Research has been completed to determine the most effective thermal control architecture for modular satellites. This research investigated principles of modularity, modular spacecraft examples, thermal control methods, and advanced thermal control technologies. A modular spacecraft was designed as a case study to determine key influences and issues. A number of thermal control architectures were developed. Each was evaluated for compatibility with modularity principles, thermal control performance, and a realizable implementation. Thermal control performance was determined by simulating on-orbit conditions for a number of design reference missions, including traditional thermal control architecture used for comparison. An effective thermal control architecture was found that has all desired attributes. The methods of development, simulation, and evaluation are presented with results and key findings.

A Variable Stability Flight Simulator is being developed in the School of Aerospace, Mechanical and Mechatronic Engineering at the University of Sydney, Australia. The device is being developed both as a teaching tool for use in flight mechanics courses in the department and as a research tool. It is reasonable to state that learning is enhanced through the experience of concepts outside of the classroom environment. It is intended that the device will be integrated into the department�s teaching program in aircraft flight mechanics. Initial studies centred around a PC based flight simulation developed at the Cranfield College of Aeronautics in the United Kingdom. This system utilises a distributed architecture with several computers connected via Ethernet. It also employs a Primary Image three channel visual system. The system has been further enhanced by the addition of a Link flight simulator provided by the Royal Australian Air Force (RAAF). The RAAF had been using the simulator as a training tool for some years until it had become surplus to requirements. Most of the work in the project has centred around re-engineering this simulator into a viable research/education tool. The Cranfield system has been incorporated into the Link simulator�s hardware to provide a fixed base simulation. The majority of the work described in this thesis revolved around the re-engineering of the flight control loading and motion systems. Previously these items were controlled by analogue circuitry with minimal digital interfaces to the main simulation software. The systems have been re-designed to replace much of the single model analogue circuitry with re-configurable digital control software. Doing so allows changes to be made to the systems in real time through a software interface. The software resides on a common computer that extensively interfaces with the rest of the simulation. To support the hardware involved and to provide for system operation and safety, an extensive Supervisory system has also been implemented. This system along with the motion and control loading software has been implemented in the Matlab / Real-Time Workshop environment. This gives the capability of making real-time changes to any part of the overall simulation. A variable stability module (vsm) is under development. The addition of this module will allow changes to be made to the simulation itself in real-time. The simulator is now functional with the motion and control loading systems operating as designed. Tuning of both systems has been done subjectively by the author. An initial objective analysis of the motion system has been undertaken in an attempt to verify the fidelity of the motion cues generated. A significant outcome of this project has been to create a safe, easily maintainable, re-configurable flight simulator from a large, complex, legacy system. The facility now forms a significant research and teaching tool in areas such as flight mechanics, propulsion, aircraft handling qualities and human factors.

In this thesis we propose to realize the performance benefits of applicationspecific hardware optimizations in a general-purpose, multi-user system environment using a dynamically extensible microprocessor architecture. We have called our dynamically extensible microprocessor design the Extensible Microprocessor without Interlocked Pipeline Stages, or eMIPS. The eMIPS architecture uses the interaction of fixed and configurable logic available in modern Field Programmable Gate Array (FPGA). This interaction is used to address the limitations of current microprocessor architectures based solely on Application Specific Integrated Circuits (ASIC). These limitations include inflexibility, size, and application specific performance optimization. The eMIPS system allows multiple secure extensions to load dynamically and to plug into the stages of a pipelined central processing unit (CPU) data path, thereby extending the core instruction set of the microprocessor. Extensions can also be used to realize on-chip peripherals, and if area permits, even multiple cores. Extension instructions reduce dramatically the execution time of frequently executed instruction patterns. These new functionalities we have developed can be exploited by patching the binaries of existing applications, without any changes to the compilers. A FPGA based workstation prototype and a flexible simulation system implementating this design demonstrates speedups of 2x-3x on a set of applications that include video games, real-time programs and the SPEC2000 integer benchmarks. eMIPS is the first realized workstation based entirely on a dynamically extensible microprocessor that is safe for general purpose, multi-user applications. By exposing the individual stages of the data path, eMIPS allows optimizations not previously possible. This includes permitting safe and coherent accesses to memory from within an extension, optimizing multi-branched blocks, and throwing precise and restart able exceptions from within an extension. This work describes a simplified implementation of an extensible microprocessor architecture based on the Microprocessor without Interlocked Pipeline Stages (MIPS) Reduced Instruction Set Computer (RISC) architecture. The concepts and methods contained within this thesis may be applied to other similar architectures. Given this simplified prototype we look forward to propose how this architecture will be expanded as it matures.

Ever increasing demand for higher data rates and better Quality of Service (QoS) for a growing number of users requires new transceiver algorithms and architectures to better exploit the available spectrum and to efficiently counter the impairments of the radio channel. Multiple-Input Multiple-Output (MIMO) communication systems employ multiple antennas at both transmitter and at the receiver to meet the requirements of next-generation wireless systems. It is a promising technology to provide increased data rates while not involving an equivalent increase in the spectral requirements. However, practical implementation of MIMO detectors poses a significant challenge and has been consistently identified as the major bottleneck for realizing the full potential that multiple antenna systems promise. Furthermore, in order to make judicious use of the available bandwidth, the baseband units have to dynamically adapt to different modes (modulation schemes, code rates etc) of operations. Flexibility and high throughput requirements often place conflicting demands on the Very Large Scale Integration (VLSI) system designer. The major focus of this dissertation is to present efficient VLSI architectures for configurable MIMO detectors that can serve as accelerators to enable the realization of next generation wireless devices feasible. Both, hard output and soft output detector architectures are considered.

Ce projet de recherche de maîtrise fait partie d'un programme de recherche et de développement appelé « Sur la piste de la performance ». Ce programme vise à améliorer les performances des athlètes en fauteuil roulant de course de l'équipe paralympique canadienne. Les chercheurs du groupe PERSEUS estiment qu'il existe une combinaison optimale des paramètres de configuration selon l'athlète et la discipline. Pour arriver à une telle optimisation de la configuration de l'équipement, le groupe PERSEUS a élaboré une démarche de maximisation du transfert de puissance. Ce projet de maîtrise visait plus particulièrement à contribuer au volet d'optimisation du transfert de puissance par expérimentation via la conception d'un ergomètre qui simulerait les conditions de course auxquelles les athlètes sont soumis sur le terrain. De plus, il devait inclure la conception d'un fauteuil configurable qui permettrait d'évaluer l'effet sur la performance des changements des différents paramètres de positionnement d'un fauteuil roulant de course. À la lumière de l'état de l'art, des essais préliminaires et d'un modèle théorique de simulation de puissance qui détermine les paramètres importants de la course en fauteuil roulant, un concept d'ergomètre à rouleaux d'inertie couplés à un servomoteur a été développé. Cet ergomètre peut recevoir à la fois le fauteuil de l'athlète ou un fauteuil configurable. En dernière étape, une validation expérimentale de l'ergomètre et du fauteuil configurable a été faite avec un athlète de la relève pour des épreuves de 100m et 400m. Cette validation en deux temps confirme que les performances obtenues en laboratoire sur l'ergomètre sont représentatives de celles obtenues sur la piste. Elle confirme aussi que les performances obtenues sur l'ergomètre avec le fauteuil configurable sont représentatives de celles obtenues sur l'ergomètre avec le fauteuil roulant de course de l'athlète.

This dissertation presents a synthesis of methods for structural optimization of aircraft wing boxes. The optimization problem considered herein is the minimization of structural weight with respect to component sizes, subject to stress constraints. Different aspects of structural optimization methods representing the current state-of-the-art are discussed, including sequential quadratic programming, sensitivity analysis, parameterization of design variables, constraint handling, and multiple load treatment. Shortcomings of the current techniques are identified and a B-spline parameterization representing the structural sizes is proposed to address them. A new configurable B-spline parameterization method for structural optimization of wing boxes is developed that makes it possible to flexibly explore design spaces. An automatic scheme using different levels of B-spline parameterization configurations is also proposed, along with a constraint aggregation method in order to reduce the computational effort. Numerical results are compared to evaluate the effectiveness of the B-spline approach and the constraint aggregation method. To evaluate the new formulations and explore design spaces, the wing box of an airliner is optimized for the minimum weight subject to stress constraints under multiple load conditions. The new approaches are shown to significantly reduce the computational time required to perform structural optimization and to yield designs that are more realistic than existing methods.

A Variable Stability Flight Simulator is being developed in the School of Aerospace, Mechanical and Mechatronic Engineering at the University of Sydney, Australia. The device is being developed both as a teaching tool for use in flight mechanics courses in the department and as a research tool. It is reasonable to state that learning is enhanced through the experience of concepts outside of the classroom environment. It is intended that the device will be integrated into the department�s teaching program in aircraft flight mechanics. Initial studies centred around a PC based flight simulation developed at the Cranfield College of Aeronautics in the United Kingdom. This system utilises a distributed architecture with several computers connected via Ethernet. It also employs a Primary Image three channel visual system. The system has been further enhanced by the addition of a Link flight simulator provided by the Royal Australian Air Force (RAAF). The RAAF had been using the simulator as a training tool for some years until it had become surplus to requirements. Most of the work in the project has centred around re-engineering this simulator into a viable research/education tool. The Cranfield system has been incorporated into the Link simulator�s hardware to provide a fixed base simulation. The majority of the work described in this thesis revolved around the re-engineering of the flight control loading and motion systems. Previously these items were controlled by analogue circuitry with minimal digital interfaces to the main simulation software. The systems have been re-designed to replace much of the single model analogue circuitry with re-configurable digital control software. Doing so allows changes to be made to the systems in real time through a software interface. The software resides on a common computer that extensively interfaces with the rest of the simulation. To support the hardware involved and to provide for system operation and safety, an extensive Supervisory system has also been implemented. This system along with the motion and control loading software has been implemented in the Matlab / Real-Time Workshop environment. This gives the capability of making real-time changes to any part of the overall simulation. A variable stability module (vsm) is under development. The addition of this module will allow changes to be made to the simulation itself in real-time. The simulator is now functional with the motion and control loading systems operating as designed. Tuning of both systems has been done subjectively by the author. An initial objective analysis of the motion system has been undertaken in an attempt to verify the fidelity of the motion cues generated. A significant outcome of this project has been to create a safe, easily maintainable, re-configurable flight simulator from a large, complex, legacy system. The facility now forms a significant research and teaching tool in areas such as flight mechanics, propulsion, aircraft handling qualities and human factors.

No description available.

No description available.

<p> This thesis presents a strategy for documenting real-time control systems, and the work products that result from its application to the development of an alternate fuel injection controller. In doing so, this document contributes technically to the areas of automotive control, and control systems documentation. The strategy was not developed independently of the control system, but in a manner which reflects its size and complexity.</p> <p> The controller is used to generate and transmit appropriately timed and sized pulses to an alternative fuel injector array, and switch auxiliary devices including a fuel heater, and an injector lock-off. Such a controller, when used to inject natural gas or propane into a gasoline burning engine, provides a reduction in both engine operating costs and harmful engine emissions.</p> <p> The controller stores a fuel map that relates the amount of energy released by the combustion of petroleum to that released by the combustion of an alternate fuel, over a range of varying environmental conditions. The fuel map is used to calculate the length of alternate injection pulses. These maps have been designed by, and are the property of Cosimo's Garage Ltd. and thus will not appear in this document.</p> <p> At present, nearly all large engine car conversion technology is more rigid than the solution provided here. Conversion costs are often prohibitive and problems requiring professional service are frequent. Should the controller described here, help to curb conversion costs and reduce the need for frequent service as is expected, the controller will be a viable candidate for production and sale.</p> / Thesis / Master of Applied Science (MASc)