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Autonomous DeLorean drives sideways to move forward

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Re: Autonomous DeLorean drives sideways to move forward

#71

Earlier quoted context omitted.

Another exception of a sort, and I believe the one this research is meant to address, is when the drift is initiated unintentionally. Say you hit a patch of black ice mid-corner, for example. This kind of work can expand the envelop of the control system to encompass these scenarios.

I don't think this is true. If you hit black ice and the tire skids, the problem is you just have no friction. Modern traction control systems already account for this as best they can - I don't see how this model would help any more except for trying to go faster through patches of black ice. And even then, drifting inherently requires traction in order to modulate the throttle and control the vehicle. If you can't…

The thing is: By the time the car has traction again it might have rotated around the up-axis. Getting back from that configuration do a less unstable configuration can very well improve if the car knows how to drift, especially how to go into the desired direction even before the drift has ended. Doing so would make the (result from the) initial lose of control on the black ice more limited and more controlled, hence less risky.

tl;dr. nothing you can do on the black ice. but if you have tracking again there might be faster and saver ways then "first stop drifting, second start driving in the correct direction".

Re: Autonomous DeLorean drives sideways to move forward

#72

Earlier quoted context omitted.

yeah but even then the autopilot need to adapt to the different conditions, it can't just throw the hands up when the conditions are hard and let the driver to crash on its own (at least the ideal full autonomous) so you need to have a "friction" (lateral and longitudinal) input to the model, so that the model forecasted car position matches the actual car future, to allow the autopilot to plan the correct avoidance…

You're assuming Autopilot can't currently account for losing traction (this is probably true). But unexpectedly hitting a patch of black ice won't favor one model over the other - in either case you'll use the same methods to slow down. The only difference would be if you also had to avoid an object some distance ahead, and the drift model helped you maneuver around it by applying the throttle. It's extremely difficu…

> contrive a scenario

pretty easy actually. car ahead swerve to avoid an obstacle. autopilot don't see the obstacle until the car ahead swerve. autopilot has to change lane to avoid obstacle.

if it has recently snow some lane will have different traction than others.

this is what happens on most of these pileup videos you see on youtube, so while not common (there are a handful a year after all) they aren't just hypoteticals

Re: Autonomous DeLorean drives sideways to move forward

#73

Earlier quoted context omitted.

You're assuming Autopilot can't currently account for losing traction (this is probably true). But unexpectedly hitting a patch of black ice won't favor one model over the other - in either case you'll use the same methods to slow down. The only difference would be if you also had to avoid an object some distance ahead, and the drift model helped you maneuver around it by applying the throttle. It's extremely difficu…

> contrive a scenario pretty easy actually. car ahead swerve to avoid an obstacle. autopilot don't see the obstacle until the car ahead swerve. autopilot has to change lane to avoid obstacle. if it has recently snow some lane will have different traction than others. this is what happens on most of these pileup videos you see on youtube, so while not common (there are a handful a year after all) they aren't just hypo…

You're right - I guess it's not that hard to imagine that scenario. But how would the car know which lanes have traction? If the car can reliably detect black ice it can avoid it without ever having to slip/skid.

Re: Autonomous DeLorean drives sideways to move forward

#74
post #69
post #55

I genuinely hope Tesla get a 2020 Roadster to lap the Nurburgring on autopiliot with nobody inside. If it lives up to promises, it will easily set the all time lap record as the fastest vehicle ever. It will be an interesting time when a $200k production car can whip the pants of a multi-million dollar F1 racecar.

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)

Re: Autonomous DeLorean drives sideways to move forward

#76
Don't get me wrong I think this is an impressive feat and I am always impressed to see universities pull off these kinds of complex system and control projects. Yet, there are a few things that I would like to mention.

The article says that the car does "doughnuts with inhuman precision" and they want to develop vehicles that can handle "emergency maneuvers or slippery surfaces like ice or snow". In this context, I feel this demo falls a bit short. The car can drive with superhuman precision, but it also gets superhuman capabilities like inch-precision localization (and an IMU is my guess) or superhuman steering wheel turning speeds. And the vehicle is heavily modified for this specific use-case. Drifting looks stable in the video but I really cannot judge how much easier it is with this car than a normal car. In addition, the asphalt also looks fresh and clean. I would like to see what happens if it suddenly encounters wet surfaces (or ice).

edit: typos

Re: Autonomous DeLorean drives sideways to move forward

#77
post #6

They did most of that back in 2015.[1] This is version 2. It's interesting what's happening as the control theory people get into machine learning. The controls people don't typically run a neural net as a controller. They use the trained net as a tool for building a controller with known continuity properties. The trouble with pure neural net controllers is that they sometimes do something totally bogus for some dat…

> "The trouble with pure neural net controllers is that they sometimes do something totally bogus for some data point within the normal input space." A friend's theory on Google Maps is that it sometimes intentionally sends you down a non-optimal path in order to gather data on alternate routes. This friend isn't in the ML space, so this is just their anecdotal observation. Are they right, then?

"Alternate routes" are still normal roads people travel on. Since the travel time of a path is just the sum of the travel time of all path segments you only need people traveling every road to estimate the total time of any path. Path finding is well understood with many algorithmic solutions, so there is no reason to use machine learning.

Google's implementation is impressive, but I see no reason why it would benefit from people traveling suboptimal paths.

Re: Autonomous DeLorean drives sideways to move forward

#78

Earlier quoted context omitted.

>They use the trained net as a tool for building a controller with known continuity properties. This sentence and comment is a revelation to me so thanks! I was very into control theory from 2001-2006 before jumping into Bayes nets and eventually ML. Having not really returned to CT since, it's always been a question in my mind how to use ML for SCADA & PLCs without running into the problems that you describe. As wit…

I would highly recommend https://www.youtube.com/watch?v=PYylPRX6z4Q as a way of framing the problem. It seems like our options for ML are currently: self-play, dataset fitting, or human feedback. It's possible to solve any problem that can fit into one of those molds. (Unfortunately the opposite is true: if a problem doesn't fit into those categories, it seems very hard to solve with any form of ML.) But, now that I…

Neural Networks are good at curve fitting which makes them useful for inference +- noise.

In control systems you need to do inference to predict feedback signals +- noise.

So you can use a neural network for that. Train it on input and feedback data from your samples.

Your control system still needs to account for predictability, smooth behaviour etc so you have the rest of your machinery to handle that.

This is not an end-to-end system though.

Anyone know if there are end-to-end deep learning controllers with guarantees on the output space?

Re: Autonomous DeLorean drives sideways to move forward

#79

Earlier quoted context omitted.

> contrive a scenario pretty easy actually. car ahead swerve to avoid an obstacle. autopilot don't see the obstacle until the car ahead swerve. autopilot has to change lane to avoid obstacle. if it has recently snow some lane will have different traction than others. this is what happens on most of these pileup videos you see on youtube, so while not common (there are a handful a year after all) they aren't just hypo…

You're right - I guess it's not that hard to imagine that scenario. But how would the car know which lanes have traction? If the car can reliably detect black ice it can avoid it without ever having to slip/skid.

yeah that the hard part, humans can't identify it visually, so car will probably be able to identify it only after it loses traction, reducing the margins significantly.

Re: Autonomous DeLorean drives sideways to move forward

#80
post #16

I guess if you can afford a DeLorean you can afford to keep replacing the tires you burn up by drifting on pavement. I'd rather have my car programmed for long tire life and high mpg please.

In the US, a new DeLorean isn't all that expensive compared to typical "jelly-bean" vehicles that are the most common. Back in 2005, I narrowed down a vehicle purchase decision to a new DeLorean, an used Lotus Elise or a new G coupe. I went with a bone-stock manual G that I kept for a few years before I got into Cold War-era West German and French vehicles. I'm not a rich person, far from it.

> a new DeLorean

They're still making them?

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