cyler

I upgraded my 2005RL for a 2006RL with tech package. The primary reason was safety. I'm sure at one time or another we have all found ourselves in a situation on a highway where we come upon traffic which has stopped ahead of us. Fortunately I have always been able to react to the problem in time.

When I first saw the news release from Hondanews last August discussing in detail the operation of the CMBS (Collision Mitigation Braking System) I new I wanted it. It read:

..The CMBS system functions only when the RL is traveling at over 10 miles per hour and when the speed differential between the RL and the car directly in front it is 10 mile per hour or more. It can be turned off by depressing a switch located on the left hand side of the instrument panel..

Here's where the disappointment comes in. In my opinion Acura left out one *IMPORTANT* fact about the operation of the system. The target vehicle in front of you MUST be in motion. If I'm going 40 miles an hour and come across a stopped vehicle in my lane it seems that the "speed differential" between my car and the car directly in front of me is 40 (my speed (40) minus the speed of the car in front of me (Zero)). Acura does not see it that way. They claim that the above paragraph does not apply (i.e. the CMBS will NOT function) in the scenario I have mentioned. They further stated that it was my responsibility to have thoroughly test driven the new vehicle before purchase.

This same issue also applies to the ACC (Active Cruise Control) System. The manual states that the vehicle in front of you must be MOVING at a speed of at least 13mph to be detected. I have not found the (13mph) information on any website or advance sales literature produced by American Honda/Acura.

The Acura representative in Torrence, CA offered me a complimentary service. I told him I believe that their website and literature should be corrected and that anyone who has purchased the '06 tech package based on their misleading advertising should be financially compensated. He rejected the compensation, but did say that they continually review their advertising.

Is the '06 RL an excellent car with the exception of the above issues? Absolutely. However, had I known what I know now, I would have kept my '05 RL.

stingerbtry

That's too bad man. Sorry you went through the trouble to trade up and aren't completely satisfied with the things you traded up for. When I bought my car I had the chance to purchase an 06 but am glad I didn't now. I figured that both of these new technologies for this car were a)doing too much driving for me and b)too new to be bug free. It would be nice if they'd at least completely inform you about what you're buying. I mean what did they expect, for you to try to get in near miss situations on purpose to test the cmbs??

autofill

This response is un-acceptable even from a non-luxury brand. This is not helping Acura's image.

AcuraRLBlue

Sorry that you have to find out with your money and be disappointed. Thank you for the information, as I also have been thinking about upgrading to the 06 from the o5.

Since safety was your primary motivation, have you found the run-flate tire a worth-while reason to upgrade? Thanks.

cyler

Thanks everyone for your comments. The run-flat tires provide an excellent ride which I find as good as the standard tires that came with the '05RL. I haven't had a flat yet so I can't comment on that. The run-flats were one of the reasons I upgraded, but I would not have upgraded for that feature alone.

Bitium

Acura is the third automaker to offer collision preparation technology, featuring it on the top-of-the-line 2006 RL sedan. Dubbed the Collision Mitigation Braking System (CMBS), it’s teamed with a millimeter-wave radar unit mounted behind the Acura symbol in the grille, which monitors the distance between the RL and objects in front of the car, as well as closing rates. CMBS then determines if a frontal collision is likely to occur. The system scans up to 330 feet in front of the car, and works at speeds above 10 mph.

CMBS operates in three stages. In the first two stages, which are non-critical situations where the driver can still avoid a collision, the system uses audible and visual alerts to inform the driver that the RL is closing on an object more rapidly than is safe. In stage one, the RL beeps and flashes a “brake” warning in the gauge display. In stage two, the RL repeats the audible and visual warnings, while also pre-tensioning the driver’s seatbelt and automatically applying light braking to reduce speed. In stage three, things get more serious. CMBS continues audible and visual warnings, but now pre-tensions the front passenger’s seatbelt and automatically applies harder braking to scrub as much speed as possible before impact. Note, however, that Acura warns the system is not designed to bring the RL to a halt. For that, the driver must step on the brakes. CMBS can pass through all three stages quickly, or can transition slowly, depending on the RL’s closing rate with a moving or stationary object.

We learned first-hand how effective CMBS is during a demonstration drive designed to fool the system into thinking that a collision was about to occur. By driving parallel to an Acura MDX with an object hanging off the side of the SUV, we were able to engage all three stages of CMBS. Though the audible alert’s beep-beep-beep is somewhat intrusive, the system works subtly and smoothly. Even in stage three, when the seatbelts tighten up and the braking system is engaged, it works with an unbelievable degree of refinement. But the best part of CMBS is that it applies the brakes automatically, so that if the driver has suffered a medical problem and can no longer operate the vehicle the RL will slow down as much as possible before impact. Lexus and Mercedes systems don’t make a move without driver intervention.

CMBS is currently offered only on the RL with the Technology Package, bundled with an active cruise control system and Michelin PAX run-flat tires, which commands an estimated premium of $4,000 over the standard model. Acura plans to equip about 10 percent of all 2006 RLs with this package.

They actually tested the car:



Here is the entire article.
http://www.autobytel.com/content/sha...cle_id_int/767

vishnus11

This system is truly amazing and seems to work as advertised. A real nice addition to an already outstanding car

DaveGee

This may not be the response you were hopong for, but I agree that you should have test-driven the car first and made sure that the feature is what you wanted before trading in your 05".

Dr. E in TN

One good thing is that you can upgrade to the cool backup camera safety feature with your 06 model. I would think that for someone concerned about safety; that is a must. Let us know if you do how satisfied you are and how much your total costs are.

AcuraRLBlue

I totally disagree with the comments that one should test drive the features before buying the car. If this were to be expected of customers, then one should also puncture a tire to see if the run-flat tires work. It is just not reasonable to expect a customer to test all features of a car. A feature that is advertized to work in a particular way should work as advertized, period.

vtecracer

The system is designed the way it is for a reason. The system is capable of scanning cars up to 330 ft ahead. If you want to activate the system, why on earth would you want to activate it if you know a car less than 330ft infront of you is stopped? I think that the system is actually very clever by NOT letting you activate it if the car infront of you is not in motion. It requires you as the driver to pay 100% attention since there is a stationary car infront of you. A GOOD feature if you ask me.

vicneo

I think acura is tempering claims re CMBS etc because of fear of laibility in case the system doesnt work as advertised. We live in a country that is constantly held to ransom and extortion by tort lawyers remember.

two points:

1 I tried the CMBS on my car with a car stopped ata red light and itdid slow down to around 10mph when i chickened out and slammed the brakes.

2. All motion is relative motion. any radar beam hitting an object in front and bouncing back and getting detected can ONLY detect the relative motion.

cyler

The Autobytel reviewer is wrong as far as a stationary object is concerned. If the CMBS is following a moving target within its 330' operational range and the target vehicle stops the CMBS WILL work. However, if you approach a stopped vehicle from more that 330' out the CMBS WILL NOT work. I tried to reach the author of the Autobytel article Friday, but he had already left for the holiday. When I do reach him I will post the results.


See my post: https://acurazine.com/forums/showthread.php?t=1726

Why would I want the system to activate if I knew the car in front of me was stopped? Answer: I would not. However, there are cases where you don't know the car in front of you is stopped or your realize it too late. For example have you have ever come across a disabled vehicle at night in the travel portion of your lane with no lights on? How about a recent accident, traffic backing up at a split between major highways, less than perfect visibility, etc. I did not expect the CMBS to be a replacement for driver attentiveness. I DID expect it to attempt to present me with a warning under circumstances where it would be difficult to impossible to realize that I have a stopped vehicle in front of me.

Did you approach the stopped car from more than 330' away?

Bitium

I think you are 100 % accurate. I have no idea what cyler is talking about. I just finish watching the video on Acura site. I does not say anything about the object in front has to be in motion. The narrator also mentions "obstacles in the road" on the video. I don't know where cyler is getting the info. A lot has to do with the rate of closure (how fast you are approaching the obstacle). Unless you proved me wrong it makes no sense to me that the system will only work with objects in motion. That is just stupid.

Rob L

I don't see any situation where a person couldn't stop the car on their own within this distance, assuming the car in front was stopped.

If a person can't stop their car in that distance then they apparently are driving too close or aren't paying attention.

Having said that, the system should do its thing if the car in front is stopped.

cyler

That's my point...after I got the car and it didn't seem to warn my about stopped cars in front of me, I called Acura Cust. Service who told me that the car in front of me must be in motion for the CMBS system to work. I asked to have a manager call me back. When he did he told me the same thing. This info should have been in the video you watched. You're right it makes no sense and is stupid.

Merry Xmas and Happy New Year to all

vicneo

and like i said in a previous post what cyler is propounding defies physics.

here is something from the wikipedia article on radar

"Speed measurement
Speed is the change in distance to an object with respect to time. Thus the existing system for measuring distance, combined with a little memory to see where the target last was, is enough to measure speed. At one time the memory consisted of a user making grease-pencil marks on the radar screen, and then calculating the speed using a slide rule.

However there is another effect that can be used to make much more accurate speed measurements, and do so almost instantly (no memory required), known as the Doppler effect. Practically every modern radar uses this principle in the pulse-doppler radar system. It is also possible to make a radar without any pulsing, known as a continuous-wave radar (CW radar), by sending out a very pure signal of a known frequency. Return signals from targets are shifted away from this base frequency via the Doppler effect enabling the calculation of the speed of the object relative to the radar."'

remember all speed measurements are relative

also the acc and the cmbs are basically using the same systems, i would argue that the cmbs is basically just an adaptation or refinement of the acc.

so a radar signal goes off from the rl - bounces off the object in it path and comes back to the radar array. the information viz the time from transmission to the reception and the frequency shift in the electromagnetic waveform is fed into the cars computer, which i am sure amongst other things performs a fast fourier transform. the computer calculates the distance and relative speed of the object. And as it already knows your speed, it calculates the speed of the object in front. and sends a signal to the braking mechanisms to engage.

same principle applies whether in acc or cmbs.

normally you can only tell relative speed, but of course if you know your own speed it would be simple to compute that the object in front is stationary. but in order for the sytem to be made inoperational you would have to give it further instructions to disengage if the object in front is stationary. now this makes sense because you do not want the system engaging say when you are parking in your garage.

So the system ( i think) disengages when realtive speed differential between you and the object in front is < 10mph as the manual says. at 10 mph you will not have a collision with major injury or loss of life.

Also remeber, that if acura claims something and an accident happens due to someones rank stupidity, the greedy tort layers will be all over acura. So I think that if acura co. is a rational player, it will put in plenty f obfuscating disclaimers essentialy to protect their behinds from the extortioning tort lawyers.

cyler

Vicneo, your post gives a good explanation of how the CMBS most likely works. You did not explain how my "propounding defies physics."

If I am going 30mph and the car in front of me is going 0mph, what is the speed differential between the two vehicles? If your answer is not 30mph please explain how you calculated it?

Under these circumstances Acura claims the CMBS will engage because:

1. My RL is going faster than 10mph AND
2. The speed differential between my vehicle and the one directly in front of me is greater than 10mph.

Only problem is the CMBS will not function because the target vehicle is stopped, thus my original point that Acura is making a misleading statement by the omission of this information.