DELEVOLPMENT OF SEMI ACTIVE

SUSPENSION SYSTEM

MOHAMMED RAGAB AHMED

B. ENG. (HONS.) MECHATRONICS

ENGINEERING

UNIVERSITI MALAYSIA PAHANG

SUPERVISOR’S DECLARATION

I hereby declare that I have checked this thesis and in my opinion, this thesis is

adequate in terms of scope and quality for the award of the degree of the Bachelor of

Engineering (Hons.) Mechatronics Engineering.

_______________________________

(Supervisor’s Signature)

Full Name : ASSOC. PROF. DR. AHMAD RAZLAN BIN YUSOFF

Position : DEPUTY DEAN

Date : 06 JUNE 2017

_______________________________

(Co-supervisor’s Signature)

Full Name :

Position :

Date :

ii

STUDENT’S DECLARATION

I hereby declare that the work in this thesis is based on my original work except for

quotations and citations which have been duly acknowledged. I also declare that it has

not been previously or concurrently submitted for any other degree at University

Malaysia Pahang or any other institutions.

_______________________________

(Student’s Signature)

Full Name : MOHAMMED RAGAB AHMED

ID Number : FB13061

Date : 06 JUNE 2017

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DEVELOPMENT OF SEMI ACTIVE

SUSPENSION SYSTEM

MOHAMMED RAGAB AHMED

This thesis is submitted as partial fulfilment of the requirements for the award of the

Bachelor of Engineering (Hons.) Mechatronics Engineering

Faculty of Manufacturing Engineering

UNIVERSITI MALAYSIA PAHANG

JUNE 2017

iv

ACKNOWLEDGEMENTS

To the light, Allah subhanahu wa ta’ala, who guided me through the way and led me to

accomplish this fine work, goes my greatest and faithful thanks…

I would like hereby to express my sincere gratitude to my supervisor Assoc. Prof. Dr.

Ahmad Razlan Bin Yusoff for his firm support, encouragement and assistant throughout

the duration of my study in the University. His invaluable guidance provided many ideas,

which have led to the completion of this thesis.

I would like also to express endless gratitude to Mr. Aminuddin Bin Ghazali, who is the

senior specialist and head of Sapura Technical Centre (STC). I want to thank him for

giving me an opportunity to follow my final year project at Supra Industrial. He had the

kindness to accept me in the company and guide me throughout the project with advice,

feedback and tips despite his busy schedule.

And not forgetting to whom I belong, whom are always there for me, my parents,

brothers, sisters and uncles, who gave me everything they could to enable me to reach the

highest possible education level. I only hope that they know how their love, support and

patience encouraged me to fulfil their dream.

And Thanks, are also due to Dr Fadhlur Rahman Bin Mohd Romlay, Muhamad Nurizan

Bin Fakir and Mohamad Amilhasan Shafie for their valuable help and guidance

throughout the project

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TABLE OF CONTENT

DECLARATION

TITLE PAGE

ACKNOWLEDGEMENTS iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENT vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF SYMBOLS xiii

LIST OF ABBREVIATIONS xv

CHAPTER 1 INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 2

1.3 Objectives 2

1.4 Thesis Outline 2

CHAPTER 2 LITERATURE REVIEW 4

2.1 Theory and Literature Review 4

2.2 Concept of Vehicle Suspension System 4

2.3 Passive Suspension System 5

2.4 Semi Active Suspension 6

2.5 Active Suspension System 8

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2.6 Classification of Semi-Active Suspension 9

2.6.1 Position Controlled Valves 9

2.6.2 Electro-Rheological (ER) Fluid 11

2.6.3 Magneto-Rheological (MR) Fluid 11

2.7 Damper Equations 13

2.7.1 Total Flow Rate 13

2.7.2 Semi-Active Valve Flow 14

2.8 Vehicle Dynamics 15

2.9 Ride Quality and Comfort 16

2.9.1 Mathematical Equation for Ride Comfort Analysis 18

2.10 Summary 19

CHAPTER 3 METHODOLOGY 20

3.1 Introduction 20

3.2 Project Guideline 21

3.3 Disassembling and Measurements 22

3.4 Variable Damper System Concept 23

3.5 Hardware Interfacing 24

3.5.1 Design of Individual Parts and Assemblies 24

3.6 Damper Construction 27

3.7 Stepper Motor Driver Circuit 29

3.8 Software Interfacing 29

3.8.1 Flow Chart 31

3.9 Experimental Setting and Testing 33

3.9.1 Vehicle Preparation 35

3.9.2 Motor Installation 35

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3.9.3 Inertial Measurement Unit (IMU) Installation 36

3.9.4 Testing Procedure 37

3.9.5 Safety Precaution 39

CHAPTER 4 RESULTS AND DISCUSSION 40

4.1 Introduction 40

4.2 Time-Domain Response Variation Analysis 40

4.2.1 Bumpy Road 40

4.2.2 Straight Road 43

4.2.3 Roundabout 45

4.3 Car Body Analysis 46

4.3.1 Roll Angle 47

4.3.2 Pitch Angle 49

4.3.3 Yaw Angle 50

4.4 Ride Quality and Comfort 52

CHAPTER 5 CONCLUSION 54

5.1 Introduction 54

5.2 Future Work and Recommendations 55

REFERENCES 56

APPENDIX A GANTT CHART 58

APPENDIX B CAR SPECIFICATIONS 61

APPENDIX C CAR DESIGN OF INDIVIDUAL PARTS OF SEMI ACTIVE

SHOCK ABSORBER 63

APPENDIX D RIDE ROUTE/TEST TRACK 65

APPENDIX E CONFERENCE PAPER 67

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LIST OF TABLES

Table 2.1 Approximation indications of acceptability based on the RMS

acceleration values. 19

Table 3.1 Damping state categorizes 24

Table 3.2 Testing road type and speed 37

Table 4.1 Calculated valuse of RMS acceleration on the various types of roads

at different damping adjustment. 53

Table B.1 Test vehicle information 61

Table B.2 Center wheel to arc fender measurement 62

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LIST OF FIGURES

Figure 1.1 Parts of a typical vehicle suspension system. 1

Figure 2.1 Quarter-car suspension systems: (a) Passive Suspension System, (b)

Semi Active Suspension (c) Active Suspension System 5

Figure 2.2 (b) Frequency response of road-to-tire 6

Figure 2.3 List of electronically controlled suspension systems 8

Figure 2.4 Active suspension system schematic diagram 9

Figure 2.5 Configuration of position controlled valves with servo motor 10

Figure 2.6 Schematic configuration of the ER damper 11

Figure 2.7 MR fluid – Working principle 12

Figure 2.8 General configuration of a MR fluid damper 13

Figure 2.9 ISO Vehicle Axis System 16

Figure 2.10 Position of passenger as in ISO2631-1 18

Figure 3.1 Project flow chart 21

Figure 3.2 Disassembled Parts of current absorber 22

Figure 3.3 Jig tool to open the shock absorber 22

Figure 3.4 Outline of controller of semi-active suspension 23

Figure 3.5 Design of upper part of motor mount. 26

Figure 3.6 Design of motor shaft 26

Figure 3.7 Cross section showed the design of motor and the piston rod 27

Figure 3.8 Final design of semi-active damper 28

Figure 3.9 (a) Stepper motor and (b) ZerOne shock absorber with stepper

motor for testing. 28

Figure 3.10 Block diagram of stepper motor controller 29

Figure 3.11 (a) Shows overall programing flow and (b) Interrupt programing 31

Figure 3.12 Flow chart explains the setting the dircetion and position in stepper

motor. 32

Figure 3.13 Electrical circuit to run the experimental testing 33

Figure 3.14 Flow chart presenting the sequence of experimental setting and

testing process. 34

Figure 3.15 Sapura Test Car 35

Figure 3.16 (a) Motor installation on FR shock absorber and (b) Motor

installation on FL shock absorber. 36

Figure 3.17 IMU installation on the wind screen 36

Figure 4.1 Graph of Longitudinal Acceleration versus Time during bumpy

test. 41

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Figure 4.2 Graph of Lateral Acceleration axis versus Time during bumpy test. 42

Figure 4.3 Graph of Vertical Acceleration versus Time during bumpy test. 42

Figure 4.4 Graph of Longitudinal Acceleration acceleration versus Time during

straigh road test. 43

Figure 4.5 Graph of lateral Acceleration versus Time during straigh road test. 44

Figure 4.6 Graph of Vertical Acceleation versus Time during straigh road test. 44

Figure 4.7 Graph of Longitudinal Acceleration versus Time during roudabout

test. 45

Figure 4.8 Graph of Lateral Acceleration versus Time during roudabout test. 46

Figure 4.9 Graph of Veritcal Acceleation versus Time during roudabout test. 46

Figure 4.10 Graph of Roll rate versus Time during bumpy test. 47

Figure 4.11 Graph of Roll rate versus Time during straight road test. 48

Figure 4.12 Graph of Roll rate versus Time during Roundabout test. 48

Figure 4.13 Graph of Pitch rate versus Time during bumpy test 49

Figure 4.14 Graph of Pitch rate versus Time during striaght road test. 50

Figure 4.15 Graph of Pitch rate versus Time during roundabout test. 50

Figure 4.16 Graph of Yaw rate versus Time during bumpy test. 51

Figure 4.17 Graph of Yaw rate versus Time during stiaght road test. 52

Figure 4.18 Graph of Yaw rate versus Time during roundabout test. 52

Figure A.1 Gantt chart Final Year Project 1 59

Figure A.2 Gantt chart Final Year Project 2 60

Figure B.3 Diagram shows the center wheel to arc fender measurement 62

Figure C.4 Jalan Permata 2 to Jln Laman Kenanga 3/1, Nilai Impian, 71800

Nilai, Negeri Sembilan. 65

Figure C.5 12, Jalan 7/5, 43650 Bandar Baru Bangi, Selangor to Jalan 7/5,

43650 Bandar Baru Bangi, Selangor. 65

Figure C.6 12, Jalan 7/5, 43650 Bandar Baru Bangi, Selangor to Jalan 7/5,

43650 Bandar Baru Bangi, Selangor. 66

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LIST OF SYMBOLS

Symbol Definition, Units

𝐴 Area, 𝑚2

𝐴𝑠𝑎 Area of semi-active orifice valve, 𝑚2

𝐴𝑐 Area of compression chamber, 𝑚2

𝐴𝑂 Area of piston orifice, 𝑚2

𝐴𝑟 Area of rebound chamber, 𝑚2

𝐴𝑟𝑜𝑑 Area of rod, 𝑚2

𝐴𝑣 Area of valve on which pressure acts, 𝑚2

𝑎𝑤 Weighted acceleration time history,𝑚𝑠−2

𝐶𝑑 Dynamic discharge coefficient

𝐶𝑑,𝑏 Dynamic discharge coefficient for the bleed orifice

𝐴𝑠𝑎 Diameter of semi-active orifice valve, in 𝑚2

𝑄 Overall volume flow rate of the damper

𝑄𝑃 Diameter of piston orifice, 𝑚

𝑄𝑠𝑎 Semi-active valve flow rate of upper damper, 𝑚3𝑠−1

𝑄𝑙𝑝 Piston leakage flow rate, 𝑚3/sec

𝑇 The duration, 𝑠

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𝑑𝑡 Differential with respect to time

𝜌 Density

xv

LIST OF ABBREVIATIONS

ER Electro-Rheological

MR Magneto-Rheological

RMS Root Mean Square

IOS International Organization for Standardization

CAD Computer Aided Design