17-12-2012, 01:27 PM
BRAKE ASSIST SYSTEM
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INTRODUCTION
This history of automobiles starts from invention of I.C. engines, but real invention was started in 1886 when the first automobile plant was started by Mercedes Benz.
During those days the automobile was not so technically advanced, a motor carriage which could carry two or more persons was the definition of automobile.
As time changed the automobile became more and more technologically advanced and its possession became a ‘status symbol’ in society.
Earlier while purchasing a car the customer would think only two directions i.e. cost & comfort, but it was a just a couple of years back when people started concentrating on the safety of the car i.e. how safe is the car / as human life is more valuable than anything else. The modern day cars like Mercedes Benz, BMW, Rolls Royce, etc. are coming up with a number of safety devices which try to save the human life in case of an accident or an emergency.
The safety equipments are installed only after a number of tests & great amount of research has been carried out.
The leading manufacturers of cars like Rolls Royce, Mercedes Benz have equipped their cars with safety devices using the most modern technology.
Purpose and Benefits of BAS
Purpose:
“BRAKE ASSIST” BAS is an active safety system. It is active when the driver brakes very quickly in emergency situations. According to the speed with which the break pedal is operated, the system recognizes whether the emergency braking situations exists. It this the case, a solenoid valve in brake booster is opened, activating the full booster power. It the driver releases the break, this is recognised and solenoid valve is closed again.
Benefits:
1 Reduces the risk of an accident in dangerous situations through optimum
brake declaration.
2. Supports ABS to the highest possible brake boost.
3. ABS maintains complete steer ability during the BAS intervention.
Switching On The Ignition And Starting The Engine
When the ignition is switched on (ignition/starter switch position “2”), The malfunction indicator lamp in the instrument cluster (bulb check) comes on and goes off when the engine is running.
If the BAS malfunction indicator lamp comes on when the engine is running, there is a fault in the BAS. The system is inoperative but the full braking effect with ABS is retained. With the combined malfunction indicator lamp (BAS/ETS, BAS/ASR, BAS/ASP), the fault may be in the BAS or in the traction system. In the first case, ETS, ASR, or ESP is retained and the second case BAS function is retained.
Function Survey Of BAS
The normal brake booster increases the force applied by the foot proportionally. It the vehicle is not braked, vacuum which is produced by the engine or a vacuum pump prevails in both chambers. When braking, air under atmospheric pressure flows in to the rear chamber though a mechanical control valve in the brake booster which is operated by the force applied by the driver’s foot. The force applied by the driver’s foot is boosted up to the point at which atmospheric pressure prevails in the rear chamber.
BAS Brake Application
The function in the BAS brake booster is controlled by the components of the electrical / electronics systems.
The voltage is supplied to the BAS control module via the base module, on some modules, via the relay module and fuse relay module on some models.
The BAS control module receives i/p signals from the following components
1. ME control module (via CAN data bus)
2. Traction system control module ( via CAN data bus)
3. BAS diaphragm travel sensor
4. BAS release switch
CONCLUSION
High growth of automobile industry shows us the results of automobile & mechanical engineering developments. Apart from quality appearance & economy of the vehicle there is one very important aspect i.e. “Safety”
In this seminar report I have concentrated on “BAS” i.e. brake assist system which is an active safety device. The use of BAS has considerably helped in increasing the braking efficiency of the cars & to prevent accidents in emergency situations.
Cars like Mercedes Benz use these technologies after a lot of research which makes it one of the safest cars in the world.
In spite of all developments rare cases are always there, which leads to casualties. Reducing accidents has always been a challenging task for engineers as human life is most precious of all. Who knows with the help of modern technology tomorrow we may have a 100% accident free car.