3 day old import P85D crashed while using TACC

[Coiled]

Cruise speed was set to 100km/h and around 50m left to collision I recognised the mistake, slammed the brakes, unfortunately to no avail

Based on the apparent speed of the collision and the car's stopping distance at 100km/h, I would guess the brakes were applied at a distance much less than 50m. Maybe more like 10-20m. The car can come to a full stop in about 33m (110ft).

In any case, thank you for sharing the story. Tesla should probably do more to make sure drivers are aware that TACC doesn't "see" stationary vehicles unless it locked onto them before they stopped. It's a serious and (for some) unexpected limitation of TACC. No one wants to see more incidents like this.

 

[JimmyAZ]

When tacc locks on to a moving car and that car steers around a stationary object, tacc assumes you will follow that car.
If there is a stationary object ahead, including dead head, tacc assumes you will steer around it. Do that, or apply the brakes yourself.

Lesson to give in deliveries.

What is your reasoning behind this? Not that I don't believe you! The analyst in me is very curious because I've experienced the car stopping itself behind stationary objects.

 

[bhzmark]

Fair point. I've experienced that too, although I wonder if it wasn't because it briefly sensed the car ahead was moving and so locked on and then did come to a stop behind the locked on car. Maybe it only does that. Maybe it can additionally sense a car that is at a dead stop even without having previously sensed it moving and locked on. That is not consistent enough to be reliable.

By using the camera it might be able to improve detection that that's a car in a lane and there's no other options to go around it and so you must stop behind it.

 

[ck1116]

I guess some people probably mixed up Adaptive Cruise Control with Auto Pilot or Autonomous Car.

Original Cruise Control only help you keep the car moving in constant speed in straight line, not turning or braking. Adaptive only make the constant speed slower or faster, not the emergency braking.

Auto emergency braking or keep in lane are safety features.
But cruise control, no matter adaptive or not, is a convenient feature. They are 2 complete different things.

 

[Khatsalano]

Emir, can we get a picture of the front of the car before the crash with the license plate on? I am sure your friend has one ... we all do because we can't stop photographing the thing as soon as we take delivery.

- K

 

[Blu Zap]

Emir, so sorry to hear about this. It is all of our worst nightmares! Thankfully your wife, child and you are all okay. Wow! I think the primary forward detection for the TACC would be the radar mounted in the lower grill. Sensors in the nose cone that may/could have been blocked by a license plate are only good for a meter or so when parking. So was the radar properly operative would be my first point of inspection. Between TACC and collision avoidance that should not have happened. My personal experience with my P85+ AutoPilot equipped has specifically alerted me if not stopped the car.

Complicated as you acquired it through the Netherlands and a local "dealer". Please keep us posted on the outcome. Good luck with it all. Best wishes.

BTW, your photos do show how well the MS crumple zone really works. Sorry you were the one to show us.

 

[emir-t]

Emir, can we get a picture of the front of the car before the crash with the license plate on? I am sure your friend has one ... we all do because we can't stop photographing the thing as soon as we take delivery.

- K

Sure here you go. There are plenty as you've correctly assumed However I don't think it is a plate positioning issue as my friend drove 100km before the accident with TACC only. It's just us not understanding the limitations of TACC correctly.

 

[Blu Zap]

Emir, you are right. The sensors in the nose cone are only for close range, i.e. parking. The radar below the plate and the camera in the windshield behind the rearview mirror all seem to be clear. Those would be the sensors for TACC and Collision Avoidance, respectively.

 

[LetsGoFast]

When tacc locks on to a moving car and that car steers around a stationary object, tacc assumes you will follow that car.
If there is a stationary object ahead, including dead head, tacc assumes you will steer around it. Do that, or apply the brakes yourself.

Lesson to give in deliveries.

I don't believe this is the right understanding of what happens when TACC ignores a stationary car. It isn't assuming you are going to go around it, it is assuming it isn't an obstacle in the road (more accurately, it doesn't know how to classify it and it isn't going to stop unless it is sure). If the car moves even a little bit when the radar can see it, it will recognize that it is a car and stop safely. If it never moves, TACC isn't sure what it is or if it is even blocking you (it could be an overhead sign, for example).

 

[MsElectric]

I don't believe this is the right understanding of what happens when TACC ignores a stationary car. It isn't assuming you are going to go around it, it is assuming it isn't an obstacle in the road (more accurately, it doesn't know how to classify it and it isn't going to stop unless it is sure). If the car moves even a little bit when the radar can see it, it will recognize that it is a car and stop safely. If it never moves, TACC isn't sure what it is or if it is even blocking you (it could be an overhead sign, for example).

This is where combining radar and camera views comes in. Radar may not "see" a car but a camera would. I guess they are still in the process of integrating all the sensors.

 

[wk057]

TACC will eventually "see" the stopped vehicle ahead and slow/stop. But generally not if you're at any appreciable speed. It usually takes too long, presumably because the camera data is used for making this decision about a stopped vehicle ahead and not the radar.

 

[JimmyAZ]

I guess some people probably mixed up Adaptive Cruise Control with Auto Pilot or Autonomous Car.

Original Cruise Control only help you keep the car moving in constant speed in straight line, not turning or braking. Adaptive only make the constant speed slower or faster, not the emergency braking.

Auto emergency braking or keep in lane are safety features.
But cruise control, no matter adaptive or not, is a convenient feature. They are 2 complete different things.

I think we need to stop confusing the situation. TACC can and will stop the car during freeway stop and go traffic. This is NOT part of emergency braking. In moving traffic that stops and goes, like during rush hour, TACC will stop the car, move to a hold position, and wait for a tap on the gas to continue. At no time does emergency braking come into play in this situation.

Also, TACC does indeed brake when needed. This was settled in other discussions.

 

[MorrisonHiker]

I think we need to stop confusing the situation. TACC can and will stop the car during freeway stop and go traffic. This is NOT part of emergency braking. In moving traffic that stops and goes, like during rush hour, TACC will stop the car, move to a hold position, and wait for a tap on the gas to continue. At no time does emergency braking come into play in this situation.

Is that equivalent to the "traffic jam assist" offered on other cars? Does Tesla have another name for it or is it still just part of TACC?

 

[JimmyAZ]

Is that equivalent to the "traffic jam assist" offered on other cars? Does Tesla have another name for it or is it still just part of TACC?

It's just part of TACC (Traffic Aware Cruise Control). I believe there are quite a few automakers that also do this. The Emergency Braking is an audible alarm, red alert on the dash display, and automatic braking that occur when radar detects a crash is imminent. I have activated the alarm while passing a car before. The braking doesn't happen if the driver gives steering or pedal inputs.

 

[ck1116]

It's just part of TACC (Traffic Aware Cruise Control). I believe there are quite a few automakers that also do this. The Emergency Braking is an audible alarm, red alert on the dash display, and automatic braking that occur when radar detects a crash is imminent. I have activated this while passing a car before.

TACC emergent brake you car when you passing a car!!!
That's also danger!

 

[JimmyAZ]

TACC emergent brake you car when you passing a car!!!
That's also danger!

My bad. So sorry for the confusion. If you read the manual, it states that braking doesn't occur when steering or pedal input is made. It only produces the audible alarm. I should have noted that.

 

[Stoneymonster]

My bad. So sorry for the confusion. If you read the manual, it states that braking doesn't occur when steering or pedal input is made. It only produces the audible alarm. I should have noted that.

What you saw was the collision warning, not Emergency Braking.

 

[JimmyAZ]

What you saw was the collision warning, not Emergency Braking.

Ah I see. Again, sorry for the confusion there.

 

[DDotJ]

It's just part of TACC (Traffic Aware Cruise Control). I believe there are quite a few automakers that also do this. The Emergency Braking is an audible alarm, red alert on the dash display, and automatic braking that occur when radar detects a crash is imminent. I have activated the alarm while passing a car before. The braking doesn't happen if the driver gives steering or pedal inputs.

TACC, Collision Warning, and Automatic Emergency Braking are 3 separate systems. Collision warning goes off if the car thinks you may have a possible collision, and you can set the sensitivity in the settings menu. I've had mine set to early, but changed it as the collision warning would sometimes go off while passing closely to parked cars on the side of the street. Normal doesn't do that anymore. It's just a visual notification accompanied with an audible alert, and the vehicle will not take any corrective action. Automatic Emergency Braking is when the vehicle intervenes and brakes when the system detects that there is an imminent collision about to occur. I've never triggered AEB so the vehicle has never braked for me ever since I got the 6.2 update (and that's a good thing :biggrin.

 

[JimmyAZ]

TACC, Collision Warning, and Automatic Emergency Braking are 3 separate systems. Collision warning goes off if the car thinks you may have a possible collision, and you can set the sensitivity in the settings menu. I've had mine set to early, but changed it as the collision warning would sometimes go off while passing closely to parked cars on the side of the street. Normal doesn't do that anymore. It's just a visual notification accompanied with an audible alert, and the vehicle will not take any corrective action. Automatic Emergency Braking is when the vehicle intervenes and brakes when the system detects that there is an imminent collision about to occur. I've never triggered AEB so the vehicle has never braked for me ever since I got the 6.2 update (and that's a good thing :biggrin.

Gotcha. So I changed my Collision Warning to early as well, but it did startle me when it went off during a passing maneuver. I think I'll set that to 'Normal' as well. I guess I'm fortunate to not have triggered AEB as, for the OP, it didn't appear to brake at all (I see from previous posts that it's only meant to reduce impact and not avoid it).