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Safety question: I would like a hard-wired override in case of computer failure/hacking

Discussion in 'Tesla, Inc.' started by Wado, Nov 24, 2019.

  1. Wado

    Wado Member

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    I have a question and I think its valid. Just let me say I really love my M3 and I have grown up with cars and bikes racing, selling, wrenching. I’ve owned a lot of vehicles and I’m not sure any have given me the level of excitement that the Tesla does.


    My question is about the automation in these cars. Many times, I’ve been in situations where something on a vehicle failed. A throttle sticking wide open or a cruise control module failing and causing a full throttle situation or many similar type situations. In the good old days, the fix was relatively simple. Everything was hard wired so you turn the key off, breaking the connection causing the motor to die or you could put the transmission in neutral, both take the power away and you are in control again. Is there any way in our cars to facilitate that kind of response? If you hit the breaks and it thinks the throttle is on will the computer just not allow the brakes? I know that an error occurs if the car thinks both are applied at the same time. The motor can overpower the brakes as proven by Toyota’s issues in the past. Will the computer stop you from putting the car in neutral while running down the road?


    I would like a hard-wired override of some type what do YOU think? Computers fail and computers get hacked, I’d like a way to put me in charge bypassing the computer if needed. Boeings MCAS is a classic example, at least they had a way to disengage it.
     
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  2. qdeathstar

    qdeathstar Active Member

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    The software will not over ride a break input. And i believe there is a mechanical connection between the break pedal and break. It wasn’t really practical to disable MCAS.... it took all of your energy and a long time and you are fighting an out fo control airplane.
     
  3. Wado

    Wado Member

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    I understand the MCAS I think, it was given far to much authority and could so rapidly put you in a bad place you just didn't have time to react. The fact that there was no redundancy in the system is beyond my imagination. Poor design poor implementation.
     
  4. cucubits

    cucubits Active Member

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    There's no "brake-by-wire" in the 3. If you press it brake, it will 100% of the time override any type of wanted or unwanted acceleration input.
     
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  5. Wado

    Wado Member

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    I believe the motors can easily overpower the brakes but good to know.
     
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  6. Chisale

    Chisale Member

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    I understand completely what you're getting at and it is a little unnerving. Especially with the possibility of the car getting hacked and completely taken over by an outside source. With physically geared cars if that happened you would always have the option of putting the car in neutral and braking the car to a stop. However, if someone took over a Tesla then you would be in a world of hurt. You'd like to think that the command to put the car in neutral would be on a separate command channel and still be able to activate in case of a take over or total malfunction of the main CPU. But I seriously doubt it is set up that way. I'd also like to hope that extreme measures have been put in place to prevent all all out hacking. If not, one day we could be going for one hell of a ride because the physical brake power is not going to overcome the acceleration power of these cars. At that point physically bailing out of the car might be your only option and you'll be happy those manual door handles are there.
     
  7. cucubits

    cucubits Active Member

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    What is the source of this assumption? I'd genuinely like to know if I'm wrong but I still believe the brakes will overpower the motors, even if all failsafes disappear and they go full speed on their own.
     
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  8. whatthe2

    whatthe2 Active Member

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    See post #722 in this thread Sudden Unexpected Acceleration today

    or any of @wk057 other posts on this matter.
     
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  9. Chisale

    Chisale Member

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    All I can remember is Car Talk had an episode about this once. And the consensus was that if applied when the car is stopped the brakes can overcome the start up power on practically any car made. But once it's going down the road at a good rate of speed, the answer was "it depends on the car". The problem as I see it is that when attempting to stop a moving wheel that is continually attempting to accelerate the brakes are going to heat up quickly. They are just not designed to function over long periods at high heat. Any trip in the mountains proves this. Now, I'm not an expert on Tesla brakes. Maybe they would be robust to do it. But that said, Teslas motors can generate a lot of power. I frankly don't know and am just guessing. I just know I wouldn't want to be on a public street conduct the experiment at that time.
     
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  10. Wado

    Wado Member

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    Look into the throttle issues that caused Toyota so much trouble and killed people. A Prius can over power brakes and they are anemic at best. CBS says that the throttle issues on the Toyota may have killed 89 people.
     
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  11. Tam

    Tam Well-Known Member

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    After the Toyota debacle, it has made sure that its brake always trumps the accelerator.

    For Tesla, you can test yourself: manual brake always wins over the accelerator too.

    There has been Tesla sudden acceleration lawsuit but the court dismissed it.

    That's why Tesla is implementing Nissan's one pedal driving so when in doubt, just lift all your feet up and the car would slow down to a stop.

    If you use TACC or Autopilot, you would notice by now that the automation uses physical pedal as well because you can feel and see the physical brake pedal automatically is applied and released on its own (pretty much the same way as the automation physically steer the steering wheel as well.)

    So, if you are hacked, just use your physical brake pedal to brake!

    Your concern is valid with future Robotaxi with no steering wheel and no pedals at all.

    But as long as Tesla has a physical steering wheel and pedals, the concern is not valid.
     
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  12. drtimhill

    drtimhill Active Member

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    #12 drtimhill, Nov 24, 2019
    Last edited: Nov 24, 2019
    This is certainly an issue that is perhaps more apparent on a Tesla, which has so many more automated systems. But its pretty much everywhere now, including ICE care. Many (most) modern "gas pedals" are drive-by-wire inputs to a computer, and increasingly the transmission selector is another such switch that just tells the computer what you want. The ignition is also push-button, so cutting off the engine is also harder. Pretty much the only systems that remain physically manual are brakes (not breaks, btw!), but as others have noted, the engines/motors are powerful enough to overcome these.

    However, to be fair the systems are still designed with safety a priority, and it takes a perfect storm of failures for something really bad to happen. Do such things happen? Of course they do, but nothing is 100% safe .. and statistically speaking you are still in FAR more danger when you walk down a simple flight of stairs.

    The MCAS tragedy will (I think) ultimately come down to a management failure. Boeing go out of the way to build safe airplanes. So they never crash. So when engineers raise an issue to management about MCAS (as they clearly did), management responds "Dont be silly, our airplanes never crash .. look at the statistics!". So the very safety culture that made airplanes safe in the first place is used as an argument against worrying about making them safe. Other examples include federal meat inspections, which are frequently defunded by congress "because no-one gets food poisoning any more!" (because the meat-inspection process works!).
     
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  13. holmgang

    holmgang Active Member

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    Pretty sure every single car in production today with 400hp+ are throttle by wire, and brakes are still all hydraulic-driven.

    So if you have this worry with Tesla, you should have the same worry about every other car.
     
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  14. DopeGhoti

    DopeGhoti Active Member

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    Teslas also have several redundant means to fail-safe:

    * If any of the various means to read accelerator input diverge, abort
    * If any of the accelerator inputs fail to max voltage, abort
    * If accelerator and brake pressure is simultaneously noted, ignore accelerator input
    * As mentioned, the brake is a physical mechanism, while there is no throttle to "stick open".
     
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  15. Az_Rael

    Az_Rael Supporting Member

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    If you are concerned, you can practice putting the car in neutral at speed.
     
  16. cucubits

    cucubits Active Member

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    Side question, putting a Tesla in neutral at speed, disables regenerative braking and just lets you coast?

    Is this also working in the 3? From what I've heard there's a sort of failsafe which won't let the car roll in neutral.
     
  17. Knightshade

    Knightshade Well-Known Member

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    yeah- those didn't actually happen.

    The folks killed in the Lexus died because:

    A) They had an SUV floor mat in a sedan so it cause the gas pedal to physically be stuck. Nothing at all to do with the electronics.

    AND

    B) The driver apparently didn't know how to turn the car off

    C)... or put the car in neutral...

    D) ...or properly use the brakes (which initially could easily have overpowered the engine- it was only after his repeatedly heating them by applying and letting off that they were unable to)


    Change any of those 4 things and nobody dies.

    None of them were Toyota (lexus)fault.

    A) was the fault of the DEALER who put the wrong floor mat in though.


    Nope. That runaway Prius thing turned out to be a hoax.


    Government documents prove "Runaway Prius" was a hoax


    "may have"

    And they said that in 2010.

    After a couple years of investigation by basically everybody- including NASA- turns out that wasn't actually true.

    The Department of Transportation reported in 2011 that the only causes for SUA were pedal misapplication and wrong mats.

    The cars' event data recorders showed application of accelerator pedal and no application of brake pedal. NASA was unable to replicate engine control failure as well.

    Turns out just as every other case in the past the issue of a car accelerating was always due to pushing the accelerator

    Either from entangled mats or confused drivers. Not electronics problems.

    Now- there WAS a "sticky pedal" recall where there could be a physical not electronic problem with the pedal in some cars... AFAIK there were only 3 incidents actually reported, and 0 deaths from them though.
     
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  18. Joshan

    Joshan Member

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    My 100+ car wash's disagree with you.
     
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  19. Az_Rael

    Az_Rael Supporting Member

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    The failsafe is at low speeds if you don't have your seatbelt on and you shift your weight in the seat.
     
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  20. lolder

    lolder Member

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    There is no such thing as a uncommanded wide open throttle in modern drive- by- wire-throttle cars. There has not been one proven instance except the floor mat jammed Lexus. No fault has ever been found by scientific investigative agencies. Ignorant juries in the US may have made awards. The brakes of all cars are several times more powerful than the motors. All recent cars close the throttle when the brake is pressed.
     

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