Apparently the problem with the LED signs is that they are effectively pulsing and that combined with the camera frame rate means that they cannot be read. I may be wrong but I've seen suggestions that this will not work with the older cameras and will need new cameras. As an IT guy, I would be hopeful that software technology can overcome the issue and make it work. These types of signs must surely be used in the USA so I'd be curious to know what happens there. FSD could surely not succeed if LED signs could not be read.................
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Tesla Software updates - Australia
- Thread starter Grenadine
- Start date
I have no idea how the car decides what to use. Today I drove past a roadworks 40 sign which the car recognised and displayed on the screen animation. Yet the car still thought the speed limit was 70.
At least we are the same as Europe (50Hz) and not some unique frequency whereas FSD is currently in North America (60Hz). Differences like this will likely impact what the cameras can detect and make the FSD rollout to the rest of the world harder.
Of course, they currently have the cameras able to detect our 50 Hz LED traffic lights (Traffic Light and Stop Sign Control), so it shouldn't be insurmountable.
However, there is a lot of difference between a traffic light and a speed sign. Red/Orange/Green blocks of LEDs in defined spots is a lot easier than a speed sign. But that aside, I am not sure I understand why LED speed signs would be pulsating at all; unless they PWM (Pulse Width Modulate) them in order to control the brightness depending upon the weather. But I really don't know anything about the LED speed signs other than I've been told that they pulse and that is the problem depending upon when they are caught in a frame.
From an article about the new cameras in "Not a Tesla App":
"More importantly, the new sensor will also support LED flicker mitigation. Camera sensors often have a hard time capturing the light emitted from LED lights in a constant fashion. Since LEDs are widely used in electronic signs and traffic lights this will be an important feature and should make it easier for Tesla to interpret such signs.
The following article (from 2020) is of interest and implies this issue affects multiple systems:
Last edited:
I thought it was reading the electronic signs on Rosanna Rd.. Now I think it goes back to 60 when I cross the intersection from GPS then back to 40 when it sees the sign 40km 7am-7pm 
Annoying as speed camera there which get you at 60km after 7pm at it beeps at 40km a few times then stops.
Also was on autopilot along the Western Ring road it dropped to 70km I took over.. Wondered how.. Then did it again..
Reading the signs on the off ramp
Annoying as speed camera there which get you at 60km after 7pm at it beeps at 40km a few times then stops.
Also was on autopilot along the Western Ring road it dropped to 70km I took over.. Wondered how.. Then did it again..
Reading the signs on the off ramp
This is exactly it, they do use PWM to control the brightness. I don't think it's in response to the weather though - just to achieve the brightness they want.
NeilA
Member
That would concur with my experience, thanks.
Occasionally, I see other LED signs through onw of the cars cameras, and they strobe badly, and I think that is the root of the problem in reading LED speed signs - the camera's frame rates are insufficient to resolve the content clearly.
yes & no - the sign probably runs in separate segments - turning each section on for short periods - so you would need to composite several frames together to read it.
raynewman
Active Member
When I was at TMC in 2015, I spoke to a Tesla Software developer who said they were working on the LED sign problem.
I would have thought they would have fixed it by now.
I suspect it might be too hard with 1.2Mpixel cameras, speed sign often being a small percentage of the frame size, individual LEDs combined with pixellation, limited frame rate, shutter speeds, LED PWM rates up to 200Hz et al. If that proves to be the case, then it might develop into an "interesting" situation for all of us with the "old" cameras.
The link I provided above has another link (below) to a paper discussing the whole situation from the perspective of the various jurisdictions responsible for signage. In Australia (of course..) there are no standards. There are also multiple (at least 12) providers of signs and they are all different with different character shapes, LED shapes, variations in colour and brightness and different frames around them. The list seems endless. However it is good to see that Oz and NZ are doing some work to try and improve signs so as to be more consistent and readable by ADAS systems. As to when our cars (and those of other manufacturers) here in Australia can reliably read all electronic signs- I predict it will be a LONG time yet.
The link I provided above has another link (below) to a paper discussing the whole situation from the perspective of the various jurisdictions responsible for signage. In Australia (of course..) there are no standards. There are also multiple (at least 12) providers of signs and they are all different with different character shapes, LED shapes, variations in colour and brightness and different frames around them. The list seems endless. However it is good to see that Oz and NZ are doing some work to try and improve signs so as to be more consistent and readable by ADAS systems. As to when our cars (and those of other manufacturers) here in Australia can reliably read all electronic signs- I predict it will be a LONG time yet.
There is no connection between the frequency of the AC voltage supply in a country and the pulsation rate of LED lights.
LEDs operate off DC power, not AC, and they rate they pulse at is totally up to the designer. Typically rates between about 300 Hz and 1 kHz are used. They use PWM on LEDs to control the brightness and also to reduce power consumption.
Totally correct and as the studies have shown, there is a further complexity in that the sign designers can and do also multiplex between sections of the sign, often at a fast rate. So that if you were to video them at an extremely (and impractical) frame rate, you might (also depending upon the shutter speed) see only a few LEDs on in a particular section of any particular frame. Most if not all of these electronic signs were designed for human eyes rather than electronic reading. I think it is a major problem and not at all easily solved.
I've just been reading an article by a Motoring Editor about Kia and Hyundai cars misreading signs and incessantly bleeping the driver if 1 km/hr (non configurable) over the incorrectly detected speed limit. Always on by default and takes several menu levels to turn off. I experienced exactly the same 18 months ago when I had a top of the line Kia ICE car as a loaner for a couple of months. This plus the wandering in the lane drove me nuts (the lane-keeping could not be turned off permanently. It turned on again automatically every time you started the car. )
The article I quoted suggested that some manufacturers take three successive frames and merge them in an attempt to "anti LED flicker" and detect the speed sign. However, I can see how one could still easily "luck out" and only detect some of the LEDs. Perhaps it is not surprising that Tesla has not solved the issue after 8yrs (according to raynewman), particularly given the cameras they are trying to use.
On a more positive note, as of the latest firmware release, my car SEEMS to have stopped detecting the 40 signs on the back of Sydney buses!
Probably the easiest option is to add an infrared illuminator that broadcasts the speed in a computer-readable code. CCD cameras can see infrared but it's pretty much invisible to human eyes.
I mean from the point of view of Austroads, who presumably care about more ADAS systems than just Tesla FSD.
Zoltrix77
Member
I must be the only one that completely ignores the onscreen speed limit. I just do it the old fashioned way with my own eyes, its less taxing on my brain!
It’s usefull for when on a street and not sure what the limit is, particularly in Adelaide where main roads can be 60, 50, or 40 and for some distance.I must be the only one that completely ignores the onscreen speed limit. I just do it the old fashioned way with my own eyes, its less taxing on my brain!
Similar threads
