Masters Degrees (Electronic Engineering)

Permanent URI for this collectionhttps://hdl.handle.net/10413/6868

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Development of a model helicopter based flight test platform for multivariable feedback control.
(2009) Moodley, Thessygan.; Boje, Edward Sidney.
The dissertation describes the development of a model helicopter based flight test platform for implementing autonomous six degree of freedom flight by a multiple input multiple output automatic control system. The focus of the research is two fold: i. Navigation system design centred about fusing multiple data and measurement sources using Kalman filtering techniques. ii. Electrical engineering of a complete avionics package to support guidance, navigation and control functions. Included are the results from several experiments conducted on the test platform, highlighting salient aspects and performance of the electrical and navigation systems.
Obstacle avoidance and trajectory optimisation for a power line inspection robot.
(2012) Rowell, Timothy.; Boje, Edward Sidney.
This dissertation presents the research, development and application of trajectory creation, obstacle avoidance and trajectory optimisation methods for an existing serial manipulator power line inspection robot (PLIR). The obstacle avoidance implementation allows the robot to navigate around an obstacle obstructing its navigation along the line. The algorithm generated end effector trajectory waypoints autonomously based on bounding box obstacle descriptions in Cartesian space, and connected them with a fifth order basis-spline end effector trajectory command. The trajectories were created taking into account the dynamic torque and velocity constraints of the robot while ignoring non-linearities. Performance was inspected and evaluated in a simulated workspace environment. The trajectory optimisation was designed to maximise the robot’s operating range, with constraints on the battery power supply, by minimising charge consumed during obstacle avoidance trajectories. The temporal components of the basis-spline trajectories were optimised by minimising a timeenergy type of cost function subject to the dynamic constraints of the robot. Cost function analyses are presented for a simple frictionless robot model based on the recursive Newton-Euler method, and for a more realistic model including viscous, Coulomb and static friction as well as gearbox backlash. It is shown that the Nelder-Mead simplex method was appropriate for optimisation. For representative trajectories that were studied, the optimiser was capable of finding global minima with satisfactory speed and accuracy in simulation. The validity of trajectory optimisation with regard to the cost function behaviour was confirmed. This was based on experiments carried out on the robot hardware in the laboratory, examining the predicted and actual actuator current profiles. The engineering design and implementation of hardware and software for the base station and on-board system is presented, together with the layout of the PLIR’s control system and PID (proportional-integral-derivative) controller design. Trajectory commands are sent from the base station to the robot via Wi-Fi for execution. Furthermore, live video feed from the robot can be sent to the ground station computer. Furthermore, high voltage testing of the PLIR showed that the engineering design of the robot and communication platform is robust.
Research and design of an embedded controller and GUI for the automation of the armature Volt-Drop test.
(2009) Matadin, Sunveer.; Boje, Edward Sidney.
In a rapidly evolving technological and industrialised society, automation is a current and growing trend. The concept is typically applied to uneconomical processes and extends from the automation of highly complex processes to those that are less complex. This dissertation discusses the automation of a previously mundane, manual, time-consuming and inefficient task using an embedded controller with dual enhanced microcontrollers as its core. Spoornet recognised the need to automate this and other processes hence a drive was initiated by Spoornet’s Engineering and Technology department into the study of automation principles and techniques that can be used as a basis for the automation of workshops and test centers. This research stems from the above mentioned drive. The Volt-Drop Test was the process that was used as a model to investigate the considerations, boundaries, design concepts and the hardware and software development that is inherent in the automation of a process. The design of the controller that facilitates the automation of the Volt-Drop Test was completed after research into embedded systems, embedded microcontrollers, programming languages and techniques, digital electronics, analogue electronics, digital system design concepts and techniques, analogue system design concepts and techniques, and the latest available electronic components. A Graphic User Interface (GUI) was developed to interface with the controller to set up test parameters, display the present test status, perform calculations on the data received from the controller and display faults in the armature under test. Further, the GUI has the functionality to save all test data in a predefined and secure location to be retrieved and viewed as historical data or used for trending. A Remote Graphic User Interface (RGUI) was also developed. This interface is used solely to view test data (retrieved from the saved history files), from any geographic location provided that the user has been granted access to the secure location in which this data is saved. In the testing phase, all tests were carried out using high quality, high accuracy and recently calibrated instrumentation. The test results obtained largely reflected what was expected from the system when compared to simulations that were carried out on the controller and the GUI during their development. With regard to the automation process, the system follows the procedure as it was designed with respect to correct switching sequences, response to system errors, timing of events and correct and efficient communication between the controller and the GUI. In terms of the data acquisition aspects the system captures, converts, calculates, analyses and logs data, within the expected input range with a level of accuracy that is considered to be high (a maximum percentage error of 0.75% - expressed as a percentage of the injected test supply) for this type of application when compared to the accuracy of present test methods.
Robust multivariable control design : an application to a bank-to-turn missile.
(2011) Reddi, Yashren.; Boje, Edward Sidney.
Multi-input multi-output (MIMO) control system design is much more difficult than single-input single output (SISO) design due to the combination of cross-coupling and uncertainty. An investigation is undertaken into both the classical Quantitative Feedback Theory (QFT) and modern H-infinity frequency domain design methods. These design tools are applied to a bank-to-turn (BTT) missile plant at multiple operating points for a gain scheduled implementation. A new method is presented that exploits both QFT and H-infinity design methods. It is shown that this method gives insight into the H-infinity design and provides a classical approach to tuning the final H-infinity controller. The use of “true” inversionfree design equations, unlike the theory that appears in current literature, is shown to provide less conservative bounds at frequencies near and beyond the gain cross-over frequency. All of the techniques investigated and presented are applied to the BTT missile to show their application to a practical problem. It was found that the H-infinity design method was able to produce satisfactory controllers at high angles of attack where there were no QFT solutions found. Although an H-infinity controller was produced for all operating points except the last, the controllers were found to be of very high-order, contain very poorly damped second order terms and generally more conservative, as opposed to the QFT designs. An investigation into simultaneous stabilization of multiple plants using Hinfinity is also presented. Although a solution to this was not found, a strongly justified case to entice further investigation is presented.

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Browsing Masters Degrees (Electronic Engineering) by Author "Boje, Edward Sidney."