The construction industry is characterised by a number of problems in crucial fields such as health, safety and logistics. Since these problems affect the progress of construction projects, the construction industry has attempted to introduce the use of innovative information and communication technologies on the construction site. Specific technologies which find applicability on the construction site are wireless sensors, and especially radio-frequency identification (RFID) technology. RFID tagging is a technology capable of tracking items. The technology has been applied on the construction site for various applications, such as asset tracking. There are many problems related to health, safety and logistics on the construction site which could be resolved using RFID technology. In the health and safety field, the problems which exist are the monitoring of dangerous areas on the construction site, such as large excavation areas, the collisions between workers and vehicles, between vehicles and equipment and between vehicles, the detection of hazardous substances on the construction site when the construction work has been completed and the collection of hazard notifications from specific areas of the construction site as feedback for the prevention of future accidents. In the logistics field, the tracking of a material during its delivery on the construction site, its transportation to specific subcontractors and its future utilisation as well as the monitoring of the rate of use of materials on the construction site, the checking of the sequence of steel members and the monitoring of the temperature of porous materials are issues which can be realised using RFID technology. In order to facilitate the use of RFID technology for the specific health, safety and logistics problems, a system has been developed. The operation of this system is based on the combined use of hardware and software elements. The hardware elements of the developed system are a wireless local area network, RFID readers and tags. Its software elements are a software development kit based on which, a number of graphical user interfaces have been created for the interaction of the users with the REID tags, and Notepad files which store data collected from REID tags through the graphical user interfaces. Each of the graphical user interfaces is designed in such a way so that it corresponds to the requirements of the health, safety or logistics situation in which it is used. The proposed system has been tested on a simulated construction site by a group of experts and a number of findings have been produced. Specifically, the testing of the proposed system showed that RFID technology can connect the different stages which characterise the construction supply chain. In addition, it showed the capability of the technology to be integrated with construction processes. The testing of the system also revealed the barriers and the enablers to the use of RFID technology in the construction industry. An example of such a barrier is the unwillingness of the people of the construction industry to quit traditional techniques in favour of a new technology. Enablers which enhance the use of RFID technology in the construction industry are the lack of complexity which characterises the operation of RFID tagging and the relatively low cost of RFID tags. In general, RFID technology is an innovative sensor technology which can help the construction industry through its asset tracking ability. However, further research should be done on the improvement of RFID technology on specific characteristics, such as its inability to provide location coordinates and the resilience of the electromagnetic signal emitted by the RFID reader when there are metallic objects around the reader.

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Sewer and oil pipeline spillage issues have become major causes of pollution in urban and rural areas usually caused by blockages in the water storage and drainage system, and oil spillage of underground oil pipelines. An effective way of avoiding this problem will be by deploying some mechanism to monitor these installations at each point in time and reporting unusual liquid activity to the relevant authorities for prompt action to avoid a flooding or spillage occurrence. This research work presents a low cost energy efficient liquid level monitoring technique using Radio Frequency Identification Technology. Passive UHF RFID tags have been designed, modelled and optimized. A simple rectangular tag, the P-shaped tag and S-shaped tag with UHF band frequency of operation (850-950 MHz) has been designed and modelled. Detailed parametric analysis of the rectangular tag is made and the optimised design results analysed and presented in HFSS and Matlab. The optimised rectangular tag designs are then deployed as level sensors in a gully pot. Identical tags were deployed to detect 4 distinct levels in alternate positions and a few inches in seperation distance within the gully pot height (Low, Mid, High and Ultra high). The radiation characteristic of tag sensors in deployment as modelled on HFSS is observed to show consistent performance with application requirements. An in-manhole chamber antenna for an underground communication system is analysed, designed, deployed and measured. The antenna covers dual-band impedance bandwidths (i.e. 824 to 960 MHz, and 1710 to 2170 MHz). The results show that the antenna prototype exhibits sufficient impedance bandwidth, suitable radiation characteristics, and adequate gains for the required underground wireless sensor applications. Finally, a Linearly Shifted Quadrifilar Helical Antenna (LSQHA) designed using Genetic Algorithm optimisation technique for adoption as an RFID reader antenna is proposed and investigated. The new antenna confirms coverage of the RFID bandwidth 860-960 MHz with acceptable power gain of 13.1 dBi.

L'identification par radio fréquence (RFID) est une technologie utilisant les ondes radio pour détecter, localiser et identifier des objets sur lesquels on place des étiquettes électroniques ou tags. Cette technologie, avec des fonctionnalités de détection supérieures à 2m, est destinée à remplacer le code-barre existant depuis les années 1970. Durant la dernière décennie, le développement de la RFID UHF a permis d'élargir le domaine des applications qui compte entre autres le marquage d'objets, le contrôle d'accès, la traçabilité, la logistique, l'inventaire, et même les transactions financières. Avec cette augmentation de la demande de services d'identification, les prévisions pour le marché de la RFID (actuellement dans les 12MM d'euros) montrent une augmentation de 3MM d'euros par an dans les 10 prochaines années. Actuellement la RFID UHF présente plusieurs limitations technologiques fortes expliquant que son développement est moins rapide que ce qui avait été envisagé il y a une vingtaine d'années. Deux problématiques industrielles importantes sont abordées dans ce travail. Tout d'abord la variété des supports sur lesquels les étiquettes RFID sont placées, cette variabilité des supports entraînant un déréglage des antennes des tags à cause du changement de la permittivité électrique et/ou de la conductivité du milieu. Dans ce contexte des solutions sont proposées au niveau de tags UHF pour une application sur surfaces en plastique ou en métal. La deuxième problématique est liée au couplage entre antennes lorsque la densité de tags est forte ou aux perturbations de diagramme (masquage) dues à l'environnement proche des antennes. Afin d'améliorer le taux de lecture dans ces conditions, une antenne lecteur miniaturisée à quatre IFAs intégrant de la diversité d'espace, de polarisation et de diagramme a été développée et testée dans un scénario à forte densité de tags / Radio Frequency Identification (RFID) is a technology designed to use the electromagnetic waves backscattering to establish detection and identification for different types of articles. Due to its longer coverage range, this technology seeks to replace the bars code existing since 1970. Recently RFID developments allow the growth in the number of applications including access control, tracking and logistic, inventory, and even electronic contactless payment between others. With this growing in the RFID services demand, the market value previsions (currently in 12MM euros) show an increase of 3MM euros per year during the next 10 years. Nowadays the RFID has many technical limitations that could explain the fact of the slow growth different of the initial estimation twenty years ago. Two main issues in RFID field are treated in this work. Initially, the variety of supports where the tags are placed on, fact that produce an antenna mismatch due to the electrical permittivity variation. For this problem some UHF tags solutions are developed and proposed to enhance the antennas performance for plastic and metallic supports applications. The second issue which is the low detection rate is clearly linked to the antennas coupling when the tags density is high or to the perturbations in the reader's radiation pattern due to the environment next to the antenna. In order to improve the detection-identification rate in these conditions, a four IFA miniaturized reader antenna with diversity is developed and tested

Sewer and oil pipeline spillage issues have become major causes of pollution in urban and rural areas usually caused by blockages in the water storage and drainage system, and oil spillage of underground oil pipelines. An effective way of avoiding this problem will be by deploying some mechanism to monitor these installations at each point in time and reporting unusual liquid activity to the relevant authorities for prompt action to avoid a flooding or spillage occurrence. This research work presents a low cost energy efficient liquid level monitoring technique using Radio Frequency Identification Technology. Passive UHF RFID tags have been designed, modelled and optimized. A simple rectangular tag, the P-shaped tag and S-shaped tag with UHF band frequency of operation (850-950 MHz) has been designed and modelled. Detailed parametric analysis of the rectangular tag is made and the optimised design results analysed and presented in HFSS and Matlab. The optimised rectangular tag designs are then deployed as level sensors in a gully pot. Identical tags were deployed to detect 4 distinct levels in alternate positions and a few inches in seperation distance within the gully pot height (Low, Mid, High and Ultra high). The radiation characteristic of tag sensors in deployment as modelled on HFSS is observed to show consistent performance with application requirements. An in-manhole chamber antenna for an underground communication system is analysed, designed, deployed and measured. The antenna covers dual-band impedance bandwidths (i.e. 824 to 960 MHz, and 1710 to 2170 MHz). The results show that the antenna prototype exhibits sufficient impedance bandwidth, suitable radiation characteristics, and adequate gains for the required underground wireless sensor applications. Finally, a Linearly Shifted Quadrifilar Helical Antenna (LSQHA) designed using Genetic Algorithm optimisation technique for adoption as an RFID reader antenna is proposed and investigated. The new antenna confirms coverage of the RFID bandwidth 860-960 MHz with acceptable power gain of 13.1 dBi. / Petroleum Technology Development Fund (PTDF) and National Space Research and Development Agency (NASRDA).

The master’s thesis is focused on the UHF RFID reader EXIN-1 signal processing. The first part describes the concept of the EXIN-1 front end, its basic testing and possible communication interfaces for reader control and for receiving and transmitting baseband signals. The second part of this work is aimed to a simple description of EPCglobal Class-1 Generation-2 UHF RFID Protocol, especially to used modulations and codings. In the last part, a block connection between the front end and an ARM Cortex-M4 microcontroller discovery board is designed. The microcontroller is used for generating of all required signals and also for receiving incoming signals and processing them for identification numbers of RFID cards (tags), which are in the reading range of the reader. A decoding algorithm is designed in MATLAB software and implemented to the selected microcontroller. Obtained identification data are displayed on an LCD display and also sent to a PC through a serial communication.