KARNATAUKA LAW SOCIETY’S

GOGTE INSTITUTE OF TECHNOLOGY

UDYAMBAG, BELAGAVI-590008
(An Autonomous Institute under Visvesvaraya Technological University, Belagavi)
(Approved by AICTE, New Delhi)

DEPARTMENT OF MECHANICAL ENGINEERING

Academic Year 2023−2024

Course Seminar Report on:

“Evolution of car braking system”

Course:
Machine Design
(21ME62)
SUBMITTED BY:
Name USN
Abhishek Khangaonkar 2GI22ME400
Vighnesh Karant 2GI21ME109
Ganaraj Karekar 2GI22ME416
Sahil Gulabani 2GI21ME071

Course Incharge:
Prof. Venkatesh Deshpande
 Acknowledgment
We would like to express our sincere gratitude to Prof. Venkatesh Deshpande
for guidance. The technical discussions with Prof. Venkatesh Deshpande are
always very insightful, and we will always be indebted to him for all the
knowledge he has shared with us. His prompt responses and availability despite
his busy schedule were truly appreciated. The reality is that Prof. Venkatesh
Deshpande was much more than an advisor to us. He always helped us with all
technical and non-technical issues during our period of work.
 Abstract

This report explores the evolution of car braking systems, tracing their development from
early mechanical designs to today’s advanced electronic systems. Initially, car brakes were
simple mechanical devices, relying on rudimentary technology to provide stopping power.
Over time, innovations such as hydraulic brakes, disc brakes, and anti-lock braking systems
(ABS) emerged, each offering significant improvements in safety and performance. Modern
braking systems now incorporate sophisticated electronics, including electronic stability
control (ESC) and advanced driver-assistance systems (ADAS), enhancing vehicle control and
safety. Looking to the future, the report examines emerging technologies such as
regenerative braking in electric vehicles and autonomous braking systems, which promise to
further revolutionize automotive safety and efficiency. By analyzing the historical
progression and future trends of car braking systems, this report aims to provide a
comprehensive understanding of their critical role in automotive development.
 Contents
 Introduction
 History
 Drum Brakes
 Disc Brakes
 Anti-lock Braking System
 Regenerative Braking
 Conclusion
 Introduction
The braking system is one of the most critical components of a vehicle, directly
impacting safety and performance. Since the inception of the automobile, the
technology and design of braking systems have undergone significant evolution.
Early cars relied on primitive mechanical brakes, which were often unreliable
and inefficient. As automotive technology advanced, so did the braking
systems, with the introduction of hydraulic brakes in the early 20th century
marking a significant leap forward. This was followed by the development of
disc brakes and the advent of anti-lock braking systems (ABS), each innovation
enhancing braking efficiency, control, and safety.

This report aims to provide a comprehensive overview of the evolution of car

braking systems, examining their historical development, current state, and
future prospects. By understanding the advancements in braking technology, we
can appreciate the pivotal role these systems play in automotive safety and
innovation.
 History

Early mechanical brakes were the first type of braking systems used in
automobiles, dating back to the late 19th and early 20th centuries. These
brakes were relatively simple and relied entirely on mechanical linkages and
physical force to stop the vehicle.

Mechanical brakes typically operated using a system of levers, rods, and

cables. When the driver pressed the brake pedal, the force was transmitted
through these linkages to apply friction to the wheels. The most common
design was the drum brake, where brake shoes pressed outward against the
inside of a rotating drum attached to the wheel. This friction slowed down and
eventually stopped the vehicle.

The simplicity of mechanical brakes was both an advantage and a limitation.

While they were straightforward to design and manufacture, they had several
significant drawbacks:

 Inefficiency: Mechanical brakes required a considerable amount of force

to be applied by the driver, often leading to inconsistent braking
performance.
 Wear and Tear: The mechanical linkages and components were prone to
wear and tear, which could lead to frequent maintenance and
adjustments.
 Heat Dissipation: Drum brakes, in particular, had poor heat dissipation,
which could cause brake fade during prolonged use, reducing their
effectiveness.
 Reliability: Mechanical systems were less reliable, as dirt, corrosion, and
stretching of cables could impair performance.
 Drum Brakes

Drum brakes are a type of braking system that was widely used in automobiles throughout much of
the 20th century. They operate by using friction to slow down and stop the vehicle. The design of
drum brakes involves several key components and a specific mechanism to achieve this.

Components and Design

 The brake drum is a cylindrical component attached to the wheel hub. When the wheel
rotates, the drum rotates along with it.
 Inside the drum are curved friction material pads, known as brake shoes. These shoes are
mounted on a stationary backing plate.
 The wheel cylinder is a hydraulic component that contains pistons. When brake fluid is
pressurized, the pistons push the brake shoes outward.
 Return springs retract the brake shoes back to their original position when the brake pedal is
released.
 The backing plate is a metal plate that serves as a mounting point for the brake shoes,
springs, and wheel cylinder, and also protects the internal components from road debris.

Working

When the driver presses the brake pedal, hydraulic pressure is generated in the master cylinder and
transmitted through brake lines to the wheel cylinder in each drum brake. The pressurized brake
fluid pushes the pistons in the wheel cylinder, which in turn forces the brake shoes outward against
the inner surface of the rotating drum. The friction between the brake shoes and the drum slows
down and eventually stops the rotation of the wheel.

Advantages

 Drum brakes are generally cheaper to manufacture and maintain compared to disc brakes.
 Drum brakes can provide adequate braking force and are durable in certain conditions.
 In drum brakes, the rotation of the drum can help pull the brake shoes into contact,
requiring less force from the driver to achieve effective braking.
Disadvantages

 Drum brakes have poor heat dissipation because the drum encloses the braking
components. This can lead to brake fade under heavy or prolonged braking.
 The design of drum brakes is more complex due to the numerous springs and moving parts,
making them harder to service.
 Drum brakes are typically heavier than disc brakes, which can impact vehicle performance
and fuel efficiency.
 Drum brakes can be less effective when wet, as water can get trapped inside the drum,
reducing friction.

Despite these drawbacks, drum brakes were the standard for many years and are still used in certain
applications, particularly in the rear wheels of some vehicles, where less braking force is required
compared to the front wheels. The evolution to disc brakes, with their superior performance in
terms of heat dissipation, responsiveness, and maintenance, has largely supplanted drum brakes in
modern vehicles, especially in the front wheels where the majority of braking force is needed.
 Disc Brakes
Disc brakes are a type of braking system that has become the standard in modern automobiles due
to their superior performance and reliability compared to drum brakes. They use a caliper to
squeeze pairs of pads against a disc or rotor to create friction, which slows down and stops the
vehicle.

Components and Design

 The brake disc (rotor) is a flat, circular metal component attached to the wheel hub. It
rotates with the wheel and provides the surface against which the brake pads press to
create friction.
 The brake caliper is a component that houses the brake pads and pistons. It straddles the
brake disc and can be of two types: floating (sliding) calipers or fixed calipers.
 The brake pads are friction materials mounted inside the caliper. When the brake is applied,
the pads are pressed against the rotor to create the necessary friction to slow down the
vehicle.
 The pistons inside the caliper are activated by hydraulic pressure from the master cylinder
when the brake pedal is pressed. The pistons push the brake pads against the disc.

Working

When the driver presses the brake pedal, hydraulic pressure is generated in the master cylinder and
transmitted through brake lines to the pistons in the brake caliper. The pistons then push the brake
pads against the rotating disc. The friction between the pads and the disc slows down and eventually
stops the wheel’s rotation.

Advantages

 Disc brakes have better heat dissipation compared to drum brakes. The open design of disc
brakes allows air to flow freely around the disc, helping to cool it down more effectively,
which reduces the risk of brake fade during prolonged use.
 They provide more consistent braking performance. Disc brakes are less susceptible to
performance degradation under heavy or prolonged braking compared to drum brakes.
 Disc brakes offer better responsiveness and shorter stopping distances, especially in
emergency braking situations. They provide a more immediate and precise response when
the brake pedal is pressed.
 They are easier to maintain and service compared to drum brakes. Inspection and
replacement of brake pads and discs are generally simpler and quicker, reducing
maintenance time and costs.
Disadvantages

 Disc brakes can be more expensive to manufacture and replace compared to drum brakes,
primarily due to the complexity of the caliper and rotor components.
 They are more susceptible to corrosion, especially in regions with harsh climates. The
exposed rotor surface can rust, affecting braking performance and longevity if not properly
maintained.

In summary, disc brakes represent a significant advancement in automotive braking technology,

offering superior performance, reliability, and safety compared to drum brakes. Their ability to
provide consistent braking performance, better heat dissipation, and improved responsiveness has
made them the preferred choice for most vehicles today, especially in applications where high
performance and safety are paramount.
 Anti-lock Braking System

The Anti-lock Braking System (ABS) is an advanced safety feature that revolutionized
automotive braking technology by preventing wheels from locking up during braking, thus
maintaining steering control and vehicle stability.

ABS utilizes a combination of electronic sensors, hydraulic valves, and a control module to
monitor and modulate brake pressure at each wheel independently. Key components include
wheel speed sensors, which monitor rotation speed and send signals to the ABS control
module. This module, in turn, adjusts hydraulic pressure through valves in the brake lines to
prevent wheel lock-up.

When a driver applies the brakes, the ABS control module continuously monitors wheel
speed. If it detects a wheel is on the verge of locking up such as during hard braking or on
slippery surfaces it rapidly modulates brake pressure by releasing and reapplying it in rapid
succession. This pulsating action prevents the wheel from locking up and maintains traction
with the road surface.

ABS offers several advantages. It significantly improves steering control by preventing

wheels from locking, allowing the driver to maintain directional stability during emergency
braking or on slippery roads. This feature also reduces stopping distances by maintaining
traction and stability, enhancing overall vehicle safety. ABS works in conjunction with
electronic stability control (ESC) and traction control systems (TCS), further improving
vehicle stability and control in various driving conditions.

However, ABS may slightly increase stopping distances on loose or gravel surfaces where
locked wheels can help slow the vehicle. Additionally, ABS systems are more complex and
expensive compared to traditional braking systems, which can impact vehicle manufacturing
and maintenance costs.

In conclusion, ABS is a critical safety feature that has dramatically enhanced vehicle braking
performance and safety by preventing wheel lock-up and enabling drivers to maintain control
during braking manoeuvres. Its integration into modern vehicles has significantly contributed
to safer driving conditions and reduced the incidence of accidents caused by loss of control
during braking.
 Regenerative Braking
Regenerative braking is a technology used in hybrid and electric vehicles to
recover and store kinetic energy that would otherwise be lost as heat during
braking. This energy can then be reused to improve overall vehicle efficiency
and increase range.

Regenerative braking works on the principle of converting kinetic energy into

electrical energy. Here’s how it typically operates:

1. Mechanism: When the driver applies the brakes or lifts off the
accelerator, the electric motor or motors in the vehicle operate in reverse,
becoming generators. This reversal causes the wheels to drive the
motor(s), converting kinetic energy into electrical energy.
2. Energy Conversion: The electrical energy generated during regenerative
braking is fed back into the vehicle’s battery pack. This process allows
the battery to be recharged while the vehicle is decelerating or coming to
a stop.
3. Benefits: The primary benefit of regenerative braking is improved energy
efficiency. By capturing and storing energy that would otherwise be lost
as heat through friction brakes, regenerative braking can significantly
extend the driving range of electric vehicles and improve fuel efficiency
in hybrid vehicles.
4. Effectiveness: Regenerative braking is most effective in city driving or in
stop-and-go traffic conditions, where frequent braking and acceleration
cycles occur. In these scenarios, it can recover a substantial amount of
energy that would otherwise be wasted.
5. Integration: Regenerative braking systems are typically integrated with
traditional friction brakes to provide seamless braking performance under
all driving conditions. The vehicle’s onboard computer manages the
transition between regenerative and friction braking based on factors such
as vehicle speed, battery charge level, and braking force applied by the
driver.
 6. Challenges: One challenge with regenerative braking is its effectiveness
at low speeds or during emergency braking situations, where most
braking energy is dissipated as heat rather than being recoverable through
regenerative means.

Conclusion
Regenerative braking has revolutionized automotive technology by effectively capturing and
storing kinetic energy during braking, thereby improving energy efficiency and extending the
range of electric and hybrid vehicles. This technology has proven its capability to reduce
reliance on traditional friction brakes, offering tangible benefits in terms of fuel economy and
environmental sustainability. As automotive manufacturers increasingly adopt regenerative
braking systems, the technology continues to play a crucial role in advancing greener
mobility solutions and mitigating the environmental impact of transportation.
 Future Scope

Looking ahead, the future of regenerative braking holds immense potential for further
innovation and refinement. Continued research and development efforts are focused on
enhancing the efficiency and reliability of regenerative systems across diverse driving
conditions. Advances in sensor technology, materials science, and control algorithms will
contribute to optimizing energy recovery and integration with other vehicle systems.
Moreover, as electric vehicle adoption grows, advancements in battery technology and
energy storage solutions will complement regenerative braking, paving the way for even
greater efficiency gains and expanded applications in the automotive industry. Regenerative
braking is poised to remain a cornerstone of sustainable transportation strategies, driving
towards a cleaner and more efficient future for mobility worldwide.