The document discusses the Anti-lock Braking System (ABS), highlighting its importance in preventing wheel lock-up during hard braking, thus allowing drivers to maintain steering control. It explains the components of ABS, including the speed sensor, pump, valves, and electronic control unit, as well as different types of ABS arrangements (four-channel, three-channel, and one-channel). The document also outlines the advantages and disadvantages of ABS, its effectiveness under varying road conditions, and emphasizes the need for safe driving practices even with ABS installed.

1. SAURABH CHAUHAN
ME III YEAR
(120970104045)
-THDC-IHET
(UTTARAKHAND)

2. What Is An ABS?
• Anti Lock Braking System is an important
safety equipment in the vehicle which
provides proper traction to the tyres of
the vehicle by preventing them to get
locked in case of sudden hard braking
and hence provides steering ability to the
driver and consequently better control of
the vehicle.

3. Why ABS?
•It is quite unnoticed that
when wheels get locked
on sudden hard braking,
the driver is not able to
steer the vehicle.ABS
provides the ability to
steer the vehicle on
wheel lock up.

4. COMPONENTS OF ABS
• SPEED SENSOR
Speed sensor continuously monitors all the
four wheels(if vehicle equipped with 4
channel,4sensor ABS) and sends the electric
signal to ECU or ABS ECU.

5. COMPONENTS OF ABS
• PUMP & VALVES
 The function of valves is to release pressure
of the brake lines when ECU signals it.
Valve Has three Positions:
 In position one, the valve is open; pressure
from the master cylinder is passed right
through to the brake.
 In position two, the valve blocks the line,
isolating that brake from the master cylinder.

6. COMPONENTS OF ABS
In position three, the valve releases some of
the pressure from the brake.
Pump’s function is to restore pressure in the
brake lines every time the valve releases it.

7. COMPONENTS OF ABS
• ELECTRONIC CONTROL UNIT(ECU)
The function of ECU is to control the valve and
pump actions and to receive the signal from
the speed sensor.
 It acts as a brain of the ABS.
 Apart from being an integral part of ABS,it
performs all the other automation work in the
vehicle viz : Electronic fuel injection(EFI) etc.

8. Illustration Of ABS

9. Block Diagram Of An ABS
Master
Cylinder
ABS ECU
Pedal
force
WHEEL
SPEED
SENSOR
Brake
lines
Brake
Lines
Continuous Electric Signal To ECU
By Speed Sensor.
Monitors
wheel

10. Types OF ABS
• Four Channel, Four Sensor
In this type, there are four sensors and four
separate valves which monitor all the four
wheels individually.
This is regarded as the best scheme of
arrangement as it provides efficient
monitoring of all four wheels and hence
maximum efficiency.

11. Types OF ABS
• Three Channel, Three Sensor
In this type of arrangement, two seperate
sensor and valves monitor front two wheels
while single sensor and valve monitors rear
two wheels.
This arrangement is also good but not as
efficient as 4 channel 4 sensor.

12. Types OF ABS
• One Channel,One Sensor
In this type of arrangement, only rear two
wheels are monitored by a single channel and
single valve.
This is the least used arrangement and
provide least safety.
Also known as REAR WHEEL ABS.

13. Types OF ABS

14. How Does It Really Work?
• SPEED SENSOR monitors wheel lock up
condition every second.
• Whenever driver applies brake and if SPEED
SENSOR detects wheel lock up conditon, it
sends the electric signal to ECU which sends
the signal to VALVE(which releases pressure)
and PUMP(which recreates pressure) and
together by releasing and pumping pressure
quickly prevents wheel lock up.

15. APPLICATION OF ABS
• ABS is effective on dry concrete roads as it
reduces stopping distance of the vehicle.
.

16. APPLICATION OF ABS
BETTER CORNERING STEERING ABILITY

17. APPLICATION OF ABS
Better Vehicle stability in case of different road conditions

18. EFFECTIVENESS OF ABS
• Prior to equipping cars with ABS, the braking
system was tested extensively and showed a ten
metre reduction in the distance required for
drivers travelling at 97 km/h to come to a
complete stop.
• In addition, the National Highway Transportation
Safety Administration (NHTSA) found that
stopping distances on wet pavement were 14%
longer for vehicles without ABS (51m with for
cars with ABS vs. 58m for cars without it).

19. EFFECTIVENESS OF ABS
• The same kind of decrease in stopping
distance was not seen on dry pavement (only
a 5% decrease in stopping distance was noted
for vehicles with ABS).
• In addition, under controlled test conditions, it
was found that 58% of drivers without ABS
strayed from their intended path, whereas
only 24% of drivers with ABS did the same.
• Effectiveness of ABS is best on wet road
condition.

20. USE OF ABS
SOURCE: INTERNET

21. ADVANTAGES OF ABS
• It provides steering ability to the driver in case of
wheel lock up.
• It provides better control of the vehicle in wet road
conditions.
• It provides better cornering.
• It reduces stopping distance of the vehicle(not
necessarily).
• Overall it is an essential safety feature when used
wisely.
• It reduces insurance cost of the vehicle(not
necessarily).

22. DISADVANTAGES OF ABS
• It is costly.
• Steering control may be working against
drivers who panic in emergency situations. In
a panic, drivers may have the tendency to
over-steer.
• It is a speed sensitive equipment.
• Since the primary objective of ABS is to give
steer ability and hence the stopping distance
may not necessarily decrease every time.

23. IMPROVEMENT IN PERFORMANCE
• Additional systems have been developed that
enhance the basic benefit of the ABS.
Electronic Brake Distribution(EBD):
EBD monitors the amount of brake force
required for each of the wheel and distributes
it accordingly thus helping in more proper
braking and extra vehicle stability.

24. IMPROVEMENT IN PERFORMANCE
• Traction Control System
TCS uses same component as ABS but works
in the other direction.
It gives wheel the necessary traction required
for movement when the whel break loose on
wet surface.

25. CONCLUSION
• ABS is a very essential safety equipment which
should be equipped in every vehicle for more
safety on road.
• Also it should be kept in mind that driver
should drive wisely, he should not over speed
the vehicle on account of ABS as a high speed
turning may roll the vehicle.

26. THANK YOU!