ELECTRONIC STABILITY PROGRAM

The greatest safety invention after seat belts

What is ESP?

A computerized technology that improves a vehicle's stability by

detecting and reducing loss of traction

TRACTION

A physical process in which a force is transmitted across an interface between two bodies through dry friction

The grip of a tyre on a road

Factors affecting traction

Material composition of each surface Macroscopic and microscopic texture Normal force pressing contact surfaces Contaminants at the material boundary, i.e. lubricants and

adhesives Relative motion of tractive surfaces - a sliding object has less

traction than a non-sliding object Direction of traction - e.g., cornering, accelerating, and braking.

Importance of Traction

It allows for higher acceleration at cornering without wheel slippage

Contact of wheels with ground increase stability

History of ESP

First iteration in 1980 by BMW Mercedes steps in, in 1992 with supplier Bosch Toyota introduces Vehicle Stability Control (VSC)

in 1995 General Motors begins introduces ESP in 1997 European Union makes ESP mandatory in 2009

Basic Physical Principles

Tractive force

Brake pressure Lateral force

Adhesion force

Basic Physical Principles

Yaw moment

Wheel and inertia moments

Basic Physical Principles

Concept of Friction Circle

Radius of friction circle

Resultant force

Inter-relationships between forces

Total force within friction circle

Low lateral force (s)

Total force=Brake pressure

Components of ESP

Steering wheel angle sensor Yaw rate sensor Lateral acceleration sensor Wheel speed sensor Longitudinal acceleration sensor Roll rate sensor

What does ESP do?

It decides-1. What wheel to brake or accelerate and to

what extent,2. Whether engine torque is reduced and3. Whether the gearbox control unit is activated

on vehicles with automatic gearbox.

How does ESP work?Speed

sensors provide

continous data

Control units

calculate desired steering action

Lateral and Yaw

sensors send

information

Calculates actual

state of vehicle

If actual and

desired values don’t

match, it intervenes

Checks if intervention successful

If yes, ends intervention

If no, repeats intervention

cycle

SENSORS/COMPONENTSCode Sensor name Location Function

J104Control unit

Front right footwell

Processing, monitoring,

commanding

G85Steering angle

sensorBetween steering column and wheel

Transfers steering wheel angle to control

unit

G200Lateral

acceleration sensor

Below driver’s seat

Determines action of lateral

forces on stability

G202 Yaw rate sensor Below driver’s seat

Determines action of torque

G201Brake pressure

sensorConnected to

hydraulic pumpCalculates

wheel braking forces

---- Button for ESP Dashboard Switch ESPon/off

EFFECTIVENESS ESC reduces crashes by 35%- National Highway

and Traffic Safety Administration, USA Upto 10,000 fatal US crashes could be

avoided annually- US Institute for Highway Safety

Improved vehicle handling reduces skids and rollovers

Induces rider confidence

COST AND AVAILABILITY Available in Indian cars even under 10

lac rupees:

Ford Ecosport 1.5 Hyundai i20 Renault Duster Hyundai Verna Nissan Micra

FUTURE SCOPE

ESP to be mandated in Japan, Korea, Russia, and Turkey in the coming years

Developing of newer algorithms to tackle problems like trailer sway, in the effect of vehicle towing

Then, now, and future

India

CONCLUSION Life saving technology An aid to human, not a substitute to

human Safe driving habits are must

References “Bosch InnoWaves”, News and Information for Customers of Bosch Automotive Technology OE

Sales & Marketing | Issue 20 | May 2014   “Electronic Stability Programme”, Self-study Programme no. 204, 840.2810.23.20,

Volkswagen Technologies  “Brief history of Electronic Stability System”,

http://www.safetyresearch.net/blog/articles/brief-history-electronic-stability-controls-and-their-applications

“Bosch predicts acceptance of ESP in Indian Vehicles” http://www.autocarpro.in/news-international/bosch-acceptance-esp-indian-vehicle-growing-percent-2021-6715 

"Real world crash evaluation of vehicle stability control (VSC) technology", G. Bahouth.  

"The Effectiveness of ESC (Electronic Stability Control) in Reducing Real Life Crashes

and Injuries", Anders Lie, Claes Tingvall, Maria Krafft, and Anders Kullgren, of the 19th Enhanced Safety of Vehicles Conference, 2005

The Greatest Advance in Safety Since Seatbelts, retrieved 2007-12-28  "Traction Control System for Improved Driving Safety", SAE Technical Papers

THANK YOU