This project deals with the design and implementation of an expert system for car faults diagnosis. The project is motivated by the need to guide car owners and learners motor mechanics in the maintenance and trouble shooting of motor problems without having to resort to presumptions and conjectures. Particularly, it is expected that the proposed design would ensure that car owners have proper assistance in times of crisis and what’s more will save them from the clutches of exploitative roadside mechanics. For this purpose a rule- base artificial intelligence (AI) technique was utilized to obtain theoretical and practical expert system parameters, and then a conceptual expert system was designed. The expert system functioning is based on the database of car faults, symptoms and their correction, which make up its knowledge base. The new system was developed using visual basic 6.0 programming language and access database. This language was chosen because of its easy syntax and features for developing windows based application.

TABLE OF CONTENTS

Title page i

Approval page ii

Dedication iii

Acknowledgement iv

Abstract v

Table of contents vi

CHAPTER ONE

1.0 Introduction 1

1.1 Background of the study 1

1.2 Problem statement 2

1.3 Objectives 3

1.4 Significance of the study 4

1.5 Scope of the study 5

1.6 Limitations 5

1.7 Methodology 5

CHAPTER TWO

2.1 Literature review 7

2.2 The Conceptual Structure of an Expert System 14

2.2.1 Problem Assessment 14

2.2.2 Knowledge Acquisition 15

2.2.3 Knowledge Representation 17

2.2.4 Verification 18

2.2.5 Validation 18

2.3 Testing Expert System 19

2.4 MYCIN 21

CHAPTER THREE

System analysis and design 27

3.0 Introduction 26

3.1 Weakness of the Present System 28

3.2 Methodology 28

3.3 Knowledge acquisition 28

3.3.1 Domain Expert 29

3.3.2 Interview 29

3.3.3 Consultation 29

3.3.4 Diagnosis 32

3.3.5 Correction/ explanation 32

3.4 System Design 33

3.4.1 Rule based development method 34

3.4.2 Inference technique 36

3.4.3 Flowchart of the proposed program 38

3.5 Program design 39

3.5.1 High level model of the proposed system 40

CHAPTER FOUR

4.0 System implementation 41

4.1 Introduction 41

4.2 System requirement 42

4.3 Testing 42

4.4 Maintenance 43

4.5 Program Documentation 44

4.5.1 Sample input/output data formats 45

4.5.2 Loading the package 46

4.5.3 Exiting 47

CHAPTER FIVE

5.0 Summary, Recommendation and conclusion 48

5.1 Summary 48

5.2 Recommendation 49

5.3 Conclusion 49

References 66

Appendix I 75

Appendix II 58

CHAPTER ONE

1.0 INTRODUCTION

In present time most households own at least one car. This figure shows that a car is very important to people’s lives as it completes the cycle of living.

This computer expert system is hoped to help those who are in need of guides to deal with their cars problems. Although it might not give a complete guide and help as a human expert, namely mechanics, at least the expert system can give temporary assistance to those who are in need of instant help, as a result of the limitation of time and distance.

1.1 BACKGROUND OF THE STUDY

With the help of a car, movement from one place to another has been made easy especially for those who are always mobile in their jobs. Cars simplify our lives and make time to be more valuable as we can save more time using the car. But at the same time, people who own cars definitely don’t want to have a problem with their cars as the troubleshooting of a car can be a nightmare to them, especially women. Some of those own a car individually don’t know how to deal with their cars whenever it has a problem. All they know is to start the engine, drag the clutch if it is not automatic, press the paddy and break when they need to. An even the worse situation is that they don’t even know how to fill the fuel tank, and that is not good. They won’t know what to do when something happens to their cars. All they can do at best is, call the mechanic for help.

So, this computer expert system is hoped to help those who are in need of guides to deal with their cars problems. Although it might not give a complete guide and help as a human expert, namely mechanics, at least the expert system can give temporary assistance to those who are in need of instant help, as a result of the limitation of time and distance.

1.2 STATEMENT OF THE PROBLEM

In dealing with problems of a car and troubleshooting, mechanics are those who can help to solve them. The use of a computer expert system is beneficial in different ways. It gives a temporary and instant guide to car owners in different situations like:

When mechanic support is unavailable
When we are in a hurry
When distance to mechanics location is far
When mechanics diagnosis wrongly, etc.

1.3 OBJECTIVES OF THE STUDY

To develop an expert system on car maintenance and troubleshooting that is capable of assisting car owners in dealing with their cars problems and troubleshooting them whenever time is limited and the human experts, also known as mechanics is not available at that very time. The development of the system surely has some significance to humans especially those who own a car and to the system developer as well. Among others, the system will perform the following functions:

It will conclude its diagnosis based on answers of the users to specific question posed by the system to the user.
It provides facility in order to take the user opinion on the following: does the use agree with the system’s diagnosis? Does the user disagree with the system’s diagnosis?
It provides explanation, picture, why and fact facility.
It stores the facts and the conclusion of the inference of the system and the facts and the conclusion of the inference of the user, for each case in data base.
It processes the data base in order to extract rules, which complete the knowledge base.

1.4 SIGNIFICANCE OF THE STUDY

The proposed system can help inexperienced mechanics or drivers in diagnosing the fault of the car.

In addition, the system has the following benefits:

Expert systems help in the improvement of productivity: Having this system will enable mechanics to do more work in less time.
Expert system reduces the need for skilled mechanics: The repairs of a car require a high level of expertise. With this system, inexperienced mechanics can be guided to find the fault.
Expert systems capture the knowledge of company experts who someday will retire, resign or die.
Expert systems train newly lived employees to solve problem the way experienced professionals do.
Expert system are not vulnerable to problems such as fatigue, emotion and overwork, all of which plaque human experts.
Expert systems place expert knowledge into machine readable form, where it can be summoned at any time.
Expert systems give consistent result.
Expert systems can complete some tasks quicker them a human.

1.5 SCOPE OF THE STUDY

The expert system may contain certain limits and flaws, as it is only a prototype. We commonly know that a car has many parts on its body and even in the body itself. However, the system will only deal with problems that are normally or commonly found in the engine part of the car as the system is just a prototype, which means the function will be expanded through time. The system will also deal with only cars produced from the year 2000 till date.

1.6 LIMITATION OF THE STUDY

TIME: Time frame for this work is short

Finance as a student
Limited literature in computer to assist the researcher
Not much work has been done in this area of computer science/ engineering.

1.8 DEFINITION OF TERMS

Actuator: This is a device in a car that uses electricity to do sort of automated mechanical movement such as power door locks or a remote trunk opener.
Car Sensor: This is a technological device that dictates or senses a signal or a physical condition in a car.
Car Diagnosis: Is the identification of the nature and causes of problem in a car.
Car Brain Box: This is an electronic device that incorporates micro processors for the monitoring and control of various functions in a vehicle.