Collision Avoidance Almost Caused an Accident

[Toolworker]

My Forward Collision Avoidance (FCA) System almost caused a collision today.

I was in a freeway exit lane, doing, at a guess, 40 or so. The distance to the vehicle in front was about 2 car lengths and decreasing slowly. So I took my foot off the accelerator and touched it lightly to the brake pedal. The brakes came on fully – it felt like they locked. The vehicle behind me slammed on its brakes and its wheels squealed, barely stopping short of hitting me.

I instantly took my foot off the brake and my vehicle resumed rolling forward normally, as if to say "Who, me?"

The FCA was set to Late responsiveness.

In no way was braking intervention necessary or at all appropriate. It was a completely normal driving situation until FCA got involved.

The manual says "The FCA provides additional braking power for optimum braking performance, when the driver depresses the brake pedal." I guess that means that once I touched the brake pedal, the FCA felt it had a free hand. Or foot.

With less than 1000 miles on the car, this is already the second time FCA has - er - fca'd up. The first time was on a freeway, with SCC operating. A car changed lanes in front of me, a little bit close, but since it was still going away the SCC did not brake. Then the car in front of it slowed, so it did too and the brake lights came on. I didn't panic - but my car did, locking the brakes for a moment. I considered this unnecessary but understandable. Today, not so much.

I'm thinking about filing a complaint on the NHTSA site. Maybe that'll get Hyundai's attention.

And I turned FCA off.

 

[R P]

Yup, FCA is way too premature on the Kona. Have had it happen to me a few times. Once when changing lanes, when it suddenly slammed on the brakes. Car behind me must have thought I was nuts.

I have another car with FCA and it never brakes prematurely, although will beep and slow gently first if I come up behind someone fast. But it has never slammed on the brakes like my Kona.

Just have had to adapt and stay further back to avoid being FCA'ed.

 

[Toolworker]

And I turned FCA off.

And the car turns it right back on again.

Per the manual: "The Forward Collision-Avoidance Assist (FCA) system is enabled whenever the vehicle is turned on."

Sometimes this car makes me feel like a beta tester.

 

[Esprit1st]

I think setting FCA to late is a mistake. That's exactly what you will get. It will surprise you!

I set it to medium, it lets me know ahead of time with the beeps that it'll activate and I can slow down a little more to prevent it from doing something crazy.

Just my two cents.

 

[KiwiME]

Yep, happened to me twice when following close to a car moving out of the lane. Smart cruise does a similar thing when rounding a RH curve with cars parked on the outside, noting that my car is RHD.

 

[electriceddy]

I think setting FCA to late is a mistake. That's exactly what you will get. It will surprise you!

I set it to medium, it lets me know ahead of time with the beeps that it'll activate and I can slow down a little more to prevent it from doing something crazy.

Just my two cents.

Good point- I will have to check where my setting is ...thanks

 

[Toolworker]

I think setting FCA to late is a mistake. That's exactly what you will get. It will surprise you!

Thanks. Since I can't deactivate FCA permanently, I set mine to medium too.

I set it to medium, it lets me know ahead of time with the beeps that it'll activate and I can slow down a little more to prevent it from doing something crazy.

I don't remember hearing the beeps before it braked. Are the beeps similar to the lane keeping beeps? I'm getting used to ignoring those.

When it's set to Late, does it still beep? Or is the sound of the beep masked by the squeal of tires and the screams of the occupants?

 

[Kathryne]

Thanks. Since I can't deactivate FCA permanently, I set mine to medium too.
I don't remember hearing the beeps before it braked. Are the beeps similar to the lane keeping beeps? I'm getting used to ignoring those.

When it's set to Late, does it still beep? Or is the sound of the beep masked by the squeal of tires and the screams of the occupants?

The beep is different than LKA and is quite jarring. I've only had it happen once and I am set on standard response time, and even then the brakes did not engage automatically. I am wondering if you have level 3 regen on all the time? The reason I ask is because I find I will lock up the wheels at high speed if I apply the brakes with any kind of force with level 3 regen on. It feels like emergency braking but the AEB was not, in fact, active.

I am wondering if the force of level three regen (front wheels only) and applying the brakes (all four wheels) is causing brake lockup on the front?I am no expert, but when I have regen turned down or off, the brakes act like normal brakes when applied. I ONLY have this issue with level 3 regen and only when I am not in auto regen.

 

[Toolworker]

I am wondering if you have level 3 regen on all the time? The reason I ask is because I find I will lock up the wheels at high speed if I apply the brakes with any kind of force with level 3 regen on. It feels like emergency braking but the AEB was not, in fact, active.

This is quite possible, although I barely touched the brake pedal. I have level 3 all the time, because I love one-pedal driving. I will have to test it when no other cars are around.

Has anyone else seen this?

 

[Kathryne]

This is quite possible, although I barely touched the brake pedal. I have level 3 all the time, because I love one-pedal driving. I will have to test it when no other cars are around.

Has anyone else seen this?

I have done some testing with brakes and regen levels on my Kona. The reason I ask is because when I locked up at 80 km/hr approaching a light and braking at what i felt was not a hard brake, there was nothing in front of me so I know it wasn't the automatic braking. Driving at regen 0, the brakes behave like they would in an ICE vehicle. Also, no FCA warning seems odd.

 

[hobbit]

I've had my FCA set to "early" -- if I'm understanding the feature right, as
I assume it's in all three trims -- the whole time, and drive in regen 0,
and there's never been a hint of, uh, autonomous operation. Of course
I'm always a *long* way from traffic ahead, fully knowing how bogus the
"oh, if you leave a lot of room everybody will cut you off" argument is.
The right answer is to make the gap even bigger, and you help smooth
overall flow. Look up "traffic waves".

_H*

 

[Wildeyed]

I don't believe there's any relationship between braking and Regen and I've been driving this car for a year. Yes, the auto-braking is twitchy but I really think it's because driver's take a lot more risks than any safety system will tolerate. We get too close, we make assumptions based on experience that a car is just not going to make. There's no machine learning going on here. The car simply has parameters it monitors. Violate them and it's going to react.

 

[R P]

Hyundai uses single cameras in front for FCA, and they are just not that precise. So to compensate, it is set to start braking early. Yet it can still hit the car in front at times, as has been demonstrated in the cardboard box tests.

My other car (Subaru) use dual cameras for its FCA and has NEVER surprised or braked prematurely for me. It will gently slow at times if you come up too fast behind a car. But no hard slamming on the brakes, like my Kona has done to me several times. And unlike the Hyundai cars, the Subaru's will not hit the cardboard box, even from 50 miles an hour. This has been tested and demonstrated many times.

I don't know how new FCA is to Hyundai, but Subaru has had it since 2012, and has been refining it ever since with new models. It is just a much better system. This includes the side and reverse blind spot monitoring, as well as LKA. My Kona LKA shuts off below 60 kph. I don't know why, as much city driving is done at that speed or less. Subaru's works right down to low speeds.

The Subaru ACC is also much better, and can be adjusted to work in all traffic situations, and is great in stop and go freeway traffic. Not so with my Kona, as it tends to slow down too late if coming up fast behind a car (and then aggressively applying brakes). Then it lags on take-off, allowing cars to cut you off. The Subaru is much smoother, and can be set to take-off fast, too, so you don't get cut off. Using ACC in the Subaru is much smoother and less stressful than in the Hyundai (where you are never fully sure if it is going to work properly). I think it is all about the cameras, single vs dual, and the associated software.