Antilock or antiskid device
The
vehicle will stop more quickly if the brakes are applied just hard
enough to get maximum static friction between the tyres and road. If the
brakes are applied harder than this then the wheels will lock, the
tyres will skid or slide on the road and a lesser kinetic friction will
result. Then braking the vehicle is much less effective.
To
prevent skidding and thus provide maximum effective braking several
devices have been proposed. Mostly skid control of the rear wheels only
is provided. Some others provide control at all the four wheels. What is
meant by “control” is this. As long as the wheels are rotating the
antiskid device permits normal application of the brakes. But if the
brakes are applied so tough that the wheels tend to stop turning and
thus a skid starts to develop the device comes into operation and partly
release the brakes so that the wheels continue to rotate. Still
intermittent braking continues. But it is held to just below the point
where a skid would start. The result is maximum braking effect.
Antilock brake system: The hydraulic unit is the
central component of an ABS system. Each of the four wheels has a speed
sensor, which measures the rotational speed of the wheel. This
information is monitored by an Electronic Control Unit: which opens and
closes the magnetic valves at the right time. If a wheel is about to
lock under heavy braking, the system continues to reduce the hydraulic
pressure on that wheel alone, till the threat of locking is past. Once
the wheel is turning freely again, the hydraulic pressure is increased.
This increase and release of pressure continues until the driver reduces
the force on the brake pedal or until the tendency to lock is overcome.
ABS is incorporated in some of the cars to prevent skidding and to rove
braking.
Senstronic
braking control (SBC) Senstronic Braking Control is basically a
brake-by-wire system which eliminates the need for mechanical linkage
between the brake pedal and brake master cylinder. SBS also work in
conjunction with ABS to enhance braking.
It was
developed by Mercedes in association with Robert Bosch GmbH. Among its
most important performance features are the dynamic building up of brake
pressure and the precise monitoring of driver and vehicle behavior
using sensors. In an emergency situation, SBC increases brake line
pressure and readies the brakes, so that they can grip instantly with
full force when the brakes are applied.
Additionally,
variable brake proportioning offers enhanced safety when braking on
bends. SBC controls each wheel individually. When in corners, they apply
varying degree of pressure on the inside and outside wheels of a car,
and in the wet road condition. The SBC is found in Mercedes Benz E cars.
No comments:
Post a Comment