Although we take anti-lock braking (ABS) for granted today, it wasn’t all that long ago that the only place where such a safety feature appeared was in a test vehicle and then in a top-of-the-line model, such as a Mercedes-Benz or Jaguar.
In automotive terms, this actually happened quickly. In less than 15 years, automobile industry saw the marketing value of offering ABS and it began appearing in more and more lines until it had become the industry standard.
Early Test Systems Finicky
The earliest test systems tended to be very finicky. Besides being electromechanical (a mixture of gears and switches and analog electronics, they required constant maintenance from technicians and specialized parts to work.
Technicians who worked on the early systems required specialized training to keep the ABS systems then in-test in the proper state of tune. That’s why they were only available as test-bed systems, at first.
(Of course, if you had the money and bought the right vehicle, a Bentley or Rolls, maybe, then you could have such a primitive ABS system sitting in your own driveway. All they were really good for at this time, though, was bragging rights.)
But, a funny thing happened on the way to showroom, the digital revolution – microcomputers, and state-of-the-art miniaturization and sophisticated programming – happened to hit at the same time. This enabled the industry to make ABS a reality, rather than just a high-end toy or test-bed system.
The ABS premise is very simple. As you probably learned when you first began to drive, the best way to control a skid or to regain traction – besides countersteering – is to pump your brakes as far as you could go quickly and then let off and then repeat the procedure as quickly as you could (there’s a scene in the movie “Twister,” where one of the characters is pumping the brakes of an International pickup just before the pickup disappears in a twister as he and his wife stand under a bridge – picture that as ABS but at about 50 to 100 times per minute).
This type of training was nearly universal before ABS was implemented – drivers were taught to get on and off the brakes quickly to control an skidding car; the key, just keep doing it quickly. In this way, the wheels were able to regain a fraction of traction each time and the driver was able to regain control of the vehicle.
Enter the Anti-Lock Braking System. It was one of those strange confluences of time when all of the pieces were ready at the same time.
The problems with early system were mechanical. Mechanical parts tended to either lose the precise settings they needed or they tended to wear out to quickly. Frankly, though, researchers agreed the early systems weren’t sensitive enough to be of any use and the electronics were not robust enough for a good ABS system as they were just too slow.
They could not handle the number of instructions per second that were generated by even the primitive sensors that were used on those primitive systems.
It all turned around in the early 1980s when real digital computers were applied to automotive problems and since the technology to produce a digital microcomputer that could operate in the harsh automotive environment was available and the industry was quick to take advantage of it.
The same technology also enabled the auto industry to build the sensors needed to make ABS a viable option.
And, finally, the materials technology was available so that the industry could create the brake subsystems that could handle the quick plunges in seconds without breaking down the first time out (source: Mercedes research group at the time and author’s experience as an automotive technology writer for more than 30 years).
Thanks primarily to Mercedes-Benz research the ABS system was born. The actual system consists of three major parts — the speed/wheel sensors, the hydraulic control unit (HCU) and the electronic control module (ECM). The ECM is the “brain” of the outfit.
The way it works is simple in concept. The system monitors sensors at the wheels and if it sees any of the wheels approaching the “lockup point,” as determined by ECM, then the HCU takes and pumps the without your intervention.
In fact, automotive safety experts, indicate that the best way to apply the brakes in a vehicle equipped with ABS is just steady pressure, since you can’t modulate them anyway as the HCU is doing it for you.
AOL’s auto news service also had a note the other day about ABS when it noted that you may find that ABS-equipped cars and trucks have brake pedals that feel harder than other systems and that when you apply them you will feel the brake pedal vibrate or pulse.
In addition, you will feel the front wheels (in a front-drive vehicle) pulse, even if you are in a slide, as this author has found out in his own testing.
ABS is, by no means, a panacea for good, defensive driving habits. Drivers should still follow guidelines of the National Safety Council and American Automobile Assn. that suggest if you have to be out in weather where ABS may be tested, then you adjust your driving for the conditions and keep a minimum two-second following distance between you and the vehicle in front of you.