Adaptive Cruise Control (experience post FW v6.1)

[anxman]

I've been using TACC for about 600-700 miles so far with mostly good results but had a problem tonight. In general, I echo a lot of the other posts on the forum where I would prefer the braking to start much earlier. I'd like the braking to start as soon as anything breaks the set following distance in the forward lane or breaks a cone within 1/2-1/4 of a car length to the left and right lanes of the car.

Basically, I was driving home on 101N around 6:30PM in the second lane from the left (4 lane highway). My following distance was set to 3 and we were traveling at about 45mph. Heavy traffic all around. A taxi cab merged in front of me from the left lane and decelerated from about 45mph to 28mph very hard. I took control of the car to decelerate it manually by slamming on the brakes and I narrowly avoided a collision. I believe that the 250-300ms of delay in the TACC braking system would have caused a collision that was avoidable if I hadn't taken over.

So, this is a good reminder, TACC should be used under ideal conditions but keep an eye on it!

 

[Saghost]

2-300 milliseconds is also typical human reaction time - after which you have to move your foot to the brake pedal and press it. If the system saw the event at the same time you did and reacts in 250-300 milliseconds, it would already be braking hard before you hit the pedal.

 

[anxman]

Drivers' Brake Reaction Times . It looks like mean human driver reaction times are as high as 900ms so your statement could certainly be accurate.

 

[anxman]

I think I found a possible answer to the scenario that I encountered above and maybe gives us some insight into how autopilot is going to be rolled out.

I was re-watching this video: Tesla S P85D Model - Worlds First Auto Pilot Car - YouTube

If you go to ~7:40 into the video, Elon Musk is talking about the 4-part autopilot system:

1) Forward long-range radar (in my experience with TACC, I'd estimate this to be as much as 150-200 feet)
2) Image recognition camera
3) 360 ultrasonic sonar at all speeds (0-155mph): Detects objects in blind spot detection, highway barriers, etc.
4) Navigation GPS and traffic data

So, in the 6.1 firmware, I am inferring that (1), (2), and (4) have been enabled but (3) has not been enabled because the vehicle has no active blindspot detection currently. Also, if the drawings in the video are roughly to scale, then I believe that the Model S did NOT detect my close encounter with the taxicab last night because the taxicab was almost completely outside of the cone of the radar and camera. TACC enabled with the 360 sonar could be especially reliable.

For the curious, there's good videos on the competing gold standard in active safety features from Mercedes. Here's one: PRE-SAFE and DISTRONIC PLUS Vehicle Safety Technology -- Mercedes-Benz 2013 ML-Class - YouTube

 

[stevezzzz]

I made my first road trip in the P85D today, and I have one major complaint with TACC: when the radar gets iced up it takes down the entire cruise control capability. Earlier VINs that don't include forward-looking radar still have standard cruise control: why can't mine?

 

[Andyw2100]

I made my first road trip in the P85D today, and I have one major complaint with TACC: when the radar gets iced up it takes down the entire cruise control capability. Earlier VINs that don't include forward-looking radar still have standard cruise control: why can't mine?

It can do a lot more than just take out the cruise control. It can take out all the driver assistance features. (See my thread here for the details. Cruise Control unavailable, with a twist (loss of all driver assistance features too)) And if it does take out the driver assistance features, it might take quite some doing to get them back. It happened to me, and another poster in the thread I referenced, and engineering wanted both of us to bring our cars in for service to be re-calibrated when the systems wouldn't re-calibrate themselves. The other poster's car corrected itself faster than mine did. Mine took almost 24 hours and several restarts and about 80-100 miles after the radar unit was cleared of ice before the error message went away.

 

[Saghost]

I made my first road trip in the P85D today, and I have one major complaint with TACC: when the radar gets iced up it takes down the entire cruise control capability. Earlier VINs that don't include forward-looking radar still have standard cruise control: why can't mine?

If a driver thinks the car has adaptive cruise and the car is actually using a conventional blind cruise, accidents happen.

In principle Tesla could allow the conventional cruise with some sort of acknowledgement to hit on the center console and/or a big warning on the instrument cluster, but if the situation is rare and Tesla is planning to make it not happen they probably won't take the time to develop such a fallback plan.
Walter

 

[EarlyAdopter]

If a driver thinks the car has adaptive cruise and the cat is actually using a conventional blind cruise, accidents happen.

So true...

 

[Todd Burch]

When I'm following a car with TACC and a car merges into my lane in front of me (perhaps going the same speed as me or only slightly slower), I would prefer the car to coast (zero power, zero regen) in order to adjust and increase following distance again. Currently it uses regen (sometimes somewhat strong regen), which is inefficient and increases potential for me to be rear-ended from behind. So whenever the speed differential between the car in front and myself is small, coasting should be sufficient to fix things. Currently the system is in too much of a "hurry" to fix the distance, so abrupt regen is used.

 

[Andyw2100]

When I'm following a car with TACC and a car merges into my lane in front of me (perhaps going the same speed as me or only slightly slower), I would prefer the car to coast (zero power, zero regen) in order to adjust and increase following distance again. Currently it uses regen (sometimes somewhat strong regen), which is inefficient and increases potential for me to be rear-ended from behind. So whenever the speed differential between the car in front and myself is small, coasting should be sufficient to fix things. Currently the system is in too much of a "hurry" to fix the distance, so abrupt regen is used.

Yes.

This could be a feature in the efficiency-priority TACC mode that Tesla will hopefully implement at some point. The first day TACC came out I pointed out the need for an efficiency-priority TACC mode and a proximity-priority TACC mode. What we have now is the latter. The car is trying too hard to stay too close to the target car. By that I mean the car tries too hard never to "lose" the target. In the hypothetical efficiency-priority TACC mode, minimizing energy usage would be the primary goal, and if target cars were lost, so be it. Another target car will come along. Coasting in the situation described above is a perfect example of something that would be added in the efficiency-priority TACC mode. And of course the user would decide which mode they would prefer to drive in.

 

[Saghost]

So true...

View attachment 70868

I like the picture. I try to proofread, but posting on the phone I have problems with the Swype keyboard grabbing the wrong word from time to time.

 

[Todd Burch]

I posted this in the other TACC-related thread, but today--on two separate occasions--while driving through a tunnel the TACC abruptly shut off and displayed a "cruise not available" message. I was a long ways (maybe 150 ft) behind the car in front of me going about 60mph, and nothing happened that would have caused the system to stop. (No cars cut over, no debris crossed the car's path, etc.) it seemed to be related to driving in a tunnel. At any rate, I reported the incident using the car's bug reporting system.

I REALLY dislike the car going into full-on regen mode when the cruise shuts off.

Very unsafe. Aside from the embarrassment of the car abruptly slowing and the brake lights going on for no reason, had someone been tailgating me they could have rear-ended me.

Edit: for those curious, after the first incident I rebooted the driver's display and cruise functionality came back. The second time, I didn't reboot but tried a few minutes later and it was working again--so not sure what it really takes to restore cruise.

Also, I washed the car really well last night so the sensors were all clean...no inclement weather (sunny day).

 

[wk057]

My biggest issue with the TACC being disabled is that it fully kills cruise control. Aside from that I can deal with whatever else it does that is silly.

 

[billarnett]

I have been wondering what TACC would do if the vehicle immediately in front is a motorcycle. Well, it turns out it works perfectly, just like it does with a car. The one I followed was a medium size street bike so it's still possible it might not work with a moped or a scooter. But I'm guessing it will.

 

[wayner]

The TACC sensor was designed by somehow who has never seen snow. Yesterday I was driving in snow and cleared it several times but it was obstructed again within five minutes. Tesla should do a retrofit on existing vehicles to put a convex lens (and they should change the design on new vehicles)- the current concave design is very poor thinking.

Is there an email address at Tesla to report issues like the poor design of the sensor and the uselessness of the wiper heater?

 

[andrewket]

The TACC sensor was designed by somehow who has never seen snow. Yesterday I was driving in snow and cleared it several times but it was obstructed again within five minutes. Tesla should do a retrofit on existing vehicles to put a convex lens (and they should change the design on new vehicles)- the current concave design is very poor thinking.

Is there an email address at Tesla to report issues like the poor design of the sensor and the uselessness of the wiper heater?

I agree, a convex lens/design would make far more sense.

 

[Andyw2100]

The TACC sensor was designed by somehow who has never seen snow. Yesterday I was driving in snow and cleared it several times but it was obstructed again within five minutes. Tesla should do a retrofit on existing vehicles to put a convex lens (and they should change the design on new vehicles)- the current concave design is very poor thinking.

Is there an email address at Tesla to report issues like the poor design of the sensor and the uselessness of the wiper heater?

I agree, a convex lens/design would make far more sense.

Please take a quick picture when your radar unit is obstructed before you clear it and then later post the picture in this thread: Pictures of radar unit obstructed: please post yours

Please keep the discussion of the issue to the thread referenced in the first post in that thread, as it would be best to keep that thread for pictures only.

 

[stevezzzz]

I was following a Jeep pulling a small flatbed trailer, with TACC on, when we arrived at a stop light. The car had no problem slowing as the Jeep slowed, but at the last moment I realized that the car had no knowledge of the trailer, and had to slam on the brakes to avoid a collision. The point I stopped was just outside the parking sensors' range; I crept a little closer and did get the parking sensor warnings.

Bottom line: TACC's not perfect. Anybody have a good email address to report this to Tesla? I think they should be able to change the algorithms to include this scenario.

 

[Saghost]

I was following a Jeep pulling a small flatbed trailer, with TACC on, when we arrived at a stop light. The car had no problem slowing as the Jeep slowed, but at the last moment I realized that the car had no knowledge of the trailer, and had to slam on the brakes to avoid a collision. The point I stopped was just outside the parking sensors' range; I crept a little closer and did get the parking sensor warnings.

Bottom line: TACC's not perfect. Anybody have a good email address to report this to Tesla? I think they should be able to change the algorithms to include this scenario.

View attachment 74810

Huh. I would have thought the radar would have no problem seeing the trailer.

 

[wk057]

I was following a Jeep pulling a small flatbed trailer, with TACC on, when we arrived at a stop light. The car had no problem slowing as the Jeep slowed, but at the last moment I realized that the car had no knowledge of the trailer, and had to slam on the brakes to avoid a collision. The point I stopped was just outside the parking sensors' range; I crept a little closer and did get the parking sensor warnings.

Bottom line: TACC's not perfect. Anybody have a good email address to report this to Tesla? I think they should be able to change the algorithms to include this scenario.

View attachment 74810

I had a similar experience once, and I noted that the trailer's tail lights were not operational. The tail lights on the trailer in front of you do not appear to be functional in that image. Image recognition appears to be a huge part of the TACC/Autopilot setup. I'm surprised the radar didn't recognize the trailer, however, since it has for me on several similar occasions so far more often than not with even smaller trailers. I think the common element with the time it didn't would be the tail lights.