Kidnapped By a Runaway Electric Car (bbc.co.uk) 351
Long-time Slashdot reader RockDoctor writes: Regardless of their other potential benefits, modern cars, and modern electric cars in particular, involve complex networks of computer code, hardware, and servo systems cooperating (?) to deliver services to the user, like acceleration, steering and braking. Slashdot nerderati know better than most that such complex networks can never show unexpected, non-designed behavior, due to the infallibility of hardware, program coders and system designers... Yeah. Right. "I'll have some of what he's been smoking!" That's Musk-grade optimism.
On Sunday evening, a middle-aged driver in a "brand new" vehicle found it would not decelerate below 30mph (50kmph). He retained steering control, and avoided crashing until police vehicles "boxed in" his vehicle and helped him exit into a police van (most have sliding side doors) from the moving vehicle. The police then "carried out a controlled halt" on the unmanned vehicle, stopping it from driving away with the van's brakes until a roadside assistance technician arrived 3 hours later and managed to shut it down. "[W]hen the [technician] got to me [...] later, he plugged in the car to do a diagnostic check and there was pages of faults," said the "kidnapped" driver from Glasgow. "He said he had never seen anything like it and decided he was not willing to turn the engine on to see what was wrong."
By inference, the vehicle did not have a mechanical brake ("hand brake": English; "parking brake": American), which should have been able to keep the vehicle halted regardless of the motor's actions (even if a "clutch" did get burned out). From the only time I've been inside an electric car, I can't say if that is normal; it's certainly something I'll look for if I ever rent another. Had the failure happened at 10 a.m. in the morning, not 10 p.m. in the evening, the body count could have been ... substantial.
A dumb question, stemming from my only use of an electric car: do they have a weight sensor under the driver's seat that locks-out the main motor unless there is (say) 30kg in the driver's seat? Most have some such sensors -- they trigger the "seatbelt not fastened" alarm or silence it for empty seats -- but whether they can override the drive system ... ?
On Sunday evening, a middle-aged driver in a "brand new" vehicle found it would not decelerate below 30mph (50kmph). He retained steering control, and avoided crashing until police vehicles "boxed in" his vehicle and helped him exit into a police van (most have sliding side doors) from the moving vehicle. The police then "carried out a controlled halt" on the unmanned vehicle, stopping it from driving away with the van's brakes until a roadside assistance technician arrived 3 hours later and managed to shut it down. "[W]hen the [technician] got to me [...] later, he plugged in the car to do a diagnostic check and there was pages of faults," said the "kidnapped" driver from Glasgow. "He said he had never seen anything like it and decided he was not willing to turn the engine on to see what was wrong."
By inference, the vehicle did not have a mechanical brake ("hand brake": English; "parking brake": American), which should have been able to keep the vehicle halted regardless of the motor's actions (even if a "clutch" did get burned out). From the only time I've been inside an electric car, I can't say if that is normal; it's certainly something I'll look for if I ever rent another. Had the failure happened at 10 a.m. in the morning, not 10 p.m. in the evening, the body count could have been ... substantial.
A dumb question, stemming from my only use of an electric car: do they have a weight sensor under the driver's seat that locks-out the main motor unless there is (say) 30kg in the driver's seat? Most have some such sensors -- they trigger the "seatbelt not fastened" alarm or silence it for empty seats -- but whether they can override the drive system ... ?
They need a PHA. (Score:4, Insightful)
They need a PHA. Chemical plants that fall under OSHA PSM regulations have to meet strict safety standards that result in extremely low probability of incidents. The systems must have enough redundancy that a single failure cannot cause such an event, to the point of even evaluating if the safety system can detect, respond, and ultimately final field element can do whatever it needs to do before the event that was detected can propagate into an accident. Some people complained that an SIS implementation resulted in more spurious unit trips, which if probably did, but that was the trade-off decided upon by management to save money installing more reliable or redundant instrumentation.
It's incomprehensible that in a vehicle there would be no e-stop that can override everything else, mechanically. You have a solenoid or relay that if it is de-energized (the default state), the car will "stop" (in some manner). You could have several of these, any one of which would stop the car and all would be interrupted by the e-stop. Whatever level of redundancy necessary to reach the reliability level required.
Crazy.
Re:They need a PHA. (Score:5, Insightful)
Motorcycles have a kill switch for the same reason.
Why an EV does not have a Big Red Button is a fair question. Bonus points if it talks back in Billie Piper's voice.
Re: (Score:2)
It's called an FMEA, in automotive and aerospace. Chances are the driver didn't read the manual and so didn't know to (typically) hit the big button for 3 seconds.
Re: (Score:2, Informative)
Maybe you should RTFA?
Re:They need a PHA. (Score:4, Informative)
What you really want is called functional safety in automotive and industrial contexts, and system safety in aerospace contexts. FMEA (or its predecessor FMECA, often used in old school military contracts) is just one tool to make sure you've captured the right set of failure detection, robustness and recovery requirements.
The aerospace standard for that kind of analysis, ARP 4761, says to use a FMEA in addition to fault tree analysis (usually in several variants with slightly different purposes) and common cause analysis as part of the overall safety assessment. In contrast to a Process Hazard Analysis (PHA), ARP 4761 expects quantified analyses when human life is at risk, meaning a lot harder/less-debatable evidence should be generated.
IEC 61508 and ISO 26262 are the usual standards for functional safety, the latter applying in the specific case of TFA; I am not familiar with their expectations.
Re: (Score:3)
It's called an FMEA, in automotive and aerospace. Chances are the driver didn't read the manual and so didn't know to (typically) hit the big button for 3 seconds.
Chances are you would be incorrect. From the fine article:
Police asked Mr Morrison to throw his electronic key through their van window before driving off, and then tried forcibly shutting off the engine - but nothing could stop the car.
He was also asked to hold the power button for a couple of seconds which also failed to stop it and the entire dashboard lit up with faults.
Re: (Score:3)
3 seconds? In many emergency situations, that could be about 3 seconds too long.
Re: (Score:2)
Technically, the car should have stopped if the police or fire crews had a charging adapter; there are boomerang looking things that have a Tesla plug on one side and a CSS plug on the other in the US. There is also a parking brake on my Tesla, although I admit I need to look up where it is again.
On a Tesla you could also do a reboot of the system, but that could be an issue if things were as bad as their tech said.
Re: (Score:3)
It's probably not a software issue. The most common cause of unwanted acceleration and not being able to stop is the floor mat getting stuck to the pedals.
Most cars have a little hook arrangement to stop the mat riding up, but if it breaks or the mat is unhooked it can interfere with the pedals. When it gets stuck to them, pressing the brake also presses the accelerator. Pressing the brake hard enough should still stop the car, but the driver tends to get confused and panic.
I remember stories about this bac
Mechanical parking brake should be mandated (Score:5, Interesting)
Any time a critical safety function such as braking can be at least backed up with a fully mechanical, fully manual capability, it must be, and that must be mandated. That's one thing that gives me the creeps about my wife's late model CRV - the parking brake is electric.
I haven't attempted to engage it while driving, because there's no granularity of control - it's either on or off, and both the application and release times are pretty slow. But I'm almost certain that brake can't be engaged when the car is in gear and/or in motion. And even if it can be applied, can I rely on it to both engage and release? The automated functions of that car are a bit flaky and have done odd unexpected things on numerous occasions; is their computer-controlled parking brake immune to those quirks, especially when used in non-ordinary circumstances?
As for the final question in TFS, I don't know the answer. But I can say that if the car has autonomous 'come when you call' capability, then the system can override any driver's seat sensor. And if it can do that, then it can do it even when it's not supposed to.
Re:Mechanical parking brake should be mandated (Score:5, Insightful)
Re: (Score:3)
A parking brake isn't going to stop a car where the motor(s) are actively working.
Agree. At best it will keep it from rolling when parked, You can't even trust it to do that when on a hill, that's why you turn the wheels to direct the vehicle to the curb if it should happen to start rolling
Re: Mechanical parking brake should be mandated (Score:4, Informative)
And also put it in gear opposing the direction of the hill if itâ(TM)s a manual.
The current proper spelling (Score:2)
of the system that slows a car to a stop is "breaking."
See the First Post.
You got to keep up with the times.
Re: (Score:2)
Please.
Re:Mechanical parking brake should be mandated (Score:5, Insightful)
I drive an Outback with an electric parking / emergency brake. This scares me too. While the chances of a double electrical AND brake malfunction are slim to none, the consequences are quite grave.
I've engaged the manual override on the parking brake at low speeds, but never at highway speeds. If I hold down the parking brake engage button, the electric brakes will engage. They're separate and apart from the hydraulic brakes. If I release the button, it will cease applying the brakes. But, that said, you're right - it's either applying the brakes or doing nothing. It's a dumb system with limited granularity of control.
In my case, it's both a gas and a manual transmission. I also have the option of shutting the car off in the case of runaway acceleration (or using the clutch or transmission to disconnect the engine from the wheels), intentionally destroying the drivetrain to stop the car, or engine braking.
None of my emergency stopping methods (engine braking, clutching, shifting to neutral, or destroying the transmission) will work in an EV. Shifting to park in an automatic (assuming you can - many cars have safety features to prevent it) will also slow the car down to a stop eventually but likely destroy the park detents. That's part of the problem - none of the classic methods to stop a car in an emergency work in an EV, and neither cars nor drivers have yet adapted.
Point being, ALL cars should have fully mechanical, manual braking systems. Add an electric assist, sure, but it should be legislated that all car brakes can be applied with no input or argument from the car.
Re: (Score:2)
Why would the drivetrain be damaged, to say nothing of destroyed, if you kill ignition while in gear in a manual, gas powered car?
I mean, not even the catalytic converter will be damaged because there won't be any fuel injected? You won't have steering, most likely since it is powersteering and you only have one good braking action, but why would the drivetrain get damaged?
Re: Mechanical parking brake should be mandated (Score:2)
I think they meant by slamming it into a lower gear and dropping the clutch.
Re: (Score:2)
That might cause strain? But if the gear you want to shift down to is too far away, the mesh won't let you shift into it. Physically. On motorbikes, yeah, most if not all are constant mesh. You can shift down to 1st going 120mph, gearbox won't complain, and almost guarantee the engine become undone right then and there.
Re: (Score:2)
Yeah, the synchros make it very difficult - but not impossible I think, if you force it. The odd time I've accidentally almost shifted to say 3rd to 2nd instead of 4th at high engine load, and you can feel it - the transmission stops you. But I'm pretty sire if I forced it, I could do it.
Re: (Score:2)
Not by killing the ignition - that will simply shut down the engine and then you coast. But I can destroy the drivetrain (the engine, the transmission, or both) by shifting to a low gear at high speeds. Cut off a limb to save the patient, as it were.
It happened to me once - I blew a gear. Trust me, it very quickly stops the car. They kind of... bunnyhop.
Re: (Score:3)
The car stops a LOT faster if you destroy the engine. You will never use the car again, but for three seconds, it will stop a lot faster.
Re: (Score:2)
It's called a "parking brake" because it's designed to hold the car in place on a hill, not stop while it is in motion. Plenty of absent-minded drivers have accidentally left it engaged while making a trip. I'm reminded of that line from the movie The Birdcage:
Armand : Is Albert here?
Agador : No.
Armand : Great. Then he's driving back from Miami at 20 miles an hour with the parking brake on.
So no, it's not going to help in most cases.
Re: (Score:2)
Older cars have a parking brake that is often significantly more powerful than the engine if you actually tighten it enough. The problem was mainly that FWD vehicles would have parking brake for rear wheels, so the car would just drag rear wheels once you lock them up with the brake.
This is in fact where drifting as a sport originally came from. Hand braking to lock your rear wheels in a turn even as you give the vehicle full power to maintain the speed. RWD vehicles with rear wheel brake have to drift with
Re: (Score:2)
My truck, a manual transmission I4, can overpower the parking brake with a bit of throttle. You'll definitely notice though.
Now, the rating to tow a 3500 pound trailer might have something to do with that, but my truck is a common one, I'd imagine that MOST trucks could thus overpower the brake, as mine's on the low end, power wise.
My old saturn coupe could also overpower the parking brake.
Now, overpower the engines with the throttle off, probably. But I'm willing to bet that if you're willing to push the
Re: (Score:2)
Like I said above, cars, not trucks.
Most trucks have air brakes anyway, not hydraulic. And these lock up when air is vented, so need for parking brake is minimal. Normal brakes also function as parking brakes.
Re: (Score:2)
You missed the part where my Saturn Coupe back in the day could do it as well. Also, my research that shows that most cars can do it, it's pretty common.
In most cars with drum rear brakes, it's as simple as having a cable that clamps those down instead of the hydraulics. Same brakes for both purposes.
Re: (Score:2)
It's called a "parking brake" because it's designed to hold the car in place on a hill, not stop while it is in motion.
Clearly you are not from the generation who was instructed to utilize it as once intended; as an emergency brake.
If emergency brakes were so ineffective at controlling how a car can maneuver in many a radical situation, it wouldn't be a primary tool in car drifting.
Re: (Score:2)
Clearly you are not from the generation who was instructed to utilize it as once intended; as an emergency brake.
I learned to drive on a '96 Toyota Camry. The parking brake in that car was pretty much just for decoration. I'm not discounting the fact that perhaps older cars had a handbrake which actually did something, but every vehicle I've ever driven you'd be lucky if the damn thing managed to even successfully hold the vehicle on a hill. It also kind of helps that since I've lived in Florida for the majority of my life, we don't really have hills here either.
Re: (Score:2)
Probably needed adjusting/maintenance. I've had quite a few older vehicles, when the brakes are working correctly, that emergency brake will lock the rear wheels if the engine is disengaged.
Example, current truck, a '98, the emergency brake was shit, replaced cables, shoes, adjusters and springs and now that brake will hold the truck on very steep hills and I sure as hell notice if I didn't release it, which happens occasionally as the switch on the emergency brake is dodgy.
Cable stretch used to be a common
Re: (Score:3)
Yup. A few times I've pulled away thinking "man, the car is really sluggish" until I notice the parking brake handle is up.
It's folly. (Score:5, Insightful)
We have recklessly given far too much control to systems that are fundamentally unreliable. The people making these decisions don't realize what they are doing (even if they are putting profit over safety, they are driving these same cars and putting themselves at risk).
Background radiation is real, and once in a while it flips a bit. Without shielding and redundancy, all electronic systems are vulnerable to rare random bit flips. Even at sea level. How much shielding and redundancy have been built into the computer systems that control our cars on our behalf?
Skimping on security is all the rage when profit is concerned. How vulnerable are our cars to drive-by hackers?
People are all worked up about AI driven cars on the road, while these more fundamental concerns are being completely ignored.
We should not need laws mandating mechanical overrides. It should be outright obvious to the manufacturers how important these things are. And yet...here we are....
If the systems were unreliable (Score:2)
If the systems were fundamentally unreliable then explain this graph. https://www.cdc.gov/nchs/image... [cdc.gov]
Re: (Score:2)
Lots of safety systems added. Simple seat belts likely saved a lot of lives, same with collapsible steering columns, then various other design decisions in frame/body, usually mandated, to protect the driver, air bags, etc. Then there are the active things starting with anti-lock brakes and all kinds of stuff currently.
The odd time something goes wrong is more then balanced out by all the safety stuff to protect the occupants. Even the car in this story could have side swiped a wall or even hit something an
Re: (Score:2)
While I can agree with you on basically every logical argument to mandate a physical emergency brake on all cars, I'd say the challenge to implement such a device and actually be effective is going to require more than the mechanical strength of an analog solution.
That's another car in weight powering that EV rolling downhill...
No need for any fancy brakes (Score:2)
During the rainy season in the US south, this wouldn't have been a problem. Just leave the road and you'll sink into the mud. Congrats, you're now stopped.
Re: Mechanical parking brake should be mandated (Score:2)
What car have you driven has a parking break that doesn't simply burn away if you drive off with it set? If you're already moving and on the accelerator just forget about it, that thing is gone. All it's good for is holding the car still against gravity.
It’s gonna get very bad (Score:5, Insightful)
I’ve driven in a Tesla on auto. It’s got an IQ of 180 with a 99.9% reliability rate, but the other 0.01% of the time it’s got an IQ of 60. Which meant that the driver only needed to intervene twice, during a complicated drive, to prevent the car from a) killing a pedestrian and b) killing us.
We’re gonna see a lot of self-driving electric cars munching their way through crowds before we get a handle on it. We’re allowing self-driving vehicles that have no hard override mechanism. The idiocy is astounding. We’re no smarter than last century.
Re:It’s gonna get very bad (Score:4, Informative)
Except this wasn't a self driving failure, it was a good old fashioned stuck throttle made worse by virtue of being drive-by-wire. Toyota had similar problems when they first started using electronic throttles.
Thing is, the news loves a good EV failure story, never mind the fact that ICE cars break in similar ways all the time. [statefarm.com] Diesel engines also have their own unique failure mode [wikipedia.org] which can result in uncontrolled acceleration and turning off the ignition does nothing.
So yeah, basically, welcome to the club, EVs.
Re: (Score:2)
ICE cars may suffer stuck throttles, sure.
But I've yet to drive an ICE car that failed to respond to the ignition key being turned to the "off" position. (I'll happily sacrifice power assist brakes, power assist steering if the car's a runaway.) ... they may exist, but I'm not buying one.
Re: (Score:3)
Re: (Score:2)
As an oldster, I remember this. One entertaining thing you leave out was that the federal government had much stronger mandates for passenger safety planned. But they wrote in an escape clause, "You don't have to do this if enough states pass seatbelt laws." Thus, car companies strongly supported seatbelt laws because this way they didn't have to figure out how to keep people safe.
Re: (Score:2)
Re: (Score:3)
I’ve driven in a Tesla on auto. It’s got an IQ of 180 with a 99.9% reliability rate, but the other 0.01% of the time it’s got an IQ of 60. Which meant that the driver only needed to intervene twice, during a complicated drive, to prevent the car from a) killing a pedestrian and b) killing us.
If that's the case, it's doing better than quite a few drivers on the road right now. There was a lady doing a video call with her phone at the 12-o'clock steering wheel position next to be driving around yesterday. Three days ago I saw someone almost plow into a building after pulling out of a gas station and cutting across four lanes of traffic going 40MPH for some reason.
All you really need to do is pay attention and not drive like a maniac. I'd say a quarter of all drivers fail to do either or both.
Re: (Score:3)
Well, the fact that you had to tie the seatbelt didn't help!
My guess, no sensor would have worked (Score:2)
Re: (Score:2)
When they removed the key from the car and had the driver press the power button
In my two EVs (Tesla and Nissan), if you throw the key out of the window (my phone in the case of the Tesla), nothing happens. A message may flash up on the screen, but neither car will stop.
But the grinding noise from the brakes suggests to me that the brakes were not assembled properly. Remember that most EVs (apart from Teslas) have mechanisms to stop the brake pads from being applied when you press on the brake pedal -- to enable regeneration.
It was an MG ZS EV (Score:4, Informative)
I'd never heard of them.
Re:It was an MG ZS EV (Score:4, Informative)
They used to be a British car company. They were basically bankrupt when they were bought out by a mainland CCP automotive manufacturer. Is anyone actually surprised that a commie piece of shit would have a fail state like this?
Re: (Score:2)
Probably a Lucas Electric (the Prince of Darkness) system.
Re:It was an MG ZS EV (Score:5, Informative)
I'd never heard of them.
MG was a British brand that failed so a Chinese manufacturer bought the brand [wikipedia.org] and has been selling their cars under it [wikipedia.org].
I did find it a bit odd how the summary avoided any mention of the brand, and even found a way to mention Musk whom, despite his many faults, has nothing to do with this car.
Re: (Score:3)
MG is an old British brand that went defunct and got picked up by SAIC. That's Shanghai Automotive Industry Corporation, one of the largest EV manufacturers in the world.
Their biggest claim to fame in the West is MG4. That's an EV that got EU legislators really freaked out, because it's an EV with decent range and performance that's about 25-35% cheaper than same feature set VW EV. And it's been getting glowing reviews everywhere for last year or so.
When you hear the moaning and whining about "Chinese dumpi
Re:It was an MG ZS EV (Score:5, Funny)
Sounds like in this market, the MG4 model will be unstoppable.
Re: (Score:3)
It has proven exceptionally successful in markets where it's been sold. Several European countries and Australia come to mind as examples.
Re: (Score:2)
The whistling noise overhead was a joke that you either missed or successfully ignored. No worries, I'm sure it'll be back around the block in a minute.
Re: (Score:2)
Hey, if they dump the Cyberster [mg.co.uk] here in America, I'll be a happy camper...
MGs are shit cars. (Score:2)
I had a petrol variant as a rental some weeks ago, the motor needed to be revved up pretty high to have at least a sense of accelerating, it was really fun to enter a german autobahn over the acceleration strip, which is normally not a problem even with small cars, this car had problems to accelerate past 85 km/h towards the end of the entry lane.
It had no navigation by android carplay/autoplay.
Halfway through the trip after changing from digital radio to FM radio, the radio wouldn't put out anything, even
Parking brakes aren't emergency brakes (Score:2)
And parking brakes would do absolutely NOTHING to stop the torque that can be put out by electric vehicles.
EVs also don't have clutches. Or transmissions.
Your understanding of EVs (well, lack of understanding) can be solved by about 5 minutes of watching any video on the Internet describing how EVs work.
Re: (Score:2)
Like almost all car brakes, parking brakes are either drums or discs. Their braking force is dependent on how much force is applied to the discs or drums.
If you pull on parking brake harder, it will brake harder. If you pull on it really hard, it will overpower the engine in pretty much any production car. If I recall correctly, that is in fact a requirement in most manufacturing in most nations for certification. Braking systems must be able to overpower the engine.
The main problem with potential runaway c
Re: (Score:3)
For my sins I was once a parking brake engineer. The technical term that went MIA was 'emergency brake'. From memory I think a reasonable hand effort (say 200N) was supposed to give 0.3g retardation. With the cluster fuck of a design I inherited anything close to that would bend or stretch various components so that a second application would come up against a hard limit and fail the test.
Re: (Score:2)
Probably, but with that sort of action, you only need to do it once. Then you're expected to give the system a full overhaul, because something failed really hard for you to need to use parking brake to stop the vehicle.
Re: (Score:2)
If you pull on parking brake harder, it will brake harder.
Pulling the little electrical switch for the fully electronic parking brake is going to apply it harder? Wow, I didn't realize switches work that way.
In any case, even with a mechanical brake lever, the parking brake is often on the rear brakes, or may even have its own pads, so the maximum braking available from the parking brakes is going to be much less than the regular brakes.
Nothing new for MG owners (Score:2)
Clicking through to the source article the vehicle in question is an MG. You can probably find similar stories from newspapers in the 1920s of MGs going rogue due to electrical system faults. Heck, you might be able to find stories from the 1920s of a prototype electric MG being unable to stop due to all the controls fusing and needing to be crashed to bring it to a halt. And in the 1930s, 1940s, 1950s... all the way to the early 1980s.
Re: (Score:2)
Cute apologia and all, but MG of that time has nothing to do with MG of today.
Today's MG is just the brand name purchased by SAIC.
Father Ted saved Dougal (Score:2)
Copy/Paste (Score:2)
This is what happens when you copy and paste all of your code.
--
"Be thou the rainbow in the storms of life." - Lord Byron
Hackers (Score:2)
Do the Chinese/Bulgarian/Nigerian/Bengali hackers use Stack Exchange posts of code to "backdoor" these systems?
Not long now until this is used for murder (Score:2)
There's a Peter F Hamilton novel where mercenaries override the electronics on a bunch of self-driving cars and use them as weapons.
This time it was an accident, next time it might not be.
Origins of the car (Score:5, Informative)
This is MG Europe. Brand wholly owned by SAIC.
For those unaware of what the name stands for, it's "Shanghai Automotive Industry Corporation". It's one of the biggest "new energy vehicle" manufacturers (PRC speak for electric cars).
This is probably Chinese QC gone wrong. Shit like this is not uncommon in Chinese automotive sector.
One World Government (Score:3)
This is going to be awesome for our global overlords.
They can drive you straight to the re-education camp gates!
Just hold the power button down (Score:2)
That shuts off all the other consumer electronics I own (phones, laptops, routers, etc).
Just remember: it's no longer a car; it's a computer with wheels (and windows, before anyone else replies with the obvious joke).
Nostalgia (Score:4, Informative)
Back when IC to EV conversions were a thing, it was a best practice to have a contactor separate to cut the high voltage feed from the main pack when you turned the key off. This served as a backup kill-switch in case the motor controller developed an emotional problem and started dumping current.
Maybe that idea is worth revisiting?
This far into the comments... (Score:2)
And not one person has said "Pop quiz, hotshot"?
No jumping into the police van... (Score:3)
The summary misreports TFA:
Mr Morrison said: "Eventually I came up to a roundabout which slowed the car down to about 15mph and the police van was waiting for me on the other side.
"I went into the back of the van while it was moving, before they put on the brakes to stop me.
''After that, a police officer jumped into my car and did something which seemed to keep the car still."
"Went into the back of..." means made contact w/ the back of the van here. Then the van put on the brakes to stop the car and then , once stopped, the police entered his car.
Re: (Score:3)
Re: (Score:3)
If the car slowed at a roundabout it sounds like some form of auto drive had been activated. Not sure about the MG, but our VW will keep a constant speed, stay in lane, and slow for traffic and roundabouts. I wonder if it actually made contact with the van or just sharply braked once it sensed the obstruction?
This is nonsense fear mongering (Score:3)
Re: (Score:3)
No, only new cars. Old cars are entirely mechanical.
Many cars even today have physical overrides that can be engaged to stop the car in the event of a runaway engine - like a mechanical gear selector which can be used to put the car into neutral.
Oblig... (Score:2)
I had an uncontrolled acceleration once (Score:3)
I was driving a plain old gas car years ago and the engine started racing. Nothing I did with the gas pedal could stop it. I was coming to a red light and had to put all of my weight on the brake pedal to keep it from going through the light. Putting it in neutral caused the engine to rev so high it was about to red line so I kept it in drive. I managed to work the brake to let it creep through the intersection and I pulled out at the first parking lot. When I was finally able to shut the engine off it just keep dieseling like mad. Fortunately there was an auto mechanic across the street and he came over to look at it and determined the throttle cable had become stuck. He just sprayed some cleaner into the cable housing and it was fine again and he didn't charge me for it.
I got rid of that car not soon after.
Re: (Score:2)
Re: (Score:2)
it destroys the breaker
Fine. I get to live. Breakers are (relatively) cheap.
With a runaway, 1000A load, I'd suspect that the EV is either accelerating violently. Or the motor/battery is on fire. Either way, fry the breaker. At 50 kmph steady state, I suspect that the motor is probably drawing tens of amps. Not a problem for most mechanical disconnects.
Perry Mason episode (Score:2)
This only happens when an unseen person takes diagonal cutters to the hydraulic lines.
Re: (Score:3)
If you watch JustRolledIn, you'll find a lot of examples of people having basically no brakes. Reasoning ranging from idiocy of "probably didn't know he needed to change brake pads since the car was new a decade ago" to "installed break lines wrong", "filled wrong kind of fluid as brake fluid and it corroded the system", etc, etc, etc.
The dumbest reason was installing the driver side mat wrong so that pedal couldn't be pressed more than a couple degrees. That was just fucked up level of stupid.
After seeing
Re: (Score:3)
In general, such electric brakes have been in existence for a very long time in things like amusement park rides and are exceptionally safe because of the mode of operation. The idea is that brakes are turned off when energized and full on when empty.
That means that if you cut off power to the system, braking system is in a "full on" mode and will stop rapidly. Then you just give operator a "big red button" (preferably under some kind of a plastic cover) to cut power in case of emergency.
Same principle as d
Re: Perry Mason episode (Score:3)
Usually its due to no maintenance.
But usually you can just you know turn off the car.
Re:Ran out of brakes... (Score:5, Insightful)
This isn't as uncommon as you think. Happens to traditional cars too when the breaks wear out....
Bullshit. Brake failure would not prevent you from removing your foot from the accelerator.
In this case the motor continued to propel the vehicle without his input
Re: (Score:3)
As for this MG, I understood that brakes were always designed to be able to overpower the motor on cars, even powerful cars, though my sources are from
Re: (Score:3)
This isn't as uncommon as you think. Happens to traditional cars too when the breaks wear out....
Bullshit. Brake failure would not prevent you from removing your foot from the accelerator.
In this case the motor continued to propel the vehicle without his input
Whilst that is physically true, a lot of modern cars are drive by wire, meaning what you physically do with the pedal can be disregarded by the control software, a la the Toyota unintended acceleration issue. As cars become more electronic, drivers become less connected to the experience and sensation of driving and drivers more dependent on aids (which are imperfect at best), this kind of even is going to happen more frequently.
I'm aware, before anyone chimes in, that this can also occur with a stuck WO
Re:Similar thing happened to a school bus (Score:5, Informative)
I call bullshit on this story.
Pneumatic brakes are failsafe. Air pressure holds the brakes off the rotors, not onto them. If there is no air pressure, the brakes do not release. If air pressure is lost, the brakes engage. If this were not the case, no vehicle with air brakes could ever park safely with the engine off. Every driver with an air brake endorsement should know this.
You cannot roll start a vehicle with air brakes. The engine must be started to generate enough pressure to release the brakes. The instant an air brake equipped vehicle shuts down, the brakes lose pressure and begin to apply. It's an intrinsically safe design.
Either that, or these buses were designed by world class idiots who somehow managed to circumvent all safety regulations.
Re: (Score:2)
Hah, I remember when I was very young and watching a movie with my Dad, there was a big rig that got the air brakes cut as indicated by the air lines blowing all over... The movie played it like the brakes quit working, and he ruined it by saying that the brakes would have seized as soon as the air line was cut. Thanks, Dad!
Re: (Score:2)
Yup. BS.
Re: Similar thing happened to a school bus (Score:2)
It happened in the 1990's and it may have been engine braking rather than pnuematic. The bus was probably built in the 80's. It was definitely blamed on the engine not running. I tried to find an article about it but it happened in the days before everything was on the Internet and there weren't any casualties so it wasn't big news.
Re: Similar thing happened to a school bus (Score:4, Informative)
Further to my other reply it seems that many older buses used "Air Brakes" and it sounds like they fail off. Here's an excerpt from a manual I found:
"Normal Braking
When the driver applies the foot brake, a plunger within the foot brake valve moves, opening channels within the valve that allow the air pressure waiting there to pass through and be delivered to the rear and front brake systems. The pressure quickly increases in the brake chambers and applies force to the push rod, transferring the force to the air disc brake (or via a slack adjuster, to a foundation drum brake). (See page 21 for more about
foundation brakes, and government-mandated stopping distances.) Frictional forces slow the wheels and the vehicle comes to a stop. When the brakes are released, the air in the brake chambers is quickly released, enabling the vehicle to drive away."
This is a system that relies on pressurised chambers. I think when the bus isn't running the chambers lose pressure.
As you pointed out modern buses probably don't use this.
Re: Similar thing happened to a school bus (Score:5, Informative)
Damn. I stand corrected. Air brakes were once that horribly designed. I'd love to know which vehicles this system was used on (for nerd reasons and to win arguments) - any chance you have a link?
Yeah, modern air brakes work completely opposite. If you've ever heard that distinct hissing when a truck or a bus comes to a stop, that's the vehicle activating the parking brake by releasing air pressure. I wonder how a parking brake would work on such a vehicle, assuming such a brake was more than just chocking the wheels.
BTW, thank you for your very logical and civil reply to my "I call BS" comment.
Re: (Score:2)
Generally, air brakes have been designed as you said, since the 19th century when they were introduced and mostly perfected for trains. Though I do wonder about the air reservoir and if that would keep the brakes off for long enough to jump start a vehicle.
As for the above quote, wonder if it was designed that way so the driver wouldn't need an air ticket.
Re: (Score:3)
Well it seems like the situation might be more complicated. I read more of the document I quoted above and it seems like normal braking works as the above but the parking brake uses a spring as you described. Assuming this bus had a similar system my best guess is driver was still able to disengage the parking brake but then unable to use the regular brakes or re-engage the parking brake once the bus was going too fast or stored pressure got too low.
I can only speculate about the model of brake and what did
Re: (Score:2)
Re: (Score:3)
Pneumatic brakes are failsafe
Large vehicle style air brakes are, on smaller vehicles, the brakes are hydraulic with a pneumatic vacuum assist so they still work but not nearly as well. If it was an older and smaller bus, it may well have been the latter.
Re: (Score:2)
You can always use the Chinese designation. New energy vehicle.