UNIVERSITÀ DEGLI STUDI DI PISA Facoltà di Ingegneria
Corso di Laurea in Ingegneria Informatica Tesi di Laurea
Gestione della logistica tramite dispositivi mobili con lettori RFID integrati
Candidato:
Luigi Berrettini Relatori:
Prof. Ing. Francesco Marcelloni Ing. Alessio Bechini
Ing. Mario G. C. A. Cimino
Anno Accademico 2006/2007
UNIVERSITY OF PISA Faculty of Engineering
School of Computer Engineering Master Degree Thesis
GPS AND RFID BASED ASSET
TRACKING WITH MOBILE DEVICES
Candidate:
Luigi Berrettini Supervisors:
Prof. Eng. Francesco Marcelloni Eng. Alessio Bechini
Eng. Mario G. C. A. Cimino
Academic Year 2006/2007
Science is not a “subject” but a moral imperative drawn from a larger narrative whose purpose is to give perspective, balance, and humility to learning.
Neil Postman
Anyone who has lost track of time when using a computer knows the propensity to dream, the urge to make dreams come true and the tendency to miss lunch.
Tim Berners-Lee
AB S T R A C T
Radio frequency identification (RFID) refers to a set of technologies that use radio waves to identify and transmit information from tagged objects.
This emerging technology has taken on increased importance in the last few years generating enormous amount of interest in the supply chain area.
Using a combination of RFID and real time location systems (RTLS), assets can be tracked accurately in real time enabling enterprises to reduce errors introduced by manual processes, processing time and labor: this kind of solution can be applied to a variety of tasks, structures, work systems and contexts along the value chain, including business-to-business logistics, internal operations, business-to-consumer marketing, and after-sales service applications.
The aim of this thesis is the development of a software suite that could illustrate the benefits of an RFID and GPS based solution in a supply chain environment.
In a first part, automatic identification and data capture technologies (AIDC) and RTLS are analyzed in detail describing the issues and the benefits they could bring in many sectors.
Successively the software development phase is described, pointing out the purpose and the logic of the software as well as the design details.
I
CO N T E NT S
CHAPTER 1 INTRODUCTION 1
CHAPTER 2 AIDC TECHNOLOGIES 6
2.1 BARCODE 6
2.1.1 HISTORY 7
2.1.2 SYMBOLOGIES 11
2.1.2.1 LINEAR SYMBOLOGIES 11
2.1.2.2 STACKED SYMBOLOGIES 13
2.1.2.3 2D SYMBOLOGIES 13
2.1.3 USES 14
2.1.4 BENEFITS AND LIMITS 15
2.2 2.2RADIO FREQUENCY IDENTIFICATION 16
2.2.1 HISTORY 17
2.2.2 RFID READERS 22
2.2.3 RFID TAGS 25
2.2.3.1 MODULATION 25
2.2.3.2 CHANNEL ENCODING 26
2.2.3.3 ANTI-COLLISION AND MULTIPLEXING 28
2.2.3.4 WRITE CAPABILITIES 28
2.2.3.5 OPERATING FREQUENCIES 29
Contents
II
2.2.3.6 POWER SOURCE 31
2.2.3.7 COUPLING 32
2.2.3.8 TAG STANDARDS 37
2.2.4 USES 41
2.2.5 BENEFITS AND LIMITS 42
CHAPTER 3 REAL TIME LOCATION SYSTEMS 47
3.1 RANGING METHODS 48
3.1.1 ANGLE OF ARRIVAL 52
3.1.2 TIME OF ARRIVAL 53
3.1.3 TIME DIFFERENCE OF ARRIVAL 55
3.1.4 RETRIEVED SIGNAL STRENGTH INDICATION 56
3.1.5 TIME OF FLIGHT 57
3.1.6 TWO WAY RANGING 58
3.1.7 SYMMETRICAL DOUBLE SIDED TWO WAY RANGING 59
3.1.8 NEAR FIELD ELECTROMAGNETIC RANGING 60
3.2 GPS 61
3.2.1 THE THREE SEGMENTS OF GPS 62
3.2.2 GPS AT WORK 67
3.2.2.1 LOCATION 67
3.2.2.2 TIME 67
3.2.2.3 POSITION 68
3.2.3 GPS RECEIVER TECHNOLOGY 69
3.2.4 ERROR SOURCES 69
3.2.5 TECHNIQUES TO IMPROVE ACCURACY 70
3.2.5.1 WAAS 72
3.2.5.2 DIFFERENTIAL GPS 73
Contents
III
3.2.6 MAPPING 74
3.2.6.1 MAPPING THE EARTH 76
3.2.6.2 MAP PROJECTIONS 78
3.2.6.3 LATITUDE AND LONGITUDE 81
3.2.6.4 TRUE, MAGNETIC AND GRID NORTH 83
3.2.6.5 MAP SCALES 84
3.3 RFID LOCATING SYSTEMS 85
3.3.1 AEROSCOUT 88
3.3.2 WHERENET 89
3.3.3 EKAHAU 89
3.3.4 UBISENSE 90
3.3.5 MULTISPECTRAL SOLUTIONS 91
CHAPTER 4 REQUIREMENT ANALYSIS 93
4.1 PROJECT DESCRIPTION 93
4.2 FUNCTIONAL REQUIREMENTS 99
4.2.1 USER REQUIREMENTS 99
4.2.1.1 ADMINISTRATOR 99
4.2.1.2 EMPLOYEE 100
4.2.2 SOFTWARE REQUIREMENTS 101
4.3 ENTITY-RELATIONSHIP MODELING 102
4.4 NON-FUNCTIONAL REQUIREMENTS 102
CHAPTER 5 ARCHITECTURAL DESIGN 104
5.1 ARCHITECTURAL CHOICES 104
5.2 SOFTWARE ARCHITECTURE 107
Contents
IV
5.2.1 GRASSTRACK MOBILE 108
5.2.1.1 SETTINGS 109
5.2.1.2 POWER MANAGEMENT 110
5.2.1.3 GPS 111
5.2.1.4 RFID 111
5.2.1.5 GTM CORE 112
5.2.2 GRASSTRACK SERVER 113
5.2.3 GRASSTRACK JOB RUNNER 114
CHAPTER 6 DETAILED DESIGN 118
6.1 XML FILES 118
6.1.1 GRASSTRACK MOBILE
6.1.1.1 SETTINGS.XML 118
6.1.1.2 GTMDATASCHEMA.XSD 119
6.1.2 GRASSTRACK SERVER 121
6.1.2.1 WEB.CONFIG 121
6.1.2.2 BLUESOFT.DATA.ANYDBMS.DLL.CONFIG 123
6.1.3 GRASSTRACK JOB RUNNER 124
6.2 DATABASE 125
6.3 DETAILED CLASS DIAGRAMS 127
6.3.1 GRASSTRACK MOBILE 127
6.3.1.1 BLUESOFT.CONFIGURATION.APPSETTINGS 127
6.3.1.2 BLUESOFT.GPS.DATA 128
6.3.1.3 BLUESOFT.RFID.DATA 129
6.3.1.4 BLUESOFT.POWERMANAGEMENT 130 6.3.1.5 BLUESOFT.GRASSTRACK.MOBILE 132
6.3.2 GRASSTRACK SERVER 138
6.3.2.1 BLUESOFT.DATA.ANYDBMS 138
Contents
V
6.3.2.2 BLUESOFT.NET.MAIL 139
6.3.2.3 BLUESOFT.GRASSTRACK.SERVER 140
6.3.3 GRASSTRACK JOB RUNNER 142
6.3.3.1 BLUESOFT.DIAGNOSTICS.TASKSCHEDULER 142 6.3.3.2 BLUESOFT.DIAGNOSTICS.EVENTLOGGER 144
6.3.3.3 BLUESOFT.NET.MAIL 144
6.3.3.4 BLUESOFT.GRASSTRACK.JOBRUNNER 145
6.4 USER INTERACTION 146
6.4.1 GRASSTRACK MOBILE 146
6.4.2 GRASSTRACK SERVER 150
6.4.3 GRASSTRACK JOB RUNNER 151
6.5 GRASSTRACK SOFTWARE REQUIREMENTS 156
CONCLUSIONS 157
REFERENCES 158
