Anti-lock braking system (ABS) – A life-saving feature in emergency situations
It has been a long time since ABS became an integral part of safety in cars. Several other vehicles also come fitted with ABS for added safety. If rumours are to be believed, the authorities will soon make it mandatory for buses also to have ABS. So, what really is ABS?
ABS or anti-lock braking system was invented by Gabriel Vyson in 1929 to be used in aircraft. Though the ABS was tried on an experimental basis in Royal Enfield’s Meteor (1958), Ford Zodiac (1960), Ferguson P99 and many other vehicles, the debate over as to who came up with the first most efficient ABS still continues.
ABS arrived in India only years after it came into use in developed countries. For the same reason, Indian’s consider ABS a luxury feature like they view airbags.
What is ABS and how does it work?
Upon sudden braking, the wheels of a vehicle that is travelling at high speeds have a tendency to lock up or stop rotating completely. But this does not bring the vehicle to a halt as the speed and mass it carried so far and the resultant inertia keeps it moving forward. This results in skidding and loss of control of the vehicle. ABS takes care of such emergency braking situations.
ABS offers superior braking as it pumps in only the required amount of braking force to each wheel. While vehicles without ABS are at a risk of skidding as tyres lock up on braking, the worst fear lies in the fact that this causes the driver of the vehicle to lose steering control.
ABS prevents the wheels from coming into an abrupt halt, thereby offering superior steering control. Thus, drivers of ABS-fitted vehicles are able to slam the brakes and make sudden directional changes to avert an accident without losing control of steering.
An ABS consists of censors that assess the wheel movements, an electronic control unit, hydraulic valves and a pump. Censors assess the wheel rotation and gives the required inputs to the control unit. Each brake will have valves to control the braking force. The pumps maintain the pressure of hydraulic brakes. The control unit controls all these components.
The control unit calibrates the pressure of the break fluids by operating the valves. Once the control unit recognises the wheel that rotates slower than the other wheels, it adjusts the breaking force to match it with the speed of the other wheels.
ABS can adjust the braking pressure in 15 times per second and by the way of application of intermittent force, it prevents wheel locking and thereby skidding.
This enables the driver to stop the vehicle sooner and safely without losing control of the steering wheel.
Things to keep in mind
While driving vehicles fitted ABS, one should not unevenly apply the brakes since it can disrupt the control unit’s proper functioning. One should keep the brake pedal pressed till the vehicle comes to a complete halt. Upon this, the brake pedal will quiver as the valves adjust the braking force to each of the wheels. The quivering of the brake pedal only shows that the ABS is at work.