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Speed limit detection problems

ZeeDoktor

Member
Dec 3, 2019
174
308
Sydney
Hi all,

I've driven about 2500km now, most of it with autopilot engaged and encountered several issues chiefly to do with speed limit detection. It appears that my brand new 2020 Model S Performance simply does not read speed limits from camera input. I've driven through a dozen roadworks zones where the limit was clearly signposted as 80km/h (down from 110 or 100km/h) and not in a single instance did it recognise it. All of those roadworks signs were analog signs, i.e. no LED signs which might not be legible by the camera because of frame rate chopping.

While using navigate on autopilot I've encountered some far worse issues: The car suddenly thinks the limit is 40km/h (in a 100km/h) zone - it shows 40km/h limit on the dash - and breaks abruptly. Rear-ending almost ensued on that one! While in the Lane Cove tunnel in Sydney (80km/h limit) it suddenly slowed to 60km/h showing the corresponding limit. It seemed to think I was not in the tunnel but on streets above. The problem corrected itself after exiting from the tunnel. On the map however it did show me correctly as being on the M2 heading towards Sydney.

This kind of stuff is worthy of reporting to Tesla, however, they don't seem to have a technical fault report email address where I could provide them with exact date/time stamps and video footage. Does anybody know how to get in touch with them?

On the upside, the autosteer has worked flawlessly so far. The only places it gets confused are places where I get confused also. The markings for the time of day dependent lane switches in the Sydney Harbour Bridge area are nothing short of criminally negligent - I've never understood how they get away with that.
 

Twiddle

Member
Nov 9, 2019
9
5
Sydney
The cars don't read speed limit signs from the cameras, they read the speed limit from built in maps (I've read the maps used are openstreetmap - not sure if its verified however). Hence road works are too temporary to make it in to a map update.
 

conman

Active Member
Aug 19, 2017
1,436
2,131
Melbourne, Australia
As others have said, there is no speed sign/limit detection in current autopilot hardware and software. It currently works off a limited database of what the road speed limits are, and limiting it to the expected speed limit is also not complete, but further limited to only high traffic areas, and only with autosteer enabled (where it will say something like autosteer limited to 60km/h in a 60 zone.)
 

ZeeDoktor

Member
Dec 3, 2019
174
308
Sydney
Thanks all for your replies. If that is true, and speed detection is purely from a database, then we're a loooong way away from FSD! Speed limit detection based on posted road signs is not only a trivial AI problem compared to obstacle detection and avoidance, it's implemented in most competitors vehicles who only implement an embarrassing subset of intelligent features otherwise! e.g. Toyota/Lexus/Subaru who will adapt cruise control speed from said AI system but won't auto start from a full stop in bumper to bumper traffic (which infuriated me to the point of wanting to burn the car), or Mercedes/Audi who do the same, but on top of that tell you when you're too tired to drive, so they are wasting time developing driver monitoring solutions instead of putting those resources into taking that arduous task off our hands. Or my absolute favourite: cars who disable a seemingly random subset of adjustments and features based on whether the wheels are turning or not - yet are intelligent enough to know whether someone is sitting in the passenger seat or not for seatbelt warnings. I like Tesla's "are you a passenger" question.
 
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ZeeDoktor

Member
Dec 3, 2019
174
308
Sydney
surprised to hear that an AI vision problem can be patented! Just goes to show how inadequate patent law is for today's technology.
 
Nov 23, 2018
77
43
Gold Coast, Australia
Regarding 'seemed to think I was on the streets above' comment, I was told that 'Australia doesn't have good GPS due to the lack of satellites' and thats why this happens. I have no idea if thats true or not but this happens to me all the time on regular roads when not in a tunnel.
 

ZeeDoktor

Member
Dec 3, 2019
174
308
Sydney
@petergarret38 the number of satellites is the same as everywhere else on the planet, GPS satellites are in a medium earth orbit a few thousand km above ground, and they remain visible for a few hours each. Coverage varies to the same degree everywhere. We don't have any atmospheric water vapour corrections in Australia however, something that is available in the continental US. This system is called WAAS (wide area augmentation system) and keeps track of water vapour induced path delays on the GPS signals, and feeds that information back to the satellites who in turn will then let your receiver know what those delays are, allowing it to correct for the signal delays. It improves accuracy by a fair bit to usually < 1.0m position error. Wide Area Augmentation System - Wikipedia explains how that works. It was implemented so GPS can be used more reliably for instrument approaches in aircraft. But now of course finds many uses on the ground.
 

aegidius

Member
Aug 27, 2018
389
279
Brisbane
AP1 cars read speed signs. Sometimes they conflict with the speed limit according to the map. In that case, the signs seem to take priority. However, signs that have extra stuff too close to the red circle (like roadwork signs, or "80 ahead" signs) can be missed.
 

Fantomsss

Member
Mar 14, 2019
122
94
Sydney
AP1 uses MobileEye technology which is patented. Pretty much everyone else on the market pays them ransom but Elon refused and advancing the good cause!
 

moemoke

Member
Oct 10, 2014
179
48
Moe, Victoria, Australia
On my daily drive to work through a small country town they have fitted new speed limit signs and road marking, the red circle and limit
is on a much larger green sign, on the road they have 2 lines about 1m apart with cross lines for about 20m each side of the sign.
I wonder if this is to make speed signs recognizable by FSD etc.
Anyone else seen this new signage?
 

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