Unit-IV

Unit-IV:Vehicle systems 

Introduction of chassis layouts, steering system, suspension system, braking system, cooling system and fuel injection system and fuel supply system. Study of Electric and Hybrid Vehicle systems. Study of power transmission system, clutch, gear box (Simple Numerical), propeller shaft, universal joint, differential gearbox and axles. Vehicle active and passive safety arrangements: seat, seat belts, airbags and antilock brake system.

• Monoque chassis: Monocoque is a type of chassis construction in which the body of the vehicle serves as the main structural component, rather than relying on a separate frame. The term "monocoque" is derived from the French words "mono," meaning "single," and "coque," meaning "shell."

• In a monocoque design, the body panels are designed to bear the loads and stresses of the vehicle, rather than relying on a separate frame to provide structural support. This results in a lighter and stronger structure, and can also improve aerodynamics and reduce the overall size of the vehicle.

• Monocoque construction is commonly used in automobiles, aircraft, and some high-performance racing vehicles. However, it can be more expensive and challenging to manufacture than other types of chassis construction, and may not be suitable for larger or heavier vehicles.

• Overall, monocoque chassis construction offers a number of advantages and disadvantages, and the choice of design is often based on the specific needs and intended use of the vehicle.

Steering system

Ackerman Steering

Ackerman Steering is a type of steering system used in vehicles, primarily in front-wheel drive vehicles, to control the direction of the wheels.

In this system, the wheels are angled such that the inner wheel turns at a smaller radius than the outer wheel during a turn. This ensures that the vehicle follows the intended path and reduces the tire wear.

The Ackerman Steering system is designed such that the wheels turn at different angles, with the inner wheel turning at a sharper angle than the outer wheel, during a turn. This design reduces tire wear and improves the stability and handling of the vehicle.

Advantages of the Ackerman Steering system include improved stability, better handling, reduced tire wear, and increased safety. Limitations include increased complexity and a tendency for the system to become worn or damaged over time.

Leaf Spring Suspension

A Leaf Spring Suspension is a type of suspension system used in vehicles, mainly in commercial and heavy-duty vehicles such as trucks and trailers. It consists of a long, flat steel or composite spring that is mounted transversely (across the vehicle) and runs between the wheels. This spring provides the necessary load-carrying capacity and acts as a shock absorber.

Types:

• Single Leaf Spring Suspension

• Multi-Leaf Spring Suspension

Function:

The main function of a Leaf Spring Suspension is to support the vehicle weight and absorb shocks and vibrations while driving. It helps to keep the wheels in contact with the road, providing stability and comfort to the occupants.

Applications:

Leaf Spring Suspension is mainly used in commercial and heavy-duty vehicles, such as trucks and trailers, due to its ability to handle heavy loads.

Advantages:

• Simple and durable design

• Can handle heavy loads effectively

• Cost-effective compared to other suspension systems

Limitations:

• Not suitable for high-performance vehicles

• Provides limited suspension travel

• Heavy and cumbersome compared to other suspension systems

Components:

• Leaf Spring

• Shackle

• U-Bolt

• Axle Seat

• Eye Bolt

Requirements of a Good Leaf Spring Suspension:

• Should be able to handle the weight of the vehicle and its load

• Should provide sufficient suspension travel

• Should provide stability and comfort to the occupants

• Should be durable and able to withstand harsh driving conditions

• Should be cost-effective.

Telescopic suspension

Braking System

A braking system is a system in a vehicle that slows down or stops the vehicle by converting its kinetic energy into heat. Braking systems are critical for vehicle safety and are typically comprised of several components including the brake pedal, master cylinder, brake lines, calipers or wheel cylinders, brake pads or shoes, and rotors or drums.

Classification of Brakes:

 The following are the classifications of Brakes:

1.By method of power

a) Mechanical brakes

b) Hydraulic brakes

c) Vacuum brakes

d) Air brakes

e) Electrical brakes

f) Magnetic brakes

g) Air assisted hydraulic brakes

2.By method of application:

a) Service or foot brakes

b)Parking or hand brakes

3.By method of operation:

a) Manual

b) Servo

c) Power operation

4.By method of Braking contact

a. Internal Expanding Brakes

b.External Contracting Brakes

Types of Braking Systems:

1. Disc Brakes

2. Drum Brakes

3. Anti-Lock Brakes (ABS)

4. Electronic Brake-force Distribution (EBD)

5. Brake Assist (BA)

Function of Braking System:

The main function of a braking system is to slow down or stop a vehicle by converting its kinetic energy into heat.

Applications:

Braking systems are used in various types of vehicles, including cars, trucks, buses, and trains.

Advantages:

1. Improved safety

2. Better control and handling

3. Shorter stopping distance

4. Increased durability and reliability

Limitations:

1. High cost

2. Complex installation process

3. Maintenance requirements

Requirements of Good Braking System:

1. Effective stopping power

2. Short stopping distance

3. Smooth and consistent brake pedal feel

4. Reduced brake fade and corrosion

5. Reduced noise and vibration

6. Compatibility with other vehicle systems

7. Cost-effectiveness

8. Ease of maintenance and replacement

Drum Brakes:

Drum brakes are a type of braking system used in vehicles. They consist of a drum-shaped component attached to the wheel and brake shoes inside the drum that press against the inner surface of the drum to slow down the wheel's rotation.

Classification:

1. Leading-Trailing Drum Brakes

2. Self-Adjusting Drum Brakes

Function:

The drum brake system functions by converting the kinetic energy of the vehicle into thermal energy through friction. The brake shoes press against the inner surface of the drum, creating friction and slowing down the wheel.

Applications:

Drum brakes are typically used in older vehicles, heavy-duty trucks, and trailers due to their low cost and simple design.

Advantages:

1. Lower cost compared to disc brakes.

2. Simple design and less maintenance required compared to disc brakes.

3. More compact and suitable for smaller wheel sizes.

Limitations:

1. Lower stopping power and performance compared to disc brakes.

2. Poor heat dissipation and cooling ability, leading to fading and reduced braking effectiveness.

3. Prone to brake fade and brake overheating with heavy use.

4. More prone to wear and tear and greater chance of brake failure.

List of Components:

1. Brake Drum

2. Brake Shoes

3. Brake Springs

4. Wheel Cylinders

5. Master Cylinder

6. Brake Hoses

Disc Brakes:

Disc brakes are a type of braking system used in vehicles. They consist of a rotating disc attached to the wheel and a caliper that squeezes the brake pads against the disc. The friction generated by the brake pads slows down the rotation of the wheel and the vehicle.

Function:

The disc brake system functions by converting the kinetic energy of the vehicle into thermal energy through friction. The caliper squeezes the brake pads against the rotating disc, creating friction and slowing down the wheel.

Applications:

Disc brakes are widely used in passenger cars, trucks, motorcycles, and racing vehicles due to their high stopping power and performance.

Advantages:

1. High stopping power and improved performance compared to drum brakes.

2. Better heat dissipation and cooling due to the vented design of the discs.

3. Longer lifespan and less wear on the brake pads.

4. Better response and feedback to the driver.

Limitations:

1. Higher cost compared to drum brakes.

2. Requires regular maintenance and replacement of brake pads.

3. Can become noisy with worn or low-quality brake pads.

List of Components:

1. Disc

2. Caliper

3. Brake Pads

4. Brake Rotor

5. Brake Fluid

6. Master Cylinder

7. Brake Hose

Cooling System

The cooling system in a vehicle helps regulate the temperature of the engine and prevent overheating. The system circulates coolant, usually a mixture of water and antifreeze, through the engine block, radiator, and other components to absorb and dissipate heat.

Types of Cooling Systems:

1. Liquid Cooling System

2. Air Cooling System

Classification of Cooling Systems:

1. Radiator Cooling

2. Fan Cooling

3. Oil Cooling

4. Charge Air Cooling

Function of Cooling System:

The main function of the cooling system is to regulate the temperature of the engine and prevent overheating by removing excess heat through the circulation of coolant.

Applications:

Cooling systems are used in a variety of vehicles, including cars, trucks, buses, and industrial equipment.

Advantages:

1. Improved engine efficiency

2. Increased reliability and longevity of the engine

3. Improved fuel economy

4. Reduced emissions

Limitations:

1. High cost

2. Complex installation process

3. Maintenance requirements

Requirements of a Good Cooling System:

1. Efficient heat transfer

2. Adequate coolant capacity

3. Consistent and stable coolant temperature

4. Reduced noise and vibration

5. Compatibility with other vehicle systems

6. Cost-effectiveness

7. Ease of maintenance and replacement

Fuel supply system

The fuel supply system in a vehicle is responsible for delivering fuel from the fuel tank to the engine in the right amount and at the right time to maintain combustion.

Types of Fuel Supply Systems:

1. Carbureted Fuel System

2. Fuel Injection System

Classification of Fuel Supply Systems:

1. Mechanical Fuel Injection System

2. Electronic Fuel Injection System

Function of Fuel Supply System:

The main function of the fuel supply system is to regulate the amount of fuel delivered to the engine based on the engine's demand and to mix the fuel with air to create a combustible mixture.

Applications:

Fuel supply systems are used in a variety of vehicles, including cars, trucks, buses, and industrial equipment.

Advantages:

1. Improved fuel efficiency

2. Improved engine performance

3. Increased reliability and longevity of the engine

4. Reduced emissions

Limitations:

1. High cost

2. Complex installation process

3. Maintenance requirements

Requirements of a Good Fuel Supply System:

1. Efficient and accurate fuel metering

2. Adequate fuel pressure and flow

3. Proper fuel/air mixing

4. Reliability and durability

5. Compatibility with other vehicle systems

6. Cost-effectiveness

7. Ease of maintenance and replacement

Electric and Hybrid Vehicle Systems

Electric and Hybrid Vehicle Systems refer to the use of electric power for propulsion in vehicles, either alone or in combination with conventional internal combustion engines.

Types of Electric and Hybrid Vehicle Systems:

1. Pure Electric Vehicles (EVs)

2. Hybrid Electric Vehicles (HEVs)

3. Plug-in Hybrid Electric Vehicles (PHEVs)

4. Range-Extended Electric Vehicles (REEVs)

Classification of Electric and Hybrid Vehicle Systems:

1. Series Hybrid Electric Vehicles

2. Parallel Hybrid Electric Vehicles

3. Series-Parallel Hybrid Electric Vehicles

Function of Electric and Hybrid Vehicle Systems:

The primary function of electric and hybrid vehicle systems is to provide efficient and environmentally-friendly propulsion for vehicles. Electric power is stored in batteries and used to drive an electric motor, which in turn powers the wheels. In hybrid vehicles, a conventional internal combustion engine is also used, and the electric motor and engine work together to provide propulsion.

Applications:

Electric and hybrid vehicles are used in a wide range of applications, including personal vehicles, commercial vehicles, buses, and trucks.

Advantages:

1. Improved fuel efficiency and reduced emissions

2. Increased driving range

3. Improved performance

4. Lower operating costs

Limitations:

1. High initial cost

2. Limited driving range in pure electric vehicles

3. Recharging infrastructure limitations

4. Dependence on battery technology

Requirements of a Good Study of Electric and Hybrid Vehicle Systems:

1. Efficient energy management

2. Reliable and durable batteries

3. Effective use of regenerative braking

4. Integration with other vehicle systems

5. Cost-effectiveness

6. Ease of maintenance and replacement

Series Hybrid Electric Vehicles (SHEVs) are a type of hybrid electric vehicle that primarily relies on an electric drive system powered by a battery pack and a secondary internal combustion engine (ICE). The primary purpose of the internal combustion engine in a series hybrid is to generate electricity to recharge the battery pack. The electric drive system is responsible for powering the wheels and the engine acts as a generator. The power from the engine never directly drives the wheels, but rather it is used to generate electricity and store it in the battery pack, which then provides power to the electric drive system when needed. Some common examples of SHEVs include the Chevrolet Volt and the BMW i3 REx. 

Parallel Hybrid Electric Vehicles (PHEVs) are a type of hybrid electric vehicle that has both an internal combustion engine (ICE) and an electric drive system that can both provide power to the wheels. The engine and electric drive system can work together or separately, depending on the driving conditions and the state of charge of the battery pack. In some cases, the engine can provide power to the wheels while the electric drive system acts as a generator to recharge the battery pack, or the electric drive system can provide power to the wheels while the engine acts as a generator. This type of hybrid allows for greater flexibility in power generation and provides a more seamless driving experience compared to series hybrids. Some common examples of PHEVs include the Toyota Prius and the Honda Clarity Plug-In Hybrid. 

Series Parallel Hybrid Electric Vehicles (SPHEVs) are a type of hybrid electric vehicle that combines the features of both series and parallel hybrids. They have both an internal combustion engine (ICE) and an electric drive system that can both provide power to the wheels. The engine and electric drive system can work together or separately, depending on the driving conditions and the state of charge of the battery pack. Unlike series hybrids, SPHEVs have a direct mechanical connection between the engine and the wheels, so that the engine can drive the wheels directly when needed. This provides greater flexibility in terms of power generation and allows for a more seamless driving experience compared to series hybrids. The combination of series and parallel modes in SPHEVs makes them more efficient than traditional vehicles while providing better performance than simple parallel hybrids. Examples of SPHEVs include the BMW i8 and the Chevrolet Volt. 

Clutch 

A clutch is a mechanical device that is used to connect and disconnect the engine and transmission in an automobile. It allows the driver to control the transfer of power from the engine to the wheels, making it possible to change gears smoothly and control the speed of the vehicle.

Types of Clutches:

1. Single Plate Clutch: It has one driving plate and one driven plate. It is commonly used in small vehicles.

2. Multi-Plate Clutch: It has multiple driving and driven plates. It is used in high-performance vehicles due to its ability to handle high torque.

3. Diaphragm Spring Clutch: It uses a diaphragm spring to separate the engine and transmission. It is used in vehicles with automatic transmissions.

Classification: Clutches can also be classified based on the mechanism used to engage and disengage the clutch. These include friction clutches, hydraulic clutches, and electromagnetic clutches.

Function: The clutch operates by gripping and releasing the spinning shafts of the engine and transmission, enabling them to be separated and connected as needed. The clutch is typically operated by a pedal or lever, which is used to engage and disengage the clutch.

Applications: Clutches are used in a wide range of vehicles, including cars, trucks, and motorcycles.

Advantages:

1. Enables smooth shifting of gears

2. Allows for control over the speed of the vehicle

3. Reduces wear on the transmission and engine

Limitations:

1. Clutches can wear out over time, leading to slipping and reduced performance

2. Clutches can be expensive to replace

Requirements of a Good Clutch:

1. Smooth engagement and disengagement

2. High torque capacity

3. Durable and reliable

4. Easy to operate

Components of a Clutch:

1. Pressure Plate

2. Clutch Disk

3. Throw-Out Bearing

4. Flywheel

Working of a single plate clutch

A single plate clutch with a coil spring works by using a pressure plate to apply pressure to a clutch disk. The pressure plate is connected to the engine flywheel and the clutch disk is connected to the transmission input shaft. The clutch disk is positioned between the pressure plate and the flywheel, and the coil spring is positioned between the pressure plate and the clutch disk. When the clutch pedal is depressed, the pressure plate moves away from the clutch disk, reducing the pressure applied to the disk and allowing it to spin freely. When the clutch pedal is released, the pressure plate moves back toward the clutch disk, applying pressure to it and causing it to engage the flywheel. The coil spring provides a biasing force that helps return the pressure plate to its engaged position. 

Gearbox 

A gearbox is a mechanical device that transmits power and torque from an engine to the wheels of a vehicle. It acts as a gear-reducing mechanism to change the speed and torque of the power output from the engine to the wheels, allowing the vehicle to move at different speeds. There are several types of gearboxes, including manual, automatic, and continuously variable transmission (CVT).

Classification:

1. Manual gearbox - a gearbox that is operated by a driver using a gear lever and a clutch pedal. eg. Sliding mesh gearbox

2. Automatic gearbox - a gearbox that automatically changes gears based on the vehicle speed and engine RPM.

3. CVT gearbox - a gearbox that uses a belt and pulley system to continuously vary the gear ratio, providing smooth and seamless acceleration.

Function:

The main function of a gearbox is to transmit power from the engine to the wheels while controlling the speed and torque. It allows the vehicle to operate at different speeds by changing the gear ratio between the engine and the wheels.

Application:

Gearboxes are used in a wide range of vehicles, including cars, trucks, motorcycles, and even construction equipment. They are used to provide control over the speed and torque of the vehicle, allowing it to move efficiently and smoothly.

Advantages:

1. Improved fuel efficiency - a gearbox can help optimize engine RPM and reduce fuel consumption.

2. Better performance - a gearbox can provide better acceleration and top speed by changing the gear ratio.

3. Increased control - a gearbox provides the driver with control over the speed and torque of the vehicle.

Limitations:

1. Complexity - gearboxes are complex mechanical systems that can be prone to failure.

2. Maintenance - regular maintenance is required to keep a gearbox functioning properly.

3. Cost - gearboxes can be expensive to repair or replace.

List of Components:

1. Gears

2. Bearings

3. Shafts

4. Synchronizers

5. Clutch

6. Selector fork

7. Shift fork

8. Shift drum

Requirements of a Good Gearbox:

1. Smooth and accurate shifting

2. Low noise and vibration levels

3. High durability and reliability

4. Efficient power transmission

5. Compatibility with the engine and vehicle characteristics.

Sliding mesh gearbox is a transmission system that consists of various sets of gears and shafts that are arranged together in an organised fashion and the shifting or meshing of different gear ratios is done by the sliding of gears towards right and left over the splined shaft with the help of a gear lever operated by the driver. 

First gear

First gear provides maximum torque at low speed which is obtained when the smallest gear on the lay shaft meshes with the biggest gear on the main shaft in order to provide high torque.

Second gear

Second gear provides less torque and higher speed than first gear and is obtained when the middle size gear of the main shaft meshes with the second smallest gear on the lay shaft and high speed and second high torque is transmitted to the final drive.

Third gear

Third gear provides maximum speed and minimum torque to the final drive and is also known as high-speed gear or top gear in sliding mesh gearbox, this gear is obtained when the smallest gear of the main shaft meshes with the biggest gear of the lay shaft. Or we can say that the drive obtained a maximum speed of the clutch shaft.

Reverse gear

When the reverse gear is selected, the rotation of the output shaft is reversed which is made possible by using an idler gear between the main shaft and lay shaft that changes the rotation of the output shaft and the vehicle starts moving in the reverse direction.

Propeller shaft

The propeller shaft, also known as the drive shaft, is a component of a vehicle's powertrain that transmits torque from the engine to the differential, which in turn drives the wheels. The propeller shaft typically consists of a series of tubes that are joined together by universal joints.

Classification:

1. One-piece propeller shaft

2. Two-piece propeller shaft

3. Constant velocity (CV) joint propeller shaft

Function: The function of the propeller shaft is to transmit torque and power from the engine to the wheels. It also accommodates the up and down movement of the suspension and the relative movement of the wheels during turns.

Application: Propeller shafts are commonly used in rear-wheel drive and four-wheel drive vehicles.

Advantages:

1. They can transmit torque over longer distances compared to a direct drive from the engine to the wheels.

2. They provide a smooth transfer of torque and power.

3. They allow for flexible suspension movement.

Limitations:

1. They are more complex than other drive systems, leading to increased maintenance costs.

2. They are heavier than other drive systems, affecting the vehicle's weight distribution.

3. They can produce more noise, vibration and harshness (NVH) compared to other drive systems.

List of components:

1. Universal Joints

2. Slip Yoke

3. Drive Flange

4. Center Support Bearings

Requirements of a good propeller shaft:

1. Strong and durable construction to withstand high torque loads

2. Properly balanced to minimize vibrations

3. Accurate alignment to prevent vibrations and wear on components

4. Appropriate length to accommodate the suspension travel and wheelbase of the vehicle

5. Lightweight design to reduce the vehicle's overall weight.

Universal joint

A universal joint, also known as a U-joint, is a component in a power transmission system that allows for rotational power to be transferred from one shaft to another when the two shafts are at different angles to each other.

Types:

1. Single U-Joints

2. Double U-Joints

3. Cross and Bearing Kit

Classification:

1. Constant velocity joints (CV joints)

2. Pin and Block Joints

Function:

A universal joint transfers torque from one rotating shaft to another while accommodating misalignment between the shafts.

Applications:

Universal joints are used in a variety of applications, including automotive drivetrains, industrial machinery, and power transmission systems.

Advantages:

1. Can accommodate misalignment between shafts

2. Can transfer rotational power between shafts

3. Can maintain torque output over a range of operating angles

Limitations:

1. Limited angle of rotation

2. Can cause vibration and noise

List of Components:

1. Yoke

2. Cross

3. Bearings

4. Retaining Rings

Requirements of a Universal Joint:

1. High strength and durability

2. Ability to handle high torque loads

3. Good resistance to wear and corrosion

4. Accurate alignment and balance.

Differential 

The differential gearbox, also known as the differential, is a key component in the power transmission system of a vehicle. It's main function is to distribute torque from the engine to the wheels while allowing them to rotate at different speeds.

Types:

1. Open differential

2. Limited slip differential (LSD)

3. Locking differential

4. Torsen differential

Classification:

1. Based on number of drive wheels - Single-Wheel Drive and Dual-Wheel Drive

2. Based on type of gears - Bevel Gear Differential, Worm Gear Differential, Epicyclic Gear Differential

Function:

1. To distribute torque to the driving wheels

2. To allow the wheels to rotate at different speeds during turns

3. To reduce wheel spin and improve traction

Application:

The differential gearbox is used in rear-wheel drive and four-wheel drive vehicles.

Advantages:

1. Improved traction

2. Better handling during turns

3. Reduced wheel spin

Limitations:

1. Higher maintenance cost

2. Complex design

List of components:

1. Pinion gear

2. Crown wheel

3. Side gears

4. Bearings

5. Case

Requirements of a good differential gearbox:

1. Durable and reliable construction

2. Efficient operation

3. Ability to handle high torque

4. Good lubrication

5. Proper gear meshing.

Axles 

Axles are mechanical components that transfer power from the vehicle's engine to the wheels and allow the wheels to rotate. They play a crucial role in the functioning of the vehicle's suspension and steering systems. Axles are typically classified into two main types: live axles and dead axles.

Live Axles: Live axles are used in vehicles with rear-wheel drive and transfer power to the wheels through a differential. They are connected to the drive shaft and are equipped with bearings that allow them to rotate with the wheels.

Dead Axles: Dead axles do not transfer power to the wheels and are used mainly for support. They are typically found in vehicles with front-wheel drive or in trailers.

Functions:

• Transfers power from the engine to the wheels.

• Supports the weight of the vehicle and the load carried.

• Maintains the alignment of the wheels and ensures stability of the vehicle while driving.

Applications: Axles are used in a variety of vehicles, including cars, trucks, buses, and trailers.

Advantages:

• Improved traction and stability

• Better weight distribution

• Increased efficiency

Limitations:

• Complex and expensive components

• Increased maintenance and repair costs

• Limited design options

Requirements of a Good Axle:

• Strength and durability

• Proper alignment with the wheels and other components

• Ability to withstand high load and torque

• Efficient design to minimize friction and increase efficiency

• Adequate lubrication to reduce wear and tear

List of Components:

• Shaft

• Bearings

• C-Clips

• Axle Housing

• Axle Shafts

• Universal Joints

• Axle Flange

Vehicle active safety

Vehicle active safety refers to the various systems and technologies installed in a vehicle that actively enhance the safety of the vehicle and its occupants in real-time during the operation of the vehicle. Some examples of active safety systems include:

1. Anti-lock Braking System (ABS)

2. Electronic Stability control (ESC)

3. Traction control system (TCS)

4. Lane departure warning system (LDWS)

5. Adaptive cruise control (ACC)

6. Blind spot monitoring (BSM)

7. Forward collision warning (FCW)

8. Automatic emergency braking (AEB)

These systems use sensors, cameras, and other components to detect potential safety issues and take immediate action to prevent or mitigate the consequences of an accident. The primary objective of vehicle active safety systems is to reduce the likelihood of accidents and to minimize the severity of any accidents that may occur.

Vehicle passive safety

Vehicle passive safety refers to the safety measures in a vehicle that protect the occupants in the event of a crash or collision. These measures are designed to minimize injury to the passengers, regardless of the cause of the accident. Passive safety features do not require the driver's active involvement and are automatically activated in the event of an accident.

Examples of passive safety features include:

• Seat belts

• Airbags

• Crumple zones

• Child safety seats

• Side-impact protection

• Rollover protection

• Energy-absorbing steering columns

• Reinforced doors and roof pillars.

Requirements of good passive safety include:

• Proper design and placement of safety features

• Compliance with safety standards and regulations

• Consistently high-quality construction and materials

• Proper maintenance and function of all safety systems.

Anti-lock Braking System (ABS)

Anti-lock Braking System (ABS) is a safety system in automobiles that helps prevent wheel lockup during braking, allowing the driver to maintain steering control. ABS works by using sensors to detect when a wheel is about to lock up and then rapidly pumping the brakes to prevent lockup.

Classification:

• 1-Channel ABS: equipped with 1 wheel speed sensor and can control 1 wheel.

• 2-Channel ABS: equipped with 2 wheel speed sensors and can control 2 wheels.

• 4-Channel ABS: equipped with 4 wheel speed sensors and can control all 4 wheels.

Functions:

• Maintaining vehicle stability during braking by preventing wheel lockup

• Improving steering control during sudden braking

• Reducing stopping distances

• Preventing skidding and loss of traction

Applications:

• Passenger vehicles

• Light commercial vehicles

• Heavy commercial vehicles

Advantages:

• Improved safety and control during braking

• Shorter stopping distances

• Improved stability and handling

• Reduced risk of skidding

Limitations:

• ABS components can wear out over time and requirespeed maintenance or replacement

• ABS can make the vehicle more difficult to control in certain conditions such as snow or ice

• ABS components can add weight and cost to the vehicle.

Components:

• Wheel speed sensors

• ABS control module

• Valves and pumps

• Hydraulic unit

Requirements of ABS:

• Adequate brake system components

• Proper installation and maintenance of ABS components

• Proper functioning of wheel speed sensors and other ABS components

• Compatibility with the vehicle's braking system.

 Seat Belts

Seat belts are a crucial component of a vehicle's passive safety system. They work by restraining the occupant's body during a crash or sudden deceleration, reducing the risk of injury or death.

Types of Seat Belts:

1. Lap Belt: A single strap that goes across the lap and provides minimal protection in the event of a crash.

2. Lap-Shoulder Belt: A combination of a lap belt and a shoulder belt that provides more comprehensive protection to the torso and upper body.

Classification of Seat Belts:

1. Manual Seat Belts: Require the driver or passenger to manually fasten the seat belt before driving.

2. Automatic Seat Belts: Automatically engage as soon as the door is closed, providing more convenience and reducing the chance of forgetting to fasten the seat belt.

Functions:

1. Reduces the risk of injury or death in the event of a crash.

2. Holds the occupant in place, preventing them from hitting the steering wheel, dashboard, or other parts of the vehicle during a collision.

Applications:

1. Used in cars, trucks, buses, and other types of vehicles.

2. Required by law in most countries to be fitted in all vehicles.

Advantages:

1. Improves the chances of surviving a crash.

2. Provides protection to the entire upper body and torso.

3. Simple and low-cost technology.

Limitations:

1. Not effective if not used correctly, i.e., not wearing the seat belt correctly or not fastening it at all.

2. Some people find it uncomfortable to wear seat belts, reducing their usage.

List of components:

1. Seat Belt Webbing

2. Seat Belt Retractor

3. Seat Belt Buckle

4. Seat Belt Pretensioner

5. Seat Belt Tensioner

Requirements of good seat belts:

1. Adequate strength to restrain the occupant's body during a crash.

2. Easy to fasten and adjust for a secure and comfortable fit.

3. Effective in preventing the occupant from hitting parts of the vehicle during a collision.

4. Compatible with other safety features of the vehicle, such as airbags.

Airbags

An airbag is a passive safety device in an automobile that helps to protect the occupants of the vehicle during a crash. It is an inflatable cushion that is deployed in the event of a collision, providing a barrier between the occupant and the vehicle's interior. Airbags are designed to deploy in a fraction of a second and are intended to work in conjunction with seat belts to provide maximum protection.

Types of airbags:

1. Driver's airbag

2. Passenger airbag

3. Side airbags

4. Knee airbags

5. Curtain airbags

Classification:

1. Front airbags

2. Side airbags

3. Head airbags

Function:

Airbags are designed to provide cushioning to the occupants of the vehicle during a crash, reducing the risk of injury and increasing the chances of survival. They are inflated by a gas generator in the event of a crash, creating a barrier between the occupant and the vehicle's interior.

Applications:

Airbags are used in passenger vehicles, trucks, and buses to provide passive safety to the occupants.

Advantages:

1. Provide additional protection in the event of a crash

2. Reduce the risk of injury and increase the chances of survival

3. Deploy quickly and efficiently

4. Inflatable, providing a cushioning effect

Limitations:

1. High cost

2. Limited protection in the event of a side impact

3. Airbags can cause injury if they deploy too close to the occupant

List of components:

1. Gas generator

2. Inflator

3. Sensors

4. Airbag module

5. Seat belts

Requirements of good airbags:

1. Quick and efficient deployment

2. Adequate cushioning effect

3. Proper deployment distance from the occupant

4. Robust and reliable components

5. Compatibility with seat belts and other passive safety systems.