10-04-2017, 09:18 PM
ABSTRACT
In today s world, the braking is the most important system in an automobile. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the Kinetic energy (momentum) of the vehicle into thermal energy. The use of it leads to command of stopping force ten times as powerful as the force that puts the vehicle in motion. It exerts thousands of pounds of pressure on each of the four brakes. Development of anti-lock braking system uses a computer controlled valves to limit the pressure delivered to each slave cylinder. If a wheel locks up, steering input can not effect the car s direction. With ABS, no matter how hard the paddle is pressed, each wheel is prevented from locking up. This prevents skidding (and allows the driver to steer while panic braking).Anti-Lock Braking System was further advanced with the introduction of Traction Control System and finally is the stability control system which has to control the vehicle. Almost all automobile manufacturers offer these systems on their select models. In this paper an attempt has been made to present the concept of anti-lock braking system along with Traction Control System with added technologies and their procedures and maintenance. An example of LUCAS-GIRLING ANTILOCK BRAKING SYSTEM had also been explained. The area still remains a challenge for automobile engineers.
1. INTRODUCTION:-
In the last decade there has been tremendous growth and expansion of braking system in terms of technology, design, implementation etc. In recent years, brakes have changed greatly in design. Disc brakes, used for years for front wheel application, are fast replacing drum brakes on the rear wheel of modern cars. The greatest advantage of disc brakes is that they provide significantly better resistance to brake fade compared to drum type braking system. Brake fade is a temporary condition caused by high temperature generated by repeated hard braking. Disc brakes allow greater air ventilation compared to drum brakes as they rapidly fling off and water that they are exposed to , and so they can be well ventilated.
Anti-lock braking system, originally developed for aircrafts braking system, reduce wear and tear on aircrafts tyres after landing, caused by flat spot. When a driver of a vehicle hits conventional brakes hard, the wheels may lock causing the vehicle to skid, especially on wet and slippery roads. ABS provides the capability for shorter stopping distances and the ability to steer and to maintain control during hard braking, especially on wet and slippery surfaces. Anti-locks were first used on airplanes beginning in the 1950s and have been extensively used on large trucks in European countries since the early 1980s. However ABS have only recently become widely available in cars , the first car to have electronic anti-lock braking system as standard equipment were the 1985 Mercedes-Benz S-class models. Front and rear wheel anti locks were available as standard or optional equipment on about thirty domestic and foreign car models by the 1987 model year. About 18% of new cars sold in 1991 model year had anti locks , 32% in 1992 model year and today it has increased up to 90% and will continue to grow.
An improvement in ABS technology now allows some system to prevent wheel spin when accelerating on wet or slippery surface. This capability is known as Traction Control .Some of these systems also provides addition control when cornering or changing.