ACC detects phantom cars when passing large vehicles

[Andoman]

I’m not sure if this is considered phantom braking, but our R1T Adventure has serious problems with adaptive cruise on interstate driving. While passing most semis/trailers/campers on the left, as we approach we will see phantom blue cars displayed either on the front or rear bumper of the semi. To be clear, there are no other cars on the road besides the impending semi. The phantom cars flicker off/on and 70% of the time cause the ACC to slow down. Not cool at any time, but especially if there is traffic behind and you slow down in the passing lane. This behavior has never happened when passing a semi on the right (three lane interstate with truck in middle lane), but we typically refrain from doing that. I also notice when sitting in stopped traffic, the display of surrounding vehicles has similar on/off flickering or angular displays that are not parallel to traffic. R1T very confused about what other vehicles in immediate vicinity are doing (and they are stationary!).

This has been reported in detail to Rivian and has been into the shop once. It was documented as normal behavior - they compared it to other trucks and found similar behavior.

Anyone else experience this?

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[zefram47]

Certainly doesn't sound normal.

 

[brbecker]

I have experienced the same thing. I was assuming it was caused by the angle of the sun causing a shadow on the left side of the semi on a East bound lane. It seems that the adaptive cruise control thinks the shadows caused by the sun angle is a car?

 

[R.I.P.]

I’m not sure if this is considered phantom braking, but our R1T Adventure has serious problems with adaptive cruise on interstate driving. While passing most semis/trailers/campers on the left, as we approach we will see phantom blue cars displayed either on the front or rear bumper of the semi. To be clear, there are no other cars on the road besides the impending semi. The phantom cars flicker off/on and 70% of the time cause the ACC to slow down. Not cool at any time, but especially if there is traffic behind and you slow down in the passing lane. This behavior has never happened when passing a semi on the right (three lane interstate with truck in middle lane), but we typically refrain from doing that. I also notice when sitting in stopped traffic, the display of surrounding vehicles has similar on/off flickering or angular displays that are not parallel to traffic. R1T very confused about what other vehicles in immediate vicinity are doing (and they are stationary!).

This has been reported in detail to Rivian and has been into the shop once. It was documented as normal behavior - they compared it to other trucks and found similar behavior.

Anyone else experience this?

Yes, definitely worse than my Model Y when it comes to phantom braking & "misreading" what it is seeing on the road ahead. Rivian is relatively new at this, so hoping for improvement in the future.

 

[Thedude]

What about the Mitsubishi motorcycles? No matter how much we drove and moved positions around the truck was convinced it was a bike.

 

[Andoman]

I have experienced the same thing. I was assuming it was caused by the angle of the sun causing a shadow on the left side of the semi on a East bound lane. It seems that the adaptive cruise control thinks the shadows caused by the sun angle is a car?

I’m pretty sure this is not related to shadows, but will keep an eye out. It seemed related to how dark/light the semi was - white/silver had less problems. Not enough data to make a conclusion.

 

[Andoman]

@Thedude - yes, we’ve seen that but not at freeway speeds.

 

[zefram47]

I have experienced the same thing. I was assuming it was caused by the angle of the sun causing a shadow on the left side of the semi on a East bound lane. It seems that the adaptive cruise control thinks the shadows caused by the sun angle is a car?

Better not be fooled by shadows. The truck has multiple radar units and ultrasonic sensors.

 

[MountainBikeDude]

What about the Mitsubishi motorcycles? No matter how much we drove and moved positions around the truck was convinced it was a bike.

Sorry, couldn't see past the efficiency gauge!

 

[mikehmb]

I’ve found ACC to be somewhere between useless and dangerous, but that’s specific to where I live (coastal CA, in an urban area but close to rural).

It misidentifies trees and rocks as cars, and on more than one occasion, has aggressively decelerated when I pass a bike on the shoulder if anything is in the oncoming lane. It’s spooky - I can’t use it.

Recommend you note the time it happens and give service a call with a time stamp. They will investigate if you tell them it was unsafe.

 

[WSea]

I’ve found ACC to be somewhere between useless and dangerous, but that’s specific to where I live (coastal CA, in an urban area but close to rural).

It misidentifies trees and rocks as cars, and on more than one occasion, has aggressively decelerated when I pass a bike on the shoulder if anything is in the oncoming lane. It’s spooky - I can’t use it.

Recommend you note the time it happens and give service a call with a time stamp. They will investigate if you tell them it was unsafe.

I saw zombies

 

[Thedude]

Sorry, couldn't see past the efficiency gauge!

I had just coasted down from the mountains for 20 miles, I wish it was like that all the time.

 

[MountainBikeDude]

I had just coasted down from the mountains for 20 miles, I wish it was like that all the time.

I assume the readout maxes at 4.00, that kinda sucks.

 

[R1TLG20BM]

What about the Mitsubishi motorcycles? No matter how much we drove and moved positions around the truck was convinced it was a bike.

I get the same thing from time to time. Finally captured a picture of it a few times. SUV motorcycle in this one

 

[Sleektruck22]

This is common, they need to realign the radar sensor on the front of the truck to reduce its wave width. This takes lots of R&D and the SC's don't have this ability/training as of yet. A fix will come.

It took Mercedes years to get this right.

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