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Autonomous DeLorean drives sideways to move forward

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Re: Autonomous DeLorean drives sideways to move forward

#171

Post by HeWhoLurksLate »

Digit-Al wrote: post #120
devit wrote: post #103

Doesn't this sort of movement cause a lot of wear on the tires, thus making it unsuitable for routine use?

It's not supposed to be for routine use. The idea is that if the car gets into a situation where stability is lost it will know how to handle it. As an example, imagine an autonomous car is going around a bend and hits a large patch of black ice and goes into a slide. Current systems will struggle to handle the car and it could result in a crash. With this knowledge added the car will know how to handle slides and wi…

This is exactly right.

Recently, I drove a big 4WD SUV at about 5 mph onto ice in the middle of a 90 degree turn and lost traction in the front, and instead of doing anything helpful, the system decided the thing to do was engage the parking brake, which instead of stopping the vehicle put it into a slide, and almost got damaged because of it- when the vehicle stopped, it was less than half an inch away from a big transformer box in the front and less than 5 inches away from a concrete pole on the passenger's side.

I think I honestly could have done better without traction control than the stupid stutter-stutter click slide that came with it in that situation.

Re: Autonomous DeLorean drives sideways to move forward

#172

Post by sap9433 »

btbuildem wrote: post #145
sap9433 wrote: post #135

If self-driving tech has become so advanced, I wonder why Waymo is not delivering anything? I wonder why is Tesla taking forever to deliver self-driving, why Uber discontinued its self-driving program, Why Apple ain't serious about Apple car yet? Does this demo hide something that we should know?

I think in this demo they simply paint a path for the car to follow. The cones etc are there just to help us see whether it's following the path well. If there was a cone in the middle of the path, it would've run right over it.

Adaptive cruise control with stop and go can understand surrounding and knows when to stop and go. With that if I add paint path as this demo then self driving should work. But in reality it ain't. So There is something else which seems like too hard to solve problem with self driving . I want to know what is that

Re: Autonomous DeLorean drives sideways to move forward

#173

Post by HeWhoLurksLate »

zzzeek wrote: post #130
toss1 wrote: post #124

Earlier quoted context omitted.

Yes, but. Yes #1 is that this is mostly Drifting techniques, which are mostly for show/style competition. The tyre slip angles mentioned are around 40deg, far past the optimal level of grip. Yes #2 Racing techniques are more explicitly seeking to optimize for maximum grip, often found around 3 to 6 degree slip angles (depending on tyres, tyre pressure, tread & road temps, road cleanliness, dryness, etc.). Both still…

> BUT, all that said, it is absolutely critical to have thise techniques in your bag of tricks, available to use when something exceptional happens. In those rare-ish events, being able to use the full performance envelope of the vehicle is a real life saver, both for you and the others nearby. are you referring to during a road race, or ordinary driving on ordinary streets? It would be great if you could try to prov…

not me, but my father's experience here:

He was on the way home from something in the winter with a sedan fully loaded with his friends, when a semi truck in the leftmost lane of a three-lane highway lost control of the trailer and it went sideways across traffic. He was in the rightmost lane and avoided crashing into the semi trailer by sliding his car into the concrete barrier and driving sideways on it, thus evading the semi trailer and saving him and his closest friends from what would've been serious injury and possible fatalities.

Driving sideways on walls is not good for vehicles- that stunt totaled the vehicle- every single body panel was damaged, the wheel rims were all toast, and the vehicle's frame and structure was not in good shape afterwards- but it did deposit its passengers on the other side of the trailer in one piece.

If my dad hadn't broken the rules he did- driving in the shoulder, driving with two wheels on the ground, pulling a handbrake on the highway, and excessively accelerating, he would likely not be around today.

Once when I was driving, I took a left-hand (cross-traffic) turn and a vehicle in the oncoming lane decided to speed up instead of slow down. If I hadn't stomped the accelerator pedal and burnt rubber, I would've had my first accident on my second day on the road.

This isn't to say that most of the stuff that people do is good, or smart- but performance envelopes of vehicles- how fast you can go from 0-60, 60-GTFO, and whatever speed you're going to dead stop matter quite a bit- not for normal driving, but for when it isn't normal anymore.

Speaking of which, my dad also once chased a driver who rear-ended someone and sped off to get his license plate number before he could escape- he hit about 120mph chasing the person across traffic long enough to memorize their plate number and make/model.

Re: Autonomous DeLorean drives sideways to move forward

#174

Post by tempestn »

HeWhoLurksLate wrote: post #170
dharmab wrote: post #143

Earlier quoted context omitted.

Modern traction control systems available on production cars and motorcycles have a polling rate of up to 1000Hz. You don't need self driving tech to handle most low traction situations. Black ice is an exception because once you start sliding on it there is not much you can do to regain control except ride it out and hope you don't hit anything before you get out of the ice.

My mouse has a 1000Hz polling rate. Is 1000Hz really good enough for excellent traction control? I'm sure it's fine for most situations, but the small amount that it's not good for are probably the ones that matter the most.

I expect you could turn your mouse's polling rate down to 200Hz and not notice any difference, even gaming. Also, a mouse is a very precise control; much more so than the controls of a car. I could certainly be wrong, but my intuition suggests that a 1000Hz sensor polling rate would be fine for an autonomous vehicle.

Re: Autonomous DeLorean drives sideways to move forward

#175

Post by Too »

bborud wrote: post #86
Neil44 wrote: post #64

Earlier quoted context omitted.

Steer and brake by wire is a safety thing, all manufacturers so far have kept a mechanical link in place despite electric assistance because of the potential for lawsuits. Infinity has gone the closest to full steer by wire so far that I’m aware of.

Well, a very key factor of steering is that it connects your fingers to the interface between tyres and road surface and imparts critical information about what’s going on there. If you decouple the steering completely from the mechanical bits you have to recreate that channel of information. Which isn’t necessarily easy to get right. Even servo assisted steering systems can easily become a bit numb. If you have ever…

I’ve heard steer by wire can have faster feedback than pure mechanical systems. Even a mechanical steering has lag in cogs and there is never 100% stiffness in the steering column, etc.

Re: Autonomous DeLorean drives sideways to move forward

#176

Post by Hamuko »

grecy wrote: post #74
danielh wrote: post #69

Earlier quoted context omitted.

Elon Musk claimed in a tweet that the roadster can beat a time of 6:44 min on the Nürburgring Nordschleife, which is (currently) 20.832 km long. The current lap record for street legal cars is 6:40 set by a Porsche GT2RS MR. The overall record is 5:19.55 set by a Porsche 919 Evo. F1 last raced the Nordschleife in the 70s. The lap record is 7:06.4, but the track was 22.835 km long back then. The Roadster might have a…

Don't forget the 2020 roadster will actually have rocket boosters. (Elon has given his word on this more than once)

Elon also gave me his word that Vernon Unsworth is a peadophile, so maybe not.

Re: Autonomous DeLorean drives sideways to move forward

#177

Post by tripzilch »

Retric wrote: post #165
wongarsu wrote: post #113

Earlier quoted context omitted.

Which is still just path finding: estimate travel time for each segment, use travel time instead of distance as edge cost. Don't take that as a dismissal of Google maps: it's the most impressive path finder I know, working with high performance over long distances, taking into account real time information, and calculating meaningful alternative routes to choose from. It's an impressive piece of technology that actua…

Gathering data is required to do travel estimates. If Google was using handset data to update congestion information, it would want to send a percentage of users down sub optimal routes to verify they are sub optimal.

I would be very upset if they did this, though. I'm not Google's test subject and it would be pretty f%$#@! dehumanizing if they treated me that way.

I'm not a bloody ant or part of their hyper-organism.

Re: Autonomous DeLorean drives sideways to move forward

#178

Post by tsimionescu »

Too wrote: post #175
bborud wrote: post #86

Earlier quoted context omitted.

Well, a very key factor of steering is that it connects your fingers to the interface between tyres and road surface and imparts critical information about what’s going on there. If you decouple the steering completely from the mechanical bits you have to recreate that channel of information. Which isn’t necessarily easy to get right. Even servo assisted steering systems can easily become a bit numb. If you have ever…

I’ve heard steer by wire can have faster feedback than pure mechanical systems. Even a mechanical steering has lag in cogs and there is never 100% stiffness in the steering column, etc.

I think the poster above wasn't talkng about input lag, but about the fact that the steering wheel acts as both input and output - you control the car through it, but you also get back information on the state of the car on the ad. If your motion was simply interpreted by computer, you would lose that information; so you in fact need a two way system, that reads your inputs and controls the car, but also reads the state of the car on the road and conveys that information to you.

Sort of like how gaming driving peripherals added force feedback to make the controls more intuitive.

Re: Autonomous DeLorean drives sideways to move forward

#179

Post by zzzeek »

Hamuko wrote: post #157
zzzeek wrote: post #130

Earlier quoted context omitted.

> BUT, all that said, it is absolutely critical to have thise techniques in your bag of tricks, available to use when something exceptional happens. In those rare-ish events, being able to use the full performance envelope of the vehicle is a real life saver, both for you and the others nearby. are you referring to during a road race, or ordinary driving on ordinary streets? It would be great if you could try to prov…

> I've never heard of accidents being avoided on highways because someone knew how to do racecar drifting. Knowing how to control oversteer is a crucial skill when driving on snow and ice.

this is very different from intentional racecar drifting. I can oversteer in snow without having racing school training.

Re: Autonomous DeLorean drives sideways to move forward

#180

Post by zzzeek »

toss1 wrote: post #140
zzzeek wrote: post #130

Earlier quoted context omitted.

> BUT, all that said, it is absolutely critical to have thise techniques in your bag of tricks, available to use when something exceptional happens. In those rare-ish events, being able to use the full performance envelope of the vehicle is a real life saver, both for you and the others nearby. are you referring to during a road race, or ordinary driving on ordinary streets? It would be great if you could try to prov…

Just to clarify here, I'm talking about driving on the edge of available grip, NOT the wholesale sideways drifting tech - that is mostly for show. Of course, in road racing, these skills are critical multiple times per lap. On the street - there are still too many examples to list from direct personal experience. Long trips, find myself in a severe snowstorm, or an ice storm where it's too slippery to even stand, car…

great, knowing how to oversteer at low speeds in snow, of course we all need to know that and yes with my current Subaru it's hardly something that really happens anyway, the scariest thing that has happened with that car was a sudden whiteout where I had to cross down a hill that ended at a red light, for which cars weren't even able to stand still on said hill due to slipperyness. I basically plotted a course to what embankment I would use to break the movement in case I kept slipping but the Subaru was able to stop.

Overall I was curious if you were suggesting I'd need to go to racing school and learn drifting in order to keep my family safe. thanks for clarifying.

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