Monday, December 29, 2008

Understanding ABS (Anti-Lock Braking System)

Have you ever encounter a situation where:
1. You met an "emergency" situation
2. You slammed the brakes and turn your steering to avoid the obstacle(s) ahead.
3. BUT... your car just won't turn! It's still going straight even tough you have turned your steering.
(From the outside, you will see your wheels actually already turned, but why does it still going straight?)

So, why does your car never response to your steering input? You already turn your steering and the wheels already turn, logically, it should turn, but why doesn't it turn and still going straight?
This is because your wheels are locked.

Some definition found about wheels lock:
"When wheels lock, they no longer have traction with the road and in turn cannot steer/stop a car efficiently."
"When wheels lock, the vehicle can no longer react to the driver's steering because the lock wheels can no longer convey the optimum braking power and necessary turning force to the street."

This is where ABS (Anti-lock Braking System) comes in; It is actually a SAFETY FEATURE meant to help preventing situations like the above, wheels locking and allows you to maintain steering (remains steerable, stable, while fully applying the brakes)
Do not mistaken or neglect this FEATURE as some fancy feature to show off; It is a SAFETY FEATURE meant to help prevent or minimize the problems resulted from wheels locking and also drivers in panic situations especially situations where human reflex conquers all (yes, even profesional drivers (racers, rally drivers) makes mistakes or looses their conscious/control, there's nothing to be shy about).

Explanation of ABS:
Without being too technical, ABS is basically a system of a computer and sensors monitoring the speed of each wheel. When you press down on the pedal, the system kicks in and it takes over how each wheel should slow down to prevent unnecessary skids. 
In short, ABS prevents wheel(s) locking when applying full brakes and promotes Steerability and Stability with the shortest possible braking distance.

The feeling when ABS kicks in:
When you slammed the brake and the ABS kicks in, you will feel occasional pulsing of the brake pedal; Do NOT panic or be afraid especially if you are not used to vehicles with ABS, just brake firmly and allow it to do its job.
If you're going pretty fast and brakes firmly on the straights, you might actually feel/experience your car "straightens" itself during the course of ABS function; Hence, you can guess what will happen if your car is without the ABS.

How to apply the brakes in a vehicle with ABS:
Should I pump the brake pedal when stopping in slippery conditions?
You absolutely should not pump the brake pedal in a car with ABS. Pumping the brakes is a technique that is sometimes used in slippery conditions to allow the wheels to unlock so that the vehicle stays somewhat straight during a stop. In a car with ABS the wheels should never lock in the first place, so pumping the brakes will just make you take longer to stop.
In an emergency stop in a car with ABS, you should apply the brake pedal firmly and hold it while the ABS does all the work. You will feel a pulsing in the pedal that may be quite violent, but this is normal so don't let off the brake.

Advantages or Key Features of ABS:
1. Prevents wheel(s) locking.
2. Shorten braking distance.
3. Ensures the vehicles remains steerable and stable.

Something you should know too:
However, this isn’t a foolproof system that would guarantee that skids won’t ever happen. Definitely, you have to consider other factors like the condition and grip of your tires. The road surface will also be a factor. Oil and tar on the blacktop will definitely give you less grip than a paved concrete road. Your speed and direction would also play a factor. The ABS doesn’t necessarily shorten the stopping distance of your car too.

So then, what's so good about it? Well, nothing is perfect. Remember, this is a SAFETY FEATURE designed to HELP prevent situations like wheel(s) locking mentioned above.

So what about those "MANUAL" ABS I heard about?
These are the "technique" when ABS wasn't available or you can call it "simulated" ABS. Have you ever heard about let off the brakes and re-apply again (or pumping the brakes)? If yes, this is the theory/technique; you release the brakes and re-apply to prevent the wheels from locking.

As many people are crazy about Initial D anime, which talks about the main character Takumi with his "manual" ABS; don't be too over-confident or "carried away" with "manual" ABS just because some anime shows off about it.
First of all, it's an anime, secondly, we're driving on the streets not tracks, and finally, we're all humans; we makes mistakes and in panic situation, sometimes, your reflex overwhelms and the "mean time between accident" is just too short for you to react in time. (don't be afraid or shy to admit, even profesionally race car drivers makes mistakes or overhwhelm by such situations)
Also, don't forget ABS works much much faster and efficient than a human, it can monitor the wheels, speed and also apply and release braking pressure up to 20 times in 1 second; It is supposed to be a SAFETY FEATURE to help the driver.
Manual ABS are useful when your car doesn't have ABS, and it often is an important technique for the driver; but don't be mistaken that one can master this technique and think they can prevent all the situations mentioned above.
Don't "play a fool" with your life and others.

Additional Information about "MANUAL" ABS:
Recently, I was told about another definition for "MANUAL" ABS - Aku Brake Sendiri. (It's a Malay word which means "I Brake Myself". Coincidence huh?

What about ESP (Electronic Stability Control) or TCS (Traction Control System) or those "techie" SAFETY FEATURE?
Well, those are more advanced SAFETY FEATURE, which consist of ABS (or includes ABS). It provides further traction control by making use of ABS and few other SAFETY FEATURES.
It can be another topic, so we will not "write" about it here.

To learn more about How ABS Works, check out HowStuffWorks:

To understand more, watch the video (A Video worth a "thousand" pictures):

Some pictures from the video:


aline said...

Great thoughts you got there, believe I may possibly try just some of it throughout my daily life.

Anti Braking System

allen perumal said...

Thanks for sharing, I will bookmark and be back again

Anti Lock Braking System