Although there is nothing more technical left to be explained here.Kudos to our forum mates for great explanation.So now let me try explaining all and everything in a simple or say 'DESI'
language(all will be my personal observations)..
Originally Posted by suvo
Before i come to the questions, let me state my understanding in brief. Understanding
I understand that in nutshell ABS
is a mechanism which prevents the wheels of your car to get locked in case of sudden and panic braking and therefore it allows you to steer the vehicle at the last moment, thereby avoiding a possible collision and also prevents your vehicle in skidding because the wheels are not locked.
Contrary to the popular myth that ABS results in reducing the braking distance, it actually elongates the effective braking distance of the vehicle, because the wheels are not getting locked.
This is partially correct.Actually it depends on the surface and load conditions.
Example:On an uneven surface or with some gravel on road.The ABS
increases the braking distance and similarly if the vehicle is loaded with passengers and is going downhill then also ABS
increases braking distance.But no issue as the vehicle is steerable.
I noticed this when I was descending a hilly road with seven passengers in my Innova and when I braked hard I noticed that the distance was longer than usual,in fact even that the ones without ABS
too(my personal observation,can be wrong too).
| Questions |
1. I have heard and read, that ABS stops working at greater speeds (more than 80 -100 KM/hr). Is it true? If Yes, then why that is so?
stops working only when the speed is below even 10 kph.Why?Because at those speeds the vehicle doesn't skid.
But on slippery surfaces where one wheel tends to lock and another not then ABS
works at even 1 kph.
2. Also at the same time, I have read or heard that even at lower speeds (less than 20 - 25 Km/hr) ABS doesn't respond well and the driver need to really brake hard to put the vehicle to stop. If this is true, why is it so?
Weather the speed is 5* kph or 500 kph..the ABS
will work.(*-Conditions apply)
3. When a driver, Panic brakes, it means that the driver wants the vehicle to stop immediately, but if ABS still allows the rolls in the wheels, then how it is effective?
Buddy when your wheels are locked that means you are in a nearly 'zero' grip situation,now however way you turn the wheel,the vehicle will skid freely in whatever direction it wants to skid.But with ABS
,you will get that extra bit of grip which keeps your tyres rolling and hence you can use the steering wheel to change the direction of movement.It is very very useful while driving on steep hilly roads during rain or snowfall especially at the time of descending the steep slopes.
Simple it is,you take four wheels and add sensors on them.
All these sensors are programmed in such a way that they send information 300(it can be 10,60,100 or even 1000 depending on the sensors) times per second to a central computer.
Now this computer is programmed in a way that this matches the tyre speeds and speed reduction etc etc.
Now in case you brake,the computer is working at 1/300th of a second and hence in that 1/300th parts it will keep on changing the brake force on each tyre and keep them rolling.
It something like when we apply brakes on our non-ABS
equipped cars then we slowly apply the brake and as soon as the wheel locks we release the brake and apply it again.
In case of ABS
,the computer does the same on all wheels 300 times per second.I hope you got the point now.
And yes,to feel the ABS
working in any car what you need to do is:-
Accelerate the car till 140-150 kph and apply hard brakes.What you will notice is that the car will try to change its direction,in fact will try to move like a snake but won't do and secondly there will be very slight vibration in the whole car if you apply hard brake in an ABS
equipped car at high speeds(My personal observation).
reduces braking distance?
Simple it is,best braking is obtained when the tyres are on the verge of locking.Or say its the condition in which even very very minute addition in brake force locks the wheels.
And since ABS
keeps the braking very near to this level hence ABS
cuts braking distance.
Many drivers are able to stop even in shorter distance with non-ABS
cars of same specs,weight and tyre width as compared to ABS
What technique they use is:-
They never pump the brakes again and again,instead they develop a habit of pressing the pedal quite slowly in one go and as soon as the braking force increases their pressure on the pedal keeps decreasing and at last comes a position where the brakes are applied at just the verge of locking.If the wheels lock,then they do it again,but its not pumping.This technique needs a lot of practice but once learnt is very usable.My chauffy taught this to me,although I am still not perfect and end up locking the wheels or non-ABS
4. As a Driver, what all things, I should know before i drive a ABS fitted Car, OR is there a change in my Driving style needed before I drive a ABS fitted car.
No need to change driving style,instead now you will have to be more careful while driving non-ABS
I hope I am clear..