its 3D printing plans in a recent webinar. Senior vice president of inkjet and graphics solution business Stephen Nigro spoke about how the technology works and expanded on HP's vision of open collaboration to commercialize its Multi Jet Fusion 3D printing technology for end-production, and open collaboration on new materials. He also said HP will create software to help users decide when to use Multi Jet Fusion versus conventional subtractive manufacturing.
Get a load of these strange product designs. What's in the water these design engineers are drinking?
The Dutch are known for their love of bicycling, and they’ve also long been early adopters of green-energy and smart-city technologies. So it seems fitting that a town in which painter Vincent van Gogh once lived has given him a very Dutch-like tribute -- a bike path lit by a special smart paint in the style of the artist's “Starry Night” painting.
More:Blogs|News
Design News Webinar Series
11/19/2014 11:00 a.m. California / 2:00 p.m. New York
11/6/2014 11:00 a.m. California / 2:00 p.m. New York
10/7/2014 8:00 a.m. California / 11:00 a.m. New York
12/11/2014 8:00 a.m. California / 11:00 a.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Dec 1 - 5, An Introduction to Embedded Software Architecture and Design
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Last Archived Class
Sponsored by Littelfuse
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service