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First look at Tesla's FSD Beta 8! (2020.48.12.15) - 4:45 - teslatrey
scottf200
Well-Known Member
I added 'custom' colors to the table that match the picture. I used this online tool to get the HTML/HEX code which I used in Google Sheets. HTH
https://imagecolorpicker.com/en/
Great information in Chucks original video and in the two posts above. This is going deep into the weeds but I'd be curious to know what speed the Tesla would have to go to get to a safe spot just before completing the left turn (as shown by the green X). Here is the question rephrased: Per the @scottf200 chart above using the B pillar maximum distance the Tesla has between 2.9 and 3.3 seconds with cross traffic at 60 or 50 MPH to get to the 'safe spot' (distance needs to be calculated @Dan D.I added 'custom' colors to the table that match the picture. I used this online tool to get the HTML/HEX code which I used in Google Sheets. HTH
https://imagecolorpicker.com/en/
). With that available time what average speed does the Tesla have to go to reach the safe spot.Here is why I ask: If the Tesla has to average 50 MPH for that short distance it simply won't happen. If it only has to go 10 MPH that leaves a good cushion to get there safely at say 20MPH +/- average (allowing for accel/decel).
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Great information in Chucks original video and in the two posts above. This is going deep into the weeds but I'd be curious to know what speed the Tesla would have to go to get to a safe spot just before completing the left turn (as shown by the green X). Here is the question rephrased: Per the @scottf200 chart above using the B pillar maximum distance the Tesla has between 2.9 and 3.3 seconds with cross traffic at 60 or 50 MPH to get to the 'safe spot' (distance needs to be calculated @Dan D.
Here is why I ask: If the Tesla has to average 50 MPH for that short distance it simply won't happen. If it only has to go 10 MPH that leaves a good cushion to get there safely at say 20MPH +/- average (allowing for accel/decel).
Distance is ~21.6m = ~70.9ft
Assume car is going to stop in the safe spot to wait for a merging opportunity (worst case)
Assume constant acceleration at 2.9/2 seconds then constant deceleration at 2.9/2 seconds to make it simple.
Speed from rest to 70.9/2 ft in 2.9/2 seconds is 48.9 ft/s == 33.3mph
Acceleration from rest to 33.3mph in 1.45 seconds is 0.72g. Deceleration is also 0.72g
Any errors please let me know.
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If we use a Model Y maximum acceleration of 0-60mph in 4.8s, that's ~0.57g. Assume acceleration is roughly linear over that range. 0-33mph would also be 0.57g
Other models have faster 0-60 times. Not sure how aggressive FSD would be, probably a significantly lower amount than full out acceleration.
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DanCar
Active Member
I agree that FSD would probably not be that aggressive. That would seem to make this a true problem intersection for a left turn.
[FSD Beta 8] Second Drive Night View - 11:47 - Tesla Owners Silicon Valley
** Very routine drive. **
** Very routine drive. **
EVNow
Well-Known Member
Too high.
G Force for Tesla Model 3 Performance (0-60mph) and other Models | Tesla Motors Club
V= Vi+at
Vi=0
a=V/t = (26.82 m/s) / 3.5s= 7.66 m/s^2
7.66/9.8 ~ -0.78g
But many people report they get 3.3. In that case,
8.13 m/s^2
8.13/9.8 ~ 0.83 g
83% of free fall acceleration is pretty impressive! Of course, it is no match against Model S at 2.28s, which gives 1.2g, faster than the free fall. That is just brutal!
For those who owns AWD and RWD, it turns out 0.61g (4.5s) and 0.54g (5.1s), respectively
Model S 75D/90D (4.2s) gets 0.65g. So AWD Model 3 and Model 75D/90D would be roughly feeling the similar acceleration. And Performance 3 and P85D (3.2s) may also be similar acceleration.
And finally, the Roadster 2020(1.9s) will get 1.44g. Speechless.
Ofcourse, 60 mph cross traffic is uncommon - and where it is common (rural areas), traffic is low.Vi=0
a=V/t = (26.82 m/s) / 3.5s= 7.66 m/s^2
7.66/9.8 ~ -0.78g
But many people report they get 3.3. In that case,
8.13 m/s^2
8.13/9.8 ~ 0.83 g
83% of free fall acceleration is pretty impressive! Of course, it is no match against Model S at 2.28s, which gives 1.2g, faster than the free fall. That is just brutal!
For those who owns AWD and RWD, it turns out 0.61g (4.5s) and 0.54g (5.1s), respectively
Model S 75D/90D (4.2s) gets 0.65g. So AWD Model 3 and Model 75D/90D would be roughly feeling the similar acceleration. And Performance 3 and P85D (3.2s) may also be similar acceleration.
And finally, the Roadster 2020(1.9s) will get 1.44g. Speechless.
If my numbers are correct, then it does not seem possible to clear the intersection in 2.9 seconds.
Another question might be: how far does a camera or person have to look to make the turn safely? If you're going to mosey across the intersection you're gonna need a lot of time. Most drivers give it a decent kick on the accelerator. Probably the best use of a car's power to clear this kind of hazard quickly.
I'm gonna say you'll need to look at least 1.5x or 120m if you're maxing out the car, much farther if you're going slower. Certainly FSD needs to be more aggressive, but then it also needs to be absolutely correct and not go at the wrong time.
That stretch of road has a 45mph limit. Of course it's the speeding cars that are gonna hurt the most. Crossing highways is worse, even if it has an unobstructed view the B pillar camera still has a listed 80m range.
EVNow
Well-Known Member
What happens after 80m ?
We can't clearly make out much at a distance, but we can guess a car is coming ...
EVNow
Well-Known Member
The car would have to learn to recognize such crossings and try a different route.
scottf200
Well-Known Member
Uncommon may depend on where you live. I was surprised to until they Joshua Brown (RIP) incident (and a TM3 one later) that there are many highways that have entry points like that (Yes, I know JB was on the highway and the truck entered from 90 degree in this example). Imagine a Tesla FSD car needing to get on the highway from a 90 degree stopsign entry point. Tesla Autopilot fatal crash with truck is under investigation, preliminary report released - Electrek
Really great question since without understanding how objects further away then 80 meters can or cannot be handled by FSD determines how we view the problem.
If the car is 81 or 85 or 90 meters away one assumes there will be reduced FSD functionality but how much and what are the safety implications?
FSD Beta 8: First Impressions Part 1: To Whole Foods and Trader Joe's 2020.48.12.15 - 17:49 - Dave Mac
FSD Beta 7: Curvy Steep Road Hooes Part 2 - 3:25 - Dave Mac
** Note that this is beta7, not 8. **
** Note that this is beta7, not 8. **
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