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Discussion Starter · #1 ·
Hello everyone,

We are close to finalizing on purchase of a 2015 QX60 which brings me to final stages of over-analysis.

Our test drive included the Intelligent Auto Brake system where we approached a stopped car at a traffic light, and the QX60 stopped itself.

I'm confused however because the IIHS under the section "Front Crash Protection" indicates the below, which seems unacceptable, yet in direct contradiction with our test drive experience:

"Low-speed autobrake: In the 12 mph IIHS test, impact speed was reduced by 1 mph." :eek:

"High-speed autobrake: In the 25 mph IIHS test, impact speed was reduced by 4 mph." :eek::eek:

Can anyone help me to understand why the IAB system appeared to function well during the test drive above 10 mph compared to the IIHS which says that the system basically did not work at all during tests?

Has anyone discussed this before? Is this your real-world experience?

Thank you,
Dave
 

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I wondered the same thing when those results came out. Mine has intelligent auto-brake and fully stops down to 0 mph, and will hold it for a few seconds. Also, the braking can be aggressive if needed.

I'm assuming the QX60 didn't "see" their test conditions (the fake car, etc...), although I've never run across this in real world driving with the auto brake. Basically, I've never had to second guess the car, typically it's me that's pushing on the accelerator to move past situations that cause my QX to slow down (e.g. vehicle turning turning right).
 

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Discussion Starter · #3 ·
Yeller,

I suspect the same - the QX60 just doesn't "see" the test car. As seen in this video, the IIHS uses what looks like an inflatable or maybe spring-wire backed dummy cars. My thought is that for vision-based systems, this would work fine. I theorize that for radar-based solutions, the test car may simply lack enough metal (high enough off the road) to provide an adequate radar return/reflection.

Given the large number of vehicles that failed this same IIHS test, it's just not realistic for me to believe that the auto makers are releasing such poor solutions.

Does anyone else out there have real-world experience with IBA? Does it work?

Thanks
Dave
 

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Discussion Starter · #4 ·
FWIW, ignore my theory above as the radar in the QX60 is Laser based radar, rather than microwave-radar. I'm still of the mind that it's something about the test vehicle and the system.
 

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I basically agree with the comments above in that something does not make sense on the testing.
I have used the feature and run a number of tests in both city and highway driving. It works great. I also tested with medium sized motorcycles and flat empty trailers in front of me without any problems.
Other than the persistence of the system in monitoring the car ahead even if it has gone into the left hand turn lane (used to help maintain control in curves), I have been very pleased with its operation. While I have yet to have it not work, I will continue to monitor it's operation under different conditions.

 

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It may be panic stop situations. While I've used auto-brake on every road trip (56K total miles), I can't recall a panic-stop situation where I needed to go full-on-ABS-initiated-slam-the-brakes. I wonder if this is where the QX fails IIHS tests.
 

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IBA works fine in my 2014 QX60. I tested it during my test drive as it's one of the cars selling points. I also use it all the time during stop and go traffic - I don't hit my brakes, just the gas pedal to move me forward and the IBA stops the car.
Bear in mind that the car is not traveling at a high rate of speed - only going about 15-20mph
I tend to agree with @yeller - IIHS mimics a panic stop type of situation. Even according to the model literature IBA is described as:

Intelligent Brake Assist (IBA)[*] system with Forward Collision Warning (FCW)[*] uses a sensor from the Intelligent Cruise Control system[*] to continuously monitor and analyze closing speeds to a vehicle or a stationary vehicle ahead. FCW can sense an imminent collision and will provide a two-stage warning to the driver as the vehicle moves towards impact. If the driver does not respond adequately to both consecutive warnings and a collision can no longer be avoided, IBA will automatically engage the brakes to help reduce the speed of a collision.
 

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I read that test result too. On my Hybrid, you have to turn it on each time by pressing the button on the steering wheel. I actually like that feature, because I only use the lane keeping and auto brake features on long interstate highway trips where it's easy to get "velocitized". Around town here in Fredericksburg or DC, I typically turn it off because it can be intrusive.

My guess is the IIHS didn't have the feature turned on!
 

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I'll try to clear some of this up.

There are two forward-facing systems that can trigger braking in this car (assuming you have Driver Assistance Package or Technology Package). And really, there are three systems that are referenced in various brochures and the manual. But two of them are linked and use the same technology and more-or-less work the same.

One is the Forward Collision Warning with Intelligent Brake Assist. This is NOT the system most users above are referring to. But I believe it IS the system IIHS may be referring to. FCW with IBA will NOT necessarily stop the car. Its intent is the reduce the speed of an impact in the case of a forward collision. I believe it also pre-loads the brakes when it warns you, which in turn gives you full braking pressure immediately if you press the brake pedal in response to the warning. The majority of you have never experienced this system - unless you come in fast to stop signs/lights with cars stopped in front of you. Again, this system is not designed to stop the car.

The two systems that will stop the car are the Intelligent Cruise Control and the Distance Control Assist features. These two systems are fundamentally the same, and use the same sensors (I don't know, but I presume the FCW uses these sensors too). The sensor is the radar sensor in the lower part of your bumper. In the case of ICC, the system will both speed up, and slow down your car based on traffic. ICC can also adjust its following distance based on user choice. In the case of DCA, the system will slow down and stop your car, based on a moving car in front of you. The difference here is it will not speed up your car, just slow it down - there is no target speed like with ICC. Also, the key word in the above sentence is "moving" car. In general, DCA will not recognize a stopped car in front of you at a light. However, if you're following a car to a stoplight, it will see that car and stop you when you get close - even if they've already stopped. The way to tell if your car is "reading" the car in front of you is by the display in the center of the speedo/tach. If DCA is turned on (you turn it on with the bottom right button on the steering wheel - the one with the circles on it), there will be a small icon of a car at the very top of the center display. That icon tells you your car is seeing the car in front and will slow if they slow.

Sorry for the long description, but this is a nuanced discussion and hopefully you've learned something. Don't go and try driving your car into a parked car or wall just to show your friends how smart it is - it isn't that smart. If you have Backup Collision Intervention (you do if you have ICC/DCA), then you can do that demo trying to back into a wall - it will stop.
 

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All I can say is that the system as described by Sinecure works very well. I'm spoiled with it and want it on the next car we purchase. I use it with ECO transmission mode when in heavy traffic. You still need to pay attention to the car in front of you however just in case.
 
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