I worked for 3 years at Bendix Truck R&D headquarters (I worked in the 
facilities management area for the building and equipment). My turf took 
me to everyone and the facility there. There is a powerhouse of 
mechanical and electrical engineers working on the products which 
included ABS and disc brakes for heavy highway vehicles. They run there 
own fleet of various including some not so common vehicles for full 
scale testing, and every winter send a considerable crew to Northern 
Michigan for ice and old weather testing.  The facilities include 
numerous  thermal test chambers and a brake dyno with a huge flywheel. 
It's exciting to see a full scale test as Semi sized tires are subject 
to a high speed test as the brakes are applied. Also there was a regular 
string of fleet equipment in and out for actual useage testing.

Matt Pobursky wrote:
> On Sat, 26 Jan 2008 17:08:27 -0200, Gerhard Fiedler wrote:
>   
>> Funny NYPD wrote:
>>
>>     
>>> this is not surprise at all. GM canceled the ABS as a standard
>>> equipment on all its America models couple of years ago, because  of
>>> the poor performance and constant issue it created.
>>>
>>>       
>> ABS may not be (and probably isn't) ABS. This seems to be a rather tricky
>> control feature, and I'm sure there are big differences between different
>> ABS manufacturers.
>>
>> Gerhard
>>     
>
> Ding, Ding, Ding! We have a winner!
>
> One of my major clients makes ABS systems for trucks and for the past
> several years I've been designing test and diagnostic equipment for them as
> well as some aftermarket add-ons. I'm not an ABS expert by any means but I
> have observed a lot of test data can tell you that the level of what passes
> for ABS hugely varies between the automotive companies.
>
> GM makes the most "brain dead" ABS system on the market for use with their
> "mainstream" models. It uses the cheapest and fewest wheel sensors,
> relatively crude brake modulators and the simplest braking algorithm. The
> reason they pulled ABS as standard was two-fold: 1) Cost and 2) It only
> worked well if you just hammered the brake pedal to the floor and kept it
> there (letting the ABS system totally control the braking). They had a lot
> of problems with drivers pumping the brakes (as they were taught to do),
> which caused the ABS system to modulate braking on top of the user
> modulating it... very bad. There were accidents (and legal actions) caused
> by this so it's no wonder GM no longer supplies it as standard equipment.
> On the other hand, I've heard the ABS systems on Cadillacs and Corvettes
> are quite excellent. Amazing, huh?
>
> The ABS systems you see from BMW, Mercedes, Acura, Lexus are much more
> sophisticated and generally tied in with the other traction and throttle
> control functions. Toyota and Honda are somewhere in the middle and the
> rest of the U.S. manufacturers bring up the rear. Generally, the more
> quality and engineering oriented auto companies have the best ABS systems
> (big surprise, huh?).
>
> Truck ABS systems are quite a bit more interesting as the better ones
> integrate things like anti-rollover algorithms where they take
> accelerometer data into account along with wheel speed to sense trailer
> sway and wheel lift and apply braking that counteracts the trailer motion.
> You should see them test these systems, it's very cool! I asked one of the
> test drivers how many trailers he's rolled over and his answer was "too
> many to count". :-)
>
> Matt Pobursky
> Maximum Performance Systems
>
>   
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