The aim of the project is to explore 3D localisation of a sensor “pill”, contained in an enclosed vessel, using multiple acoustic transducers mounted on the pill‟s surface. The thesis suggests strategies for placement, excitation and synchronisation of the transmitters on the pill and receivers on the vessel wall to deliver 3D localisation. Motivation for the project has emerged from the desire to develop wireless sensor networks to monitor the internals of industrial processes. A major challenge relates to the ability to accurately determine the location of the pill within the vessel, in the presence of multipath reflections. The main challenges relate to the determination of suitable transmission methodologies and synchronisation strategies to allow accurate localisation. The pill has to be a finite size in order to contain the required sensor hardware and transducers must be mounted on the surface of the pill such that signals are able to propagate directly to receivers on the vessel wall. This presents challenges in optimising the transmitter and receiver layout to maximise signal strength and also to determine how the separation of multiple transmitters on the pill impacts localisation accuracy. Time-Difference-of-Arrival (TDOA) has been investigated as a localisation technique, with simulations revealing that the separation of transmitters on the pill influences the accuracy. By modifying the standard TDOA equations with offset knowledge it has been demonstrated, in simulation, that this error can be reduced and by uniquely coding transmitters it is possible to resolve rotation of the pill in the vessel allowing further reduction in localisation error. Simulations have investigated how the location of receivers on the vessel wall influences the localisation error when the TDOA values are compromised by noise. It has been demonstrated that by mounting receivers at the extremities of the vessel the localisation error of the pill can be reduced. Work has also been undertaken to characterise both the vessel reflection properties and also the transmitter beam profile to allow a suitable transmitter layout on the pill to be determined. Simulations, supported by experimental results, have shown that a curved vessel surface can focus the reflected signals and therefore compromise peak detection signal methodologies. As a result amplitude thresholding is suggested for detecting received signals. The research is substantiated with a simple demonstrator that suggests, for both Time-of-Flight (TOF) and Time-Difference-of-Arrival techniques, that the location of the pill can be determined with an accuracy of ± 5 cm throughout a 250 litre vessel. This is the first time that underwater localisation in a confined space using multiple transmitters on the surface of a sensor “pill” has been reported.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The successful design, implementation and testing of a feedback control system for tab-deflection control of a shape memory alloy (SMA) based control surface actuator is presented. The research is performed as part of the Control Surfaces in Confined Spaces (CoSICS) research project conducted at Stellenbosch University. The research group investigates ways to provide control surface actuation in size-restricted spaces in commercial aircraft such as the Airbus A320 and A330. This is achieved by investigating the concept of trailing edge tabs to reduce the required torque load, resulting in reduced actuator requirements enabling the use of smaller actuators. This thesis contributes to the project by investigating the possibility of using SMA-based actuators in reduced hinge moment requirement applications. An SMA-based tab actuator demonstrator design is presented. Mathematical models are derived for the SMA material, thermodynamics and actuator geometry. The models are combined to formulate an SMA-based control surface actuator model. The model is utilised in four tracking feedback controller designs; two based on linear and two based on non-linear control techniques. The manufactured prototype is presented along with the incorporated hardware for controller implementation. System identification follows and validates the three mathematical models. Practical verification of the model and two of the controllers is conducted. The unimplemented controllers are implemented through a validated model simulation. Controller evaluation, based on the dynamic controller performance, is conducted. The results validate the concept of using an SMA actuator for tab-deflection control and indicate important limitations for the intended application. / AFRIKAANSE OPSOMMING: Die tesis behels die ontwerp, implementering en toetsing van ’n terugvoer beheerstelsel vir hulpvlak defleksie beheer van ’n vorm-geheue allooi (SMA) gebaseerde aktueerder. Die navorsing vorm deel van die Beheervlakke in Begrensde Ruimtes (CoSICS) navorsingsprojek by Stellenbosch Universiteit. Die CoSICS navorsing behels ’n ondersoek na beheervlak aktueering in beknopte spasies in kommersiële vliegtuie soos die Airbus A320 en A330. Die probleem word aangespreek deur ’n ondersoek na aerodinamiese hulpvlakke wat ’n vermindering in skarnier moment tot gevolg het en sodoende die aktueerder vereistes verminder. Hierdie tesis dra by tot die projek deur die moontlikheid van die gebruik van SMAgebaseerde aktueerders in verminderde skarnier moment vereiste toepassings te ondersoek. ‘n SMA gebaseerde hulpvlak demonstrasie aktueerder ontwerp word voorgelê. Wiskundige modelle vir die SMA materiaal, termodinamika en prototipe geometrie is geformuleer en gekombineer om ‘n SMA gebaseerde beheervlak aktueerder model te ontwikkel. Die model word in vier beheerder ontwerpe toegepas. Twee ontwerpe is op liniëre en twee op nie-liniëre beheer tegnieke gebaseer. Die prototipe en nodige hardeware vir beheerder implementasie is voorgedra. Stelsel identifikasie is toegepas en verifieer die drie wiskundige modelle. Praktiese verifikasie van die model en twee beheerders is gedoen. Die ongeïmplementeerde beheerders is deur die geverifieerde aktueerder model gesimuleer. ‘n Beheerder evaluasie gebaseer op die dinamiese beheerder gedrag word toegepas. Die evaluasie beklemtoon kritiese aspekte en beperkinge in verband met SMA aktueering. Die resultate regverdig die gebruik van ‘n SMA aktueerder vir hulpvlak defleksie beheer en beklemtoon belangrike beperkinge ten opsigte van die voorgestelde toepassing.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis describes the first project relating to the Control Surfaces in Confined Spaces (CoSICS) project at Stellenbosch University. The aim of CoSICS project is to reduce the size of control surface actuators, and this thesis considers the aileron system of commercial aircraft such as the Airbus A320 and A330. Specifically the project aims to reduce the aileron hinge moment, as this will result in smaller actuators. Possible methods are discussed where aerodynamic forces are used to reduce the aileron hinge moment through the use of a wing-aileron-tab configuration. In order to examine the use of the configuration, first order aerodynamic modelling is performed using two-dimensional thin-aerofoil theory, which is also extended to a basic three-dimensional approximation. To determine the maximum reduction in hinge moment several optimisations are performed where only the tab chord length is varied, both tab and aileron chord lengths are varied, and finally the tab chord length and aileron span are varied. The optimisation methods used, namely the gradient-based sequential quadratic programming (SQP) and a real-encoded genetic algorithm (REGA) are discussed in detail and include general implementations which are then applied to the problem. The optimisations performed are dual-layered where optimal deflection angles are determined as well as the optimal geometry. The results of the optimisation are tested using a roll manoeuvre in a specially developed Simulink simulation environment for this purpose. The study produces results where new hinge moment values are an order of magnitude smaller than those of the old configuration, while maintaining suitable lift and rolling moment coefficients. The optimisation and simulation infrastructure developed in this thesis provides a platform for higher-fidelity models and components being developed in future work to provide higher fidelity results. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die eerste projek in die Control Surfaces in Confined Spaces-projek1 (CoSICS-projek) uitgevoer by die Universiteit Stellenbosch. Die doel van die COSICs-projek is om die grootte van beheervlak aktueerders te minimeer en hierdie tesis handel oor die aileron stelsel van kommersiële vliegtuie soos die Airbus A320 en A330. Die doel van hierdie tesisis om die skarnier draaimoment van die aileron te minimeer deur aërodinamiese kragte in te span in ’n vlerk-aileron-hulpvlak konfigurasie. Eerste-orde aërodinamiese modelle is afgelei met behulp van twee-dimensionele dunvlerkteorie en is gebruik om die konfigurasie te analiseer. ’n Eerste orde drie-dimensionele benadering is ook ontwikkel. Om die maksimum vermindering in die skarnier draaimoment te bepaal, is verskeie optimerings uitgevoer waar eers die hulpvlak se koordlengte gevarieer word, daarna beide die aileron en hulp-vlak se koordlengtes en laastens die hulp-vlak se koordlengte en wydte. Die twee optimerings metodes wat gebruik is, nl. ’n sekwensiële kwadratiese programmerings (SKP) tegniek, en ’n reële getal-geënkodeerde genetiese algoritme (RGGA), word bespreek en ontwikkel voor hulle toegepas word op die probleem. Twee-vlak optimerings word uitgevoer waar beide die optimale defleksiehoeke en die optimale geometrie bepaal word. Die resultate van die optimering word daarna getoets deur middel van ’n rol maneuver wat uitgevoer word in ’n Simulink simulasie omgewing wat daarvoor geskep is. Hierdie studie lei tot goeie resultate met skarnier draaimoment waardes ’n ordegrootte kleiner as dié van die vorige stelsel, terwyl goeie waardes van rol-moment en verheffingskrag koëffisiënte behou word. Die optimering en simulasie infrastruktuur wat hier ontwikkel word verskaf ’n platform vir meer akkurate modelle en komponente wat ontwikkel word in toekomstige projekte om meer akkurate resultate te lewer.

Submitted by RICARDO CESAR FERNANDES DA SILVA (ricardo.cesarf@hotmail.com) on 2013-11-06T15:49:25Z No. of bitstreams: 1 Dissertação Ricardo Cesar Fernandes MEX 2012_Versão Final.pdf: 962302 bytes, checksum: 8bbec6b5902285b8ba4e87e66c73c44f (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2013-11-06T19:24:00Z (GMT) No. of bitstreams: 1 Dissertação Ricardo Cesar Fernandes MEX 2012_Versão Final.pdf: 962302 bytes, checksum: 8bbec6b5902285b8ba4e87e66c73c44f (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-11-11T17:14:59Z (GMT) No. of bitstreams: 1 Dissertação Ricardo Cesar Fernandes MEX 2012_Versão Final.pdf: 962302 bytes, checksum: 8bbec6b5902285b8ba4e87e66c73c44f (MD5) / Made available in DSpace on 2013-11-11T17:15:27Z (GMT). No. of bitstreams: 1 Dissertação Ricardo Cesar Fernandes MEX 2012_Versão Final.pdf: 962302 bytes, checksum: 8bbec6b5902285b8ba4e87e66c73c44f (MD5) Previous issue date: 2013-10-23 / The Brazilian maritime shipping industry is currently under going a fast growing expansion driven by, amongst other reason, Government policies towards encouraging new building ships to the Oil & Gas industry in local shipyards . At the same time , the exploration and production of petroleum demand s chartering a large number of foreign f lag vessels to support its operations. The fast growing fleet counters the fact of the shortage of skilled workforce manning those vessels , notably the Merchant Maritime Officers . Worsening the critical situation the National Council of Immigration issued the Normative Resolution n° 72/2006, with mandatory minimum proportion of Brazilian seafarers after 90 days of cont inuous operation in the Brazilian jurisdiction waters . Moreover , a study ordered by the National Union of Shipowners shows that the turnover of Maritime Officers , in the first years of their career aboard, is about 30 percent. For this reason, this study , from a literature review about Brazilian culture, motivation , work - f amily conflict , confined spaces working and turnover , has develope d into an exploratory and field research , through personal interviews analyzed accordingly with the method of content analysis with seasoned professional s with regard the thematic approach , and Maritime Officers , in order to identify the factors contributing to the turnover of Maritime Officers in the early years of his career aboard. As a result , the study showed that the intrinsic and extrinsic motivators’ agents act continuously directing the behavior of Marit ime Officers to stay or quit the career aboard . In the process of alter ing beha vioral and psychological forces , associated with motivation, the decision making process is influenc ed by a high number of alternatives represented by available employment oppor tunities to the Maritime Officers , the work - family conflicts and the difficulty to adapt working in a confined environment. In the case of Maritime Officers , females’ genre , the situation is even more sensitive because they struggl e to accomplish with the motherhood and wifely role . Therefore , the motivation to stay or quit the c areer aboard is strongly related of seeking fulfillment of personal expectations and the desire to balance personal and professional life / A indústria de transporte marítimo brasileira passa por um momento de forte expansão decorrente, entre outros fatores, de políticas governamentais que incentivam a construção, nos estaleiros nacionais, de navios para serem utilizados em apoio às atividades da indústria de óleo e gás. Ao mesmo tempo, para complementar a frota brasileira, as empresas petroleiras demandam a contratação de grande quantidade de navios estrangeiros para apoiar as suas operações. Este quadro de crescimento da frota, observado, particularmente, nos últimos 10 anos, contrasta com a escassez de mão de obra qualificada para tripular as embarcações, de modo especial dos Oficiais da Marinha Mercante (OMM). Acentuando o contraste, o Conselho Nacional de Imigração editou a Resolução Normativa n° 72/2006, determinando às empresas de navegação, que operam barcos de bandeira estrangeira, a contratação de proporções mínimas de tripulantes brasileiros, após 90 dias contínuos de operação no país. Além disso, estudos encomendados pelo Sindicato dos Armadores, SYNDARMA, apontam que a taxa de evasão dos OMM, nos anos iniciais da carreira embarcada, é de cerca de trinta por cento. Assim, o presente estudo, a partir de uma revisão bibliográfica acerca da história da Marinha Mercante brasileira, da cultura brasileira, da motivação, dos conflitos família-trabalho, do trabalho em espaço confinado e da rotatividade, se desenvolveu em uma pesquisa exploratória e de campo, por meio de entrevistas pessoais, analisadas à luz da técnica da análise de conteúdo, com profissionais de reconhecida experiência com o tema, além de OMM, com o objetivo de identificar os fatores contribuintes para a evasão dos OMM nos anos iniciais da carreira embarcada. Como resultado, o estudo mostrou que os agentes motivadores intrínsecos e extrínsecos agem continuamente direcionando o comportamento dos OMM para a permanência ou saída da carreira embarcada. Nessa alternância de forças psicológicas e comportamentais, associadas à motivação, influenciam no processo decisório as alternativas existentes representadas pelas oportunidades de emprego oferecidas aos OMM, os conflitos trabalho-família e a dificuldade de adaptação ao trabalho em ambiente confinado. No caso dos OMM, do gênero feminino, a situação é ainda mais sensível, pois enfrentam dificuldades para conciliar a vida embarcada com o papel de mãe e esposa. Portanto, a motivação para a permanência ou saída da carreira embarcada está fortemente relacionada à busca pela realização das expectativas pessoais e ao desejo de equilibrar vida pessoal com a profissional.

Sammanfattning Denna studie har utförts på en svensk medelstor fabrik som tillverkar gipsbaserade byggprodukter och tillhör en internationell koncern. Vissa arbetsuppgifter i fabriken innebär att personalen utför planerat underhåll och rengöring i områden som klassificeras som slutna utrymmen med otillräcklig ventilation där det kan bildas en farlig atmosfär och/eller att det kan vara svårt att komma in och ut. Brist på syre, brand och explosionsrisker kan leda till allvarliga, till och med dödliga olyckor i slutna utrymmen. Vid studiens start uppfyllde fabrikens befintliga rutiner för arbete i slutna utrymmen inte säkerhetskraven från koncernen och inte heller från lagstiftningen. Koncernen har uppmanat fabriken att ta fram ”bäst praxis” för arbete i slutna utrymmen så att andra fabriker kan implementera samma typ av åtgärder. Syftet med denna studie är därför att utveckla ett verktyg för att förebygga ohälsa och olycksfall i arbetet i slutna utrymmen. Studien avgränsas till att undersöka riskerna på två slutna utrymmen i fabriken.Studien utfördes som en fallstudie. Datainsamling har gjorts genom litteraturstudier, en översikt av lagstiftningskrav, granskning av fabrikens befintliga dokument och verktyg för riskbedömningar, anteckningar under projektmöten, intervjuer av medlemmar i projektgruppen, samt kunskapsinhämtningen via deltagandet i endagsseminarium om ”arbete i slutet utrymme”. För bedömning av kvalitet och funktionalitet av verktyget genomfördes en workshop med öppna frågor.Utifrån dessa forskningsaktiviteter har ett verktyg utvecklats för att systematiskt identifiera och hantera risker i slutna utrymmen på den aktuella fabriken som har följande cykel: 1) Bakgrund, 2) Kartläggning, 3) Risklista, 4) Stratifiering, 5) Riskbedömning, 6) Organisatoriska och tekniska åtgärder, 7) Implementering, 8) Revisioner, 9) Inspektioner, 10) Korrigerande åtgärder.Verktyget kommer att implementeras för arbete även i de andra slutna utrymmena i fabriken. Nästa steg är att testa verktyget i andra gipsfabriker i koncernen och justera efter behov samt sprida kunskapen vidare.Vi rekommenderar att 1) Fabrikens räddningsteam utvecklar specifik nöd-plan för varje slutet utrymme samt ett schema för inspektion av utrustning, samt att 2) Projektgruppen utvecklar ”ett flöde” för att underlätta genomgång av rutinerna när arbete i slutna utrymmen behövs. / Abstract The research study presented in this master thesis was done in a Swedish medium-sized factory that manufactures plaster-based construction products and belongs to an international corporate group. Some work tasks in the factory involve staff carrying out scheduled maintenance and cleaning in areas that are classified as confined spaces with inadequate ventilation that can form a hazardous atmosphere, and/or that it is difficult to get in and out. Lack of oxygen, fire and explosion risks may result in serious, even fatal, accidents in confined spaces. At the start of this research study, the existing factory procedures for working in confined spaces did not fully meet the requirements of the corporate group, nor Swedish legislation. The corporate group has challenged the factory to develop "best practices" for work in confined spaces so that other factories can implement the same kind of counter measures. The aim of this study is therefore to develop a tool to prevent accidents by identifying and managing risks associated with work in confined spaces.The research study was performed as a case study. Data collection was done through literature studies and collection an overview of legislative requirements, review of existing company documents, risk assessment tools, notes during project meetings, interviews of the project team, as well as the acquisition of knowledge through participation in the seminar on "work in the confined spaces". To evaluate the quality of the tool, a workshop was conducted with open questions.Based on these research activities a tool is developed to systematically identify and manage risks in confined spaces at the current factory and has the following cycle: 1) Background, 2) Mapping, 3) Risk List, 4) Stratification, 5) Risk Assessment, 6) Organizational and technical counter measures, 7) Implementation, 8) Audits, 9) Inspections, 10) Corrective actions (continuous improvement)The tool can be implemented in the future for the other confined spaces in the factory. The next step is to test the tool in other gypsum factories in the Group and adjust as needed, and to spread the knowledge further.We recommend that 1) the factory Rescue Team develop specific emergency plans for each confined space as well as a schedule for equipment inspection, and that the 2) Project team develop a "flow" to facilitate the review of routines when work in confined spaces is required.

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