Adaptive Cruise Control (experience post FW v6.1)

[stevezzzz]

No. Way. Jo. Se.

Because of the increased likelihood of inattention after a stop, I think it's way too dangerous to have automatic resume.

I'm advocating creep (and only if creep is On), not full resume. I do see your point.

- - - Updated - - -

How to we suggest improvements to Tesla?

I have it from a reliable source that Tesla's autopilot team reads this thread regularly for the real-world experience and suggestions.

 

[drsaab]

The way the BMW ACC works is after coming to a complete stop, if the car in front starts moving again within two or three seconds, ACC will stay active and automatically resume. After two or three seconds of a full stop, ACC turns off and requires re-activation with either accelerator pedal input or "resume" on the CC controls. There is a subtle indicator on the dash to show if it's active or not (green colored speed setting vs red colored).

The Tacc does that. It says cruise if it's going to resume speed on its own and will say hold if you need to press the accelerator to resume.

 

[drsaab]

So FYI. My Tacc not working was seat belt issue. Seems fine last 4 days after learning it does not work with seat belt off.

 

[MarcG]

So FYI. My Tacc not working was seat belt issue. Seems fine last 4 days after learning it does not work with seat belt off.

Ha so my wild guess was correct! ;-)
Glad to hear it wasn't any other issue.
Thanks for the update!

 

[ecarfan]

So FYI. My Tacc not working was seat belt issue. Seems fine last 4 days after learning it does not work with seat belt off.

Are you saying you were driving without your seatbelt connected and trying to get the TACC to engage and it would not? If so, glad to hear that Tesla made it work that way.

 

[MarcG]

Are you saying you were driving without your seatbelt connected and trying to get the TACC to engage and it would not? If so, glad to hear that Tesla made it work that way.

I think that scenario is right. In my case I was already cruising with my seatbelt attached, but at some point took it off to remove a layer, and TACC disabled right away with the "cruise not available" message.

 

[Andyw2100]

How to we suggest improvements to Tesla?

I'd like to have an option for TACC to be either more performance or more efficiency.

I notice with TACC that if traffic slows and speeds up a lot, that the Tesla launches to get back up to the cruise set speed.
I actually would prefer on longer trips to have it gently get back up to speed more efficiently.

Anyone else feel the TACC is less efficient?

Yes, it's definitely less efficient.

I've posted about this a couple of times. I believe below is what I had written most recently:

This is pretty much what I was getting at with a post I made the first day we were all using TACC when I suggested Tesla may want to tweak things by adding options to either maximize efficiency or maximize the proximity to the car being tracked. In the current mode, it is maximizing the proximity to the car being tracked, braking too hard and too late (for some of our tastes), and also accelerating too hard at times, in an attempt to stay close. Adding a "range optimizing TACC mode" would allow us to let the Model S drive more "normally", which would also be more efficiently, at the expense of "losing" the target car more frequently. People who love the TACC exactly as it is now would choose the proximity priority mode. People who think it is a little too aggressive would choose the range optimizing, more mellow TACC mode.

 

[MikeBur]

Yes, it's definitely less efficient.

I've posted about this a couple of times. I believe below is what I had written most recently:

+1 here. TACC is great, and I look forward to the additional functionality coming.

I too wish the aggressiveness of the following algorithm could be decreased to being more conservative and thereby smoother.

Freeway exits appear to be the most noticeable. Although the minority of times for longer journeys, without an option to have regular cruise mode this will likely become frequent. From a human perspective, I know what I am merging onto. Using gps/freeway data for exit ramps, I suspect the car could have better heuristics, eg freeway to freeway could attempt to maintain speed, and freeway to streets ( with a high probability of significant speed reduction) could benefit from more regen and less friction braking, by increasing the distance to car in front.
Add freeway, street, congestion data and this could be even better.

All would need to be conservative and deal with human drivers diving in front of the car.

 

[TTT]

Whoa, just got 6.1 update last night and tested TACC today. Slowed down as expected as I approached slower traffic and the alarms sounded and showed a graphic of a crashing car as someone pulled right into my lane andcutting me off. Kudos to Tesla, love the new update.

 

[stevezzzz]

I've been surprised (not in a good way) by the modal behavior of the cruise control stalk when interacting with TACC. The 'pull stalk and hold' action does different things depending on context, and it annoys me. For instance, sometimes PaH causes the set speed to change to the system's 'speed limit plus offset' value (the gray line on the speedo, displayed when TACC has a value for the current speed limit). But if TACC isn't currently engaged, pull-and-hold does nothing until you release the stalk, at which point it performs the Resume function (i.e., accelerating/decelerating to the previous set speed as denoted by the gray triangle on the speedo). I find having TACC accelerate to the previous set speed instead of the current 'speed limit plus offset' both surprising and objectionable, especially when the former is faster than the latter.

Seems to me that the pull-and-hold action should always do the same thing: it should engage TACC with a target of the current 'speed limit plus offset' value. If the system has no current knowledge of the speed limit, then it should do nothing, and maybe beep to acknowledge the input and to inform the driver that it can't honor the request. A quick pull-and-release of the stalk should initiate a Resume.

 

[Todd Burch]

Here's my feedback to Tesla after using TACC for a few days:

1) WAY too much use of the brakes. Way too much. Lots of situations where I see hydraulic braking engage when I still have plenty of regen available. Since I'd like my pads to last the life of the car and I dislike wasting energy, I currently disengage TACC when I see traffic slowing ahead of me. That kinda defeats the purpose of TACC.

2) Deceleration is way too late and too aggressive. My sphincter tightens almost every time I rely on TACC to brake for the car in front of me. I prefer not to feel like I'm going to rear end the person in front of me every time the car slows (my following distance is set to 5). The radar can clearly track cars to a much greater distance ahead. It should use up to full regen to match the deceleration rate of the car in front, then resort to hydraulic braking only if no more regen is available. And only allow the following distance to close once the cars have reached a lower speed.

Moreover the late deceleration increases the probability that the car behind me (which is almost certainly following too close) will rear-end me.

3) Acceleration is too timid after the car in front of you turns to an adjacent road or otherwise leaves your forward path. If I wait to let TACC do it, I feel like the car behind me is going to honk because it takes so long to get back up to speed.

It's possible that (3) exists because Tesla wants to thoroughly test their systems before they allow a little more immediate, slightly more aggressive acceleration.

 

[NoMoGas]

Here's my feedback to Tesla after using TACC for a few days:

1) WAY too much use of the brakes. Way too much. Lots of situations where I see hydraulic braking engage when I still have plenty of regen available. Since I'd like my pads to last the life of the car and I dislike wasting energy, I currently disengage TACC when I see traffic slowing ahead of me. That kinda defeats the purpose of TACC.

2) Deceleration is way too late and too aggressive. My sphincter tightens almost every time I rely on TACC to brake for the car in front of me. I prefer not to feel like I'm going to rear end the person in front of me every time the car slows (my following distance is set to 5). The radar can clearly track cars to a much greater distance ahead. It should use up to full regen to match the deceleration rate of the car in front, then resort to hydraulic braking only if no more regen is available. And only allow the following distance to close once the cars have reached a lower speed.

Moreover the late deceleration increases the probability that the car behind me (which is almost certainly following too close) will rear-end me.

3) Acceleration is too timid after the car in front of you turns to an adjacent road or otherwise leaves your forward path. If I wait to let TACC do it, I feel like the car behind me is going to honk because it takes so long to get back up to speed.

It's possible that (3) exists because Tesla wants to thoroughly test their systems before they allow a little more immediate, slightly more aggressive acceleration.

#2 just happened to me as my son rear ended me with another Tesla. Truth is it was his fault but yes it brakes unnecessarily aggressively like the Disney Tram. I would think the bigger concern is that in the event of a failure there simply would not be enough time for the driver to react and stop the car.

Also i agree with #3. Not sure if I'm with you on #1.

This is system is amazing but people do need to know it needs to be watched. Huge improvement and I have no doubt more tweaking is coming.

 

[EarlyAdopter]

Here's my feedback to Tesla after using TACC for a few days:

1) WAY too much use of the brakes. Way too much. Lots of situations where I see hydraulic braking engage when I still have plenty of regen available. Since I'd like my pads to last the life of the car and I dislike wasting energy, I currently disengage TACC when I see traffic slowing ahead of me. That kinda defeats the purpose of TACC.

2) Deceleration is way too late and too aggressive. My sphincter tightens almost every time I rely on TACC to brake for the car in front of me. I prefer not to feel like I'm going to rear end the person in front of me every time the car slows (my following distance is set to 5). The radar can clearly track cars to a much greater distance ahead. It should use up to full regen to match the deceleration rate of the car in front, then resort to hydraulic braking only if no more regen is available. And only allow the following distance to close once the cars have reached a lower speed.

Moreover the late deceleration increases the probability that the car behind me (which is almost certainly following too close) will rear-end me.

3) Acceleration is too timid after the car in front of you turns to an adjacent road or otherwise leaves your forward path. If I wait to let TACC do it, I feel like the car behind me is going to honk because it takes so long to get back up to speed.

It's possible that (3) exists because Tesla wants to thoroughly test their systems before they allow a little more immediate, slightly more aggressive acceleration.

I agree with all of this (and posted much the same earlier up-thread).

It's as if there's too much latency in the system currently, from sensing to acting. Car in front starts slowing down? Lag... lag... lag... oh, TACC needs to brake! Car in front starts accelerating? Lag... lag... lag... oh, TACC needs to get going!

 

[wk057]

So had my first actual problem with TACC today. Was cruising down a two lane ~45 MPH road using TACC. No cars in front of me. I've done this on this road several times since the update.

Out of no where the car decides its time to nearly slam the brakes and decel from ~50 to 25... fortunately no one was behind me...

There was nothing in the road nor anything I could think would have made it think it needed to stop quickly. Strange.

 

[Bet TSLA]

Strange.

So did you use the "Note" voice command to let Tesla know about it?

 

[wk057]

So did you use the "Note" voice command to let Tesla know about it?

I called the Tesla HQ 877 # and reported it.

 

[gzerninplatz]

One nice little feature of using TACC in stop-and-go in town is that on a slight incline, not enough to engage Hill Hold, you won't have to ride the brake until light changes or traffic moves, the car stays put....I used to pull up the parking brake in my Z3, just didn't like having to lean on the brake...

 

[ReversePolarity]

Haven't tried this one to its entirety, I was actually a little curious and tried to "break" the system:

Set TACC distance to 1 to follow the car ahead of me (this 1 distance is pretty far away as others mentioned).... manually pressed the accelerator to increase speed... triggered the collision warning... but I don't remember the car intervening or if its even supposed to intervene in the case of "imminent" collisions? Other feedbacks mirror what has been mentioned, the system is rough on the edges and need a bit of tunning. Quite a bit of accel/decel jerking, a lot more than say, if the driver were to press the accelerator manually. Good first release though, hope the next update comes soon

 

[wk057]

TACC seems to do nothing in terms of braking/slowing if you have your foot on the accelerator. This is pretty expected. I've been in the habit of overriding TACC when someone turns off the road or exits to another lane while the TACC is still tracking them (and usually slowing with them if I don't override) while no one is actually in front of me anymore.

 

[Andyw2100]

triggered the collision warning... but I don't remember the car intervening or if its even supposed to intervene in the case of "imminent" collisions?

The car is not yet supposed to intervene. For now it is just a collision warning system. At some point it is supposed to become a collision avoidance system, at which point the car will intervene.