Semi – Automatic Cadence Braking System

P R O J E C T M E M B E R S

J O S E P H U S K I N G S T O N B E R Y L S I N G H S . ( 9 6 9 1 0 1 1 4 0 2 3 )M U T H U K U M A R M . ( 9 6 9 1 0 1 1 4 0 3 4 )S A N T H O S H K U M A R S . ( 9 6 9 1 0 1 1 4 0 4 8 )U M A R M U K T H A R A . M . ( 9 6 9 1 0 1 1 4 0 6 1 )

U N D E R T H E G U I D A N C E O F

M R . E L A Y A R A J A M . E . ,A S S I S T A N T P R O F E S S O R ,D E PA R T M E N T O F M E C H A N I C A L E N G I N E E R I N G ,S C A D C O L L E G E O F E N G I N E E R I N G A N D T E C H N O L O G Y.

Design and Fabrication Semi – Automatic Cadence Braking System

(SACBS)

Aim

To design and fabricate a Semi-Automatic Cadence Braking system

Objective

To fabricate a low-cost Semi-Automatic emergency braking system which employs cadence braking technique to give the rider decent control of the motorcycle under hard braking.

Literature review

Jingang Yi, Student Member, IEEE, Luis Alvarez, Member, IEEE, and Roberto Horowitz, Member, IEEE – “Adaptive Emergency Braking Control With Underestimation of Friction Coefficient.”

In this paper, a control scheme for emergency braking manoeuvres in automated highway systems (AHSs) and a new online identification scheme to determine the tire–road friction characteristics of the vehicle are presented. The proposed controller determines the required pressure in the master cylinder of the braking system to achieve maximum deceleration during braking, based on the estimation of the tire–road friction characteristics and the overall braking system gain, for the given set of parameter estimates.

Literature review

Kaempchen, N, Sch. of Eng. & Comput. Sci., Univ. of Ulm, Ulm, Germany – “Situation Assessment of an Autonomous Emergency Brake for Arbitrary Vehicle-to-Vehicle Collision Scenarios”

The autonomous emergency brake (AEB) is an active safety function for vehicles which aims to reduce the severity of a collision. An AEB performs a full brake when an accident becomes unavoidable. Even if this system cannot, in general, avoid the accident, it reduces the energy of the crash impact and is therefore referred to as a collision mitigation system. A new approach for the calculation of the trigger time of an emergency brake will be presented.

Types of Braking Techniques

Threshold Braking Technique

It is employed when the rider needs maximum braking performance regardless of steering performance.

When it comes to stopping the vehicle as quickly as possible, threshold braking is most effective.

It is usually practiced by professional racers and can be done properly only with a lot of practice.

Threshold Braking Technique

It is performed as follows-

(1) Squeeze the brake lever with maximum pressure(2) As soon as the wheels start to lockup, gently

reduce the braking pressure (3) When the wheels rotate again, gently increase

the braking pressure (4) Repeat the cycle till the vehicle stops

Threshold Braking Technique

Advantages Shortest braking distance

• Disadvantages Very low steering control Difficult to master

Locked wheels

Under hard braking, if enough traction is not available, the wheels get locked to the brakes

This results in severe loss of steering control and may cause the motorcycle to skip or wheelie depending on the road surface

Although its very dangerous and unpredictable, few studies show that locked wheels have shorter stopping distances than braking using an ABS

Locked Wheels

Cadence Braking Technique

Cadence braking was developed originally for very low grip surfaces such as an icy road

It is essentially applying and releasing the brakes rhythmically in order to get a compromise between steering and braking performance

The purpose of cadence braking is not about how quick the vehicle stops but its rather concerned with how well the vehicle can be controlled under hard braking.

Cadence Braking Technique

It is performed as follows-

(1) Squeeze and release the braking lever in a quick cycle

(2) Steer the motorcycle out of the danger area(3) End the cycle to continue riding or continue the

cycle to bring the vehicle to a halt

Cadence Braking Technique

Advantages Good steering control Better deceleration in slippery surfaces Easy to practice and perform

Disadvantages Long stopping distance

Anti-Lock Braking System (ABS)

It’s an electro-hydraulic system which applies the principles of threshold braking and cadence braking

Its uses a complex system of sensors, pressure relief valves and a hydraulic motor – all controlled by a computer

ABS is the most safest braking solution available, giving an optimum combination of braking and steering performance

Anti-Lock Braking System

Advantages Safest Braking System Optimum combination of braking and steering performance

• Disadvantages Expensive Difficult to service

Anti-Lock Braking System

Semi-Automatic Cadence Braking System

Need Anti-Lock Braking System is still an expensive device

available only on high end motorcycles Hence, there is a need for developing a safety braking device

which is available at a considerably low budget

Main Components

Disk Brake LeverCamDC Electric MotorHydraulic disc brake setupActivation SwitchConnecting Wires

Diagram

Fabrication

For this project, we’ll fabricate our system specifically for the front wheels of a commuter segment motorcycle with standard hydraulic disc brakes

Usually the standard hydraulic disc brakes consist of a metal disc attached to the wheel, brake shoes on either sides of the disc.

When the brake lever is pulled, the actuator pushes the hydraulic fluid from the reservoir to the brakes shoes thus activating the brakes

Fabrication

In the Semi-Automatic Cadence braking system, in the place of the actuator, a cam powered by a small motor is fitted onto the brake lever itself

This motor can be switched ON/OFF by a simple button which is fitted on the motorcycle’s handle bar

The electric power required to run the system is derived from the battery

Working

When the rider pulls the brake lever and activates the SACBS by pressing its activation button, the cam coupled with the motor starts to rotate

Due to the nature of rotation of the cam, the hydraulic fluid will be pumped in and out of the brake pads in quick intervals to simulate the cadence braking technique

Thus, the rider will retain control of the motorcycle as the wheels won’t lockup and will be able to steer the motorcycle safely out of danger’s way.

Semi-Automatic Cadence Braking System

Advantages Inexpensive to own and maintain Compatible with most hydraulic disc brake systems Good steering control in emergency situations Easy to practice and perform

Disadvantages Depends on the rider’s alertness

Observations

Braking with Maximum Braking Pressure

Disc Brakes with no safety systems

Anti-Lock Braking System

Semi-Automatic Cadence braking system

Braking Distance

Short Shortest Long

Manoeuvrability Worst Best Good

Cost (Rs.) 2.500 13,000 2,500+1,516

Conclusion

The Semi-Automatic Cadence braking system was found to be very effective in maintaining the overall steer-ability of the motorcycle even under hard braking. It helps the rider to steer the motorcycle away from danger and at the same time provide ample deceleration through braking.

Thank you

THANK

YOURide safely!!!