Slashdot Mirror
A Car With A Mind Of Its Own
mindriot writes "When Hicham Dequiedt, driving on a highway between Vierzon and Riom in central France in his Renault Vel Satis this Sunday, was overtaking a truck, his car began accelerating to 120 mph on its own, apparently due to a defect in the cruise control system. Stomping on the brakes proved pointless and, having a magnetic card for a car key, he could not cut the ignition. After calling the police from his cell phone who then attempted to clear the streets of any danger to him, in what he described as the most fearful event of his life, he raced down the highway for another hour before finally managing to stop the car. Read about the incident here or, in more detail, in this article by the German 'Spiegel' (translation). The case is still under investigation. Are we putting too much trust in the increasing number of electronic systems that our lives depend upon?"
In A.D. 2004
Trouble was beginning.
Driver: What happen?
Car: How are you gentlemen !!
Car: All your brakes belong to us.
Car: You are on the way to destruction.
Driver: What you say !!
Car: You have no chance to slow down make your time.
Car: HA HA HA
Driver: Take off every 'cell phone'
Driver: Move cars off road.
Driver: For great justice.
Something smells rotten with this story. Stomping on the brakes didn't do anything, but as he approaches a toll booth, the brakes suddenly work and he's able to stop the car??? Catastrophic system failures don't often repair themselves...
Stop by my site where I write about ERP systems & more
The emergency brake may help to slow or stop a vehicle if the normal braking system goes out, but it can't fight the force of the engine -- especially if the cruise control makes the engine rev higher when the vehicle slows down.
Yes, hello, 911?
... I'm sure I'll have it resolved by the time I reach my home.
It seems my car *refuses* to stop at red lights. Whenever I approach one turning red, the car mysteriously speeds up through the intersection.
Do be a peach and clear the way for me until I can get this under control
The little guy just ain't getting it, is he?
He was driving a Renault?
People -- there is a reason the least often uttered phrase in the world is Quality French Engineering
How does the Slashdot Effect happen given that no slashdotters ever RTFA?
Emergency brakes no longer exist. They are called parking brakes now, because they aren't designed to resist the torque of the engine, they just have enough power to hold the car from rolling, and even then, cars with manual transmissions are recommended to be put in either reverse or first gear to give additional resistance to keep from rolling.
The "emergency brake" is really just a parking break or "hill holding break" (designed to hold a car on a hill while engaging a manual transmission). Generally, enough force cannot be applied by the "emrgency brakes" to slow down a rapidly moving car without significant stopping distance. The "emergency break" also has the added disadvantage of ususally being attached to only two wheel breaks. Because of this, when applied at higher speeds, they tend to spin the car (usful for sheading speed only if you are an expert and have the road clearence - also usefull for "cool bootlegger moves").
I wonder if the electronic transmission has "safety sensors" that won't shift to a lower gear if it might cause engine damage. If so, even if you put the selector down to the first gear, the computer would override the driver in order to protect the engine.
Hmm, the computer overriding the human for self-preservation. That could be interesting.....
. 62,400 repetitions make one truth -- Brave New World, Aldous Huxley
Um.. ya, all the swiss cars have it!
-Guns kill people like spoons made Rosie O'Donnell fat-
You: Hello, police? Oh my god, my cruise control is stuck at full throttle! Help!
Police: Stay calm, sir. Can you shift to neutral?
You: No, and I can't shut it off! Help!
Police: We'll send officers to clear the road, sir. Remain calm, keep on the freeway.
You: Thanks, I'll call back if I need more help. [click]
You: YEEEEEEEHAAAAAWWWWW!!!!!!!! I'm goin' 120 MPH and the cops are clearing the road for me! How sweet is that?!?!?!
John
"If you can't steer and/or stop your car with the power off, you need less car."
Did you mean with brakes, or by hand? If the latter, I'm going to be really polite to you.
"Using electric brakes with metallic pads means no brake fade, ever, up to the point where you warp your rotors. There's no brake fluid to take on water and boil, not necessarily in that order."
Fade is gaseous buildup from the pads ablating against the disc, which is why you do graduated braking on a non-fancy car, but personally I wouldn't trust a solenoid to do the force multiplying work of a caliper.
As for the brake fluid taking on water...if you have a non-tight hydraulic system you'll be screwed anyway, let alone getting to the point where you have water in it. Compare the relatively low tech and _reliable_ cylinder and caliper system with the voltages/currents required to produce braking forces and you'll probably notice that there's going to some power applied.
"unreliability of automotive hydraulic systems."
Probably _the_ most reliable portion of the average motor car, if maintained and kept in good repair and not driven with utter faith in the ability to tailgate other drivers at 80mph. Most accidents involving brakes are people locking the wheels at speed.
Oddly Draconis
Too cynical to live, too stubborn to die.
Most every car made since the mid eighties has an electronic rev limiter on it. Attempt to rev past this limit, and the ECU will selectively cut fuel/spark to keep the engine speed under control.
;)
It's very accurate; +/- 20 RPM typically.
Sticking an engine with a stuck throttle into neutral will result in it banging off the limiter and making a lot of noise, but it won't overrev.
You can, however, MECHANICALLY overrev a manual transmission by downshifting into a lower gear while the wheels are turning at a faster speed than is otherwise proper for that gear. The wheels and the engine are mechanically connected, and downshifting to too low a gear will spin the motor up - no rev limiter can protect against this.
In certain BMW M3s, the transmission mounts get a little sloppy, and engine torque reaction under hard acceleration can rotate the transmission enough to move the shift gates. It's possible then to try and go 2->3 or 3->4, and hit 1 or 2 instead. This is invariably fatal to the motor. You will bring your pistons home in a bucket.
Depending on the contstruction of any given automatic transmission, it may or may not allow you to take it out of gear and go into neutral under throttle. If you are silly enough to be driving an automatic, this could be a problem - but anybody who'd buy an auto trans where a manual was availible would steal sheep - so you probably had it coming.
DG
Want to learn about race cars? Read my Book
Brakes, Brakes Burning bright
on the highway, in the night
what awful error made system die
and made the poor driver cry
On what distant tollboth lies
The crappy break that you did buy?
What disaster did you sire?
And with what rod did you make fire?
"goodbye and hello, as always" ~Prince Corwin, from Zelazny's Amber series
Oblig: I can't let you do that, Dave.
But what about .. uhm .. say Neutral .. ? or don't european cars have that?
No, Europeans don't believe in neutral. It's either forward or backward, but never neutral!
Don't ask which gears the American's don't believe in...
We need a "If nations were tansmissions..." page. We;ve got automatic, manual, continuously variable, single speed, bicycle derailleur, hydraulic, no transmission...
-Adam
But you need to be *very* careful about this at 120 mph.
GreyPoopon
--
Why is it I can write insightful comments but can't come up with a clever signature?
do not ever attempt to turn the ignition all the way off... In most cases you will lose both your power steering and your power braking.
Of course, power steering and brakes are specifically designed to work if the power component fails.
Losing power steering at a high rate of speed is not a problem - you turn the wheel very little when at speed. Power steering is only important when you're going very slowly and/or stopped.
You can easily lock up the brakes using your own leg power alone. Power brakes are just a vacuum booster, to make it way-easy to lock up the brakes. Without power, you just have to press harder. But it certainly is far from being impossibly difficult. And in any case, the vacuum ramains in the booster for some period of time. Just try it the brakes in your garage with the engine off, and you'll get a feeling for it.
Of course, many cars of the up into the 1970's didn't have power brakes or steering. And do you know what? They were steerable and stopable at all speeds. Basic steering and braking systems have NOT changed at all since then.
The only significant danger is enabling the steering wheel lock while turning off your ignation at speed. Watch out if you turn off your ignition while moving - you don't want to mistakenly LOCK your steering wheel while at speed.
Mod down parent.
There are many great ideas that people came up with on how the driver could have slowed the car. But nobody has listed the obvious one yet.
He should have kicked his way through the floor boards to the engine compartment. At which point he would have seen 6 wires, 2 of them being blue, 1 brown, 1 orange and 2 red. He would then have taken the brown, orange and 1 of the reds and spliced them together with a bit of electrical tape. But making sure that he was at all times grounded and that the blue wires did not come in contact with the red ones (Then you would have a whole new set of problems).
Once these wires are connected together, it is all downhill from there. You just have to use a screwdriver to crack open the steering column where you will find 4 more wires (blue, green, yellow/blue, red). Take the connected wires that you finished with earlier, use a 3 foot spare wire to run a bridge to the steering column connecting to the green and blue wire. Once this is all done, just push your horn 3 times in rapid succession and the car will slow right down.
Still makes me laugh that this guy never thought of this. Silly French people.
"If at first you don't succeed, destroy all evidence that you tried"
.. It was just running from the volkswagen behind it.
---- "Excuse me. Where's the children's gun section?"
Some newer cars don't have a neutral gear. You can only select forward, backward or park and that's it.
One example is the 2004 Prius, you have no direct control over the engine and, much like the car in the article, there isn't even a key to take out of the ignition. If there's a problem and the computer doesn't want to stop, there's really not much you can do. There isn't even an option for a manual transmission.
When you downshift from, say, 4th to 3rd in an AOD transmission, the lever may go into the 3rd slot but the system will not actually shift down until it's "safe" to do so. It's the same premise that the system uses to shift up. You can hold the car in 2nd gear and it won't go over, but it also won't shift up to 3rd immediately if you push the lever into third gear. In an AOD, you more or less have to look at your gear lever as a nice suggestion that the car USUALLY follows.
I don't really know how you could safely stop a modern AOD if you lose control of the throttle unless you've removed the rev limiter. The car will not shift down or into neutral if doing so would throw you over the rev limit and you can't gun the engine further to try and blow it either.
As a sidenote, you can get a shift kit that will let you shift up and down in an AOD at your command. If you had something like that and you were going that fast, you MIGHT be able to override the rev limiter simply by throwing the lever back into first gear as hard as you can. Rev limiters aren't perfect and you can rev the engine to explosion if you do something stupid enough.
Alito: A vote for Alito is a punch in the eye to put that bitch back in her place!
"A car must obey the orders given to it by human beings, except where such orders would conflict with the First Law."
The problem with Slashdot memes is that YOU INSENSITIVE CLOD!
The Audi 5000, and many other cars over the years, have had reported cases of "unintended acceleration", often resulting in deaths. In most (if not all) cases, it turns out to be driver error, wherein the driver BELIEVES they're stomping on the brakes, but instead they're pressing the gas. The truth is, in all modern automobiles, the brakes can bring the car to a halt even with the accelerator floored.
Historically, this usually occurs when something else malfunctions and causes the driver to get distracted. In the case of the Audi 5000, it was an idle control that went awry, and when people shifted into drive with their foot off the brake, the higher idle would make the car lurch forward. They'd slam on the brakes, but accidentally hit the gas, and keep their foot to the floor until they hit something. They found this out by inviting a number of people who experienced this "unintended acceleration" to a parking lot, and had them drive engineers around for two days in front of cameras while the engineers played with the computer to force errors.
On the second day of this testing, a woman putting the car into reverse went tearing across the parking lot at high speed until the engineer reached over and shut the car off. She jumped out of the car, and on camera, shouted something like "It happened! There's your proof! The car is at fault!" -- but the cameras inside the car showed she had been hitting the gas, the cameras outside showed no brake lights, and the engineer riding with her bore witness as well.
As a result of this study, and all of the fallout surrounding the related lawsuits, the US requires an automatic transmission interlock on all cars sold here. You MUST have your foot on the brake to shift into gear.
- - -
Now, to the case at hand. I am fairly certain that this was the course of events:
1. The driver recently purchased the car, or it was a rental, so he was relatively unfamiliar with it (the Audi 5000 incident found that the vast majority of people having these incidents were drivers for whom the Audi was not the primary vehicle, or whom had just purchased it);
2. The driver was cruising along on cruise control, and pressed the gas without manually disengaging the control.
3. When the driver lifted off the gas and pulled back in, the car either didn't slow down as quickly as he thought it should (remember, we're assuming he was unfamiliar with the car), he accidentally hit the button to reset the cruise control to the newer, higher speed, or there was a genuine malfunction that reset the cruise to the newer, higher speed.
4. In the next few seconds that followed, he panicked and went for the brake -- but instead he hit the gas. Having done this, and firmly believing that he was hitting the brake to no effect, he continued to floor the gas. The car continued to accelerate.
5. Between trying to shut the car off, calling the police and swerving around traffic, it never occurred to him to look down and see if he was actually hitting the brake. No shame there; none of us would have, either.
6. As he approached the tollbooth, he made another attempt at the brakes (probably using both feet this time) and brought the car to a stop.
So, is the cruise control at fault? Possibly, but not definitely. Either way, similar past incidents suggest that it was a relatively minor issue until he hit the gas by mistake.
For what it's worth, with no witnesses in the car and no instruments monitoring, we'll never know for sure. Also, unless he realized his mistake just before stopping the car, he may well spend the rest of his life believing it's the car's fault -- and if he DID realize his mistake, there's no way he's ever going to admit it.