PRELIMINARY STUDY FOR RIDE DYNAMICS MODEL OF SEMAR-T USING MATLAB-SIMULINK.

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PRELIMINARY STUDY FOR RIDE DYNAMICS MODEL OF SEMAR-T

USING MATLAB-SIMULINK

FINAL PROJECT

Submitted as a bachelor requirement in obtaining degree in the mechanical engineering department,

faculty of engineering

by:

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DEDICATIONS

To those who have been responsible, to them I dedicate this work anyway.

They are:

Allah SWT.

The creator and the master himself

Muhammad SAW. The miracle and the inspiring

Taruni

A mother who always gave love and support

Mamad

A father who has always worked hard for the welfare of him children

Dedi Suwikyo, Tiyas Sismaya and Ina Susanti Brother and sisters who has been assisting

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MOTTO

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Preliminary Study For Ride Dynamics Model of Semar-T Using

MATLAB-Simulink

Ipnu Candra

Mechanical Engineering Department Faculty of Engineering Universitas Sebelas Maret

Surakarta, Indonesia

E-mail: [email protected]

Abstrack

The work is aimed to study the vertical, longitudinal and lateral response of

ride performance of Semar-T. The issues related to the design of vehicle model

with passive suspension system are discussed. A complete-vehicle

seven-degree-of-freedom model is used to investigate the dynamics response by applying road

disturbances in sinusoidal road input excitation. Frequency response of the heave,

roll, pitch of the sprung mass and suspension deflection is obtained for the need of

studying the effect of given variation of both suspension stiffness coefficient and

suspension damping coefficient. Finally, the resulted responses in frequency

domain are then evaluated using ISO-2631 criteria to evaluate the passenger

comfortability.

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Pembelajaran Awal Untuk Model Dinamika RideSemar-T Menggunakan

Matlab-Simulink

Ipnu Candra

Jurusan Teknik Mesin Fakultas Teknik Universitas Sebelas Maret

Surakarta, Indonesia

E-mail: [email protected]

Abstrak

Tujuan dari penelitian ini adalah untuk mempelajari respon vertikal,

longitudinal dan lateral dari performa rideSemar-T. Masalah-masalah yang terkait

dengan desain model kendaraan menggunakan sistem suspensi pasif akan dibahas

dalam penelitian ini. Model penuh kendaraan tujuh derajat kebebasan (DOF)

digunakan untuk meneliti respon dinamik dengan memberikan gangguan jalan

yang berbentuk sinusoid. Respon domain frekuensi heave, roll, pitch dari massa

sprung dan perpindahan suspensi diperoleh untuk mempelajari pengaruh dari

variasi nilai konstanta pegas dan peredam. Respon domain frekuensi kemudian

digunakan untuk evaluasi berdasarkan standar ISO-2631 guna mengevaluasi

kenyamanan penumpang.

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PREFACE

First of all, the writer wants to thank to Allah SWT for the blessing and

guidance. Sholawat and also salam for my prophet Muhammad SAW, the person

who we will hope his syafaat in the end world later. The writer also would like to

say very much thank you to all family and friends for supporting writer to finish

this final project report well.

In this report, the writer is interested to discuss the Preliminary Study For

Ride Dynamics Model Of Semar-T Using Matlab-Simulink, including the

problem of influence road profile and variation of suspension stiffness coefficient

and suspension damping coefficient on the ride comfort of Semar-T. The writer

tried to make this final project report become the best final project report that ever

writer made.

The writer realized that this report is still far from being perfect. Therefore,

the writer will be happy to accept the suggestion and constructive criticism to

make this report be better. The writer hopes, this final project report would give

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ACKNOWLEDGEMENT

Praise be to Allah SWT who always gives the power from first until end so

that Writer can finish this final project report well. However, the writer could not

accomplish this report without the help of many people. Therefore, the writer

would like to thank to all of them. They are:.

1. Ubaidillah S.T., M.Sc., as supervisor, who has patiently given his

guidance, advice, suggestions and time from the beginning up to the

complection of writing this report.

2. Wibowo S.T., M.T., as co-supervisor, who has given his guidance,

advice and encouragement in writing this report.

3. Didik Djoko Susilo S.T., M.T., the head of mechanical engineering

department for his permission to write this report.

4. Parents, you are everything in here, thanks for everything that you have

given for the writer.

5. Brother and sisters, for being the writer’s inspiration and giving strength

in facing this life.

6. Hadana Ulufannuri, who has given her support everyday.

7. All poeple and friends who can’t able to mention one by one.

Surakarta, July 2013

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LIST OF TABLES

Page

Table 3.1. Semar-T parameters ... 15

Table 3.2. Description of free body diagram symbol ... 16

Table 3.3. Schedule of project ... 19

Table 4.1. Simulation Setup ... 20

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LIST OF FIGURES

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Figure 2.1. Vehicle body acceleration due to road excitation in

comparison with ISO ride comfort boundaries ... 7

Figure 2.2. Vehicle coordinate systems ... 9

Figure 2.3. Complete-vehicle model ... 10

Figure 2.4. (a) Rectangular cleat and (b) cosine-shaped bump ... 11

Figure 3.1. Flow chart of project ... 14

Figure 3.2. Complete Semar-T model ... 16

Figure 3.2.a Wheels Responses ... 17

Figure 3.2.b Body Responses ... 17

Figure 3.2.c Scopes ... 18

Figure 3.3. Complete Semar-T block diagram ... 18

Figure 4.1. Suspension damping coefficient testing result ... 21

Figure 4.2. Suspension stiffness coefficient testing result ... 22

Figure 4.3. Mode sinusoidal test ... 23

Figure 4.4. Validation graphic of body displacement response ... 24

Figure 4.5. Validation graphic of body acceleration response ... 24

Figure 4.6. Validation graphic of pitch angle response ... 25

Figure 4.7. Validation graphic of roll angle response ... 25

Figure 4.8. Validation graphic of front-left suspension travel response . 26

Figure 4.9. Validation graphic of front-left wheel acceleration response 26

Figure 4.10. Validation graphic of rear-left suspension travel response .. 27

Figure 4.11. Validation graphic of rear-left wheel acceleration response 27

Figure 4.12. Validation graphic of rear-right suspension travel response 28

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damping coefficients (c_s) and constant value of the

suspension stiffness coefficients (k_s= 18000 N/m) ... 31

Figure 4.17. Bode plots of (a) roll angle and (b) pitch angle response, for

different values of the suspension damping coefficients (c_s)

and constant value of the suspension stiffness coefficients

(k_s= 18000 N/m) ... 32

Figure 4.18. Bode plots of (a) left suspension travel and (b)

front-left wheel acceleration response, for different values of the

suspension damping coefficients (c_s) and constant value of

the suspension stiffness coefficients (k_s= 18000 N/m) ... 33

Figure 4.19. Bode plots of (a) right suspension travel and (b)

front-right wheel acceleration response, for different values of the

Figure 4.20. Bode plots of (a) rear-left suspension travel and (b) rear-left

wheel acceleration response, for different values of the

rear-right wheel acceleration response, for different values of the

Figure 4.22. Peak-to-Peak values of (a) body displacement and (b) body

acceleration response, for different values of the suspension

damping coefficients (c_s) and constant value of the

suspension stiffness coefficients (k_s= 18000 N/m) ... 38

Figure 4.23. Peak-to-Peak values of (a) roll angle and (b) pitch angle

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coefficients (c_s) and constant value of the suspension

stiffness coefficients (k_s= 18000 N/m) ... 39

Figure 4.24. Peak-to-Peak values of (a) front-left suspension travel and

(b) front-left wheel acceleration response, for different

values of the suspension damping coefficients (c_s) and

constant value of the suspension stiffness coefficients (k_s=

18000 N/m) ... 40

Figure 4.25. Peak-to-Peak values of (a) front-right suspension travel and

(b) front-right wheel acceleration response, for different

18000 N/m) ... 41

Figure 4.26. Peak-to-Peak values of (a) rear-left suspension travel and

(b) rear-left wheel acceleration response, for different

18000 N/m) ... 42

Figure 4.27. Peak-to-Peak values of (a) rear-right suspension travel and

(b) rear-right wheel acceleration response, for different

18000 N/m) ... 43

Figure 4.28. Bode plots of (a) body displacement and (b) body

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(c_s= 900 Ns/m) ... 46

Figure 4.30. Bode plots of (a) left suspension travel and (b)

front-left wheel acceleration response, for different values of the

suspension stiffness coefficients (k_s) and constant value of

the suspension damping coefficients (c_s= 900 Ns/m) ... 47

front-right wheel acceleration response, for different values of the

Figure 4.32. Bode plots of (a) rear-left suspension travel and (b) rear-left

wheel acceleration response, for different values of the

rear-right wheel acceleration response, for different values of the

Figure 4.34. Peak-to-Peak values of (a) body displacement and (b) body

stiffness coefficients (k_s) and constant value of the

suspension damping coefficients (c_s= 900 Ns/m) ... 51

Figure 4.35. Peak-to-Peak values of (a) roll angle and (b) pitch angle

response, for different values of the suspension stiffness

coefficients (k_s) and constant value of the suspension

damping coefficients (c_s= 900 Ns/m) ... 52

Figure 4.36. Peak-to-Peak values of (a) front-left suspension travel and

(b) front-left wheel acceleration response, for different

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constant value of the suspension damping coefficients (c_s=

900 Ns/m) ... 53

Figure 4.37. Peak-to-Peak values of (a) front-right suspension travel and

(b) front-right wheel acceleration response, for different

values of the suspension stiffness coefficients (k_s) and

900 Ns/m) ... 54

Figure 4.38. Peak-to-Peak values of (a) rear-left suspension travel and

(b) rear-left wheel acceleration response, for different

900 Ns/m) ... 55

Figure 4.39. Peak-to-Peak values of (a) rear-right suspension travel and

(b) rear-right wheel acceleration response, for different

900 Ns/m) ... 56

Figure 4.40. ISO 2631 “fatigue-decreased proficiency boundary”:

vertical vibration limits as a function of frequency and

exposure time [2] ... 58

comparison with ISO ride comfort boundaries, for different

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comparison with ISO ride comfort boundaries, under full

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LIST OF EQUATIONS

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Equation 2.1. RMS value of the sprung mass displacement ... 7

Equation 2.2. The second law of Newton ... 10

Equation 2.3. Body vertical response ... 10

Equation 2.4. Body pitch response ... 10

Equation 2.5. Body roll response ... 11

Equation 2.6. Front-left wheel response ... 11

Equation 2.7. Rear-left wheel response ... 11

Equation 2.8. Rear-right wheel response ... 11

Equation 2.9. Front-right wheel response ... 11

Equation 2.10. Height of rectangular cleat ... 12

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LIST OF NOTATIONS

s

m = Sprung mass ... (kg)

yy

I = Pitch moment of inertia ... (kgm2)

xx

I = Roll moment of inertia ... (kgm2)

1

mu = Front-left unsprung mass ... (kg)

2

mu = Rear-left unsprung mass ... (kg)

3

mu = Rear-right unsprung mass ... (kg)

4

mu = Front-right unsprung mass ... (kg)

1

ks = Front-left suspension stiffness coefficient ... (N/m)

2

ks = Rear-left suspension stiffness coefficient ... (N/m)

3

ks = Rear-right suspension stiffness coefficient ... (N/m)

4

ks = Front-right suspension stiffness coefficient ... (N/m)

1

cs = Front-left suspension damping coefficient ... (N/m)

2

cs = Rear-left suspension damping coefficient ... (N/m)

3

cs = Rear-right suspension damping coefficient ... (N/m)

4

cs = Front-right suspension damping coefficient ... (N/m)

f

l = Side distance from center of gravity to the front axle ... (m)

r

l = Side distance from center of gravity to the rear axle ... (m)

fl

a = Frontal distance from center of gravity to the front-left axle .. (m)

rl

a = Frontal distance from center of gravity to the rear-left axle ... (m)

rr

a = Frontal distance from center of gravity to the rear-right axle . (m)

fr

a = Frontal distance from center of gravity to the front-right axle (m)

1

x = Sprung mass heavy displacement ... (m)

2

x = Sprung mass pitch angular displacement ... (rad)

3

x = Sprung mass roll angular displacement ... (rad)

4

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5

x = Rear-left unsprung mass displacement ... (m)

6

x = Rear-right unsprung mass displacement ... (m)

7

x = Front-right unsprung mass displacement ... (m)

1 in

x = Front-left displacement input ... (m)

2 in

x = Rear-left displacement input ... (m)

3 in

x = Rear-right displacement input ... (m)

4 in

x = Front-right displacement input ... (m)

RMS

PRELIMINARY STUDY FOR RIDE DYNAMICS MODEL OF SEMAR-T USING MATLAB-SIMULINK.

PRELIMINARY STUDY FOR RIDE DYNAMICS MODEL OF SEMAR-T

Submitted as a bachelor requirement in obtaining degree in the mechanical engineering department,

DEDICATIONS

MOTTO

Preliminary Study For Ride Dynamics Model of Semar-T Using

Pembelajaran Awal Untuk Model Dinamika RideSemar-T Menggunakan

PREFACE

ACKNOWLEDGEMENT

TABLE OF CONTENTS

CHAPTER IV RESULTS AND ANALYSIS

LIST OF TABLES

LIST OF EQUATIONS

LIST OF NOTATIONS