As the world is moving toward a greener, more sustainable future, the use of HVAC (Heating, Ventilation and Air-conditioning) systems are detrimental toward providing more efficient structures. Current UAVs (Unmanned Aerial Vehicle) used for surveying purpose are highly priced, with costs ranging upwards of R25 000. In this project, we propose a possible cost effective solution, with a budget of R10 000, that can be used in order to accurately survey a building for cracks and thermal inefficiencies within the envelope of the building. The project proposes a low cost Thermal camera to be used for the surveying as well as a validation of thermal camera for temperature reading. The project also proposes a low cost drone to be used for the possible prototype. The project follows a typical engineering design approach, specifically via the use of a V-model for the thermal camera used for image processing. After the constraints and requirements were defined, the engineering design commenced with a careful selection of both the IR camera and drone to be used for the possible prototype. Thereafter, experiments were set up to validate the use of the drone and IR camera as a viable option as a tool for building envelope surveyance. There were 6 experiments that were recorded during the process of this project. Firstly as statistical validation occurred through four tests whereby the thermal camera was validated with a mercury thermometer for temperature measurement. The second experiment was focused on the capability of the thermal camera to detect anomalies in a structure. This experiment made use of 3 holes of varying size drilled into a ceramic material with a heat source behind. Thermal images were then taken at various distances and then processed accordingly. The third experiment was focused on the ability to detect the area of the anomaly given a known distance from the thermal camera to the anomaly. The experiment followed the same set-up as described in the second experiment, however instead of 3 holes of varying size, only one hole was used. The fourth experiment looked at the building envelope and was focused on developing an algorithm to calculate the weighted average of the temperature of the structure rather than using the given structure temperature at a single point. In addition, the experiment qualitatively showed a difference between new and older insulation types. The fifth experiment focused on the development of an algorithm that would result in automatic image segmentation. The sixth experiment focused on the low cost drone and its ability to be used to survey a building. All experiments were successfully carried out. The thermal camera was validated as a reliable source for temperature measurement and could be used to detect anomalies as small as 3mm in diameter from a distance of 750mm from the target. In addition, an algorithm was developed that could be used to automatically tell the user the area of the anomaly with a 95% accuracy in certain cases. An algorithm was also developed to indicate the weighted mean temperature of an area of a building envelope. Lastly, the drone was successfully used to survey a building via the use of a developed protocol.

Large-scale bread bakeries generally exist as ‘Islands of Control’ - a long line of processes interrelated, but not interconnected in terms of their control systems. To successfully implement a control system that encompasses the entire bakery, much information must be gathered and processed in such a form that process and control engineers can deduce control algorithms. This project involved the instrumentation of an entire bakery with a view to providing production reports that merge the processes. New methods of tracking products through the entire process were investigated and tested. Methods were also proposed and tested to log temperature/humidities of various bakery processes and align with products passing through to produce a loaf/time/temperature profile.

Thesis (Ph.D.)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The primary purpose of this dissertation is to further the understanding of the influence of plenum chamber aerodynamic behaviour on mechanical draught air-cooled heat exchanger (ACHE) performance. The investigation, which included both forced and induced draught ACHEs, was conducted through the use of a commercially available computational fluid dynamics (CFD) code. A numerical axial flow fan and heat exchanger model that simulates the effect of the axial flow fan and heat exchanger bundle respectively on the flow field within the ACHE was developed and included in the CFD-code through user-programming. Where appropriate the numerical investigation was augmented with experimental data. The plenum chamber aerodynamic behaviour is characterised and included in the draught equations associated with forced and induced draught ACHEs through the introduction of dimensionless plenum chamber recovery and plenum chamber loss coefficient respectively. The influence of changes made to a range of mechanical draught ACHEs on plenum chamber aerodynamic behaviour was investigated. These changes include: • Operating conditions of the axial flow fan. • The height of the plenum chamber in the fan axial direction. • The heat exchanger bundle isothermal flow resistance. • The fan to heat exchanger area ratio. • The axial position of the fan in the fan casing. From the results of the numerical investigation a set of design guidelines are set for both forced and induced draught ACHEs. The design guidelines include recommended values for the dimensionless plenum chamber recovery and plenum chamber loss coefficient to be used in the respective draught equations enabling a more accurate prediction of the operating point of a proposed mechanical draught ACHE. KEYWORDS: air-cooled heat exchanger numerical investigation plenum chamber aerodynamic behaviour / AFRIKAANSE OPSOMMING: Die primere doel van hierdie proefskrif is om die kennis aangaande die invloed van plenum ruimte lugdinamiese gedrag op die werking van meganiese-trek lugverkoelde warmteruilers (LVWRs) te verbreed. Die ondersoek wat geforseerde- asook geinduseerdetrek LVWRs ingesluit het is uitgevoer deur gebruik te maak van In kornmersiele verkrygbare berekeningsvloeimeganika-pakket. In Numeriese aksiaalwaaier- en warmteruilermodel wat die invloed van respektiewelik die aksiaalwaaier en die warmteruiler op die vloeiveld in die LVWR simuleer is ontwikkel en in die berekeningsvloeimeganika-pakket geinkorporeer d.m.v gebruikers-roetines. Waar van toepassing is die numeriese ondersoek aangevul met eksperimentele data. Die plenumruimte lugdinamiese gedrag word gekarakteriseer en ingesluit in die onderskeie trekvergelykings vir geforseerde- en geiduseerde-trek LVWRs deur die daarstelling van In dimensielose plenumruimteherwinnings- en plenumruimteverlieskoeffisient. Die invloed van veranderinge wat aangebring is aan In reeks meganiesetrek LVWRs op die plenumruimte lugdinamiese gedrag is ondersoek. Hierdie veranderinge sluit die volgende in: • Die werking van die aksiaalwaaier. • Die hoogte van die plenumruimte in die aksiale rigting van die waaier. • Die isotermiese lugweerstand van die warmteruiler. • Die waaier-tot-warmteruiler area-verhouding. • Die aksiale posisie van die aksiaalwaaier in die waaierring. In Stel ontwerpsriglyne Vir beide geforseerde- en geinduseerde-trek LVWRs word geformuleer gebaseer op die resultate van die numeriese ondersoek. Die ontwerpsriglyne sluit aanbevole waardes vir die dimensielose plenumruimte-herwinnings- en plenumruimteverlieskoeffisient in wat op hulle beurt aangewend kan word om In meer akkurate aanduiding van die werkspunt van In beplande LVWR te bereken deur gebruik te maak van die toepaslike trekvergelyking. SLEUTEL WQORDE: lugverkoelde warmteruiler numeriese ondersoek plenurnruimte, lugdinamiese gedrag

Medical mannequins provide the first hands-on training for nurses and doctors and help eliminate human mistakes that would otherwise take place with a real person. The closer the mannequin is to mimicking a human being, the more effective the training; thus, additional features such as movable limbs and eyes, vision processing and realistic social interaction will provide a more fulfilling learning experience. A humanoid robot with a 23 degree of freedom (DOF) hand was developed which is capable of performing complex dexterous tasks such as typing on a keyboard. A single DOF elbow and two DOF shoulder was designed and optimized to maintain human form while being able to dynamically lift common household items. A 6 DOF neck and 13 DOF face with a highly expressive silicone skin-motor arrangement has been developed. The face is capable of talking and making several expressions and is used to train the student to pick up on emotional cues such as eye contact and body language during the interview stage. A pair of 3 DOF legs and a torso were also developed which allows the humanoid to be in either the laying down or sitting up position. An algorithm was developed that only activates necessary areas of code in order to increase its cycle time which greatly increases the vision tracking capabilities of the eyes. The simulator was tested at Carilion Clinic in Roanoke VA with several of the medical staff and their feedback is provided in this document. / Master of Science

Multidomain modeling has become more and more important, especially since integrated design strategies have imposed themselves for reaching higher standards in system efficiency and precision. This research deals with electromechanical systems with large multibody structure and tight interaction between electrical and mechanical parts. In the first part of this work, the author present an in depth confrontation of existing unified modeling theories: Bond Graphs, Linear Graphs and Virtual Work Principle. A simple example is used to illustrate the use of these theories and their application on multibody systems is discussed. A new modeling strategy is proposed in the second part of this text. On the basis of a symbolic implementation of dedicated formalisms, the author proposes to generate the symbolic submodels for the mechanical and the electrical parts separately and to couple the obtained equations into one global symbolic model, provided to the numerical integrator. This modeling strategy is then applied to several applications. Firstly, simple electrical circuits and electromechanical systems are considered in order to validate the tools which were developed during this work. The validation was achieved by comparison with existing modeling tools and also with experimental measurements. Secondly, more complex industrial applications are presented : 1. a parking gate system, consisting in a flexible barrier mounted on a six-bar mechanism driven by a three phase induction motor, 2. an articulated railway bogie actuated by two induction motors.

A design for a novel tubular high-precision direct-drive brushless linear motor has been developed. The novelty of the design lies in the orientation of the magnets in the mover. In conventional linear motors the magnets of the armature are arranged such that the attractive poles are adjacent throughout, in an NS-NS-NS orientation, where N denotes the north pole and S denotes the south pole of the magnet. In the new design, the magnets in the moving part are oriented in an NS-NS-SN-SN orientation. This change in orientation yields greater magnetic field intensity near the like-pole region. The magnets of the mover are encased within a brass tube, which slides through a three-phase array of current-carrying coils. As the coils are powered, they induce a force on the permanent magnets according to the Lorentz force equation. The primary advantages of the motor are its compact nature, fast, precise positioning due to its low-mass moving part, direct actuation, extended travel range, and ability to extend beyond its base. The linear motor is used in conjunction with a position sensor, power amplifiers, and a controller to form a complete solution for positioning and actuation requirements. Controllers were developed for two applications, with a lead-lag as the backbone of each. For the first application, the principal requirements are for fast rise and settling times. For the second application, the primary requirement is for near-zero overshoot. With the controller for application 1, the motor has a rise time of 55 ms, a settling time of 600 ms, and 65% overshoot. With the controller for application 2 implemented, the motor has a rise time of 1 s, a settling time of 2.5 s, and 0.2% overshoot. The maximum force capability of the motor is measured to be 26.4 N. The positioning resolution is 35 ?m. This thesis discusses the motor's physical design, construction, implementation, testing, and tuning. It includes specifications of the components of the motor and other necessary equipment, desired and actual motor performance, and the primary limitations on the precision of the system.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2009. / Pulmonary tuberculosis is a common and potentially deadly infectious disease, commonly affecting the respiratory area. Over one-third of the world’s population is infected with the tuberculosis bacterium. Since pulmonary tuberculosis damages the respiratory area, the sound properties of infected lungs differ from those of non-infected lungs. However, auscultation is often ruled out as a reliable diagnostic technique due to the random position and severity of damage to the lungs as well as requiring the personal and trained judgment of an experienced medical practitioner. This project investigates a possible improvement in the pulmonary diagnostic and treatment field by applying electronic and computer-aided sound analysis techniques to analyze respiratory actions beyond human audible judgment. Respiratory sounds of both healthy subjects and subjects who were infected with pulmonary tuberculosis were recorded from seven locations per lung on both the posterior and anterior chest walls, using self-designed hardware. Adaptive filtering signal and analysis techniques yielded a wide range of signal features. This included analysis for time, frequency and both wheeze and crackle adventitious respiratory sounds. Following the analysis, statistical methods identified the most attractive signal measurements capable of separating the recordings of healthy and unhealthy respiratory sounds. Selected signal features were used with neural network optimization to obtain a successful implementation for the semi-automated identification of healthy and unhealthy respiratory sounds originating from pulmonary tuberculosis, with a performance of over 80% for sensitivity, specificity and accuracy. The success of categorizing the recordings justifies the capabilities of the digital analysis of respiratory sounds and supports an argument for further research and refinement into the assessment of pulmonary tuberculosis by electronic auscultation. Further research is recommended, with improvements justified and highlighted in this report.

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Nystagmus is an eye movement pattern that consists of a drifting gaze component, known as the slow phase, followed by a corrective quick phase component. The presence of nystagmus or the lack thereof under certain conditions can be used for various diagnostic purposes including the diagnosis of physiological, pathological and neurological conditions. The angular velocity of the quick phase can make the detection of nystagmus a challenging task for the untrained eye, since the quick phases are usually comparable with saccadic eye motions. The goal is thus to develop a fully automated diagnostic tool that can identify the presents of nystagmus in a patient’s eye motions. In this thesis, an appropriate eye tracking method was selected from a number of eye tracking methods that are commonly implemented in the literature. A video-oculography goggle concept was chosen based on criteria such as invasiveness, sampling rate, accuracy and telemedicine capability, amongst other nystagmus related necessities. A binocular video-oculography concept was chosen that satisfied the technical requirements and provided a cost-effective design. An automated analysis algorithm was developed for automatic nystagmus identification from eye motion data. The algorithm was validated by testing the performance of the algorithm on an optokinetic nystagmus signal. It proved to provide a reliable automatic identification of nystagmus beats, even in signals that contained nystagmus as well as random motion components. A statistical analysis showed that the algorithm provided a sensitivity of 91.8% and a specificity of 96.5% for pure nystagmus signals, and a sensitivity and specificity of 87.8% and 91.1% respectively for mixed signals. / AFRIKAANSE OPSOMMING: Nystagmus is ’n oogbewegingspatroon wat bestaan uit ’n dwalende tuurkomponent, wat die stadige fase genoem word, gevolg deur ’n vinnige korrigereringsbeweging wat bekend staan as die vinnige fase. Die teenwoordigheid van nystagmus, of afwesigheid daarvan in sekere gevalle, kan gebruik word in ’n verskeidenheid diagnostiese toepassings, onder andere die diagnose van fisiologiese-, patalogiese- en neurologiese kwale. Die hoeksnelheid van die vinnige fase lei daartoe dat nystagmus dikwels moeilik is om te bespeur vir ongeöefende oë, aangesien dit vergelykbaar is met saccade bewegings. Die doel van hierdie navorsing is dus die ontwikkeling van ’n stelsel wat ’n volledige automatiese identifisering van nystagmus kan behartig. ’n Gepaste oogvolgtegniek was gekies vanuit ’n aantal verskillende oogvolgmetodes wat dikwels in die praktyk gebruik word. Die finale keuse was ’n skermbril, video-oogvolgmetode wat gekies was op grond van kriteria soos onder andere, invallendheid, meetfrekwensie, akkuraatheid en geskiktheid vir telemedisyne toepassings. Die ontwikkelde brilkonsep bied ’n koste-effektiewe oplossing, met die moontlikheid om albei oë te volg en bevredig al die bogenoemde tegniese spesifikasies. ’n Geoutomatiseerde nystagmus identifiseringsalgoritme is ontwikkel. Die algoritme se effektiwiteit is getoets op optokinetiese nystagmusseine. Betroubare resultate is vekry vanaf die algoritme, selfs in die geval van gemengde seine wat bestaan uit arbritrêre- en nystagmus komponente. Statistiese analiese het gewys dat die algoritme ’n sensitiwiteit van 91.8% en ’n spesifisiteit van 96.5% kon behaal vir seine met slegs nystagmus inhoud. Vir gemengde inhoud seine het die algoritme ’n sensitiwiteit van 87.8% en spesifisiteit van 91.1% behaal.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2007. / An abnormal sized mass in the neck is a common clinical finding and it can be the result of inflammation caused by bacterial or viral infection or it can be due to more serious diseases and malignant tumours. The most popular method of examining the neck is by manual palpation. Other methods include ultrasound, CT scan, MRI and PET. These methods though are expensive to perform and require specialists to interpret the results. The aim of this thesis was to design and develop a neck palpation device for telemedicine applications. The device uses an array of Force Sensing Resistors (FSRs) attached to an inflatable bladder. The bladder is mounted to the inside of a neck brace and it is inflated with an air pump controlled by a computer. As the bladder inflates the sensors press against the patient’s neck and the necessary data can be collected. A technique known as image registration is used to improve the resolution of the images sensed with the FSRs. The device provides a reproducible record of the examination for both the surgeon and the patient’s medical record, and provides the patient information as if the doctor examined the patient with his own hands without physically being there. A prototype of the device was built and used to perform numerous tests. The tests were conducted using different objects which are inserted into a silicone neck to simulate different lymph nodes. The device was used to test for shape, smallest size, different sizes, repeatability and hardness. The results showed that the device works well for spherical objects of different sizes but gives unsatisfactory results when the objects have sharp edges and complex forms. The image registration algorithm enhanced the images to a good representation of the object. Different sizes could be distinguished as well as hardness to some extend.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The conceptual design of a fixtureless reconfigurable automated spot welding system for manufacturing subassemblies for residential circuit breakers was investigated. This research was aimed at developing a possible low cost automation alternative to a South African industrial manufacturer, which is presently heavily dependent on personnel for manual assembly of their core products. System reconfiguration allows for the assembly of a range of subassemblies with geometric component variation on a given system configuration, as well as the potential for the system to be reconfigured to assemble other ranges of circuit breaker subassemblies. The subassembly selected as focus consists of six different components, which vary geometrically from one product variant to another. A fixtureless approach was selected, to minimise reconfiguration down time and the need for reconfigurable fixtures since reconfigurable fixtures have not found significant acceptance in industry. This varies from a fixture-based approach, which was considered in related research. The conceptual assembly system presented here consists of the following modules: a flexible vision based part feeder, twin 6 DOF robotic manipulators each with a multipurpose gripper, and a stationary spot welding station. Critical conceptual design elements were further investigated to refine their selection and confirm feasibility with respect to the target industry application. This process ended with a preliminary cost estimate which served as a basis for comparison between the fixtureless, fixture-based and present manual assembly process. The fixtureless concept was overall more expensive than the fixture-based concept, primarily because of the limits to production throughput. The fixtureless concept was however cheaper than the present manual assembly approach but had a far longer payback period than desired by the industry. The complexity and possible uncertainties of the concept combined with the long payback period indicated that the fixtureless concept is not suitable for the target application. / AFRIKAANSE OPSOMMING: Die konsepsionele ontwerp van 'n setmaatlose herkonfigureerbare outomatiese puntsweisstelsel vir die vervaardiging van subsamestellings van huishoudelike stroombrekers is ondersoek. Hierdie navorsing is gemik op die ontwikkeling van 'n moontlike lae koste outomatiese alternatief vir 'n Suid Afrikaanse industriële vervaardiger, wat tans sterk afhanklik is van werkers wat die montering van hul kern produkte met die handsamestelling doen. Stelsel herkonfigurasie laat die samestelling van 'n reeks subsamestellings, met geometriese komponentvariasies, op 'n gegewe stelsel toe, asook die potensiaal om die stelsel te herkonfigureer om ander reekse van stroombreker-subsamestellings te monteer. Die subsamestelling wat as fokus gekies is, bestaan uit ses verskillende komponente met geometriese verskille van tussen produkvariante. 'n Setmaatlose benadering is gekies ten einde aftyd vir herkonfigurasie en die noodsaaklikheid van herkonfigureerbare setmate te minimeer, omdat laasgenoemde nie noemenswaardig deur die industrie aanvaar word nie. Hierdie benadering verskil van 'n setmaat-gebaseerde benadering wat in verwante navorsing ondersoek is. Die konsepsionele monteringstelsel wat hier aangebied word, bestaan uit die volgende modules: 'n plooibare, visiegebaseerde voerapparaat; dubbele sesvryheidsgraad robotiese manipuleerders, elk met 'n veeldoelige gryper; en 'n statiese puntsweisstasie. Kritiese elemente van die konseptuele ontwerp is verder ondersoek om hul keuses te verfyn en uitvoerbaarheid in die teiken industriële toepassing te bevestig. Hierdie proses is afgesluit deur 'n voorlopige kosteraming wat gedien het as 'n basis vir die vergelyking van setmaatlose, setmaat-gebaseerde en die huidige handsamestellingstelsels. Die setmaatlose konsep was oorhoofs duurder as die setmaat-gebaseerde konsep, hoofsaaklik as gevolg van beperkings op die produksie-deurset. Die setmaatlose konsep was egter goedkoper as die huidige handmonteringsproses, maar het 'n veel langer terugbetalingstydperk as wat deur die industrie verlang word. Die kompleksiteit en moontlike onsekerhede van die konsep, gepaard met die lang terugbetalingstydperk, dui daarop dat die setmaatlose konsep nie vir die teiken toepassing geskik is nie.