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1. Control System in Brake and Steering

2. Antilock Braking System
• Anti-lock Braking System also known as anti-skid braking
system (ABS) is an automobile active safety system which
• prevents the locking of wheels during sudden braking
• It also avoid uncontrolled skidding..
• The main advantages of using ABS system in vehicle is that it
provides better control over the vehicle.
• It decreases stopping distance on dry and slippery surfaces.

3. Continue
• Since in ABS installed vehicle the chance of skidding is very
less and hence it provides a better steering control during
braking.
• Without ABS system, even a professional driver can fail to
prevent the skidding of the vehicle
• But with ABS system, a normal person can easily prevent the
skidding of the vehicle and get better steering control during
braking.

4. Objective of ABS
• To reduce stopping distance
• To maintain stability
• To obtain good steerability

6. Why Anti-lock Braking System (ABS) is essential in vehicles?
To understand this in a better way lets us take an inciden
during driving of car on a highway and suddenly an obstacle
comes in front we apply brake with full power.
This will locks wheels of your car and your car will start
skidding on the road.
during skidding we loose our steering control and unable to
move the car in desired direction

7. With ABS & Without ABS

8. Continue
• When vehicle equipped with anti-lock braking system. We
encounter with an obstacle on the road and suddenly apply
the brakes.
• ABS system of your car prevent the locking of the wheel and
avoid skidding.
• At this time we can control the steering and can stops car
hitting from the obstacle.

9. Skid vs Slip
• Skid: when horizontal movement or longitudinal movement is
greater than rotational movement then it's called skid
• Slip: when horizontal movement is less than the rotational
movement than it's called Slip
• Slide: When vehicle move along a inclined path.

10. Skidding

11. SLIPPING

12. Main Components of ABS System
• It has four main components
• 1. Master Cylinder
• 2. Hydraulic Control Unit
• 3. Electronic Control Unit
• 4. Wheel Speed Sensor

13. Components of ABS

14. 1.Master cylinder
It is a device that is used to pump the brake fluid and
• Piston rod is connected to brake pedal
• The oil reservoir is connected to the master cylinder,
• The outlet of the master cylinder is connected to the hydraulic
control unit.

15. 2. Hydraulic control unit (HCU):-
• It is a control unit that works as per signals received from an
electronic control unit (ECU).
• As per ECU signals, the Hydraulic control unit (HCU)
control the flow of brake fluid
Hydraulic Control Unit Consists of
1) Pump,
2) Accumulator
3) Solenoid valve

16. Pump
• The Inlet of the pump is connected to the master cylinder
outlet is connected to the accumulator.
• The pump pressurizes the brake fluid received from the
master cylinder & sends it to the accumulator.
• Pump is used to restore the pressure to the hydraulic brakes
after the valve releases the pressure.

17. Accumulator
• It is a storage device, which is used to store the pressurized
brake fluid.
• The outlet of the accumulator is connected to the solenoid
valves

18. Solenoid valves
• Solenoid valves work as per signal received from the ECU to
• Supply pressurizes brake fluid to apply the brake,
• To stop the supply of brake fluid,

19. 3. Electronic Control Unit
• The controller used in the ABS system is of ECU.
• It receives information from each individual wheel speed
sensors
• As per the signal received from wheel speed sensor it activate
the ABS Modulator
• ABS modulator actuates the braking valves and varies the
pressure to the brakes.

20. 4. Wheel Speed Sensor
• It is used to calculate the acceleration and deceleration of the
wheel.
• It Consist of
1) Toothed wheel
2) Electromagnetic coil
3) Hall Effect sensor to generate signal.

21. Continue
• When the wheel the vehicle rotates it induces magnetic field
around the sensor.
• The fluctuation in this magnetic field generates voltage in the
sensor.
• This voltage generated sends signals to the controller.
• With the help of the voltage the controller reads the
acceleration and deceleration of the wheel.

22. Working

23. Working of Anti-lock Braking System (ABS)
• As the brakes are suddenly
• it decelerate the wheel and may cause the wheel to Lock.
• The speed sensor send the signal to ECU
• ECU read the signal and make the valve to close
• This reduces the pressure of brake pad and prevents the
wheel from locking.

24. Continue
• The wheel again starts to accelerate, again the signal sends to
the controller,
• this time it opens the valve,
• increasing the pressure to the brake pad and brakes are
applied,
• this again reduces the speed of the wheel and tries to make it
stop.

25. Continue
• This process of applying brakes and releasing it happens 15
times in a second when a driver suddenly applies the brake
harder.
• Due to this the locking of the wheel is prevented and the
skidding of the vehicle eliminated.
• During braking with ABS system, the driver can steer the
vehicle and reduces the risk of vehicle collision.

26. Traction Control System
• The traction control system (TCS) detects if a loss of traction
occurs among the car's wheels. If the wheels lose their grip on
the road,
• Such traction loss commonly occurs on snowy or icy roads
and in rainy weather.
• traction control is an electronic system that uses the same
sensors as the anti-lock braking system (ABS) to reduce or
prevent wheel spin.

27. Continue
• If a wheel is spinning this means the tyre is no longer
effectively gripping the road surface,
• If the ABS sensors detect that a wheel is spinning, it sends the
signal to ECU
• ECU will open the valve
• valve will increase the brake pressure and reduces the
spinning of wheel So that wheel get proper traction with road
surface

28. ABS VS TCS
• Traction Control systems and Anti-Lock braking systems are
often paired together as they help improve the vehicle's
stability with by working in tandem.
• The major difference between an ABS and a Traction Control
system is that while ABS stops the wheel from spinning
while braking.
• Traction Control stops the wheel from spinning while the
vehicle is accelerating.

29. Types of ABS
Four-channel ABS -
• it works only on the affected wheel out of all the four wheels
in case of sudden braking.
• It has sensors employed on all four wheels of the car.
• Almost all the passenger cars now available in India are being
compulsorily equipped with four-channel ABS.

30. Three-channel ABS
.
• In this system, both the front wheels are equipped with
separate wheel sensors
• whereas at the rear, only a single sensor is placed on the axle
housing, which acts as a common link between both the rear
wheels
• if even any one of the two of the rear wheels gets affected in
hard braking, the ABS system works on both of them

31. One-channel ABS -
• The one channel ABS is preferably used in commercial
vehicles to keep the cost as low as possible.
• In this system, only a single ABS sensor s placed on the rear
axle housing
• ABS system works only on the rear wheels in case of hard
braking.

32. ADVANCEMENTS IN ABS
• Traction Control System (TCS)
• Electronic Stability Program
• Roll Stability Control (RSC)
• Electronic Brake-Force Distribution (EBD)

33. Electronic Stability Control
• When ESC detects loss of steering control by using
• Steering angle sensor,
• Yaw rate, and
• lateral acceleration sensor
• Braking is automatically applied to wheels individually.
• Some ESC systems also reduce engine power until control is
regained.

34. Electronic Brakeforce Distribution
• Electronic Brakeforce Distribution or EBD is an extension of
the Anti-Lock Braking System (ABS).
• Though the Anti-Lock Braking System or ABS ensures that
the wheels do not lock under heavy braking,
• EBD makes sure that each wheel gets the right amount of
braking force.

35. Roll Stability Control (RSC)
• Roll Stability Control (RSC) This advanced safety system
recognizes the possibility of a rollover through signals from
• The roll rate sensor and
• The wheel speed sensor and
• It adjusts braking and/or torque to affect a roll moment in
the opposite direction.
• As a result, the vehicle recovers stability rather than rolling
over.

36. Problems of ABS
• The most common ABS problems occur when sensors
become contaminated with debris or metal shavings.
• Malfunctions also occur when sensor wiring becomes
damaged, resulting in intermittent or no continuity.

37. Advantages
• It prevents the locking of the wheel and thus eliminates the
chance of skidding.
• The skidding of the vehicle is completely removed, which
results in excellent control during braking.
• A better steering control is obtained with the ABS system.
• It reduces the chance of collision by 30 %.
• It reduces Stopping Distance

38. Disadvantages
• A vehicle equipped with ABS (Anti-lock Braking System) is
costlier as compared with a vehicle without ABS.

39. Electric Power Steering

40. Working
• Steering angle sensor measure the position of steering wheel
• Torque sensor measure the torque applied by the driver on the
steering wheel respectively.
• This data is fed to the Electronic control unit
• In addition, ECU also monitors the overall speed of the
vehicle by vehicle speed sensor

41. Continue
• analog signals from potentiometer sensor is converted into
digital signal through the ADC channel of the Peripheral
Interface controller
• The controller generates necessary outputs to drive the DC
Motor that assist the rack and pinion movement.

42. Column-Assist Type:
•The power assist unit,
controller and the torque
sensor are attached to the
steering column.
•This system is compact and
easy to mount on vehicle.

43. Pinion-assist type:
•The power assist unit is
attached to steering
gears pinion shaft.

44. Rack Assist Type
•The power assist unit is
attached to the steering
gear rack.
•The power assist unit
can be located freely on
the rack, allowing great
flexibility in layout design.

45. Hydraulic Power Steering

46. Advantages of EPAS:
• It is highly accurate system and thus gives a better control
over vehicle.
• Helps to improve the fuel economy of vehicle as no fuel is
required to run the steering pump.
• It is a lighter system.
• More efficient than hydraulic steering system