i design and simulation of adaptive cruise...

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DESIGN AND SIMULATION OF ADAPTIVE CRUISE CONTROL USING

MATLAB/SIMULINK

MOHD FIRDAUS BIN JAHAR

This report is submitted in partial fulfillment of the requirements for the award of

Bachelor of Electronic Engineering (Industrial Electronics) With Honours

Faculty of Electronic and Computer Engineering

Universiti Teknikal Malaysia Melaka

APRIL 2009

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UNIVERS TI TEKNIKAL MALAYS IA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk

Projek :

DESIGN AND SIMULATION OF ADAPTIVE CRUISE CONTROL USING

MATLAB/SIMULINK

Sesi

Pengajian : 2008/2009…………………………………………………………………

Saya _________________MOHD FIRDAUS BIN JAHAR_____________________________

(HURUF BESAR)

mengaku membenarkan Laporan Projek Sarjana Muda ini d isimpan di Perpustakaan dengan sy arat-

syarat kegunaan seperti berikut:

1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.

2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.

3. Perpustakaan dibenarkan membuat salinan laporan in i sebagai bahan pertukaran antara in stitusi

pengajian tinggi.

4. Sila tandakan ( √ ) :

SULIT*

(Mengandungi maklumat yang berdarjah keselamatan atau

kepentingan Malaysia seperti yang termaktub di dalam AKTA

RAHSIA RASMI 1972)

TERHAD*

(Mengandungi maklumat terhad yang telah ditentukan oleh

organisasi/badan di mana penyelidikan dijalankan)

TIDAK TERHAD

Disahkan oleh:

__________________________ ___________________________________ (TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)

Alamat Tetap: KAMPUNG BARU JALAN PANJANG,

28030 TEMERLOH, PAHANG DARUL MAKMUR.

Tarikh: 30 APRIL 2009 Tarikh: 30 APRIL 2009

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―I hereby declare that this report is the result of my own work except for quotes as

cited in the references.‖

Signature : …………………………………

Name : MOHD FIRDAUS BIN JAHAR

Date : 30 APRIL 2009

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―I hereby declare that I have this report and in my opinion this report is sufficient in

terms of the scope and quality for the award of Bachelor of Electronic Engineering

(Industrial Electronics) With Honours. ‖

Signature : ……………………………………

Supervisor‘s Name : EN. ZULKARNAIN ZAINUDIN

Date : 30 APRIL 2009

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Dedicated especially to my father

and my beloved mother.

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ACKNOWLEDGEMENT

First and foremost, I would like to take this opportunity to thank my project

supervisor, Zulkarnain bin Zainudin for his invaluable guidance, assistance and

support throughout the project. Under his supervision, many aspects regarding on

this project has been explored, and with the knowledge, idea and support received

from him, this thesis can be presented in the time given.

I also would like to thank all the lecturers at FKEKK for the lessons and

guidance given. Not forget to all my friends and course mate for their help and ideas

during the course of this study.

Finally, I would like to thank my family for their continuous concerns,

encouragement and support.

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ABSTRACT

This project presents the design and implementation of an adaptive cruise

control (ACC), which is a system that maintains the speed of a car and also keeps a

minimum distance to the closest vehicle in front. The speed of the car be maintained

by using a Proportional-Integral-Derivative (PID) controllers that based on the

desired speed from the driver. The classical method of tuning process of setting the

P, I, and D tuning constants for the CC system is used.will be compare to the ACC

system simulation. Further, the ACC system has been evaluated based on the eleven

test cases with Signal Builder. The Simulink is used as the simulation software

because of the short learning curve that most students require to start using it, its

wide distribution, and its general-purpose nature. This project will demonstrate the

advantages of using Simulink for analyzing the proposed PID Controllers in ACC

system.

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ABSTRAK

Projek ini membincangkan mengenai merekabentuk dan mengaplikasikan

Kawalan Adaptif Kelajuan Kenderaan (Adaptive Cruise Control), iaitu suatu sistem

yang boleh mengekalkan kelajuan kereta dan juga mengekalkan jarak minimum

kereta dengan kenderaan di hadapan. Kelajuan kereta ini dapat dikawal

menggunakan pengawal PID berdasarkan kelajuan yang dikehendaki oleh pemandu.

Proses klasik digunakan bagi menala pemalar P,I dan D untuk sistem CC akan

dinilai dengan simulasi sistem ACC. Selanjutnya tindak balas respon ACC akan

dinilai dan disimulasi berdasarkan sebelas ujian kes dengan pembina signal.

Simulink diguna sebagai perisian pensimulasian kerana pembelajaran jangka pendek

yang sangat diperlukan oleh pelajar untuk mula menggunakannya iaitu bidang yang

luas dan pelbagai guna dengan alam semulajadi. Projek ini akan mendedahkan

kelebihan menggunakan Simulink untuk menganalisis pengawal PID dalam sistem

ACC.

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TABLE OF CONTENTS

CHAPTER CONTENT PAGE

PROJECT TITLE i

VERIFICATION FORM ii

DECLARATION iii

VERIFICATION iv

DEDICATION v

ACKNOWLEDGEMENT vi

ABSTRACT vii

ABSTRAK viii

TABLE OF CONTENTS ix

LIST OF TABLES xiii

LIST OF FIGURES xiv

LIST OF ABBREVIATIONS xvii

LIST OF APPENDICES xviii

I INTRODUCTION

1.1 Background of Project 1

1.2 Objectives of Project 4

1.3 Statement of Research Problem 5

1.4 Scope of Project 6

1.5 Method of Project 6

1.6 Outline of the Thesis 7

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II LITERATURE REVIEW

2.1 Signal Builder 8

2.2 ACC Controller 9

2.2.1 Stateflow chart 11

2.2.1.1 Stateflow Debugger 12

2.2.1.2 Stateflow Chart Model Coverage 13

2.2.1.3 Coverage Reports 14

2.2.2 PID Controller 16

2.2.2.1 Zero-Order Hold 17

2.2.2.2 Discrete-Time Integrator 17

2.2.2.3 IC 19

2.2.2.4 Unit Delay 20

2.2.2.5 Proportional 21

2.2.2.6 Integral 22

2.2.2.7 Derivative 23

2.3 Tuning a PID Controller 25

2.4 ACC vehicle dynamics 27

III METHODOLOGY

3.1 Modeling Process of ACC System 29

3.1.1 Defining the System 31

3.1.2 Identifying System Components 31

3.1.3 Modeling the System with Equations 32

3.1.4 Building the Simulink Block Diagram 32

3.1.5 Running the Simulation 32

3.1.6 Validating the Simulation Results 33

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3.2 Design Requirements 33

3.2.1 Creating Test Cases 33

3.2.2 Constructing the Test Cases 33

3.2.2.1 Test Case 1 34

3.2.2.2 Test Case 2 35

3.2.2.3 Test Case 3 36

3.2.2.4 Test Case 4 37

3.2.2.5 Test Case 5 38

3.2.2.6 Requirements 5–9 39

3.2.2.7 Custom Signals 42

3.2.3 Command Line API 43

3.2.4 Running the Tests 44

IV SIMULATION RESULT AND DISCUSSION

4.1 Simulation Parameters 45

4.2 Simulation of the Transfer Function 46

4.3 Implementation of the PID Controller 47

4.4 Tuning Results of PID Controller 48

4.5 Simulation of ACC system 54

4.6 Analysis and Discussion of ACC Performances 59

V CONCLUSION AND SUGGESTION FOR FUTURE

DEVELOPMENT

5.1 Conclusion 62

5.2 Suggestion for Future Development 63

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REFERENCE 64

APPENDIX A 66

APPENDIX B 67

APPENDIX C 68

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LIST OF TABLES

NO. TITLE PAGE

2.1 Effects of each of controllers gain on a closed- loop system 26

2.2 Equation created by Ziegler Nichols 26

3.1 Functional Requirements 5–9 39

4.1 Values of constant and parameter used in the block diagram 46

4.2 Gain value by Ziegler Nichols for each controller 49

4.3 Gain value by Ziegler Nichols for each controller after adjustment 49

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LIST OF FIGURES

NO. TITLE PAGE

2.1 Signal Builder block 9

2.2 Controller block 10

2.3 Graphical Components of a Stateflow 11

2.4 The Debugger main window 12

2.5 Summary for coverage report 15

2.6 PID Controllers 16

2.7 PID controller subsystem 16

2.8 Zero-Order Hold block 17

2.9 Discrete-Time Integrator 17

2.10 IC block 19

2.11 Unit Delay block 20

2.12 Proportional Gain 21

2.13 Integral Gain 22

2.14 Derivative Gain 23

2.15 Vehicle dynamics 27

2.16 Vehicle dynamics subsystem 27

2.17 Hills block for road resistance 28

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2.18 Hills setting values 28

3.1 Flowchart 30

3.2 Test Case 1 34

3.3 Requirement 1/Test Case 2 35



3.6 Test Case 5 38

3.7 Test Case 6 39

3.8 Test Case 7 40

3.9 Test Case 8 40

3.10 Test Case 9 41

3.11 Test Case 10 41

3.12 Accelerator pedal signal 42

4.1 Simulink block diagram for ACC 46

4.2 Open loop response for ACC 47

4.3 Simulink block diagram for CC with PID Controller 47

4.4 Open-loop poles from Root Locus 48

4.5 Open-loop value for gain and frequency 48

4.6 P Controller step response 50

4.7 PI Controller step response 50

4.8 PID Controller step response 51

4.9 PID Controller step response (after Tuning) 51

4.10 PID Controller step response (after Tuning) 52

4.11 Satisfied open- loop system 53

4.12 Satisfied open- loop system respond 53

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4.13 Simulation results for Test case 1 54











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LIST OF ABBREVIATION

ACC - Adaptive Cruise Control

ADAS - Advanced Driver Assistance Systems

CC - Cruise Control

D - Derivative

I - Integral

P - Proportional

PI - Proportional-Integral

PID - Proportional-Integral-Derivative

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LIST OF APPENDICES

NO. NAME PAGE

A ACC system in Simulink 66

B Controller Subsystem 67

C Model Viewing Shortcuts 68

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CHAPTER I

INTRODUCTION

1.1 Background of Project

The cars of tomorrow [8] will be more and more equipped with Advanced

Driver Assistance Systems (ADAS) to support the driver in the driving task. One of

the ADAS is the Adaptive Cruise Control (ACC). Pauwelussen and Minderhoud in

[8] noted that the ACC could be defined as an extension of the Cruise Control (CC)

and maintains, next to a certain set speed, a certain set distance with respect to the

lead vehicle.

The conventional CC only has control over the engine, which means that it

cannot switch gears and it cannot break. This means that it is only used on roads

where the velocity of the car is somewhat constant, for example on highways. The

driver cannot relax too much though, since the CC does not care about vehicles in

front. This is what the ACC is trying to solve.

The ACC takes both a desired (maximum) velocity and a desired (minimum)

distance as input values from the driver. As long as no vehicle in front is closer than

the desired distance, the ACC functions exactly as a CC. If a vehicle in front comes

closer than the desired minimum distance the ACC will adapt the velocity to follow

the vehicle. In order to keep this set distance, the ACC is able to accelerate and

decelerate the vehicle. The acceleration and deceleration of the system is limited,

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because of comfort reasons and by law [8]. This means that the driver has to

intervene if the system is not able to achieve the required needs [8]. Ideally, the

driver only has to control the steering and only interrupt the ACC at takeovers or

situations that might lead to accidents [9].

The ACC is mainly a comfort system that takes over the car-following task,

but the driver remains responsible for steering and collision avoidance. If the

deceleration of the ACC is not sufficient enough to avoid a collision, the ACC warns

the driver with a warning sound [8]. This system is usually used on the highway,

where it is common to cruise at a constant velocity for long periods of time, as a

relief for the driver [9].

These system [11], use radar to measure the distance from the vehicle they

are in to the car ahead and its speed relative to theirs. If a car crosses into the lane

ahead, and the distance is now less than the preset minimum, the system applies the

brakes, slowing the car with a maximum deceleration until it is following at the

desired distance [11]. If the leading car speeds up or moves out of the lane, the

system opens the throttle until the trailing car has returned to the cruise control speed

set by the driver [11].

The advanced features of ACC systems include the ability to track a car in the

lane ahead using forward looking radar. If the distance to a vehicle in front is below

a pre-set value, the ACC system is designed to slow the car down, using brakes if

required, to track the speed of the vehicle in front, then returning the car to its pre-set

speed once the lane ahead is clear. Next, an intelligent lane prediction using steering

angle and yaw rate sensors predict curves in the road, and to ensure that any vehicle

ahead being tracked is in the same lane as the car itself.

One of the potential advantages of ACC is the foundation that it provides for

next generation advancements in collision avoidance systems that are expected to

include radar and cameras. ACC is also anticipated to be beneficial in cities and

towns with heavy urban stop-and-go traffic by functioning at low stop/start speeds in

city traffic. It is expected to have the ability to stop the car completely when sitting

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in traffic, re-starting and following the car in front when the traffic begins to move

again. Potential Key benefits of ACC are reduction in accident rate for vehicles

fitted with collision avoidance type systems, reduction in driver fatigue and increase

in fuel efficiency due to very gradual speed increase / decrease in traffic.

The controller developed for ACC consists of PID controller and Stateflow.

The PID controller is a closed loop controller; designed to make the throttle decisions

(control). The controller is created using parameters to allow easy modification

(tuning) of the operation of the controller. This controller also included the

Stateflow chart that is used to address design challenges that often occur when

developing and implementing embedded software.

Matlab is the main software used for computation, model implementation,

and simulation. The Matlab simulation tool Simulink, which is used for modeling

and simulating dynamic systems, has been playing a major role during this work

[12].

MATLAB/Simulink is a high- level technical computing language and object

orientated environment for algorithm development, data visualization, data analysis,

and numerical computation. MATLAB/Simulink allows the development of a

solution to technical computing problems faster than with traditional programming

languages, such as C, C++, and Fortran. The easy of development along with the

extensive toolboxes and functions available were the major reasons for selecting

MATLAB/Simulink as the simulation environment.

The simulation environment starts as an overview of the implementation of

the PID controller to the CC model. Next, the second model about the ACC model

incorporates the high- level system blocks representing, the signal input, vehicle

dynamics, distance and velocity controller will be designed to get the performances

of the proposed controller.

The goals for the simulation environment were to be able to create the test

cases based on 10 high- level requirements. To ensure that the controllers meet those

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requirements, we need to build test cases that check the design against each

requirement. The simulation environment is flexible and if someone is interested in

testing out another ACC algorithm, the controller is a single function that can be

replaced easily.

Simulink software models, simulates, and analyzes dynamic systems. It

enables user to pose a question about a system, model the system, and see what

happens. With Simulink, we can easily build models from scratch, or modify

existing models to meet our needs. Simulink supports linear and nonlinear systems,

modeled in continuous time, sampled time, or a hybrid of the two systems can also

be multirate-having different parts that are sampled or updated at different rates.

1.2 Objectives of Project

The objectives of this project are:

i) To design the ACC system in MATLAB/Simulink.

ii) To evaluate the simulation of ACC system.

The main objective of this project is to design the ACC system in

MATLAB/Simulink. This design process is the important part in this thesis. The

PID controller is used to observe the characteristics of each controller gain.

The evaluation of the simulation is completed using MATLAB/Simulink.

Results obtained from PID controller‘s step response will evaluate to study the

controller‘s performances in order to draw a conclusion of this simulation study [1].

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1.3 Statement of Research Problem

A lot of drawbacks of the designed ACC system in the real life environment

pursue the researcher make the analysis and of the system in various aspect before

the system will implemented to the wide range of country. This is because of the

difference in weather condition in the other country. Thus, in Asian country the most

challenge drawback problem is the effectiveness of the ACC system in heavy rain.

In the rain periods, the degree of fog and rain also increased over time, and

then decreased symmetrically; the sight distance similarly decreased from 1000 to

10m at 90s then gradually increased back to 1000m [10].

Rain degraded the ability of the radar to detect vehicles ahead, as it attenuated

the sensor sensitivity, masking the sensors and causing them to fail temporarily.

With no lead vehicle detected, vehicle speed will increase [10].

As the intensity of the rain increased, the sensors failed for longer periods and

failed more frequently. The momentary failure of the sensors to detect vehicles

ahead compromised the ability of the ACC to maintain at safely headway

In contrast, Malaysia‘s geographical system has various structured condition.

So the road system in Malaysia will give road resistance to the ACC system. Then,

the road resistance will use to assume the disturbance to the ACC system.

We only focus to the road resistance as the disturbance because the hills

block already built in the Simulink. Thus, hills will represent as the load to the ACC

system. So the rain will be the other choices to use as the disturbance and also give

the big challenge to implement the ACC system

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1.4 Scope of Project

The scope of work for this project includes:

i) Designing and modeling the ACC system in based on previous model.

ii) Implementing the PID controller into the ACC system.

iii) PID Controller with derived transfer function.

iv) Auto tuning PID Controller which is used as a comparison in analyzing the

performance of the controller in part (iii).

v) Simulation study conducted in MATLAB/Simulink on the vehicle speed, road

resistance and set distance with respect to the lead vehicle.

1.5 Method of Project

The research work is undertaken in the following stages:

1) Design the ACC system based on the previous model.

2) Use PID controller with Stateflow.

3) Simulation of the proposed controller in MATLAB/Simulink.

4) Comparison of the performance of PID controller in CC system and ACC

system.

5) Analysis of the simulation results.

i design and simulation of adaptive cruise...

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