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I’m curious: how do you do ABS without software control? Is there a mechanical way to detect lockup and pump the brakes?
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May 31, 2018 19:13
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Subjunctive posted:I’m curious: how do you do ABS without software control? Is there a mechanical way to detect lockup and pump the brakes? Yes, purely hardware electronic works as well. There's even purely mechanical anti-lock systems for old trains.
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May 31, 2018 19:23
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Subjunctive posted:I’m curious: how do you do ABS without software control? Is there a mechanical way to detect lockup and pump the brakes? Large airplanes have had anti-skid brakes since like the 1940s and they work by using a mechanical modulator. Basically a weighted flywheel that applies the brakes when the wheel is spinning, but if it stops rotating the weights come back in and open the hydraulic circuit. It's neat. It can only really be set up for one particular kind of behavior, but that's fine on a plane because most of your landings should have a very similar braking profile. Don't know if any cars ever did that and they certainly don't now. Electronic ABS is much more flexible. The problem I see here is that usually ABS is a self-contained unit with its own microcontroller and it will continue to work even if the rest of your computers crap out. We've seen from the FCA hacks what a bad idea it is to link the infotainment system to the control computers, but that's what Tesla (and undoubtedly more and more manufacturers these days) do in order to enable OTA updates to the brakes. What happens if a hacker inserts a logic bomb that makes your brake valves lock open the next time you exceed 70mph?
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May 31, 2018 19:24
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Subjunctive posted:I’m curious: how do you do ABS without software control? Is there a mechanical way to detect lockup and pump the brakes? There are tons of ways to do logic without software. They amount to analog computers, using stuff like pneumatic pressure instead of voltage and actual physical gates instead of transistors.
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May 31, 2018 19:27
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bawfuls posted:This is already a thing, though it’s not super cheap it is manageable for enthusiasts. I know. Too expensive even in the US, which means it's way too expensive in my country. Also a tedious process of reregistering the whole vehicle as an EV, which means passing pretty thorough inspections and getting certificates that prove the electrics is up to professional standards. I'm willing to jump through the hoops, but not getting ruined in the process. A man can dream though.
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May 31, 2018 20:07
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MrOnBicycle posted:I know. Too expensive even in the US, which means it's way too expensive in my country. Also a tedious process of reregistering the whole vehicle as an EV, which means passing pretty thorough inspections and getting certificates that prove the electrics is up to professional standards. I'm willing to jump through the hoops, but not getting ruined in the process. A man can dream though. Here's some nicer examples: https://www.youtube.com/watch?v=osKEOiZ31zA https://www.youtube.com/watch?v=BmDyK4Dyu-E https://www.youtube.com/watch?v=AJLdzRJdKrs (skip to ~12 minutes for donuts and burnouts): https://www.youtube.com/watch?v=TIZ5IEWk2iM Registering as EV depends on where you are, but here in CA it's not that difficult. Just need to get it inspected once by a state-approved inspector and then the registration is changed within the DMV to EV for good, and you're thereafter exempt from smog emissions testing. Here's a guy in Ireland attempting a conversion for 1000 euros (far from his first conversion though): https://www.youtube.com/watch?v=nkg8Rk-aP4U 300hp/300 ft.lbs out of a salvaged Leaf power train in a CRX: https://www.youtube.com/watch?v=d_r_HKV_ZgQ bawfuls fucked around with this message at 20:32 on May 31, 2018 |
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May 31, 2018 20:19
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It'd be neat if someone really optimized a conversion kit for a car that's stupid cheap and pretty much universally available. Like an early 2000s ford focus. Engine condition doesn't matter. Buy a bunch of em for a grand each, convert them, put in some modern niceties like an Android auto/apple car play compatible receiver, backup sensors and camera. So many commuters don't care about their car except that it works reliably, blows cold air, and plays music off their phone. I know I'm day dreaming here, but the combination of reusing old stuff and getting gas cars off the road is getting me all  .
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May 31, 2018 21:01
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You must live in the south. Anything early 2000s around here is likely going to need body work and some structural suspension work either already or soon due to corrosion. Cars are disposable and the power plant isn't the issue.
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May 31, 2018 21:20
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Powershift posted:Is the e-brake in a model 3 in a menu on the touchscreen? lol If it is I haven’t found it. If you press and hold the Park button, the car will apply brakes to a stop and hold them. (IIRC, I haven’t read that section of the manual in awhile.)
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May 31, 2018 21:21
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MrYenko posted:If it is I haven’t found it. If you press and hold the Park button, the car will apply brakes to a stop and hold them. (IIRC, I haven’t read that section of the manual in awhile.) That’s how it works on the S.
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May 31, 2018 21:25
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The S also has one under Settings - Controls - E-brake & power off, probably a similarly named menu on the 3.
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May 31, 2018 21:28
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RZA Encryption posted:It'd be neat if someone really optimized a conversion kit for a car that's stupid cheap and pretty much universally available. This is a great idea but I sincerely doubt it’d happen as you’d have to rely on conversion companies for the average schmoe (and the conversion companies will charge you out the rear end). Even if you were to buy the cars up yourself and set up an assembly line of sorts for the “refurbished” cars, you’d still have to battle ignorance and a general fear of all things EV. I’ve been at my job for 2 years almost and I still have coworkers who are confused by the presence of an EV motorcycle design that’s almost been around for a decade at this point. People also are shocked to hear that the i3 in the family can keep up in traffic on the highway. I hate to say it but we’re all a bunch a cutting-edge super-nerds here when it comes to transportation, and your average driver is now just coming to understand how wagons are a good idea, they’re just doing it wrong by lifting them sky-high for some dumb reason. Goddamn what I’d do for a solid man-tran EV Setup for my R55 Mini, though. 
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May 31, 2018 21:29
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Ripoff posted:...People also are shocked to hear that the i3 in the family can keep up in traffic on the highway. .. When people ask about my Volt, after the obligatory first "How far?" question, the second is always "Isn't it slow?". Even my own mother asked "Why would you buy something you can't drive on the highway?" Though given that no one selling EVs of any type does any sort of marketing, it is not surprising.
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May 31, 2018 21:39
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Sagebrush posted:Large airplanes have had anti-skid brakes since like the 1940s and they work by using a mechanical modulator. Basically a weighted flywheel that applies the brakes when the wheel is spinning, but if it stops rotating the weights come back in and open the hydraulic circuit. It's neat. It can only really be set up for one particular kind of behavior, but that's fine on a plane because most of your landings should have a very similar braking profile. FW on newer modules is thankfully signed / encrypted now in much the same fashion as mobile phones / consoles / etc, which is nice. It makes the insertion of said type of logic bomb much more difficult. Any sane FW update process I would hope uses a common A/B approach where interrupted/corrupted/etc. FW updates have no effect on the status quo functionality of the system. The new image has to be verified before being switched active. It doesn't save you if the new image has a bug in it that locks valves open, but that's what your regression / validation testing is for. Ola posted:It isn't really that amazing. It relies on few inputs, it does fairly basic calculations, has very simple outputs and it makes no decisions. When it correctly detects errors, it just sounds a warning and gives up. When it fails to detect errors, it can kill everyone on board, as has happened multiple times. It completely ignores the traffic around it and it will happily fly into a mountain if you tell it to. All of this is ok because it is operated in a very controlled environment with rigorous external controls. An autonomous car is the opposite. Complex calculations, constantly adapting to traffic around it and operated by a total moron who would not notice if a wheel was about to fall off. Regarding redundancies for a truly autonomous vehicle, it must have those implemented in some fashion. Whether it's duplicating a sensor or ensuring a combination of other sensors can make up for the lost input long enough to safe the vehicle, it can't count on a person helping out, because they're dumb or not even in the vehicle (truly autonomous cargo trucks or similar wouldn't even need a person). The regulatory environment had better enforce this type of reliability standard. drgitlin posted:Everyone is designing redundant hardware, and that’s been a recommendation in every version of the DoT AV guidance so far. GM has an executive position that is responsible for cybersecurity efforts. However, there's also knee-jerk reactions like "encrypt everything" that results in CAN traffic for the driver seat control module being encrypted to protect your precious memory seats  . It's good the thought is being given, though it does little for vehicles on the road already. Most of those vehicles remain "safe" simply by being air-gapped, honestly.
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May 31, 2018 22:00
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RZA Encryption posted:It'd be neat if someone really optimized a conversion kit for a car that's stupid cheap and pretty much universally available. Like an early 2000s ford focus. Engine condition doesn't matter. Buy a bunch of em for a grand each, convert them, put in some modern niceties like an Android auto/apple car play compatible receiver, backup sensors and camera. So many commuters don't care about their car except that it works reliably, blows cold air, and plays music off their phone. I know I'm day dreaming here, but the combination of reusing old stuff and getting gas cars off the road is getting me all Ripoff posted:Goddamn what I’d do for a solid man-tran EV Setup for my R55 Mini, though.
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May 31, 2018 22:27
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Dang.quote:California’s electric utility companies will spend nearly $768 million on charging infrastructure for electric cars, trucks and buses, under a series of proposals approved Thursday by state regulators. https://www.sfchronicle.com/business/article/Energy-revolution-California-approves-massive-12957685.php
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May 31, 2018 22:27
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Does the 2018 Nissan Leaf (the 150 mile range one) have proper battery thermal management now? Or do I need to wait for the 2019 model for that?
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May 31, 2018 22:43
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2019. And then, wait a little longer for the 60kwh battery. That's what I'm waiting to see right now.
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May 31, 2018 22:49
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FistEnergy posted:2019. And then, wait a little longer for the 60kwh battery. That's what I'm waiting to see right now. Thanks. Any chance Nissan will release a re-branded ZOE in the USA as well?
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May 31, 2018 23:06
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Sagebrush posted:Of course as Ola points out a car is not quite in the same ballpark as an airliner, and even if you suddenly lost all control at freeway speeds you would probably just run off the road and skid/roll to a stop and there's a good chance you'd survive. But given the, uh, level of polish we've seen on Tesla software to this point, what sort of backup systems have they got? That's actually one of the biggest criticisms of Tesla's self-driving program - where Waymo and GM have redundant computers and control systems, Tesla doesn't: https://arstechnica.com/cars/2018/01/why-analysts-put-gm-and-waymo-far-ahead-of-tesla-in-driverless-car-race/ Plus they have no real solution for keeping their cameras clean, meanwhile Waymo has had LIDAR wipers for about a year now: https://www.autoblog.com/2017/05/19/waymos-lidar-wipers-self-driving-cars-safer/
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Jun 1, 2018 03:35
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Cockmaster posted:That's actually one of the biggest criticisms of Tesla's self-driving program - where Waymo and GM have redundant computers and control systems, Tesla doesn't: I’m on my phone and apologies for the brevity of the post, but talking about redundancy for a second. Bit flips / single-event effects / single-event upsets are a big deal in space applications because ionizing radiation can impart sufficient energy transfer into silicon devices to potentially cause bits to change value / get stuck / a variety of other effects. We use ECC (usually SECDED) to mitigate against this, along with software mitigation’s like multiple copies of important structs in memory, voting, re-running calculations and other things, but it’s not perfect. Why I bring this up is as we dive into deep sub-micron technologies, SEEs/SEUs can and do occur on Earth in the abscence of ionizing radiation. At high altitudes (even including mountainous regions), FPGAs have been shown to take upsets and flips from neutrons. With the push towards using mobile-inspired chips like the Tegra and friends on their 16nm and smaller processes, it’s possible that they could be vulnerable to upsets in normal usage. L1 and L2 caches generally already feature parity as a simple form of protection. With normal usage patterns and running the probability of the specific bit being upset that causes something catastrophic to happen, the chances are admittedly tiny. For an airliner carrying 300 people, this is of concern and critical systems like engine FADECs will be redundant and hardened against such issues. For a car carrying a few occupants...may be acceptable risk, may not be. Lots of arguments to be made there. Bitsquatting was an interesting study that I think someone should pick up and run with. It essentially took popular domain names and flipped a few bits at random, such as aeazon.com instead of amazon.com. These garbage domains that had low chances of being from typos actually saw traffic over a period of time, skewed towards mobile devices. Whether these are from errors during transmission that were not corrected, “silent” flips in phones, who knows, but it’s interesting data. (http://dinaburg.org/bitsquatting.html) The trick question is being the person or organization that stamps their approval or not in having to worry about this type of failure / anomaly condition and then seeing if it ends up roasting anyone (and proving what caused it). Plenty of other failure methods exist as well that may push towards redundancy as a mitigation. This is of course independent of whether the car is ICE or EV. ADAS systems like those that control steering or ABS/ESP systems already utilize lockstep MCUs to achieve their ASIL or ISO 26262 qualifications for not killing people, but they are performing relatively simple computation compared to advanced neural nets / ML type stuff.
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Jun 1, 2018 06:31
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movax posted:For a car carrying a few occupants...may be acceptable risk, may not be. Lots of arguments to be made there. But practically, in order to not be unfairly crushed by irrational people and media outlets, a system needs to be pretty close to infallible.
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Jun 1, 2018 07:00
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roomforthetuna posted:Rationally, it should only have to be more reliable than human drivers, which have a failure rate much higher than the bitflip rate. True statement. I guess corporations are people though?
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Jun 1, 2018 07:23
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movax posted:FW on newer modules is thankfully signed / encrypted now in much the same fashion as mobile phones / consoles / etc, which is nice. It makes the insertion of said type of logic bomb much more difficult. GM even let me meet their red team last year; there’s been a sea change among the OEMs in the last 18 months because if you asked any of them about cybersecurity back then they’d all refuse to even comment. And sure, all of this is only really good news for new vehicles.
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Jun 1, 2018 11:45
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It feels wrong having went nearly 2 years without an oil change, or indeed any maintenance at all. 21k later I'm still at 31% oil life... Guess I need to go take advantage of one of my free oil changes before they expire 
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Jun 1, 2018 18:21
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Ola posted:Dang. As someone who bought a PHEV, this is amazing news. However, it doesn't tackle the real issue of neighberhoods of old houses with increased ev usage https://arstechnica.com/cars/2018/01/how-many-electric-cars-can-the-grid-take-depends-on-your-neighborhood/ and for completeness, ARS take on the same news. E: on the off chance someone has successfully done it, has anyone gotten their job to plop a EV stand in their parking lot? We've got two PHEV and a EV in the office and i'm sure more are to come. incoherent fucked around with this message at 01:00 on Jun 3, 2018 |
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Jun 3, 2018 00:58
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incoherent posted:As someone who bought a PHEV, this is amazing news. However, it doesn't tackle the real issue of neighberhoods of old houses with increased ev usage We have 20 at my office. But I work for an electric utility....
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Jun 3, 2018 01:02
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California, the state that has had insufficient-baseload brownouts in recent memory, is spending money on infrastructure to allow increased use of energy... Like, I’m all for it, but they’re missing a large part of the equation, because it’s not sexy or helping poor people.
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Jun 3, 2018 01:13
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But imagine if you could store energy in your car off-peak and sell it back onto the grid at peak. The excess capacity of your telsa could be sold to the state as a power bank. Or burned up mining bitcoin or whatever because nothing really matters.
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Jun 3, 2018 01:22
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MrYenko posted:California, the state that has had insufficient-baseload brownouts in recent memory, is spending money on infrastructure to allow increased use of energy...
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Jun 3, 2018 03:31
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incoherent posted:As someone who bought a PHEV, this is amazing news. However, it doesn't tackle the real issue of neighberhoods of old houses with increased ev usage Ars is not an acronym, please do not ALLCAPS. Thank you for reading we appreciate your visits. 
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Jun 3, 2018 03:31
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MrYenko posted:California, the state that has had insufficient-baseload brownouts in recent memory, is spending money on infrastructure to allow increased use of energy... Unless I'm missing some more recent history, and IIRC, the brownouts in the early 2000s were more related to deregulation of the energy market and energy companies doing some really shady poo poo so they could charge $$$.
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Jun 3, 2018 03:37
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drgitlin posted:Ars is not an acronym, please do not ALLCAPS. Thank you for reading we appreciate your visits. it's short for arse, amirite
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Jun 3, 2018 04:05
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Internet Explorer posted:Unless I'm missing some more recent history, and IIRC, the brownouts in the early 2000s were more related to deregulation of the energy market and energy companies doing some really shady poo poo so they could charge $$$. California was simultaneously delaying construction of new (more efficient) capacity while they capped retail energy prices, and deregulated wholesale energy markets. They were then surprised when the energy market got squiggly due to Enron (and others) gaming the wholesale commodity side of this atrociously broken system. Deregulation as-implemented was absolutely a mistake. It was “deregulation” written by the companies that stood to gain the most from it, with no actual market-forces to drive costs back down.
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Jun 3, 2018 13:54
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Powershift posted:it's short for arse, amirite Arse Technica sounds like a high-tech sex toy store. Come get your very own F.I.S.T.O.! Also, went to see the Clarity PHEV yesterday, decent car. The interior quality is much better than that of the Volt, it’s just a bit “Honda Boring” in its interior design, aside from the weird and wonderful little pass-through rear view window thing they have going to the back. Still much more interesting than the Accord, but I wish they’d fit the tech into the new Civic chassis instead and just kept that interior. The Volt’s got a better looking interior but still has that cheap plastic-y GM parts bin feel. The only thing about the Clarity I honestly didn’t like is that they said it’ll just kick the gas engine when accelerating with a full battery, while the Volt will keep the gas motor off until the last minute. Kinda defeats the purpose if it’s using the electric motors to augment the gas motor vs. actually behaving as a full EV.
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Jun 3, 2018 14:25
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The Volt has a lot of clever design features. I don't know for sure, but I think it's the best plugin hybrid out there, and if development continues to get skewed towards all electrics, it will remain so.
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Jun 3, 2018 14:56
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Ola posted:The Volt has a lot of clever design features. I don't know for sure, but I think it's the best plugin hybrid out there, and if development continues to get skewed towards all electrics, it will remain so. I’d give it serious consideration if I needed a new car; 0 gas around the city and then cheap tank fills to drive it out for hikes and camping. Plus, hatch! The Chevy badge bugs me but that’s because I’m an elitist rear end in a top hat (and what other nameplate would they have intro’d it as anyway, Pontiac or Saturn if they were still around? A new EV only nameplate?)
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Jun 3, 2018 21:59
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movax posted:I’d give it serious consideration if I needed a new car; 0 gas around the city and then cheap tank fills to drive it out for hikes and camping. Plus, hatch! The Chevy badge bugs me but that’s because I’m an elitist rear end in a top hat (and what other nameplate would they have intro’d it as anyway, Pontiac or Saturn if they were still around? A new EV only nameplate?) I was HUGELY anti-GM until I sat in the Volt and realized that they did a fantastic job with this car (at least the Premier). Check it out and swallow your pride, I think you will be satisfied with it. I did go fully loaded (minus Nav) though as the lower trim lines for GM are too cheap and spartan. That is likely my bias kicking back in but I did buy it so there's that.
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Jun 3, 2018 22:06
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movax posted:I’d give it serious consideration if I needed a new car; 0 gas around the city and then cheap tank fills to drive it out for hikes and camping. Plus, hatch! The Chevy badge bugs me but that’s because I’m an elitist rear end in a top hat (and what other nameplate would they have intro’d it as anyway, Pontiac or Saturn if they were still around? A new EV only nameplate?) I don't know which models you get in the US, but I really like the VW Passat GTE station wagon hybrid. Shorter EV range and perhaps less clever hybrid stuff, but with nice VW stuff.
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Jun 3, 2018 22:43
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Ola posted:The Volt has a lot of clever design features. I don't know for sure, but I think it's the best plugin hybrid out there, and if development continues to get skewed towards all electrics, it will remain so. I think part of this is that GM seemed to have designed it to be a EV first... instead of a ICE car with a electric motor tacked on as so many other PHEVs seem to be. It is also one of the few where the EV drivetrain is more powerful than the ICE drivetrain and also one the few that doesn’t have any compromises running in one mode or the other. The majority of PHEVs are the other way around, hence the Clarity using the ICE under heavy load, or having worse performance in EV only mode. I did a lot of research before buying my Volt. I was really surprised that such a great product came from GM. Couldn’t be more happier with my choice.
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Jun 3, 2018 23:31
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