Browsing by Author "Bright, Glen."

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An automated apparatus for non-contact inspecting of mass produced custom products.
(2009) Davrajh, Shaniel.; Bright, Glen.
The evolution of the manufacturing industry may be viewed as proceeding from Dedicated Manufacturing Systems (DMS) to Reconfigurable Manufacturing Systems (RMS). Customer requirements change unpredictably, and so DMS are no longer able to meet modern manufacturing requirements. RMS are designed with the focus of providing rapid response to a change in product design, within specified part families. The movement from DMS to RMS facilitates mass-production of custom products. Custom parts require inspection routines that can facilitate variations in product parameters such as dimensions, shape, and throughputs. Quality control and part inspection are key processes in the lifecycle of a product. These processes are able to verify product quality; and can provide essential feedback for enhancing other processes. Mass-producing custom parts requires more complex and frequent quality control and inspection routines, than were implemented previously. Complex, and higher frequencies of inspection negatively impact inspection times, and inherently, production rates. For manufacturers to successfully mass-produce custom parts, processes which can perform complex and varying quality control operations need to be employed. Furthermore, such processes should perform inspections without significantly impacting production rates. A method of reducing the impact of high frequency inspection of customized parts on production rates is needed. This dissertation focuses on the research, design, construction, assembly, and testing of a Non- Contact Automated Inspection System (NCAIS). The NCAIS was focused on performing quality control operations whilst maintaining the maximum production rate of a particular Computer Integrated Manufacturing (CIM) cell. The CIM cell formed part of a research project in the School of Mechanical Engineering, University of KwaZulu-Natal; and was used to simulate mass-production of custom parts. Two methods of maintaining the maximum production rate were explored. The first method was the automated visual inspection of moving custom parts. The second method was to inspect only specified Regions of Interest (ROIs). Mechatronic engineering principles were used to integrate sensor articulation, image acquisition, and image processing systems. A specified maximum production rate was maintained during inspection, without stoppage of parts along the production line occurring. The results obtained may be expanded to specific manufacturing industries.
Automatic calibration of a tool-changing unit for modular reconfigurable machines.
(2011) Collins, James.; Bright, Glen.
Modern trends in customer demand have resulted in the development of a class of manufacturing system known as Reconfigurable Manufacturing Systems (RMS). Reconfigurable systems are designed around the idea that they must be able to be reconfigured in both their production capacity as well as in the machining processes they perform. A subset of the RMS paradigm is a group of machines called Modular Reconfigurable Machines (MRMs). Modular machines are built up from different hardware modules. They offer the user the possibility of only purchasing the required tooling for the specific need at the time. As reconfigurable machines are able to offer flexibility in machining functions, their ability to have easy access to a variety of machine tools would greatly influence their effectiveness and production capacity. This project presents a machine tooling system that would provide MRMs with an efficient way to change tools. A major requirement of the unit was that it should automatically calibrate itself in terms of its position relative to the machine it was servicing. In order for the unit to realize this requirement, it needed a method that would provide it with real-time 3D tracking of the spindle with which it was interacting. Commercially available systems that offer this facility are very costly. A popular gaming controller, the Nintendo Wii remote, was used to provide the tool-changing unit with a very economical real-time 3D tracking capability. This dissertation details the design, implementation and testing of the positioning system for the tool-changing unit.
Autonomous materials handling robot for reconfigurable manufacturing systems.
(2010) Butler, Louwrens Johannes.; Bright, Glen.
The concept of mass producing custom products, though extremely beneficial to the commercial, and retail industries, does come with some limitations. One of these is the occurrence of bottlenecks in the materials handling systems associated with reconfigurable manufacturing systems tasked with achieving the goal of mass customisation manufacturing. This specific problem requires the development of an intervention system for rerouting parts and materials waiting in line, around bottlenecks and/or work flow disruptions, to alternative destinations. Mobile robots can be used for the resolution of bottlenecks, and similar disruptions in work flow, in these situations. Embedding autonomy into mobile robots in a manufacturing environment, releases the higher level production management systems from routing of parts and materials. The principle of the inverted pendulum has recently become popular in mobile robotics applications, and is being implemented in research projects around the world. The use of this principle produces a two-wheeled mobile robot that is able to actively stabilise itself while in operation. The dissertation is focused on the research, design, assembly, testing and validation of a two-wheeled autonomous materials handling robot for application in reconfigurable manufacturing systems. This robot should be dynamically or statically stable during different phases of operation. The mechatronic engineering approach of system integration has been used in this project in order to produce a more reliable robotic system. The application of the inverted pendulum principle requires that a suitable control strategy be formulated. It also necessetates the ues of sensors to track the state of the robot. Control engineering theory was used to develop an optimal control strategy that is robust enough to cope with varying payload characteristics. The Kalman filter is employed as state estimation measure to improve sensor data. For a mobile robot to be deemed autonomous, one of the requirements is that the robot should be able to navigate through its environment without colliding with obstacles in its path, and without human intervention. A navigation system has been designed, through field specific research, to enable this. The robot is also required to communicate with remote computers housing production management systems as well as with mobile robots that form part of the same materials handling system. Performance analysis and testing proves the feasibility of a mobile robot system.
Autonomous mobile materials handling platform architecture for mass customisation.
(2008) Walker, Anthony John.; Bright, Glen.
In order to facilitate the materials handling requirements of production structures configured for Mass Customisation Manufacturing, the design of requisite materials handling and routing systems must encompass new conceptual properties. Materials handling and routing systems with the capacity to support higher-level management systems would allow for mediated task allocation and structured vertical integration of these systems into existing manufacturing execution and management systems. Thus, a global objective in designing a materials handling and routing system, for such production configurations. is to provide a flexible system mechanism with minimal policy on system usage. With the recent developments in mobile robot technologies, due to various advancements in embedded system, computational, and communication infrastructures, mobile robot platforms can be developed that are robust and reliable, with operating structures incorporating bounded autonomy. With the addition of materials handling hardware, autonomous agent architectures, structured communication protocols and robotic software systems, these mobile robot platforms can provide viable solution mechanisms in realising real-time flexible materials handling in production environments facilitating Mass Customisation Manufacturing. This dissertation covers the research and development of a materials handling and routing system implementation architecture, for production environments facilitating Mass Customisation Manufacturing. The materials handling and routing task environment in such production structures is characterised in order to provide a well defined problem space for research purposes. A physical instance of a functional subset of the architecture is constructed consisting of a semi-autonomous mobile robot platform equipped with the infrastructure for materials handling and routing task execution. The architecture orientates the mobile robot platform in such a way as to present a collection of functional units, integrated and configured for a range of applications, and prevents viewpoints in the sense of monolithic mobile robots less susceptible to reconfiguration and stochastic utilisation.
Autonomous sea craft for search and rescue operations : marine vehicle modelling and analysis.
(2011) Onunka, Chiemela.; Bright, Glen.; Stopforth, Riaan.
Marine search and rescue activities have been plagued with the problem of risking the lives of rescuers in rescue operations. With increasing developments in sensor technologies, it became a necessity in the marine search and rescue community to develop an autonomous marine craft to assist in rescue operations. Autonomy of marine craft requires a robust localization technique and process. To apply robust localization to marine craft, GPS technology was used to determine the position of the marine craft at any given point in time. Given that the operational environment of the marine was at open air, river, sea etc. GPS signal was always available to the marine craft as there are no obstructions to GPS signal. Adequate cognizance of the current position and states of an unmanned marine craft was a critical requirement for navigation of an unmanned surface vehicle (USV). The unmanned surface vehicle uses GPS in conjunction with state estimated solution provided by inertial sensors. In the absence of the GPS signal, navigation is resumed with a digital compass and inertial sensors to such a time when the GPS signal becomes accessible. GPS based navigation can be used for an unmanned marine craft with the mathematical modelling of the craft meeting the functional requirements of an unmanned marine craft. A low cost GPS unit was used in conjunction with a low cost inertial measurement unit (IMU) with sonar for obstacle detection. The use of sonar in navigation algorithm of marine craft was aimed at surveillance of the operational environment of the marine craft to detect obstacles on its path of motion. Inertial sensors were used to determine the attitude of the marine craft in motion.
Bio-mechatronic implementation of a portable upper limb rehabilitative exoskeleton.
(2011) Naidu, Dasheek.; Stopforth, Riaan.; Bright, Glen.; Davrajh, Shaniel.
The rationale behind this research originates from the lack of public health care in South Africa. There is an escalation in the number of stroke victims which is a consequence of the increase in hypertension in this urbanising society. This increase results in a growing need for physiotherapists and occupational therapists in this country which is further hindered by the division between urban and rural areas. The exoskeleton device has been formulated to encapsulate methodologies that enable the anthropomorphic integration between a biological and mechatronic limb. The physiotherapeutic mechanism was designed to be portable and adjustable, without limiting the spherical motion and workspace of the human arm. The exoskeleton was portable in the sense that it could be transported geographically and is a complete device allowing for motion in the shoulder, elbow, wrist and hand joints. The avoidance of singularities in the workspace required the implementation of non-orthogonal joints which produces extensive forward kinematics. Traditional geometric or analytical derivations of the inverse kinematics are complicated by the nonorthogonal layout. This hindrance was resolved iteratively via the Damped Least Squares method. The electronic and computer system allowed for professional personnel, such as an occupational therapist or a physiotherapist, to either change an individual joint or a combination of joints angles. A ramp PI controller was established to provide a smooth response in order to simulate the passive therapy motion.
The computational investigation of the wind-induced vibration of overhead conductors.
(2013) Athol-Webb, Avern Malcolm.; Bright, Glen.; Loubser, Richard Clive.
The reliable transmission of high-voltage electricity through overhead electrical conductors is a cornerstone of the modern industrialised world. Any situation or phenomenon that impedes the functioning of this network warrants investigation. An example of which is the occurrence of aeolian vibration. This is caused by airflow over the conductor breaking off into alternating turbulent vortices. These vortices can cause an alternating lift force on the conductor, resulting in unwanted vibrations and damaging fatigue loading. The Vibration Research Testing Centre (V.R.T.C.) of the University of Kwa-Zulu Natal is investigating the effects of this problem experimentally by oscillating an overhead conductor in a test facility. An electrodynamic shaker is used in a frequency and amplitude range equivalent to that produced by measured wind power input. This method is limited because only a single point force input to the conductor is possible as well as the limited span length. The aim of this research was to investigate the effects of aeolian vibrations and to develop a model that can verify the results of the V.R.T.C. This model can also be used to analyse scenarios that cannot be experimentally tested. A mathematical simulation of an overhead conductor subject to various wind power and single point oscillator inputs was developed. The mathematical simulation was performed using the MATLAB computing environment in the form of a finite element model. The model consists of a number of beam elements, arranged linearly to form a cable model, with suitable end conditions and driving inputs. The system was solved using a varying time-step 4th order Runge-Kutta solving method. The results of the model were compared to tests performed at the V.R.T.C. on a sample conductor length.
Condition monitoring of a rotor bearing system.
(2011) Grobler, Herbert Alfred.; Bright, Glen.; Loubser, Richard Clive.
The key objective for this research was to construct an experimental test rig along with a finite element model. Both had to accommodate a certain extent of misalignment and unbalance to provide induced vibrations in the system. Misalignment and unbalance was then varied in magnitude to identify the effect it has on the system. The next variable was the rotor speed and its effects. Finally the experimental and theoretical results were compared and the slight differences have been outlined and described. A rotor supported by two bearings with a disk attached to the middle and a three jaw coupling at the one end was considered for this research. The three jaw coupling consists out of two hub elements with concave jaws and a rubber element that fits in-between the jaws. The rotor-bearing system was subjected to unbalance at the disk and both angular and parallel misalignment at the coupling. Misalignment was achieved by offsetting the centre of rotation of the rotor and the motor shaft. Finite element analysis, along with Lagrange method, was used to model the behaviour of the system. A mathematical model for the three jaw coupling was derived to simulate its behaviour. The second order Lagrange model was reduced to a first order and solved using the Runge-Kutta method. Experimental results were obtained from a test rig and used to validate the theoretical results. Time domain and frequency spectrum were used to display the results.
Contractible arms elevating search and rescue (Caesar) robot : improvements and modifications for urban search and rescue (Usar) robots.
(2010) Stopforth, Riaan.; Bright, Glen.; Harley, Ronald G.
Rescuers have lost their lives in events requiring them to go into dangerous areas that have unstable structures and gases. Robots are necessary for search and rescue purposes, to access concealed places and environments to which fire fighters and rescue personnel cannot gain entry. Robots that were previously used encountered problems with communication, chassis design, traction and sensory systems. Improvements are required for the successful localization of victims. Research on improvements in these areas were carried out for the use in the CAESAR (Contractible Arms Elevating Search And Rescue) robot. Contributions were made in the area of Urban Search And Rescue (USAR) robots focusing on antenna design, communication protocols, chassis design, traction system and artificial intelligence on decisions relating to gas danger levels for humans and the robot. The capabilities of CAESAR is audio, video and data communication irrespective of the orientation of the robot and the antennas. Penetration of radio frequencies through building material is possible. Reliable data communication is achieved with the designed Robotics Communication Protocol (RCP). The chassis is designed to have traction on unstable terrain and autonomously transform flipper arms for the best orientation. Materials for the body were selected and constructed to be able to withstand the unstable environments and high temperatures which they will encounter. The control station display gives the rescuers immediate indication of the gas concentrations detected by the on-board gas sensors. Developed analytical models determine the danger of the gas concentrations for victims, rescuers and the robots.
Controlling chaos in a sagittal plane biped model using the Ott-Grebogi-Yorke method.
(2012) Feng, Chung-tsung.; Bright, Glen.
Controlling a system with chaotic nature provides the ability to control and maintain orbits of different periods which extends the functionality of the system to be flexible. A system with diverse dynamical behaviours can be achieved. Trajectory flows of chaotic systems can be periodically stabilised using only small perturbations from the controlled parameter. The method of chaos control is the Ott-Grebogi-Yorke method. In non-chaotic systems large system parameters changes are required for performance changes. A sagittal plane biped model which is capable of exhibiting periodic and chaotic locomotion was researched and investigated. The locomotion was either periodic or chaotic depending on the design parameters. Nonlinear dynamic tools such as the Bifurcation Diagram, Lyapunov Exponent and Poincaré Map were used to differentiate parameters which generated periodic motion apart from chaotic ones. Numerical analytical tools such as the Closed Return and Linearization of the Poincaré Map were used to detect unstable periodic orbit in chaotic attractors. Chaos control of the model was achieved in simulations. The system dynamic is of the non-smooth continuous type. Differing from other investigated chaotic systems, the biped model has varying phase space dimensions which can range from 3 to 6 dimensions depending on the phase of walking. The design of the biped was such that its features were anthropomorphic with respect to locomotion. The model, consisting of only the lower body (hip to feet), was capable of walking passively or actively and was manufactured with optimal anthropometric parameters based on ground clearance (to avoid foot scuffing) and basin of attraction simulations. During experimentation, the biped successfully walked down an inclined ramp with minimal aid. Real time data acquisitions were performed to capture the results, and the experimental data of the walking trajectories were analysed and verified against simulations. It was verified that the constructed biped exhibits the same walking trend as the derived theoretical model.
The cooperation of heterogeneous mobile robot configurations in advanced manufacturing environments.
(2014) Naidoo, Nicol.; Bright, Glen.; Stopforth, Riaan.
Cooperation of Multiple Mobile Robot Systems (MMRS) have drawn increasing attention in recent years since these systems have the ability to perform complex tasks more efficiently compared to Single Mobile Robot Systems (SMRS). An implementation of a cooperative MMRS in a manufacturing environment can, for example, solve the issue of bottlenecks in a production line, whereas the limitations of a SMRS can lead to a lot of problems in terms of time wastage, loss of revenue, poor quality products and dissatisfied customers. The study of cooperation in heterogeneous robot teams has evolved due to the engineering and economic benefits attribute as well as the existence of diversities in homogeneous robot teams. The challenge of cooperation in these systems is a result of the task taxonomies and fundamental abilities of each robot in the team; there is therefore a need for an Artificial Intelligence (AI) system that processes these heterogeneities to facilitate robot cooperation. This dissertation focuses on the research, design and development of an artificial intelligence for a team of heterogeneous mobile robots. The application of the system was directed towards advanced manufacturing systems, however, it can be adapted to search and rescue tasks. An essential component of the AI design is the machine learning algorithm which was used to predict suitable goal destinations for each mobile robot, given a set of input parameters. Mobile robot autonomy was achieved through the development of an obstacle avoidance and navigation system. The AI was also interfaced to a Supervisory Control and Data Acquisition System (SCADA) which facilitates end-user interaction - a vital ingredient to manufacturing automation systems.
Cordless linear synchronous motor material handling system for computer integrated manufacturing.
(2000) Lindsay, Craig Vaughn.; Bright, Glen.; Hippner, Maciej.
Advanced material handling systems' impact on flexible manufacturing systems (FMS) have increased the efficiency and work rate over conventional manufacturing assemblies. The interaction of automated guided vehicles (AGVs), roller conveyors and conveyor belts with robots and machine tools forms highly sophisticated assembly operations. Whilst material handling in FMS today is conventionally used to transport assembly units from one work station to another, it does not take an active role in the manufacturing process. With manufacturers implementing more advanced manufacturing principles to perform agile manufacturing, there is a growing need to implement "smarter" material handling systems that would perform essential, integral roles in the assembly process. This research outlines the development of a cordless linear synchronous motor (CLSM) material handling system. The CLSM incorporates a permanent magnet courier that moves without tether restrictions on an integrated reverse air bearing system which eliminates friction. The CLSM provides a material handling system with enhanced travel, flexibility and accuracy. The CLSM material handling system is designed to integrate with overhead manipulators and part feeders to form a comprehensive flexible manufacturing system. This research covers the 2-D finite element modeling (FEM) used to determine the CLSM's optimal parameters. The development of the motor windings design and construction, together with the control system for the CLSM, is also covered. The CLSM novel air bearing system is outlined and compared to other conventional linear bearing systems. The possible impact of the CLSM on current manufacturing systems is explored to determine the validity of the research project and possible further research opportunities.
The design and analysis of a novel 5 degree of freedom parallel kinematic manipulator.
(2019) Dharmalingum, Wesley Emile.; Padayachee, Jared.; Bright, Glen.
Abstract available in PDF.
Design and construction of Meercat : an autonomous indoor and outdoor courier service robot.
(2011) Bosscha, Peter Antoon.; Bright, Glen.
This project details the construction and development of, and experimentation with a mobile service courier robot named Meercat. This robot has been built from the ground up using parts sourced from various places. The application for this service robot is the delivery of internal mail parcels between the buildings situated on the campus of the Council for Scientific and Industrial Research (CSIR) in Pretoria. To achieve this, the robot has to be able to localise and navigate through indoor office and laboratory environments and over outdoor tarred roads which interconnect the various buildings. Not many robots are intended for operation in both indoor and outdoor environments, and to achieve this, multiple sensing systems are implemented on the platform, where the correct selection of sensing inputs is a key aspect. Further testing and experiments will take place with algorithms for localisation and navigation. As a limited budget was available for the development of this robot, cost-effective solutions had to be found for the mechanical, sensing and computation needs. The Mechatronics group from the Mechatronics and Micro Manufacturing (MMM) competency area at the CSIR is involved with the development of various autonomous mobile robots. The particular robot developed in this project will be an addition to the CSIR’s current fleet of robots and will be used as a stepping stone for experimentation with new sensors and electronics, and the development of further positioning and navigation algorithms.
Design and development of a low-cost high-performance vehicle mounted UHF RFID system for tracking goods and inventory.
(2019) Hoskins, Gareth Oregan.; Bright, Glen.; Padayachee, Jared.
Abstract available in the PDF.
Design and performance analysis of hybrid photovoltaic-thermal grid connected system for residential application.
(2012) Mutombo, Ntumba Marc-Alain.; Inambao, Freddie Liswaniso.; Bright, Glen.
High output electrical energy is obtained from photovoltaic (PV) systems subject to high irradiance. However, at high irradiance, the efficiency of PV systems drops due to increase of the temperature of the systems. In order to improve the efficiency of photovoltaic systems, much effort has been spent on developing hybrid photovoltaic thermal (PVT) systems using water as a coolant to withdraw heat from solar modules. This research is focused on the study of the behavior of hybrid PVT collectors using rectangular channel profiles which provide a large surface for heat exchange between PV panels and thermal collectors unlike the circular channel profile used in conventional PV systems. In hybrid PVT systems, coolant water circulates in a closed circuit by means of the thermosyphon phenomenon and the heat from this water is extracted from a storage tank and can be used in hot water systems instead of an electric geyser. Numerical models of water velocity in channels due to the thermosyphon phenomenon and the temperature of solar modules was developed and a system was designed for modest Durban household demand. A simulation was run for specific summer and winter days comparing a conventional PV system and a hybrid PVT system. The results were very encouraging, and demonstrated that the equipment is capable of extending the PVT application potential in the domestic sector where more than 40% of electricity cost is heating water.
Design and testing of a composite material for modelling wind turbine blade structures in tropical region.
(2018) Tefera, Getahun Akulu.; Adali, Sarp.; Bright, Glen.; Davidson, Innocent Ewean.
Currently large wind turbine blades have been installed in several offshore and onshore wind farms around the world, particularly in the desert areas of North East Africa where wind turbine blades and nacelles are affected by elevated temperatures. The aim of this study is to investigate the effect of temperature variation on the mechanical behaviour of composite wind turbine blades installed in tropical wind farms. The blades are constructed from unidirectional carbon fibre/epoxy, glass fibre/epoxy and hybrids of these two composite materials. ASTM standards were taken into account when the composite specimens were manufactured for testing purposes. Short Beam Shear (SBS), Dynamic Mechanical Analysis (DMA) and tensile tests were conducted under increasing temperatures to investigate the mechanical behaviour of composite materials when used for structural modelling of wind turbine blades. Experimental findings revealed that the strength and stiffness properties of composite specimens were reduced when temperatures increased. Betz’s element momentum theory and Glauert’s modelling methods were used to investigate the characteristics of composite wind turbine blades measuring 54m and generating 2MW power. Flap-wise loading was taken into account along the length of the wind turbine blades when they were analysed using the Blade Element Momentum (BEM) theory. The wind turbine blades were developed using carbon fibre/epoxy, glass fibre/epoxy, glass-carbon fibre/epoxy and carbon-glass fibre/epoxy composite materials. The tip deflection of the blades was analysed allowing for different flap-wise and thermal loadings. Simulation results indicated that a glass/epoxy blade has the highest and a carbon/epoxy blade the lowest tip deflection. The values for the tip deflections of the blades show minimal change under thermal loading. To study the mechanical behaviour of the blades under thermal loading, an element-wise approach was developed and the failure index for different composite materials was computed. Tsai-Wu failure criterion was employed to determine the failure index of each composite material under thermal and mechanical loadings. Blades failed when the thermal loading was above 40ºC irrespective of the flap-wise loading. This finding was similar to the experimental results mentioned above. Carbon/epoxy showed non-linear behaviour when the test temperature approached 40ºC. Generally, experimental and numerical results are comparable and can be considered valid. To conclude carbon-glass fibre/epoxy composite wind turbine blades are observed to be a better option for tropical wind farms based on experimental and simulation results. Iqoqa Njengamanje sekufakwe ophephela bomoya abakhulu emapulazini amaningi omoya asolwandle nasezweni emhlabeni jikelele, ikakhulukazi ezindaweni eziwugwadule zaseMpumalangantshonalanga Afrika lapho amazinga okushisa aphakeme enomthelela kophephela bomoya nakuzembozo zezihambisiphephela. Inhloso yalolu cwaningo ngukuhlola umthelela wokuguquguquka kwamazinga okushisa endleleni okusebenza ngayo ophephela bomoya abafakwe emapulazini asezindaweni ezishisa kakhulu. Ophephela bakhiwe ngomabhekanxazonke befayibha yekhabhoni/ ephoksi, ifayibha yengilazi/ephoksi, Kucatshangelwe amazinga e-ASTM ngenkathi kwakhiwa amasampula ayindidiyela ngenhloso yokuhlola. Kwenziwe uhlelo lwe-Short Beam Shear (SBS), Dynamic Mechanical Analysis (DMA) nokuhlola kwamathensayili ngaphansi kwamazinga okushisa anyukayo, ukuhlola indlela ezisebenza ngayo izakhi eziyindidiyela uma zisetshenziselwa ukubona ukuthi singama kanjani isakhiwo sophephela bomoya. Imiphumela yokuhlola iveze ukuthi amazinga amandla nokuqina kwamasampula ayindidiyela kwehlile uma kunyuswa amazinga okushisa. Kusetshenziswe injulalwazi ka-Betz yomthamosivinini kanye nezindlela zika-Glauret zesibonelokulinga ukuhlola izimpawu zophephela bomoya abayindidiyela, abanesikalo esingu-54m futhi esiphehla amandla angu-2MW. Kucatshangelwe isisindo sokuthwala uma ophephela bebheke phansi noma phezulu ngokunjalo nobude bophephela bomoya ngenkathi behlaziywa, kusetshenziswa injulalalwazi i-Blade Element Momentum (BEM). Ophephela bomoya benziwe kusetshenziswa izakhi eziyindidiyela zefayibha yekhabhoni/ ephoksi, ifayibha yengilazi/ ephoksi nefayibha yekhabhoni-ngilazi/ ephoksi. Impebezo yezihloko zophephela ihlaziywe kuvunyelwa okuhlukahlukene kwesisindo sokuthwala netemali, uma ophephela bebheke phansi noma phezulu. Imiphumela yokulingisa ikhombise ukuthi uphephela wengilazi/ ephoksi unempebezo yesihloko ephakene kanti uphephela wekhabhoni/ ephoksi unempebezo yesihloko ephansi. Amavelu empebezo yezihloko zophephela akhombisa uguquko olusesilinganisweni esincane, ngaphansi kokulayishwa kwetemali. Ukucwaninga okwenziwa ngophephela okuphathelene nokusebenza kwemishini uma kulayishwe itemali, kwenziwe ngokuqamba indlela evuna i-elementi, kwase kwenziwa uhlelo lokubala ngekhompyutha inkomba kwehluleka yezakhi eziyindidiyela ezihlukahlukene. Kuthathwe indlelakukhetha kuhluleka kaTsai-Wu ukubona inkomba kuhluleka yesakhi ngasinye esiyindidiyela uma kulayishwe itemali nokusebenza ngemishini. Ophephela behlulekile uma umthamo wetemali ungaphezu kuka-40ºC kungakhathaliseki izinga kulayisha elivuna ukubheka phansi noma phezulu kophephela. Okutholakele bekufana nemiphumela yokuhlola ebalulwe ngenhla. Ikhabhoni/ ephoksi ikhombise indlela okwenza ngayo ophephela engaqondile uma amazinga okushisa okuhlola esondela ku-40ºC. Ezimweni eziningi, imiphumela yokulinga neyezibalo iyaqhathaniseka futhi ingase ibhekwe njengekholakalayo. Ukuphetha, ophephela bomoya abayindidiyela yefayibha yekhabhoningilazi/ ephoksi babonakala beyisu elingalunga kahle emapulazini omoya uma kuthathelwa emiphumeleni yokuhlola nokufanisa.
Design of an autonomous mobile robot for service applications.
(2011) De Villiers, Mark.; Bright, Glen.
This research project proposes the development of an autonomous, omnidirectional vehicle that will be used for general indoor service applications. A suggested trial application for this service robot will be to deliver printouts to various network users in their offices. The robot will serve as a technology demonstrator and could later also be used for other tasks in an office, medical or industrial environment. The robot will use Mecanum wheels (also known as Swedish 45° or Ilon wheels) to achieve omnidirectionality. This will be especially useful in the often cramped target environments, because the vehicle effectively has a zero radius turning circle and is able to change direction of motion without changing its pose. Part of the research will also be to investigate a novel propulsion system based on the Mecanum wheel. The robot will form part of a portfolio of service robots that the Mechatronics and Micro Manufacturing (MMM) group at the CSIR is busy developing. Service robots are typically used to perform Dull, Dangerous or Dirty work, where human presence is not essential if the robot can perform the task reliably and successfully.
Design of an autonomous underwater vehicle : vehicle tracking and position control.
(2010) Holtzhausen, Servaas.; Bright, Glen.
This project proposes the development of an autonomous underwater vehicle that can be used to perform underwater research missions..The vehicle can be pre-programmed to complete a specified mission. Missions may include underwater pipe inspection, a survey of the sea floor or just the transport of given sensors to a certain depth or position and take measurements of underwater conditions. The Mechatronics and Micro Manufacturing group at the CSIR is engaged in developing a portfolio of autonomous vehicles as well as fur- ther research into the development and implementation of such vehicles. Underwater vehicles will form part of the portfolio of autonomous vehicle research. Autonomous underwater vehicles (AUVs) are mostly used for research purposes in oceanographic studies as well as climate studies. These scientists use AUVs to carry a payload of sensors to specified depths and take measurements of underwater conditions, such as water temperature, water salinity or carbon levels as carbon is being released by plankton or other ocean organisms. Very little information is available about what is happening below the surface of the oceans and AUVs are being used to investigate this relatively unknown environment. The area covered by the world's ocean is 361 million km2 with an average depth of 3790 m. The deepest surveyed depth point in the ocean is at a depth of about 11 000 m at the southern end of the Mariana Trench in the Pacific Ocean. This just shows the need for research into this mostly unexplored world. Research and exploration in the oceans can be achieved through the use of autonomous underwater vehicles. A big problem to overcome is the fact that GPS is not available for navigation in an underwater environment. Other sensors need to be found to be used for navigational purposes. The particular vehicle developed for this study will be used to facili- tate further research into underwater vehicle navigation and underwater robotics.
Design, modelling and simulation of 2 novel 6 DOF hybrid machines.
(2012) Shaik, Ahmed Asif.; Bright, Glen.
Industrial robot arms are an essential part of automated manufacturing, and perform tasks such as component assembly, welding, light machining, spray painting, etc. They are highly repeatable, can be calibrated to be sufficiently accurate and they eliminate human error. The serial robot architecture is by far the most ubiquitous in modern day manufacturing, as the technology is highly refined in its current state; the machine architecture provides great dexterity and it has a large useful workspace. This architecture however does have some problems, one of which is a large machine moving mass. The primary reason for this lies in the location of its motors and gearboxes. Due to the robot's significant inertia it utilizes a large amount of energy. This thesis focused on the mechanical design, mathematical modelling and simulation of 2 robotic arm designs which had a hybrid nature. They were classified as hybrid due to the fact that their architectures departed from both the classic definitions of serial kinematics manipulators/machines (SKMs) and parallel kinematics manipulators/machines (PKMs). The primary design goal was to merge some of the advantages of both architectures, i.e. a large workspace to footprint ratio and high end-effector dexterity which was found in serial robots, combined with the low inertia of a parallel robot for improved dynamics. Serial and parallel robots were complementary, and these design goals could not co-exist in a single purist robot architecture. The designs had a full complement of 6 DOFs (degrees of freedom), 3 DOFs for spatial position of the wrist and 3 DOFs for orientation of that wrist. They also had a lower machine moving mass, a fact that was thought to improve speed and energy usage. A major contribution of this research PhD project was a comparative energy usage study, which was performed against the serial robot as a measure. This was done for both hybrid designs as well as another model which represented 2 existing patented designs. The purpose of that was to determine if lowering the machine moving mass would improve energy efficiency, and to determine which design was best.