anyone knows how does mechanical ABS works?
MMamdouh
Mechanical ABS
Moderators: daewoomofo, Moderators Group
Mechanical ABS
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anyone?
MMamdouh
MMamdouh
Driving is the utmost fun you can have with your pants on!
Check out my ride: http://www.cardomain.com/ride/567267
Check out my ride: http://www.cardomain.com/ride/567267
What a stupid answer.
1999 3-door HB Lanos 1349cc SOHC - 16" Alloys, Short Ram Intake, Strutbar, Alarm & Remote Locking, Electric Windows, CarPC!
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3 years serving the daewoo community and this is the answer i get... thanks for nothing.Alan_98SE wrote:fucked brake pads??
that way theres no way the wheels can lock up...
MMamdouh
Driving is the utmost fun you can have with your pants on!
Check out my ride: http://www.cardomain.com/ride/567267
Check out my ride: http://www.cardomain.com/ride/567267
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daewoomofo
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hope this helps
http://auto.howstuffworks.com/anti-lock-brake.htm
ABS at Work
There are many different variations and control algorithms for ABS systems. We will discuss how one of the simpler systems works.
The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car five seconds to stop from 60 mph (96.6 kph) under ideal conditions, but a wheel that locks up could stop spinning in less than a second.
The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. This gives the system maximum braking power.
When the ABS system is in operation you will feel a pulsing in the brake pedal; this comes from the rapid opening and closing of the valves. Some ABS systems can cycle up to 15 times per second.
Types of Anti-Lock Brakes
Anti-lock braking systems use different schemes depending on the type of brakes in use. We will refer to them by the number of channels -- that is, how many valves that are individually controlled -- and the number of speed sensors.
Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.
One-channel, one-sensor ABS - This system is commonly found on pickup trucks with rear-wheel ABS. It has one valve, which controls both rear wheels, and one speed sensor, located in the rear axle.
This system operates the same as the rear end of a three-channel system. The rear wheels are monitored together and they both have to start to lock up before the ABS kicks in. In this system it is also possible that one of the rear wheels will lock, reducing brake effectiveness.
This system is easy to identify. Usually there will be one brake line going through a T-fitting to both rear wheels. You can locate the speed sensor by looking for an electrical connection near the differential on the rear-axle housing.
http://auto.howstuffworks.com/anti-lock-brake.htm
ABS at Work
There are many different variations and control algorithms for ABS systems. We will discuss how one of the simpler systems works.
The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car five seconds to stop from 60 mph (96.6 kph) under ideal conditions, but a wheel that locks up could stop spinning in less than a second.
The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. This gives the system maximum braking power.
When the ABS system is in operation you will feel a pulsing in the brake pedal; this comes from the rapid opening and closing of the valves. Some ABS systems can cycle up to 15 times per second.
Types of Anti-Lock Brakes
Anti-lock braking systems use different schemes depending on the type of brakes in use. We will refer to them by the number of channels -- that is, how many valves that are individually controlled -- and the number of speed sensors.
Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.
One-channel, one-sensor ABS - This system is commonly found on pickup trucks with rear-wheel ABS. It has one valve, which controls both rear wheels, and one speed sensor, located in the rear axle.
This system operates the same as the rear end of a three-channel system. The rear wheels are monitored together and they both have to start to lock up before the ABS kicks in. In this system it is also possible that one of the rear wheels will lock, reducing brake effectiveness.
This system is easy to identify. Usually there will be one brake line going through a T-fitting to both rear wheels. You can locate the speed sensor by looking for an electrical connection near the differential on the rear-axle housing.
thanks for the valuable reply.
this is how a standard issue electronically controlled ABS works, my concern is the mechancical one... i saw that on a daewoo espero and it is kinda like a pressure regulator on the oil line of both front brake calipers and there were no electroincs involved whatsoever... i was wondering how can a mechanical device do the ABS job without "sensing" the tendance of a tire to lock.
MMamdouh
this is how a standard issue electronically controlled ABS works, my concern is the mechancical one... i saw that on a daewoo espero and it is kinda like a pressure regulator on the oil line of both front brake calipers and there were no electroincs involved whatsoever... i was wondering how can a mechanical device do the ABS job without "sensing" the tendance of a tire to lock.
MMamdouh
Driving is the utmost fun you can have with your pants on!
Check out my ride: http://www.cardomain.com/ride/567267
Check out my ride: http://www.cardomain.com/ride/567267
well I searched and did not have time to read but here are two more links I hope they help
I think this one has the answer http://www.answers.com/topic/anti-lock-braking-system
http://www.autoshop101.com/forms/brake09.pdf
I think this one has the answer http://www.answers.com/topic/anti-lock-braking-system
http://www.autoshop101.com/forms/brake09.pdf
thank you very much for the help man.
MMamdouh
MMamdouh
Driving is the utmost fun you can have with your pants on!
Check out my ride: http://www.cardomain.com/ride/567267
Check out my ride: http://www.cardomain.com/ride/567267