This document provides an overview of vehicle dynamics, tools, and techniques for assessing vehicle dynamics. It discusses various aspects of vehicle dynamics including body flex, roll, bump steer, directional stability, understeer, oversteer, pitch, roll, yaw, noise vibration and harshness, ride quality, and speed wobble. It also discusses power and torque characteristics of automobiles, including engine power output, automotive resistances and propulsive power, tractive resistance and propelling power. Finally, it discusses various tests and measurements that can be performed on test vehicles, including bench tests to determine center of gravity and moment of inertia, as well as driving tests and tests to determine brake force distribution.

1. A
REPORT
ON
VEHICLE DYNAMICS, TOOLS AND TECHNIQUE
TO ASSES VEHICLE DYNAMICS
SUBMITTED TO SUBMITTED BY
Mr. R.K. AMBIKESH SHIVANAND
ASSISTANT PROFESSOR Final ME
(ROLL NO: 3604540010)
DEPARTMENT OF MECHANICAL ENGINEERING
HARCOURT BUTLER TECHNICAL UNIVERSITY
KANPUR, 208002
APRIL, 2019

2. ACKNOWLEDGEMENT
First of all I would like to acknowledge the help provided to me by our presentation guide Mr.
R. K. AMBIKESH for his valuable guidance, constant encouragement and kind help at different
stages for the execution of this dissertation work. I would also like to thank our HOD Prof. ANAND
KUMAR SIR who finalized the topic and gave useful tips regarding the approach and the objectives
to be kept in mind while making this seminar. I would also like to acknowledge the help of my
classmates who helped me with the content that was to be included in this project. Last but not the
least; I would like to thank the college management for providing us with an environment apt for such
activities and a library that was of great use for extracting knowledge in the concerned field of my
seminar. I express my heartfelt gratitude to them for their help and support, this seminar is a result of
our combined efforts and hard work.
SHIVANAND
3604540010
Mechanical Engineering
HBTU Kanpur

3. ABSTRACT
The overall objective of this compendium is to contribute to education of automotive engineers
with good skills to design for, and verify, requirements on complete vehicle level functions,
regarding vehicle dynamics or motion. It is important to qualitatively understand the characteristics
of the vehicle’s sub-systems and, from this, learn how to quantitatively predict and analyse the
vehicle’s behaviour. These skills support the overall goal of engineering design for desired
attributes and functions. It is an applied subject, applied on a certain group of products, namely
vehicles. Vehicle Dynamics always uses theories and methods from Mechanical engineering, but
often also from Control/Signal engineering and Human behavioural science. Attributes and
Functions are used to establish processes and structures for requirement setting and verification
within a vehicle engineering organisation. Such processes and structures are important to enable a
good overall design of such a complex product as a vehicle intended for mass production at
affordable cost for the customers.

4. TABLE OF CONTENT
TOPIC PAGE NO.
TITLE PAGE………………………………………………………………………..………..…...…I
ACKNOWLEDGEMENT………………………………………………………………...…………II
ABSTRACT……………………………………………………………………………....………...III
1. INTRODUCTION……………………………………………………………...….………….…..1
2. ASPECTS OF VEHICLE DYNAMICS ……………………………………………………….…2
2.1 BODY FLEX…………………………………………………………………………….......2
2.2 BODY ROLL. ………………………………………………………………………….…....2
2.3 BUMP STEER……………………………………………………………………….……....2
2.4 BUNDORF ANALYSIS..…………………………………………………………….…...…3
2.5 DIRECTIONAL STABILITY………………………………………………………….……3
2.6 UNDERSTEER, OVERSTEER .………………………………………..………………..….3
2.7 PITCH.. ………………………………………………………………………….……..….…4
2.8 ROLL……………………………………………………………………………………........5
2.9 YAW……………………………………………………………………………………..…...5
2.10 NOISE, VIBRATION, AND HARSHNESS…………………………………………..…....5
2.11 RIDE QUALITY. ………………………………………………..……………………..…...5
2.12 SPEED WOBBLE.. ………………………………………………………………..…..……5
2.13 WEIGHT TRANSFER AND LOAD TRANSFER.……………………………………........5
3. POWER AND TORQUE CHARACTERISTICS OF AUTOMOBILE……………………...…….7
4. ENGINE POWER OUTPUT……………………………………………………………………......7
4.1. INDICATED POWER (IP)…………………………………………………………………..7
4.2. BRAKE POWER (BP) ……………………………………………………………......….…8
4.3. FRICTIONAL POWER (FP) ………………………………………………….…………….8
4.4. TAXABLE HORSEPOWER (THP)……………………………………………...……….…8
4.5. DRAWBAR POWER (DHP)……………………………………………………..……….…9
5. AUTOMOTIVE RESISTANCES AND PROPULSIVE POWER……………………………..…...9
5.1. ROAD RESISTANCES………………………………………………………………......….9
(A) ROLLING RESISTANCE ……………………………………………………....……9
(B) FRICTIONAL RESISTANCES………………………………………………...……10

5. 5.2. ROAD GRADIENT RESISTANCE …………………………………………………...11
5.3. AIR (OR WIND) RESISTANCE …………………………………………………...….11
5.4. ACCELERATING RESISTANCE…………………………………………….....….…11
6. TRACTIVE RESISTANCE AND PROPELLING POWER ………………………….…..….12
7. MEASUREMENT OF THE TEST VEHICLES………………………………………............13
7.1. BENCH TESTS…………………………………………………………………….......13
7.1.1. LOCATION OF CENTRE OF GRAVITY……………………………….....…..13
7.1.2. MOMENT OF INERTIA………………………………………………......……14
7.2. BRAKE FORCE DISTRIBUTION………………………………………………........16
7.3. DRIVING TESTS……………………………………………………………….……..17
8. CONCLUSION………………………………………………………………………………..18