IIvIPROVED DESIGN SOLUTION FOR MOTION RESISTANCE PROBLEM

TI{ROUGH INTEGRATION OF ROBUST DESIGN AND TT{EORY OF

INVENTIVE PRINCIPAL (TRIZ)

ARMAN BIN ALIAS

A project repofr submitted in partial fulfilment of the

requirements for the award of the degree of

Master of Engineering (Indushial Engineering)

Faculty of Mechanical Engineering

UniversitiTeknologi Malaysia

JANUARY 2OI5

iii

Alhamdulillah, praise to Allah S.W.T for blessing me and giving me the strength to

complete this project in time.

Specially dedicated to

My beloved wife Khairani Abdul Rahman,

My parents, family and friends.

For their endless love, encouragement, sacrifices and support

iv

ACKNOWLEDGEMENTS

Firstly, I wish to express my sincere appreciation to my project supervisor,

Dr. Syed Ahmad Helmi for encouragement, guidance and critics throughout the

completion of this project. Without his continued support and interest, this thesis

would not be the same as presented here.

I am also very thankful to my lovely wife for his morale support during

preparation of this research. I am very appreciating for your sincere kindness.

Librarians at Universiti Teknologi Malaysia also deserve special thanks for

their assistance in supplying the relevant literatures.

I am also indebted to my employer for understanding my commitment to my

study. It has been a hectic years and without his support I would never make it to the

end.

Finally, thank to my family, friends, colleagues, classmates and all those

unmentioned that helped me with direct or indirectly.

v

ABSTRACT

Solving design problem related to technical contradiction are very

challenging for engineers. There are always design constraints which require

engineers to compromise certain specification and requirement. Trying to solve

design problems traditionally is difficult and often leads to trial-and-errors. This

research is a study of systematic problem solving approach related to technical

contradiction through combination of robust design method and TRIZ methodology

to generate concept solutions. Using a case study of vacuum cleaner motion

resistance issue, five solutions options are identified and tested to verify the

improvement ideas. The result shows that the integration of TRIZ into robust design

method at problem formulation stage has created a more capable problem solving

definition and solution generation scheme. The motion resistance is reduced

significantly to more than half, which is from 76.47N to 26.48N. The pick-up

performance is slightly dropped by 5% compare to the original design. However, this

5% drop is considerably minimal when compare to significant improvement on

motion resistance.

vi

ABSTRAK

Menyelesaikan masalah rekabentuk yang berkaitan dengan percanggahan teknikal

sentiasa menjadi cabaran kepada jurutera. Kebiasaannya wujud kekangan rekabentuk

yang memerlukan jurutera berkompromi terhadap spesifikasi produk dan

keperluannya. Menyelesaikan masalah rekabentuk secara tradisional kebiasaannya

adalah sukar dan sering menggunakan kaedah cuba dan jaya. Projek ini

membentangkan kajian tentang pendekatan menyelesaikan masalah secara sistematik

yang berkaitan dengan percanggahan teknikal melalui gabungan kaedah “robust

design” dan kaedah TRIZ untuk menghasilkan konsep penyelesaian. Pembersih

vakum digunakan sebagai kajian kes berkenaan masalah rintangan pergerakan. Lima

pilihan penyelesaian dikenalpasti dan diuji untuk mengesahkan idea

penambahbaikan. Keputusan kajian menunjukan bahawa integrasi kaedah TRIZ ke

dalam kaedah“robust design” di peringkat formulasi masalah telah menghasilkan

satu kaedah penyelesaian masalah yang lebih berkebolehan. Rintangan pergerakan

dapat dikurangkan dengan ketara iaitu lebih dari separuh, daripada 76.47N ke

26.48N. Prestasi “pick-up” sedikit menurun iaitu sebanyak 5% berbanding dengan

rekabentuk asal. Walau bagaimanapun penurunan sebanyak 5% ini adalah minima

jika dibandingkan dengan hasil yang besar ke atas pengurangan masalah rintangan

pergerakan.

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENTS iv

ABSTRACTS v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xii

LIST OF ABREVIATIONS xiv

LIST OF APPENDICES xv

1. INTRODUCTION

1.1 Introduction 1

1.2 Background of the Problem 1

1.3 Statement of the Problem 3

1.4 Research Question 6

1.5 Objective of the Project 6

1.6 Scope and Limitation 7

1.6.1 Scope 7

1.6.2 Limitation 8

1.7 Important of the Project 8

1.8 Organization of Report 9

1.9 Conclusion 10

viii

2. LITERATURE REVIEW

2.1 Introduction 11

2.2 Overview of Robust Design Method 11

2.3 Definition of TRIZ 15

2.4 Basic Principal of TRIZ 16

2.5 TRIZ Tools 18

2.6 Technical Contradiction/Inventive Principle Tool 19

2.7 Review of Previous Study about TRIZ …23

2.8 Review of Previous Study about Vacuum Cleaner 34

2.9 Summary of Literature 36

2.10 Critical Comments on Literature Review 37

2.11 Conclusion 37

3. METHODOLOGY

3.1 Introduction 39

3.2 Research Framework 39

3.3 Case Study Selection 41

3.4 Basic Product Features 43

3.5 Product Overview 44

3.6 Product Technical Specification 45

3.7 Test Method 46

3.8 Data Collection 47

3.9 Conclusion 47

4. RESULTS AND ANALYSIS

4.1 Introduction 48

4.2 Problem Formulation of Robust Design 48

4.2.1 Function Analysis 49

4.2.2 Cause and Effect Chain 53

4.3 Contradiction Mapping 54

4.4 TRIZ Tool 54

4.5 Improvement Solution 58

4.6 Prototype Solution 65

ix

4.7 Test Setup 68

4.8 Test Result 68

4.9 Conclusion 72

5. DISCUSSIONS AND CONCLUSION

5.1 Introduction 73

5.2 Test Result Evaluation 73

5.3 Finding 75

5.4 Significance of Study 76

5.5 Limitations of the Project 77

5.6 Contribution of the Project 78

5.7 Challenges 79

5.8 Recommendation for Future Study 79

5.9 Conclusion 81

REFERENCES 82

APPENDICES 86

x

LIST OF TABLES

TABLE NO. TITLE PAGE 2.1 Competing parameters in Physical Device 20

2.2 List of journal paper study about TRIZ 23

2.3 Application of TRIZ to Develop an In-Service 28 Diagnostic System for a Synchronous Belt Transmission for Automotive Application

2.4 Using TRIZ and human-centered design for consumer 29 product Development

2.5 A general innovation optimization using TRIZ 30

2.6 Innovative product development process by integrating 31 QFD and TRIZ

2.7 TRIZ to invent your future utilizing directed evolution 32 methodology

3.1 Product Performance Data 41

3.2 Product technical Specification 44

3.3 Data collection table 46

4.1 Sub function design elements 51

4.2 Summary of contradiction matrix suggested inventive 55 principles

4.3 Summary of contradiction matrix suggested solution to 56 the system problem

4.4 Suction Power Data 61

4.5 Performance comparison 62

4.6 Motion resistance result for full validation 69

5.1 Summary of performance test result 72

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LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Upright Vacuum cleaner operation 4

1.2 Detail section view of cleaner head assembly 4

1.3 Conceptual Framework 6

2.1 P-Diagram 12

2.2 TRIZ process for creative problem solving 16

2.3 Overall TRIZ procedure 17

2.4 TRIZ contradiction table 21

2.5 Passive head 33

2.6 Principle sketch of passive head on hard floor (to the left) 33 and carpet (to the right)

2.7 Active head 34

2.8 Principle sketch of an active head on hard floor 34 (to the left) and carpet (to the right)

3.1 Research framework 38

3.2 Performance Chart 40

3.3 Main feature of Vacuum Cleaner 41

4.1 Exploded view of cleaner head assembly main components 47

4.2 Dust suction system 48

xii

4.3 Cleaner head function 49

4.4 Cause and effect diagram of motion resistance issue 51

4.5 Engineering Contradiction 52

4.6 Contradiction matrix result 53

4.7 Cleaner Head contact face with carpet 57

4.8 Small gap between cleaner Head and Floor 57

4.9 Rollers (RED) added and increase ride height 58

4.10 Location of additional rollers 58

4.11 Rubber Strip added to the soleplate 59

4.12 Rubber strip from side view 59

4.13 Air suction direction 60

4.14 Performance graph across different brand 61

4.15 Bleed holes 62

4.16 Rotation of brush bar on carpet 63

4.17 Drive belt system 63

4.18 Small motor transmission system 64

4.19 Additional roller and rubber strip 65

4.20 Rubber strip stick to soleplate 66

4.21 Roller at both sides of cleaner head 66

4.22 Machine on pickup test rig 67

4.23 Motion resistance test result 68

4.24 Wilton carpet pick up performance result 70

5.1 Propose future TRIZ study 80

xiii

LIST OF ABBREVIATIONS TRIZ - TeoriyaResheniyaIzobretatelskikhZadatch

TIPS – Theory of Inventive Problem Solving

QFD – Quality Function Deployment

IFR - Ideal Final Result

ARIZ - Algorithm of inventive problems solving

USIT – Unified Structured Inventive Thinking

HCD – Human Centre Design

IPDP - Innovative Product Development Process

CNC - Computerized Numerical Control

DPU – Dust Pick Up

IEC – International Electrotechnical Commission

xiv

LIST OF APPENDICES

APPENDIX TITLE PAGE

A TRIZ 39 X 39 Contradiction Matrix 86

B TRIZ 40 Inventive principle 87

C Test Method 99

D Motion Resistance test result 104

E Pickup performance test result 107

CHAPTER 1

INTRODUCTION

1.1 Introduction

This chapter discusses the general overview of the paper. This study is about

improving system design by using integration of robust design method with TRIZ

methodology. The vacuum cleaners ease of use or handling problem is used as a

case study in this project. This study provides a framework that facilitates the use of

TRIZ and robust design method in solving system design issues. The objective,

scope and limitation of the project are discussed in this chapter.

1.2 Background of the Problem

System design issue is one of the biggest challenges faced by designer. To solve

a complex system design problem, it requires a systematic problem solving approach,

good engineering knowledge and skills in order to get the most effective solution,

reliable and productive. The engineering decision involved in product development is

categorized into two:

Make no error by implementing past experience and knowledge.

Generate new design information including performance, quality, reliability

and cost.

Many companies in the industry are seeking better ways to solve technical issue

so that they can minimize the development cost and time to market. Currently one of

2

the popular approaches to solve design problem in product development is by using

robust design method. This method provides a thorough analysis of the design

parameters. However the generation of the idea to solve the problem is still relying

on brainstorming, engineer experience and skills. These processes involved trial and

errors and usually result in developing more than one design iterations to achieve

the requirements. That process also takes longer time to complete the development

work and involves high expenditure. To optimize the development process, this

study proposes to combine robust design method with TRIZ methodology.

In this study vacuum cleaner has been chosen for a case study as it has a

complex system design. Vacuum cleaner is a household product that is used to clean

floor, wall, ceiling fan and optionally for other areas in a household environment.

There are wide-ranging technologies, configurations, and designs are available for

both domestic and commercial vacuum cleaner. For domestic vacuum cleaner there

are several types available in the market like upright, canister, stick, hand held and

robot. These days the choices in vacuum cleaners are amazing and depending on type

they perform differently and offer an assortment of features and benefits. People

normally choose vacuum cleaner based on their performance, suction power (ability

to collect dust), usability, outlook and the price.

Larsson and Petersson (2009) explained that customers need to determine the

type of vacuum that works best for their house. If they have a house with large

rooms, an upright vacuum is the best choice for them. Upright type generally is

heavier than canister vacuums, so they usually clean better than canisters. However,

if the users have a lot of furniture that needs to be cleaned, upright type can be

awkward. For a smaller house or floor surfaces that have rugs covering hardwood

floors underneath, a canister or stick vacuum is the best solution. Both of these

models are lightweight and easy to maneuver.

When users buy a vacuum cleaner, there is an area that they normally cannot

make initial judgment. It is about handling of the product in use. There are a lot of

comments or review from users complaining about the handling. The machine is

3

difficult to move forward, backward and maneuver. This problem is related to high

motion resistance between cleaner head and the cleaning surface.

Larsson and Petersson (2009) describe motion resistance as a certain amount

of force required to move a cleaner head across a surface. The amount of force

depends on the friction between the nozzle and surface, the different surface

roughness which is also increased friction on carpet, vacuum pressure and airflow.

Vacuum cleaner with low airflow generally has lower motion resistance. There is a

high variation between different nozzles but a maximum motion resistance of 50N is

considered to be user friendly.

To solve the motion resistance issues, there are a lot of problem solving

approach and design tools available. However to choose the systematic approach and

effective tools for problem solving some time is difficult. Trying to solve design

problems traditionally is challenging and often engineer have to do trial-and-errors

1.3 Statement of the Problem

To become more competitive in market, engineers needs to consider more

design aspects of its requirements when designing products. Also in the future

markets, products need to adapt fast changes in their business environments over

their lifecycle. To cope with this challenge, manufacturers need to have a systematic

design and problem solving approach. In the increasing complexity of the

technological–economic environment, product manufacturers must evolve in a

framework led by the principles of the ‘science of complexity’ in order to cope better

with rapid changes and to explore and exploit high-level creativity and innovation

(Brad, 2008).

Manufacturer always struggle to design a vacuum cleaner that can provide

high performance cleaning and good handling (easy to move around). Figure 1.1

illustrates the interaction between human and the vacuum cleaner. Base on this

concern, designing a product that can meet customer needs is always a big challenge

4

to designers. There are always limitations or design constraints, which require

designer to compromise certain requirements when developing a product. This issue

is also called technical contradictions. Engineer can solve or improve one parameter

but put negative impact on other parameter. At some point a tradeoff is required

between these two elements.

Figure 1.1: Upright vacuum cleaner operation

For the upright vacuum cleaner, one of the system design contradictions is the

high air speed or air flow as illustrated in Figure 1.2 although it is required to

increase dust pick up ability, it also increases the force needed to move the cleaner

head/nozzle i.e. motion resistance, over the floor or carpet.

Figure 1.2: Detail section view of cleaner head Assembly

Cleaner Head

Brush Bar

Air flow

Floor

Moving Direction

5

Because of the existing constraints requirements in this product, based on the

literature survey, TRIZ methodology is one of the tools that can be used to solve

technical problem systematically and the robust design method is the other method

that can be used to ensure the solutions are reliable and efficient. A combination of

TRIZ and robust design methods is analyzed in this study.

Robust design method is an important approach to improve engineering

productivity and reliability. Founded by Dr. Genichi Taguchi after the end of the

Second World War, the method has developed over the last five decades. Robust

design is a set of engineering methods for achieving high-quality function despite

variations due to deterioration, the environment, manufacturing and customer use

patterns [Jugulum and Frey, 2007]. Many companies have made savings by reducing

their manufacturing cost by using this method in different industries such as

automobiles, home appliances, medical equipment, electronics, software,

telecommunications, etc.

TRIZ is a creativity method and described as a structured problem solving

approach. It involved the integration of a problem definition and resolution tools that

were created based on the analysis of millions of world-wide patents. With more than

a few decades of development and practices, TRIZ has been proven in its efficiency

and effectiveness in solving technical issues for product design.

1.4 Research Question

In order to solve the identified problem, following research questions must be

answered in this study:

i. How to solve system design problem using integration of robust

design and TRIZ?

ii. How to integrate TRIZ to problem formulation in robust design

method to enhance engineering design problem solving process?

6

1.5 Objective of the Project The main objective of this study is to find the effectiveness of integrating robust

design method with TRIZ methodology in solving system design problem related to

technical contradictions. This design improvement study is presented by structured

problem analysis and generation of inventive solution. Also this study uses vacuum

cleaner head as case study to reduce motion resistance problem through systematic

problem solving approach. The conceptual framework is illustrated in Figure 1.3.

Figure 1.3: Conceptual Framework

Figure 1.3 presents the combination of robust design method with TRIZ

methodology in systematic problem solving approach. TRIZ is applied at problem

formulation stage in parameter design study as outlined in robust design method.

1.6 Scope and Limitation

The scope of the study describes the focuses area of the project and to set out an

idea of the purpose of the study. The limitation describes the restriction or difficulty

in conducting the study.

1. Problem Formulation

2. Data collection or Simulation

3. Factor Effect

Analysis

4. Prediction and

Confirmation Robust design

(Parameter Design)

Apply TRIZ

7

1.6.1 Scope The following are the scopes of the study:

i. The study is confined to motion resistance issue

ii. The study uses one of the upright vacuum cleaners as a case study.

iii. The study uses product performance data taken from vacuum cleaner

manufacturer’s competitors test result.

iv. The study focuses only problem formulation in robust design method

and use technical contradiction tool from TRIZ methodology.

v. The study is conducted at a manufacturing company in southern

peninsular Malaysia.

vi. The propose solution validation is conducted in test lab at the

company.

1.6.2 Limitation The following are the limitation of the study:

i. This study only focuses on making improvements to vacuum cleaner

head and its functions, other parts of the vacuum cleaner are not

considered in this study.

ii. The improvement design validation is conducted on a single unit only.

1.7 Importance of the Project

This study provides an idea on how different problem solving methods or

tools help design engineer to solve engineering problem thoroughly in systematic

approach. The result from this study can be used as a reference for design base

company to the select best problem solving tool. Also a combination of robust design

method and TRIZ methodology has never been use at a manufacturing company in

southern peninsular Malaysia.

8

The study is focused on the usability of the product versus the performance.

Pelt (2011) describes usability as the methods and the easiness of users interact with

a product. It is not just about how easy a product can be used, also the senses that are

engaged, the contexts in which engagement take place, and the affordances that the

product can provides. Excellent product usability will provide high user satisfaction

and good user experience.

1.8 Organization of Report

Chapter 1 provides the introduction of the study which is to describe what are

the problems and the objectives. The introduction includes the background of the

study and also the idea of TRIZ and robust design method.

Chapter 2 provides the literature review of the study. This chapter discuss the

theoretical aspects of TRIZ and their application. As robust design method is already

widely known in industry, this chapter only discuss the overview of the robust design

process.

Chapter 3 provides the methodology, tool and technique Chapter 4 discusses the detail analysis, solution ideas and testing Chapter 5 discusses the finding of the study, significance of the study,

suggestion for future work and conclusion.

9

1.9 Conclusion

This chapter presents the justification of the study by carrying out the

research, background to the problem, problem statement, identify research questions,

objective, scope and limitation and the organization of the thesis. The next chapter

reviews the literature of area of the study and problem solving methodology.

82

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