+publisher:"Stellenbosch University" +contributor:("Schreve, K.") – OATD
You searched for +publisher:"Stellenbosch University" +contributor:("Schreve, K."). Showing records 1 – 20 of 20 total matches.
1. Christiane, Peter-John. Development of a minimally invasive robotic surgical manipulator.
Christiane, Peter-John. “Development of a minimally invasive robotic surgical manipulator.” 2009. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/4497.
Christiane, Peter-John. “Development of a minimally invasive robotic surgical manipulator.” 2009. Web. 19 Jan 2020.
Christiane P. Development of a minimally invasive robotic surgical manipulator. [Internet] [Masters thesis]. Stellenbosch University; 2009. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/4497.
2. Rugbani, Ali. Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes.
ENGLISH ABSTRACT: Polysulfone hollow-fibre membranes were fabricated via the dry-wet solution spinning technique. The objective… (more)
ENGLISH ABSTRACT: Polysulfone hollow-fibre membranes were fabricated via the dry-wet solution spinning technique. The objective was to demonstrate the influence of the various fabrication parameters on the diameter and mechanical properties of the hollow-fibre membranes and to optimize the spinning process by controlling these parameters with a computer control system. The effects of the operation parameters were investigated using an experimental design based on a fractional factorial method (Taguchi’s design of experiments). The parameters that were considered are the spinneret size, dope solution temperature, bore fluid temperature, coagulation bath temperature, dope extrusion rate, bore flow rate and the take-up speed. A new pilot solution spinning plant was installed and upgraded, and a computer control system, based on LabView, was developed to control, monitor and log the experimental data. The diameter of the hollow-fibres were determined using a scanning electron microscope (SEM) while the mechanical properties were measured using a tensile tester. The effects of diameter size and wall thickness of the hollow-fibres on the performance of the membranes were studied. The results showed the significance of the fabrication parameters that dominate the diameter and strength of the hollow-fibres.
AFRIKAANSE OPSOMMING: Polisulfoon holvesel membrane is met ‘n droë-nat oplossingspin proses vervaardig. Die doel hiermee was om die invloed van verskeie vervaardigingsparameters op die deursnee en meganiese eienskappe van die holvesel membrane te demonstreer asook om die spin proses te optimeer deur gerekenariseerde beheer van die aanleg. ‘n Eksperimentele ontwerp, gebaseer op ‘n gedeeltelike faktoriaal metode (Taguchi se eksperimentele ontwerp) is gebruik om die invloed van die vervaardigingsparameters te ondersoek. Die parameters wat oorweeg is, is spindop grootte, materiaal temperatuur, boorvloeistof temperatuur, stolbad temperatuur, materiaal ekstrusie tempo and opwen spoed. ‘n Nuwe oplossingspin loodsaanleg was geïnstalleer en opgegradeer en ‘n rekenaar beheerstelsel, gebaseer op LabView, is ontwikkel om die aanleg te beheer, moniteer en eksperimentele data te stoor. Die deursnee van die holvesel is gemeet met ‘n skanderingelektron mikroskoop (SEM) terwyl die meganiese eienskappe bepaal is met ‘n trektoets apparaat. Die effek van die deursnee en wanddikte van die holvesels op die werkverrigting van die membrane is ook bestudeer. Die resultate toon watter vervaardigingsparameters is beduidend vir die deursnee en sterkte van die holvesels.
Subjects/Keywords: Mechanical engineering; Polysulfone hollow-fibre membranes; Membranes (Technology); Mechanical and Mechatronic Engineering
Rugbani, A. (2009). Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/2677
Rugbani, Ali. “Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes.” 2009. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/2677.
Rugbani, Ali. “Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes.” 2009. Web. 19 Jan 2020.
Rugbani A. Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes. [Internet] [Thesis]. Stellenbosch University; 2009. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/2677.
Rugbani A. Investigating the influence of fabrication parameters on the diameter and mechanical properties of polysulfone ultrafiltration hollow-fibre membranes. [Thesis]. Stellenbosch University; 2009. Available from: http://hdl.handle.net/10019.1/2677
3. Greeff, Gabriel Pieter. A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology.
ENGLISH ABSTRACT: Accurate dimensional measurement devices are critical for international industrial competitiveness for South… (more)
ENGLISH ABSTRACT: Accurate dimensional measurement devices are critical for international industrial competitiveness for South Africa. An overview of all the necessary components of a laser tracking system using a multilateration technique for very accurate dimensional metrology is presented. A prototype laser tracker station was built to further investigate this type of system. The prototype successfully tracks a target within a volume of at least 200 200 200 mm3, approximately 300 mm away from the tracker. This system includes the mechanical design of a prototype tracker station, electronic implementation of ampli cation and motor control circuits, a tracking control algorithm, microcontroller programming and interfacing, as well as a user interface. Kinematic modelling along with Monte Carlo analyses nd the main error source of such a tracker as the beam steering mechanism gimbal axes misalignment. Multilateration is also motivated by the results found by the analysis. Furthermore, an initial sequential multilateration algorithm is developed and tested. The results of these tests are promising and motivate the use of multilateration over a single beam laser tracking system.
AFRIKAANSE OPSOMMING: Dit is van kritieke belang dat Suid-Afrika akkurate dimensionele metingstoestelle ontwikkel vir internasionale industriële medinging. 'n Oorsig van al die nodige komponente vir 'n Laser-Volgsisteem, wat slegs van multilaterasie gebruik maak om baie akkurate drie dimensionele metings te kan neem, word in hierdie projek voorgestel. 'n Prototipe Laser-Volgsisteem-stasie word gebou om so 'n sisteem verder te ondersoek. Die prototipe slaag wel daarin om 'n teiken, binne 'n volume van 200 200 200 mm3 op 'n afstand van omtrent 300 mm te volg. Die sisteem sluit die meganiese ontwerp van die sodanige stasie, elektroniese seinversterking, motorbeheer, 'n volgingsbeheer algoritme, mikroverwerker programeering en intergrasie, asook 'n gebruikerskoppelvlak program in. Kinematiese modelering, tesame met Monte Carlo simulasies, toon aan dat die hoof oorsaak van metingsfoute by so 'n stasie by die rotasie-asse van die laserstraal-stuurmeganisme, wat nie haaks is nie, lê. Die multilaterasie metode word ook verder ondersteun deur dié modelering. 'n Algoritme wat sekwensiële multilateratsie toepas word boonop ontwikkel en getoets. Die resultate van die toetse dui daarop dat die algoritme funksioneer en dat daar voordele daarin kan wees om so 'n metode in plaas van 'n Enkelstraal-Volgsisteem te gebruik.
Subjects/Keywords: Mechatronic engineering; Metrology; Lasers – Industrial applications; Coordinate measuring machines
Greeff, G. P. (2010). A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/3181
Greeff, Gabriel Pieter. “A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology.” 2010. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/3181.
Greeff, Gabriel Pieter. “A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology.” 2010. Web. 19 Jan 2020.
Greeff GP. A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology. [Internet] [Thesis]. Stellenbosch University; 2010. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/3181.
Greeff GP. A study for the development of a laser tracking system utilizing multilateration for high accuracy dimensional metrology. [Thesis]. Stellenbosch University; 2010. Available from: http://hdl.handle.net/10019.1/3181
4. Swart, Wayne. Nystagmus and eye reflex sensor.
Swart, Wayne. “Nystagmus and eye reflex sensor.” 2011. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/18019.
Swart, Wayne. “Nystagmus and eye reflex sensor.” 2011. Web. 19 Jan 2020.
Swart W. Nystagmus and eye reflex sensor. [Internet] [Masters thesis]. Stellenbosch University; 2011. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/18019.
5. Dippenaar, D. J. A technical and economical evaluation of RP technology for RTM tooling.
Dippenaar, D J. “A technical and economical evaluation of RP technology for RTM tooling.” 2010. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/4193.
Dippenaar, D J. “A technical and economical evaluation of RP technology for RTM tooling.” 2010. Web. 19 Jan 2020.
Dippenaar DJ. A technical and economical evaluation of RP technology for RTM tooling. [Internet] [Thesis]. Stellenbosch University; 2010. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/4193.
6. Vogt, Christian. An experimental cost model for composite parts using vacuum assisted resin transfer moulding (VARTM).
7. Janse van Vuuren, Frank. Design of a hexapod mount for a radio telescope.
ENGLISH ABSTRACT: The world's astronomy community is working together to build the largest and most… (more)
ENGLISH ABSTRACT: The world's astronomy community is working together to build the largest and most sensitive radio telescope in the world namely: the SKA (Square Kilometre Array). It will consist of approximately three thousand dishes which will each require accurate positioning. The Square Kilometer Array has a testbed called the Phased Experimental Demonstrator (PED) in Observatory, Cape Town. A hexapod positioning mechanism is required to position a 3.7 m radio telescope which forms part of an array of seven radio telescopes. This thesis details the design process of the hexapod system. The design consists of the mechanical design of the joints and linear actuators, a kinematic and dynamic model, a controller and a user interface. In order to verify the design for the PED hexapod a scaled prototype was designed, built and tested. The hexapod's repeatability as well as ability to track a path was tested using an inclinometer. The tests confirmed the design feasibility of the PED hexapod and also highlight issues that require care when constructing the full scale hexapod, such as the amount of play in the platform joints. The designed full scale hexapod will have an error angle less than 0.13°, a payload capacity of 45 kg, withstand wind speeds of 110 km/h and cost R160 000.
AFRIKAANSE OPSOMMING: Die wêreld se sterrekundige gemeenskap is besig om saam te werk om die grootste en mees sensitiewe radioteleskoop in die wêreld te bou, naamlik: die SKA (Square Kilometre Array). Dit sal uit ongeveer drie duisend skottels bestaan wat elkeen akkurate posisionering benodig. Die SKA het 'n toetssentrum, genaamd die “Phased Experimental Demonstrator” in Observatory, Kaapstad. 'n Sespoot posisionering meganisme word benodig om die 3.7 m radioteleskoop te posisioneer, wat deel vorm van 'n stelsel van sewe radioteleskope. Hierdie tesis beskryf die proses om die sespoot stelsel te ontwerp. Die ontwerp bestaan uit die meganiese komponent van die koppelings en lineêre aktueerders, 'n kinematiese en dinamiese model, 'n beheerder, asook 'n gebruikersintervlak. 'n Geskaleerde prototipe is ontwerp, gebou en getoets om die ontwerp te verifieer. Die platform se herhaalbaarheid sowel as akkuraatheid om 'n pad te volg was getoets met 'n oriëntasie sensor. Die toetse het probleme uitgelig wat versigtig hanteer moet word gedurende die konstruksie van die volskaalse sespoot, veral die hoeveelheid speling in die koppelings. Die volskaalse sespoot ontwerp het 'n hoek fout van minder as 0.13°, 'n ladingsvermoë van 45 kg en kan 'n windspoed van 110 km/h weerstaan en kos R160 000.
Advisors/Committee Members: Kim, Y., Schreve, K., University of Stellenbosch. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering..
Subjects/Keywords: Mechatronic engineering; Radio telescopes; Phased Experimental Demonstrator (PED)
Janse van Vuuren, F. (2011). Design of a hexapod mount for a radio telescope . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/6693
Janse van Vuuren, Frank. “Design of a hexapod mount for a radio telescope.” 2011. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/6693.
Janse van Vuuren, Frank. “Design of a hexapod mount for a radio telescope.” 2011. Web. 19 Jan 2020.
Janse van Vuuren F. Design of a hexapod mount for a radio telescope. [Internet] [Thesis]. Stellenbosch University; 2011. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/6693.
Janse van Vuuren F. Design of a hexapod mount for a radio telescope. [Thesis]. Stellenbosch University; 2011. Available from: http://hdl.handle.net/10019.1/6693
8. Worst, Siebert Christo. Development of a low cost secondary slave manipulator for a minimally invasive robotic surgical system.
Worst, Siebert Christo. “Development of a low cost secondary slave manipulator for a minimally invasive robotic surgical system.” 2012. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/71618.
Worst, Siebert Christo. “Development of a low cost secondary slave manipulator for a minimally invasive robotic surgical system.” 2012. Web. 19 Jan 2020.
Worst SC. Development of a low cost secondary slave manipulator for a minimally invasive robotic surgical system. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/71618.
9. Garth-Davis, Bryan. A needle positioning system for percutaneous procedures.
Garth-Davis, Bryan. “A needle positioning system for percutaneous procedures.” 2012. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/71626.
Garth-Davis, Bryan. “A needle positioning system for percutaneous procedures.” 2012. Web. 19 Jan 2020.
Garth-Davis B. A needle positioning system for percutaneous procedures. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/71626.
10. Heunis, Jacobus Stephanus. A user interface for a seven degree of freedom surgical robot.
Heunis, Jacobus Stephanus. “A user interface for a seven degree of freedom surgical robot.” 2012. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/71833.
Heunis, Jacobus Stephanus. “A user interface for a seven degree of freedom surgical robot.” 2012. Web. 19 Jan 2020.
Heunis JS. A user interface for a seven degree of freedom surgical robot. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/71833.
11. Van der Westhuizen, Gareth. Design, implementation & analysis of a low-cost, portable, medical measurement system through computer vision.
Van der Westhuizen, Gareth. “Design, implementation & analysis of a low-cost, portable, medical measurement system through computer vision.” 2011. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/6764.
Van der Westhuizen, Gareth. “Design, implementation & analysis of a low-cost, portable, medical measurement system through computer vision.” 2011. Web. 19 Jan 2020.
Van der Westhuizen G. Design, implementation & analysis of a low-cost, portable, medical measurement system through computer vision. [Internet] [Thesis]. Stellenbosch University; 2011. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/6764.
12. Holtzhausen, David Schalk. Development of distributed control system for SSL soccer robots.
ENGLISH ABSTRACT: This thesis describes the development of a distributed control system for SSL soccer robots. The project continues on work done to develop a… (more)
ENGLISH ABSTRACT: This thesis describes the development of a distributed control system for SSL soccer robots. The project continues on work done to develop a robotics research platform at Stellenbosch University. The wireless communication system is implemented using Player middleware. This enables high level programming of the robot drivers and communication clients, resulting in an easily modifiable system. The system is developed to be used as either a centralised or decentralised control system. The software of the robot’s motor controller unit is updated to ensure optimal movement. Slippage of the robot’s wheels restricts the robot’s movement capabilities. Trajectory tracking software is developed to ensure that the robot follows the desired trajectory while operating within its physical limits. The distributed control architecture reduces the robots dependency on the wireless network and the off-field computer. The robots are given some autonomy by integrating the navigation and control on the robot self. Kalman filters are designed to estimate the robots translational and rotational velocities. The Kalman filters fuse vision data from an overhead vision system with inertial measurements of an on-board IMU. This ensures reliable and accurate position, orientation and velocity information on the robot. Test results show an improvement in the controller performance as a result of the proposed system.
AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die ontwikkeling van ’n verspreidebeheerstelsel vir SSL sokker robotte. Die projek gaan voort op vorige werk wat gedoen is om ’n robotika navorsingsplatform aan die Universiteit van Stellenbosch te ontwikkel. Die kommunikasiestelsel is geïmplementeer met behulp van Player middelware. Dit stel die robotbeheerders en kommunikasiekliënte in staat om in hoë vlak tale geprogrameer te word. Dit lei tot ’n maklik veranderbare stelsel. Die stelsel is so ontwikkel dat dit gebruik kan word as óf ’n gesentraliseerde of verspreidebeheerstelsel. Die sagteware van die motorbeheer eenheid is opgedateer om optimale robot beweging te verseker. As die robot se wiele gly beperk dit die robot se bewegingsvermoëns. Trajekvolgings sagteware is ontwikkel om te verseker dat die robot die gewenste pad volg, terwyl dit binne sy fisiese operasionele grense bly. Die verspreibeheerargitektuur verminder die robot se afhanklikheid op die kommunikasienetwerk en die sentrale rekenaar. Die robot is ’n mate van outonomie gegee deur die integrasie van die navigasie en beheer op die robot self te doen. Kalman filters is ontwerp om die robot se translasie en rotasie snelhede te beraam. Die Kalman filters kombineer visuele data van ’n oorhoofse visiestelsel met inertia metings van ’n IMU op die robot. Dit verseker betroubare en akkurate posisie, oriëntasie en snelheids inligting. Toetsresultate toon ’n verbetering in die beheervermoë as ’n gevolg van die voorgestelde stelsel.
Advisors/Committee Members: Schreve, K., Blanckenberg, M. M., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering..
Subjects/Keywords: Mechatronic engineering; Dissertations – Mechatronic engineering; Multisensor data fusion
Holtzhausen, D. S. (2013). Development of distributed control system for SSL soccer robots . (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/80221
Holtzhausen, David Schalk. “Development of distributed control system for SSL soccer robots.” 2013. Masters Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/80221.
Holtzhausen, David Schalk. “Development of distributed control system for SSL soccer robots.” 2013. Web. 19 Jan 2020.
Holtzhausen DS. Development of distributed control system for SSL soccer robots. [Internet] [Masters thesis]. Stellenbosch University; 2013. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/80221.
Holtzhausen DS. Development of distributed control system for SSL soccer robots. [Masters Thesis]. Stellenbosch University; 2013. Available from: http://hdl.handle.net/10019.1/80221
13. Labuschagne, P. A critical investigation into the accuracy of a parallel coordinate measuring machine.
Labuschagne, P. “A critical investigation into the accuracy of a parallel coordinate measuring machine.” 2019. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/106229.
Labuschagne, P. “A critical investigation into the accuracy of a parallel coordinate measuring machine.” 2019. Web. 19 Jan 2020.
Labuschagne P. A critical investigation into the accuracy of a parallel coordinate measuring machine. [Internet] [Thesis]. Stellenbosch University; 2019. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/106229.
14. Burke, Michael Glen. Visual servo control for a human-following robot.
ENGLISH ABSTRACT: This thesis presents work completed on the design of control and vision components… (more)
ENGLISH ABSTRACT: This thesis presents work completed on the design of control and vision components for use in a monocular vision-based human-following robot. The use of vision in a controller feedback loop is referred to as vision-based or visual servo control. Typically, visual servo techniques can be categorised into imagebased visual servoing and position-based visual servoing. This thesis discusses each of these approaches, and argues that a position-based visual servo control approach is more suited to human following. A position-based visual servo strategy consists of three distinct phases: target recognition, target pose estimation and controller calculations. The thesis discusses approaches to each of these phases in detail, and presents a complete, functioning system combining these approaches for the purposes of human following. Traditional approaches to human following typically involve a controller that causes platforms to navigate directly towards targets, but this work argues that better following performance can be obtained through the use of a controller that incorporates target orientation information. Although a purely direction-based controller, aiming to minimise both orientation and translation errors, suffers from various limitations, this thesis shows that a hybrid, gain-scheduling combination of two traditional controllers offers better targetfollowing performance than its components. In the case of human following the inclusion of target orientation information requires that a definition and means of estimating a human’s orientation be available. This work presents a human orientation measure and experimental results to show that it is suitable for the purposes of wheeled platform control. Results of human following using the proposed hybrid, gain-scheduling controller incorporating this measure are presented to confirm this.
AFRIKAANSE OPSOMMING: Die ontwerp van ’n visiestelsel en beheer-komponente van ’n enkel-kamera robot vir die volging van mense word hier aangebied. Die gebruik van visuele terugvoer in die beheerlus word visie-gebaseerde of visuele servobeheer genoem. Visuele servobeheer tegnieke kan tipies onderskei word tussen beeld-gebaseerde servobeheer en posisie-gebaseerde visuele servobeheer. Altwee benaderings word hier bespreek. Die posisie-gebaseerde benadering word aanbeveel vir die volging van mense. Die posisie-gebaseerde servobeheertegniek bestaan uit drie duidelike fases: teiken herkenning, teiken oriëntasie bepaling en die beheerder berekeninge. Benaderings tot elk van hierdie fases word hier in detail bespreek. Dan word ’n volledige funksionele stelsel aangebied wat hierdie fases saamvoeg sodat mense gevolg kan word. Meer tradisionele benaderings tot die volging van mense gebruik tipies ’n beheerder wat die platvorm direk laat navigeer na die teikens, maar hier word geargumenteer dat beter werkverrigting verkry kan word deur ’n…
Advisors/Committee Members: Engelbrecht, J. A. A., Brink, W. H., Schreve, K., University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering..
Burke, M. G. (2011). Visual servo control for a human-following robot . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/6813
Burke, Michael Glen. “Visual servo control for a human-following robot.” 2011. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/6813.
Burke, Michael Glen. “Visual servo control for a human-following robot.” 2011. Web. 19 Jan 2020.
Burke MG. Visual servo control for a human-following robot. [Internet] [Thesis]. Stellenbosch University; 2011. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/6813.
Burke MG. Visual servo control for a human-following robot. [Thesis]. Stellenbosch University; 2011. Available from: http://hdl.handle.net/10019.1/6813
15. Brink, Yolandi. Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students.
Degree: PhD, Physiotherapy, 2012, Stellenbosch University
► ENGLISH ABSTRACT: Introduction: The increased prevalence of adolescent upper quadrant musculoskeletal pain (UQMP) is becoming a great concern to health professionals. The risk factors associated… (more)
▼ ENGLISH ABSTRACT: Introduction: The increased prevalence of adolescent upper quadrant musculoskeletal pain (UQMP) is becoming a great concern to health professionals. The risk factors associated with adolescent UQMP are complex and multifactorial, including, among others sitting as a physical risk factor. However, no evidence exists to support sitting postural angles as a potential predictive factor for adolescent UQMP in computing high school students. Thus, the current project aimed to describe the three-dimensional (3D) sitting postural angles of computing South African high school students in a real-life setting, using a well-tested and documented posture measurement instrument. Methodology: This research project is comprised of seven related studies. Part I of the dissertation presents a systematic review describing the reliability and validity testing of posture measurement instruments. This is followed by three primary correlation and repeated measures observational studies aimed at ascertaining the reliability and validity of a newly developed 3D Posture Analysis Tool (3D-PAT) in the measurement of nine sitting postural angles of computing high school students. Part II of the dissertation presents a systematic review, that evaluates the latest published research evidence of whether sitting is related to UQMP, and, if so, to identify the elements of sitting that significantly contribute to UQMP. This review is followed by a description of a cohort study, with a prospective period of one year. The 3D-PAT was implemented in a clinical research setting in order to measure the 3D sitting posture of a cohort of asymptomatic computing high school students and in order to assess the outcome, seated-related UQMP, prospectively. The prospective study design enabled the research project to contribute to an understanding of any causative relationship between the exposure (sitting postural angles) and the outcome (seated-related UQMP) in a subgroup of adolescents (computer users). Results: After the first phase of psychometric testing of the 3D-PAT using high school students, the findings indicated that the instrument required modifications prior to further psychometric testing. The second phase of testing revealed that the 3D-PAT compared very well with the reference standard for measurement of the X-, Y- and Z-coordinates of the reflective markers on a mannequin. The findings from the phase three study, again using high school students, indicated that the 3D-PAT compared very well with the reference standard and justified its use for the measurement of six sitting postural angles of the upper quadrant in computing high school students. For the cohort study, a 60% response rate for participation was achieved at baseline, with 98% of the students participating at six-month and 80% at one-year follow up. Of the students, 33.5% complained of seated-related UQMP during the follow-up period. Exposure to increased head flexion (>80°) (ρ=0.0001) and the combination of increased head flexion and decreased cranio-cervical angles… Advisors/Committee Members: Louw, Q. A., Schreve, K., Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Physiotherapy..
Subjects/Keywords: Physiotherapy; Dissertations – Physiotherapy; Sitting position – Research; Pain in adolescence – Diagnosis – Research; Musculoskeletal system – Physical therapy – Research; Department of Physiotherapy, Faculty of Medicine and Health Sciences
…Stellenbosch University http://scholar.sun.ac.za ACKNOWLEDGEMENTS… …Research Fund and the Division of Research Development and Support of Stellenbosch University… …my dream. viii | P a g e Stellenbosch University http://scholar.sun.ac.za TABLE OF… …14 ix | P a g e Stellenbosch University http://scholar.sun.ac.za 2.2.1 Search… …40 x|Page Stellenbosch University http://scholar.sun.ac.za 3.2.4 Marker placement…
Brink, Y. (2012). Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students . (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/71876
Brink, Yolandi. “Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students.” 2012. Doctoral Dissertation, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/71876.
Brink, Yolandi. “Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students.” 2012. Web. 19 Jan 2020.
Brink Y. Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students. [Internet] [Doctoral dissertation]. Stellenbosch University; 2012. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/71876.
Brink Y. Sitting posture : a predictive factor for upper quadrant musculoskeletal pain in computing high school students. [Doctoral Dissertation]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/71876
16. Rugbani, Ali Milud. The design, kinematics and error modelling of a novel micro-CMM parallel manipulator.
Degree: PhD, Mechanical and Mechatronic Engineering, 2014, Stellenbosch University
ENGLISH ABSTRACT: The research presented in this dissertation establishes a micro-CMM parallel manipulator as a viable positioning device for three degree of freedom micro measurement… (more)
ENGLISH ABSTRACT: The research presented in this dissertation establishes a micro-CMM parallel manipulator as a viable positioning device for three degree of freedom micro measurement applications. The machine offers the advantages associated with parallel kinematic manipulators, such as light carrying weight, high stiffness and no accumulation of errors, while avoiding some of the traditional disadvantages of parallel manipulators such as the associated effects of angular errors (Abbé error), singularity problems, work space limitation and the extensive use of spherical joints. In this dissertation, the direct position kinematic solution is developed analytically and the solution of the inverse position kinematic is solved numerically. A workspace analysis has been performed. A fully functional prototype demonstrator is fabricated to demonstrate this machine. While the demonstrator was not intended to achieve submicron accuracy, it was intended to validate the error models. Computer controlled measurement is developed and used to position the probe and to record measurements. A reliable kinematic error model based on the theory of error propagation is derived analytically. A numerical method is used to verify the analytical results. Comparison shows that the results of the error model, both analytical and numerical, represent a very good match and follow the same trend. The kinematic position model is validated using a conventional CMM. Results show that an average difference of less than 0.5 mm over a set of 30 points is achieved. This result of the micro-CMM demonstrator measurements falls within the error budget of approximately 0.75 mm estimated by the proposed analytical error model.
AFRIKAANSE OPSOMMING: Die navorsing in hierdie tesis vestig ‘n mikro-CMM parallelle manipuleerder as ‘n lewensvatbare posisioneringstoestel vir drie vryheidsgraad-mikrometing toepassings. Die masjien bied voordele geassosieer met parallelle kinematiese manipuleerders, bv. ligte dra-gewig, hoë styfheid en geen ophoping van foute nie. Die tradisionele nadele van parallelle manipuleerders soos die geassosieerde gevolge van hoekfoute (Abbé fout), enkelvoudigheidsprobleme, werkspasiebeperking en die uitgebreide gebruik van sferiese koppelings word vermy. In hierdie tesis word die direkte posisie kinematiese oplossing analities ontwikkel en die oplossing van die omgekeerde posisie kinematies word numeries opgelos. ‘n Werkspasie analise is uitgevoer. ‘n Ten volle funksionele prototipe demonstrasie-model is vervaardig om hierdie masjien te demonstreer. Die model is nie vervaardig om submikron akkuraatheid te bereik nie, maar eerder om foutmodelle geldig te verklaar. Rekenaar-beheerde metings is ontwerp en gebruik om die toetspen te posisioneer en om metings te neem. ‘n Betroubare kinematiese foutmodel gebaseer op die teorie van foutvoortplanting is analities afgelei. ‘n Numeriese metode word gebruik om die analitiese resultate te bevestig. Vergelyking toon aan dat die resultate van die foutmodel, beide analities en numeries, goeie…
Advisors/Committee Members: Schreve, K., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering..
…Stellenbosch University http://scholar.sun.ac.za CHAPTER 3: 3.1 3.2 3.3 3.3.1 3.3.2 3.4… …84 viii Stellenbosch University http://scholar.sun.ac.za 6.2.5 6.2.6 6.2.7 6.2.8 Abbé… …155 ix Stellenbosch University http://scholar.sun.ac.za Appendix C: Measurements data and… …and data sheets ................................. 163 x Stellenbosch University http… …76 xi Stellenbosch University http://scholar.sun.ac.za Figure 36: Photograph of the…
Rugbani, A. M. (2014). The design, kinematics and error modelling of a novel micro-CMM parallel manipulator . (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/86518
Rugbani, Ali Milud. “The design, kinematics and error modelling of a novel micro-CMM parallel manipulator.” 2014. Doctoral Dissertation, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/86518.
Rugbani, Ali Milud. “The design, kinematics and error modelling of a novel micro-CMM parallel manipulator.” 2014. Web. 19 Jan 2020.
Rugbani AM. The design, kinematics and error modelling of a novel micro-CMM parallel manipulator. [Internet] [Doctoral dissertation]. Stellenbosch University; 2014. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/86518.
Rugbani AM. The design, kinematics and error modelling of a novel micro-CMM parallel manipulator. [Doctoral Dissertation]. Stellenbosch University; 2014. Available from: http://hdl.handle.net/10019.1/86518
17. Prinsloo, Gerhardus Johannes. Automatic positioner and control system for a motorized parabolic solar reflector.
ENGLISH ABSTRACT: Most rural African villages enjoy high levels of sunlight, but rolling out solar power generation technology to tap into this renewable energy resource… (more)
ENGLISH ABSTRACT: Most rural African villages enjoy high levels of sunlight, but rolling out solar power generation technology to tap into this renewable energy resource at remote rural sites in Africa pose a number of design challenges. To meet these challenges, a project has been initiated to design, build and test/evaluate a knock down 3 kW peak electrical stand-alone self-tracking dual-axis concentrating solar power system. This study focusses on the mechatronic engineering aspects in the design and development of a dynamic mechatronic platform and digital electronic control system for the stand-alone concentrating solar power system. Design specifications require an accurate automatic positioner and control system for a motorized parabolic solar reflector with an optical solar harnessing capacity of 12 kWt at solar noon. It must be suitable for stand-alone rural power generation. This study presents a conceptual design and engineering prototype of a balanced cantilever tilt-and-swing dual-axis slew drive actuation means as mechatronic solar tracking mobility platform for a ∼12 m2 lightweight parabolic solar concentrator. Digital automation of the concentrated solar platform is implemented using an industrial Siemens S7-1200 programmable logic controller (PLC) with digital remote control interfacing, pulse width modulated direct current driving, and electronic open loop/closed loop solar tracking control. The design and prototype incorporates off-the-shelf components to support local manufacturing at reduced cost and generally meets the goal of delivering a dynamic mechatronic platform for a concentrating solar power system that is easy to transport, assemble and install at remote rural sites in Africa. Real-time experiments, conducted in the summer of South Africa, validated and established the accuracy of the engineering prototype positioning system. It shows that the as-designed and -built continuous solar tracking performs to an optical accuracy of better than 1.0◦ on both the azimuth and elevation tracking axes; and which is also in compliance with the pre-defined design specifications. Structural aspects of the prototype parabolic dish are evaluated and optimized by other researchers while the Stirling and power handling units are under development in parallel projects. Ultimately, these joint research projects aim to produce a locally manufactured knock down do-it-yourself concentrated solar power generation kit, suitable for deployment into Africa.
AFRIKAANSE OPSOMMING: Landelike gebiede in Afrika geniet hoë vlakke van sonskyn, maar die ontwerp van betroubare sonkrag tegnologie vir die benutting van hierdie hernubare energie hulpbron by afgeleë gebiede in Afrika bied verskeie uitdagings. Om hierdie uitdagings te oorkom, is ’n projek van stapel gestuur om ’n afbreekbare 3 kW piek elektriese alleenstaande selfaangedrewe dubbel-as son-konsentreeder te ontwerp, bou en te toets. Hierdie studies fokus op die megatroniese ingenieurs-aspekte in die ontwerp en…
Advisors/Committee Members: Dobson, R. T., Schreve, K. S., Stellenbosch University. Faculty of Engineering. Department of Mechanical and Mechatronic Engineering..
Subjects/Keywords: Concentrated solar power systems; Parabolic solar reflectors; Solar power plants – Automated control; Solar thermal energy; UCTD
…Stellenbosch University http://scholar.sun.ac.za NOMENCLATURE f Δ Subscripts a az c e… …Stellenbosch University http://scholar.sun.ac.za CONTENTS 2.8 ix Literature Study Motivation… …123 Stellenbosch University http://scholar.sun.ac.za CONTENTS L.0.1 L.0.2 L.0.3 L.0.4… …128 List of References 133 Stellenbosch University http://scholar.sun.ac.za List of… …eﬃciencies (Greyvenstein, 2011) Stellenbosch University HOPE Project identiﬁed energy and…
Prinsloo, G. J. (2014). Automatic positioner and control system for a motorized parabolic solar reflector . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/96137
Prinsloo, Gerhardus Johannes. “Automatic positioner and control system for a motorized parabolic solar reflector.” 2014. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/96137.
Prinsloo, Gerhardus Johannes. “Automatic positioner and control system for a motorized parabolic solar reflector.” 2014. Web. 19 Jan 2020.
Prinsloo GJ. Automatic positioner and control system for a motorized parabolic solar reflector. [Internet] [Thesis]. Stellenbosch University; 2014. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/96137.
Prinsloo GJ. Automatic positioner and control system for a motorized parabolic solar reflector. [Thesis]. Stellenbosch University; 2014. Available from: http://hdl.handle.net/10019.1/96137
18. Van der Merwe, Willem Johannes. Rapid 3D measurement using digital video cameras.
A rapid measurement system is implemented using two digital video cameras, presenting a faster and… (more)
A rapid measurement system is implemented using two digital video cameras, presenting a faster and less expensive solution to certain metrology problems. The cameras are calibrated from one stereo image-pair of a 3D calibration grid that allows an immediate assessment of the achievable metric accuracy of the system. Three different methods, using either laser tracking or structured light patterns, were developed and employed to solve the coordinate extraction and correspondence matching problems. Different image processing techniques were used to speed up the entire measurement process. All software development was accomplished using only freely distributed software packages. The system achieves calibration in less than a minute and accumulates point correspondences at 12 frames per second. Accuracies of greater than 0.4 mm are achieved for a 235 x 190 x 95 mm measurement volume using a single pair of images with 640 x 480 pixel resolution each.
Subjects/Keywords: Mechatronic engineering; Optical measurements; Digital video tape recorders – Calibration
Van der Merwe, W. J. (2008). Rapid 3D measurement using digital video cameras . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/1658
Van der Merwe, Willem Johannes. “Rapid 3D measurement using digital video cameras.” 2008. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/1658.
Van der Merwe, Willem Johannes. “Rapid 3D measurement using digital video cameras.” 2008. Web. 19 Jan 2020.
Van der Merwe WJ. Rapid 3D measurement using digital video cameras. [Internet] [Thesis]. Stellenbosch University; 2008. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/1658.
Van der Merwe WJ. Rapid 3D measurement using digital video cameras. [Thesis]. Stellenbosch University; 2008. Available from: http://hdl.handle.net/10019.1/1658
19. Conradie, Jean-Pierre. Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures.
Thesis (MScEng (Mechanical and Mechatronic Engineering)) – Stellenbosch University, 2008.
A fluoroscopy-guided needle-positioning system is designed and tested as a first prototype for aiding urologists in… (more)
A fluoroscopy-guided needle-positioning system is designed and tested as a first prototype for aiding urologists in gaining fast, accurate and repeatable kidney calyx access during a PCNL procedure while also reducing radiation exposure of the people involved. Image guidance is realized by modelling the fluoroscopic system as an adapted pinhole camera model and utilizing stereo vision principles on a stereo image pair. Calibration, distortion correction and image processing algorithms are implemented on images of a designed calibration object. Thereafter the resulting variables are used in the targeting of the calyx with the aid of a graphical user interface. The required relative translation and rotation of the needle from its current position to the target is calculated and the system is adjusted accordingly. Using digital cameras, needle placement accuracies of 2.5 mm is achieved within the calibrated volume in a simulated environment. Similar results are achieved in the surgery room environment using the fluoroscopic system. Successful needle access in two porcine kidney calyxes concluded the testing
Subjects/Keywords: Mechatronic engineering; Image processing
Conradie, J. (2008). Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/1768
Conradie, Jean-Pierre. “Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures.” 2008. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/1768.
Conradie, Jean-Pierre. “Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures.” 2008. Web. 19 Jan 2020.
Conradie J. Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures. [Internet] [Thesis]. Stellenbosch University; 2008. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/1768.
Conradie J. Fluoroscopy based needle-positioning system for percutaneous nephrolithotomy procedures. [Thesis]. Stellenbosch University; 2008. Available from: http://hdl.handle.net/10019.1/1768
20. Van den Heever, David Jacobus. Development of a neck palpation device for telemedical environments.
An abnormal sized mass in the neck is a common clinical finding and it can… (more)
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.
Advisors/Committee Members: Schreve, K., Scheffer, C., University of Stellenbosch. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering..
Subjects/Keywords: Mechatronic engineering; Palpation; Tactile sensors; Robotics; Biomedical engineering; Neck – Abnormalities – Diagnosis
Van den Heever, D. J. (2007). Development of a neck palpation device for telemedical environments . (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/1869
Van den Heever, David Jacobus. “Development of a neck palpation device for telemedical environments.” 2007. Thesis, Stellenbosch University. Accessed January 19, 2020. http://hdl.handle.net/10019.1/1869.
Van den Heever, David Jacobus. “Development of a neck palpation device for telemedical environments.” 2007. Web. 19 Jan 2020.
Van den Heever DJ. Development of a neck palpation device for telemedical environments. [Internet] [Thesis]. Stellenbosch University; 2007. [cited 2020 Jan 19]. Available from: http://hdl.handle.net/10019.1/1869.
Van den Heever DJ. Development of a neck palpation device for telemedical environments. [Thesis]. Stellenbosch University; 2007. Available from: http://hdl.handle.net/10019.1/1869