Dissertations / Theses: 'Aerospace systems design'

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Pfaender, Jens Holger. "Competitive Assessment of Aerospace Systems using System Dynamics." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14014.

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Aircraft design has recently experienced a trend away from performance centric design towards a more balanced approach with increased emphasis on engineering an economically successful system. This approach focuses on bringing forward a comprehensive economic and life-cycle cost analysis, which can be addressed by the introduction of a dynamic method allowing the analysis of the future attractiveness of such a concept in the presence of uncertainty. One way of addressing this is through the use of a competitive market model. However, existing market models do not focus on the dynamics of the market, which results in poor predictive capabilities. The method proposed here focuses on a top-down approach that integrates a competitive model based on work in the field of system dynamics into the aircraft design process. The primary contribution is the demonstration of the feasibility of such integration. This integration is achieved through the use of surrogate models, which enabled not only the practical integration of analysis techniques, but also reduced the computational requirements so that interactive exploration as envisioned is actually possible. An example demonstration of this integration is built on the competition in the 250 seat large commercial aircraft market. Two aircraft models were calibrated to existing performance and certification data and then integrated into the system dynamics market model, which was then calibrated with historical market data. This calibration showed a much improved predictive capability as compared to the conventional logit regression models. The resulting market model was then integrated into a prediction profiler environment with a time variant Monte-Carlo analysis resulting in a unique trade-off environment. This environment was shown to allow interactive trade-off between aircraft design decisions and economic considerations while allowing the exploration potential market success in the light of varying external market conditions and scenarios. Another use of the existing outputs of the Monte-Carlo analysis was then realized by visualizing the model variables on a multivariate scatter plot. This enables the designer to define strategic market and return on investment goals for a number of scenarios and then directly see which specific aircraft designs meet these goals.

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Fernandez, Martin Ismael. "Valuation of design adaptability in aerospace systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22584.

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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Dr. Mavris, Dimitri; Committee Member: Dr. Hollingsworth, Peter; Committee Member: Dr. McMichael, Jim; Committee Member: Dr. Saleh, Joseph; Committee Member: Dr. Schrage, Daniel.

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Waslander, Steven L. "Multi-agent systems design for aerospace applications /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.

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Borer, Nicholas Keith. "Decision Making Strategies for Probabilistic Aerospace Systems Design." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10469.

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Modern aerospace systems design problems are often characterized by the necessity to identify and enable multiple tradeoffs. This can be accomplished by transformation of the design problem to a multiple objective optimization formulation. However, existing multiple criteria techniques can lead to unattractive solutions due to their basic assumptions; namely that of monotonically increasing utility and independent decision criteria. Further, it can be difficult to quantify the relative importance of each decision metric, and it is very difficult to view the pertinent tradeoffs for large-scale problems. This thesis presents a discussion and application of Multiple Criteria Decision Making (MCDM) to aerospace systems design and quantifies the complications associated with switching from single to multiple objectives. It then presents a procedure to tackle these problems by utilizing a two-part relative importance model for each criterion. This model contains a static and dynamic portion with respect to the current value of the decision metric. The static portion is selected based on an entropy analogy of each metric within the decision space to alleviate the problems associated with quantifying basic (monotonic) relative importance. This static value is further modified by examination of the interdependence of the decision metrics. The dynamic contribution uses a penalty function approach for any constraints and further reduces the importance of any metric approaching a user-specified threshold level. This reduces the impact of the assumption of monotonically increasing utility by constantly updating the relative importance of a given metric based on its current value. A method is also developed to determine a linearly independent subset of the original requirements, resulting in compact visualization techniques for large-scale problems.

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Wang, Jennifer Y. "Migration of aerospace technologies to adjacent markets." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/105302.

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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 51-56).
Shrinking government budgets due to economic woes has aerospace and defense contractors scrambling to sustain their business and minimize the effects of budget sequestration. Given the global economic climate and the level of federal debt, government budget spending is unlikely to recover in the near future to previous levels, where aerospace and defense contractors had enjoyed an abundance of million and billion dollar cost-reimbursable contracts. In current business conditions, company leadership has put a new focus on finding and developing business in adjacent markets, where core competencies can be utilized to generate alternative streams of revenue. In order to provide insight into potential adjacent markets for aerospace technologies and entry strategies that increase chances of success, this thesis analyzes cases of technologies originally developed for an aerospace application that were eventually adopted for use in another (non-aerospace) industry. Analysis of metrics and 35 cases compiled from NASA's Spinoff and Technology Databases reinforce several observations that have been generalized in other literature: 1) a wide variety of industries could be considered adjacent markets, 2) entering established industries may offer the highest technology adoption rate, 3) partnership with an existing firm or organization with knowledge of the adjacent market has played a key role in the successful adoption of the technology in the adjacent market, and 4) building-block technologies at the subsystem, component and base material level most often traversed market boundaries. However, a handful of cases prove that systems can traverse market boundaries in whole under certain conditions. Most importantly, the role of the aerospace industry as advanced analog lead users is a unique advantage that aerospace firms should leverage.
by Jennifer Y. Wang.
S.M. in Engineering and Management

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Hart, Peter Bartholomew. "A plm implementation for aerospace systems engineering-conceptual rotorcraft design." Thesis, Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28278.

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The thesis will discuss the Systems Engineering phase of an original Conceptual Design Engineering Methodology for Aerospace Engineering-Vehicle Synthesis. This iterative phase is shown to benefit from digitization of Integrated Product&Process Design (IPPD) activities, through the application of Product Lifecycle Management (PLM) technologies. Requirements analysis through the use of Quality Function Deployment (QFD) and 7 MaP tools is explored as an illustration. A "Requirements Data Manager" (RDM) is used to show the ability to reduce the time and cost to design for both new and legacy/derivative designs. Here the COTS tool Teamcenter Systems Engineering (TCSE) is used as the RDM. The utility of the new methodology is explored through consideration of a legacy RFP based vehicle design proposal and associated aerospace engineering. The 2001 American Helicopter Society (AHS) 18th Student Design Competition RFP is considered as a starting point for the Systems Engineering phase. A Conceptual Design Engineering activity was conducted in 2000/2001 by Graduate students (including the author) in Rotorcraft Engineering at the Daniel Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology, Atlanta GA. This resulted in the "Kingfisher" vehicle design, an advanced search and rescue rotorcraft capable of performing the "Perfect Storm" mission, from the movie of the same name. The associated requirements, architectures, and work breakdown structure data sets for the Kingfisher are used to relate the capabilities of the proposed Integrated Digital Environment (IDE). The IDE is discussed as a repository for legacy knowledge capture, management, and design template creation. A primary thesis theme is to promote the automation of the up-front conceptual definition of complex systems, specifically aerospace vehicles, while anticipating downstream preliminary and full spectrum lifecycle design activities. The thesis forms a basis for additional discussions of PLM tool integration across the engineering, manufacturing, MRO and EOL lifecycle phases to support business management processes.

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Agte, Jeremy S. (Jeremy Sundermeyer). "Multistate analysis and design : case studies in aerospace design and long endurance systems." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68167.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, September 2011.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
"September 2011." Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 221-230).
This research contributes to the field of aerospace engineering by proposing and demonstrating an integrated process for the early-stage, multistate design of aerospace systems. The process takes into early consideration the many partially degraded states that real-world systems experience throughout their operation. Despite advancing efforts aimed at maintaining operation in a state of optimum performance, most systems spend very substantial amounts of time operating in degraded or off-nominal states (e.g. Hubble space telescope, Mars Spirit rover, or aircraft flying under minimum-equipment-list restrictions). There exist relatively few methods and tools to address this at the beginning of the design process. At one end of the spectrum is design optimization, but this typically concentrates on the system in its nominal state of operation, only infrequently considering failure states through piecemeal application of constraints. There is reliability analysis, which focuses on component failure rates and the benefits of redundancy but does not consider how well or poorly the system performs with partial failures. Finally, there is controls theory, where control laws are optimized but the plant is typically assumed to be given a priori. The methodology described within this thesis coordinates elements from each of these three areas into an effective integrated framework. It allows the designer deeper insight into the complex problem of designing cost effective systems that must operate for long durations with little or expensive opportunity for repair or intervention. Specific contributions include: 1) the above methodology, which evaluates responses in system expected performance and availability to changes in static design variables (geometry) and component failure rates, accounting for control design variables (gains) where appropriate, 2) the demonstration of the cost and benefits associated with a multistate design approach as compared to reliability analysis and the nominal design approach, and 3) a multilayer extension of Markov analysis, for translating single sortie vehicle level metrics into measures of multistate campaign performance. The process is demonstrated through three application case studies. The first of these establishes the feasibility of the approach through the multistate analysis of performance for an existing twin-engine aircraft. This analysis was enabled through the development of a multidisciplinary simulation based design model for evaluation of multistate aircraft performance. A medium-altitude long endurance unmanned aerial vehicle is designed in the second case study, first from a single-sortie, ultra long endurance perspective and then from a multiple sortie, mission campaign perspective. Finally, the third case study demonstrates applicability of the approach to a lower level subsystem, that of the lubrication system for a geared turbofan engine. Several major findings result from these case studies, including that: 1) multistate performance output spaces have distinctly unique shapes and boundaries, depending on whether formed through variation of component failure rates, static design variables (geometry), or a multistate combination of both, 2) a region of multistate performance results from the combined variation of failure rates and static design variables that is unachievable through the independent variation of either one, 3) small changes in static design variables may be used to significantly improve system availability, and 4) the general multistate design problem is one of competing objectives between system availability, expected performance, nominal performance, and cost.
by Jeremy S. Agte.
Ph.D.

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Hollingsworth, Peter Michael. "Requirements Controlled Design: A Method for Discovery of Discontinuous System Boundaries in the Requirements Hyperspace." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-04092004-151914/unrestricted/hollingsworth%5Fpeter%5Fm%5F200405%5Fphd.pdf.

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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2004.
Nickol, Craig, Committee Member ; Goodman, Seymour, Committee Member ; Schrage, Daniel, Committee Member ; Craig, James, Committee Member ; Mavris, Dimitri, Committee Chair. Vita. Includes bibliographical references (leaves 272-283).

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Papageorgiou, George. "Robust control system design : H∞ loop sharing and aerospace applications." Thesis, University of Cambridge, 1998. https://www.repository.cam.ac.uk/handle/1810/272494.

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Daberkow, Debora Daniela. "A formulation of metamodel implementation processes for complex systems design." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/12478.

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Parrish, Jefferson Carter. "Reduced order techniques for sensitivity analysis and design optimization of aerospace systems." Thesis, Mississippi State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618312.

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This work proposes a new method for using reduced order models in lieu of high fidelity analysis during the sensitivity analysis step of gradient based design optimization. The method offers a reduction in the computational cost of finite difference based sensitivity analysis in that context.

The method relies on interpolating reduced order models which are based on proper orthogonal decomposition. The interpolation process is performed using radial basis functions and Grassmann manifold projection. It does not require additional high fidelity analyses to interpolate a reduced order model for new points in the design space. The interpolated models are used specifically for points in the finite difference stencil during sensitivity analysis.

The proposed method is applied to an airfoil shape optimization (ASO) problem and a transport wing optimization (TWO) problem. The errors associated with the reduced order models themselves as well as the gradients calculated from them are evaluated. The effects of the method on the overall optimization path, computation times, and function counts are also examined.

The ASO results indicate that the proposed scheme is a viable method for reducing the computational cost of these optimizations. They also indicate that the adaptive step is an effective method of improving interpolated gradient accuracy. The TWO results indicate that the interpolation accuracy can have a strong impact on optimization search direction.

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Wu, Marcus Shihong. "Design for affordability in defense and aerospace systems using tradespace-based methods." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/89937.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.
Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 262-270).
Program failures have plagued the defense and aerospace industry for decades, as unanticipated cost and schedule overruns have rendered the development of systems ineffective in terms of time and cost considerations. This raises the need to holistically include performance, cost and schedule considerations during the early-phase design of systems to perform valuable tradeoffs that derive more feasible and affordable solutions. This paradigm is the design for affordability. This design for affordability conundrum is targeted at defense and aerospace systems, which have complex mission requirements and stakeholder involvement that are susceptible to changes and perturbations over time. Without a systematic framework, the design for affordability process can potentially become cognitively challenging to system architects and lead to unsatisfactory results. To resolve affordability, it can first be defined as the property of becoming or remaining feasible relative to resource needs and resource constraints over time. Affordability can then be treated as an ility that drives the design of more affordable yet technically sound architectures. Tradespace-based methods are introduced to drive affordability and incorporate these holistic considerations into the design process. They facilitate the systematic and disciplined search for affordable solutions to the system, program and portfolio of interest. Multi-Attribute Tradespace Exploration (MATE), Epoch-Era Analysis (EEA) and the Multi-Attribute Expense (MAE) function were modified for affordability analysis. Their feasibility was demonstrated through application to two design case studies. Results from both case studies demonstrated the dynamic tradeoffs among performance, cost and schedule parameters. Tradespace-based methods can thus be applied to the progressive design of systems, programs and portfolios using either a bottom-up or top-down approach to deliver affordable solutions in these cases. Affordability is not only an engineering problem; it is also a policy and management problem. Therefore, affordability can be approached through perspectives beyond engineering design. New policies and refined management practices can be used alongside tradespace-based methods for affordability analysis to ensure the continued delivery of affordable systems for the future.
by Marcus Shihong Wu.
S.M.
S.M. in Technology and Policy

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Hebbal, Ali. "Deep gaussian processes for the analysis and optimization of complex systems : application to aerospace system design." Thesis, Lille, 2021. http://www.theses.fr/2021LILUI016.

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En ingénierie, la conception de systèmes complexes, tels que les lanceurs aérospatiaux, implique l'analyse et l'optimisation de problèmes présentant diverses problématiques. En effet, le concepteur doit prendre en compte différents aspects dans la conception de systèmes complexes, tels que la présence de fonctions coûteuses en temps de calcul et en boîte noire , la non-stationnarité des performances optimisées, les multiples objectifs et contraintes impliqués, le traitement de multiples sources d’information dans le cadre de la multi-fidélité, et les incertitudes épistémiques et aléatoires affectant les modèles physiques. Un large éventail de méthodes d'apprentissage automatique est utilisé pour relever ces différents défis. Dans le cadre de ces approches, les processus Gaussiens, bénéficiant de leur formulation Bayésienne et non paramétrique, sont populaires dans la littérature et divers algorithmes d'état de l'art pour la conception de systèmes complexes sont basés sur ces modèles.Les processus Gaussiens, bien qu'ils soient largement utilisés pour l'analyse et l'optimisation de systèmes complexes, présentent encore certaines limites. Pour l'optimisation de fonctions coûteuses en temps de calcul et en boite noire, les processus Gaussiens sont utilisés dans le cadre de l'optimisation Bayésienne comme modèles de régression. Cependant, pour l'optimisation de problèmes non stationnaires, les processus Gaussiens ne sont pas adaptés en raison de l'utilisation d'une fonction de covariance stationnaire. En outre, dans l'optimisation Bayésienne multi-objectif, un processus Gaussien est utilisé pour chaque objectif indépendamment des autres objectifs, ce qui empêche de prendre en considération une corrélation potentielle entre les objectifs. Une autre limitation existe dans l'analyse multi-fidélité où des modèles basés sur les processus Gaussiens sont utilisés pour améliorer les modèles haute fidélité en utilisant l'information basse fidélité, cependant, ces modèles supposent généralement que les différents espaces d'entrée de fidélité sont définis de manière identique, ce qui n'est pas le cas dans certains problèmes de conception.Dans cette thèse, des approches sont développées pour dépasser les limites des processus Gaussiens dans l'analyse et l'optimisation de systèmes complexes. Ces approches sont basées sur les processus Gaussiens profonds, la généralisation hiérarchique des processus Gaussiens.Pour gérer la non-stationnarité dans l'optimisation bayésienne, un algorithme est développé qui couple l'optimisation bayésienne avec les processus Gaussiens profonds. Les couches internes permettent une projection Bayésienne non paramétrique de l'espace d'entrée pour mieux représenter les fonctions non stationnaires. Pour l'optimisation Bayésienne multiobjectif, un modèle de processus Gaussien profond multiobjectif est développé. Chaque couche de ce modèle correspond à un objectif et les différentes couches sont reliées par des arrêtes non orientés pour coder la corrélation potentielle entre objectifs. De plus, une approche de calcul de l'expected hyper-volume improvement est proposée pour prendre également en compte cette corrélation au niveau du critère d'ajout de point. Enfin, pour aborder l'analyse multi-fidélité pour différentes définitions d'espace d'entrée, un modèle de processus gaussien profond à deux niveaux est développé. Ce modèle permet une optimisation conjointe du modèle multi-fidélité et du mapping entre les espaces d'entrée des différentes fidélités.Les différentes approches développées sont évaluées sur des problèmes analytiques ainsi que sur des problèmes de conception de véhicules aérospatiaux et comparées aux approches de l'état de l'art
In engineering, the design of complex systems, such as aerospace launch vehicles, involves the analysis and optimization of problems presenting diverse challenges. Actually, the designer has to take into account different aspects in the design of complex systems, such as the presence of black-box computationally expensive functions, the complex behavior of the optimized performance (e.g., abrupt change of a physical property here referred as non-stationarity), the multiple objectives and constraints involved, the multi-source information handling in a multi-fidelity framework, and the epistemic and aleatory uncertainties affecting the physical models. A wide range of machine learning methods are used to address these various challenges. Among these approaches, Gaussian Processes (GPs), benefiting from their Bayesian and non-parametric formulation, are popular in the literature and diverse state-of-the-art algorithms for the design of complex systems are based on these models.Despite being widely used for the analysis and optimization of complex systems, GPs, still present some limitations. For the optimization of computationally expensive functions, GPs are used within the Bayesian optimization framework as regression models. However, for the optimization of non-stationary problems, they are not suitable due to the use of a prior stationary covariance function. Furthermore, in Bayesian optimization of multiple objectives, a GP is used for each involved objective independently, which prevents the exhibition of a potential correlation between the objectives. Another limitation occurs in multi-fidelity analysis where GP-based models are used to improve high-fidelity models using low-fidelity information. However, these models usually assume that the different fidelity input spaces are identically defined, which is not the case in some design problems.In this thesis, approaches are developed to overcome the limits of GPs in the analysis and optimization of complex systems. These approaches are based on Deep Gaussian Processes (DGPs), the hierarchical generalization of Gaussian processes.To handle non-stationarity in Bayesian optimization, a framework is developed that couples Bayesian optimization with DGPs. The inner layers allow a non-parametric Bayesian mapping of the input space to better represent non-stationary functions. For multi-objective Bayesian optimization, a multi-objective DGP model is developed. Each layer of this model corresponds to an objective and the different layers are connected with undirected edges to encode the potential correlation between objectives. Moreover, a computational approach for the expected hyper-volume improvement is proposed to take into account this correlation at the infill criterion level as well. Finally, to address multi-fidelity analysis for different input space definitions, a two-level DGP model is developed. This model allows a joint optimization of the multi-fidelity model and the input space mapping between fidelities.The different approaches developed are assessed on analytical problems as well as on representative aerospace vehicle design problems with respect to state-of-the-art approaches

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Sar, Preeti. "Eco-Inspired Robust Control Design Algorithm For Linear Systems with Real Parameter Uncertainty." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1367439491.

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Diller, Nathan P. (Nathan Philip) 1978. "Utilizing Multiple Attribute Tradespace Exploration with Concurrent Design for creating aerospace systems requirements." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/83680.

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Tseng, Yuan-Wei. "Control design of linear dynamic systems with matrix differential equations for aerospace applications /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487943610783999.

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Bandte, Oliver. "A probabilistic multi-criteria decision making technique for conceptual and preliminary aerospace systems design." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12503.

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Knox, Lenora A. "Use of Model-Based Design Methods for Enhancing Resiliency Analysis of Unmanned Aerial Vehicles." Thesis, The George Washington University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10265223.

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The most common traditional non-functional requirement analysis is reliability. With systems becoming more complex, networked, and adaptive to environmental uncertainties, system resiliency has recently become the non-functional requirement analysis of choice. Analysis of system resiliency has challenges; which include, defining resilience for domain areas, identifying resilience metrics, determining resilience modeling strategies, and understanding how to best integrate the concepts of risk and reliability into resiliency. Formal methods that integrate all of these concepts do not currently exist in specific domain areas. Leveraging RAMSoS, a model-based reliability analysis methodology for Systems of Systems (SoS), we propose an extension that accounts for resiliency analysis through evaluation of mission performance, risk, and cost using multi-criteria decision-making (MCDM) modeling and design trade study variability modeling evaluation techniques. This proposed methodology, coined RAMSoS-RESIL, is applied to a case study in the multi-agent unmanned aerial vehicle (UAV) domain to investigate the potential benefits of a mission architecture where functionality to complete a mission is disseminated across multiple UAVs (distributed) opposed to being contained in a single UAV (monolithic). The case study based research demonstrates proof of concept for the proposed model-based technique and provides sufficient preliminary evidence to conclude which architectural design (distributed vs. monolithic) is most resilient based on insight into mission resilience performance, risk, and cost in addition to the traditional analysis of reliability.

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Thomas, Victoria Katherine. "A Method for Scenario-based Risk Assessment for Robust Aerospace Systems." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14536.

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A methodology for the conceptual design phase risk assessment of an aerospace system was proposed. The method was designed to examine political, social, and economic risk over a systems lifecycle through the use of future scenarios to bound uncertainty. A decision support framework was developed to allow the user to visualize the differences in performance and economic metrics between design options as well as allowing the user to visualize the effects of mitigating certain risks. A historical proof of concept was developed to test the methodology. The results indicated that the new method will work to examine political, social, and economic risk during conceptual level design, and that this information can be used to aid in design down-selection and decision making. The use of scenario-based analysis as an alternative to traditional probabilistic analysis allowed for better traceability and bounding of uncertainty. Other findings regarding the use of a risk analysis early during concept design and future work are also discussed.

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Saranathan, Harish. "Algorithmic Advances to Increase the Fidelity of Conceptual Hypersonic Mission Design." Thesis, Purdue University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10792495.

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The contributions of this dissertation increase the fidelity of conceptual hypersonic mission design through the following innovations: 1) the introduction of coupling between the effects of ablation of the thermal protection system (TPS) and flight dynamics, 2) the introduction of rigid body dynamics into trajectory design, and 3) simplifying the design of hypersonic missions that involve multiple phases of flight. These contributions are combined into a unified conceptual mission design framework, which is in turn applicable to slender hypersonic vehicles with ablative TPS. Such vehicles are employed in military applications, wherein speed and terminal energy are of critical importance.

The fundamental observation that results from these contributions is the substantial reduction in the maximum terminal energy that is achievable when compared to the state-of-the art conceptual design process. Additionally, the control history that is required to follow the maximum terminal energy trajectory is also significantly altered, which will in turn bear consequence on the design of the control actuators.

The other important accomplishment of this dissertation is the demonstration of the ability to solve these class of problems using indirect methods. Despite being built on a strong foundation of the calculus of variations, the state-of-the-art entirely neglects indirect methods because of the challenge associated with solving the resulting boundary value problem (BVP) in a system of differential-algebraic equations (DAEs). Instead, it employs direct methods, wherein the optimality of the calculated trajectory is not guaranteed. The ability to employ indirect methods to solve for optimal trajectories that are comprised of multiple phases of flight while also accounting for the effects of ablation of the TPS and rigid body dynamics is a substantial advancement in the state-of-the-art.

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Miao, Cheng Hsi. "The design of phased synthetic aperture imaging systems using a minimum number of elements." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185625.

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The research described in this report resulted from my participation in the design study for the Phased-Array Imaging Telescope. To maintain high transmission, a practical system should contain a minimum number of components. This consideration leads to the concept of shared symmetries between the subtelescope and final collector. This report presents an approach to the design of such arrays, and examines the implications of including aspheric correction for the telescope array. As expected, the number of elements in this correction design concept seems to work well. Four array systems based on this concept are presented; each uses only one spherical mirror as the beam collector. The effects of changing the primary mirror's relative aperture, and of changing the system length, on the symmetry and order of aberrations arising from the use of an eccentric aspheric, are explained in this report. The subtle limitations of techniques for adding special surfaces for decentered aspheric correction to optical design programs are discussed as well. Two additional design concepts are examined and compared. A preliminary tolerancing analysis is performed, and error budgets developed. An adaptive element is considered for relaxing the alignment and fabrication tolerances.

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Bradley, Thomas Heenan. "Modeling, design and energy management of fuel cell systems for aircraft." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26592.

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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Parekh, David; Committee Member: Fuller, Thomas; Committee Member: Joshi, Yogendra; Committee Member: Mavris, Dimitri; Committee Member: Wepfer, William. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Paxton, Brendan. "Systems Design and Experimental Evaluation of a High-Altitude Relight Test Facility." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1448037233.

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Solodilova-Whiteley, I. "A design strategy for human-system integration in aerospace : where to start and how to design information integration for dynamic, time and safety critical systems." Thesis, University of Bath, 2005. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428372.

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The aim of this research is to develop a framework that provides systemic design guidance for future interfaces that are to provide effective and cognitively suitable information presentation to operators in dynamic and time-critical domains. The aerospace domain has been chosen as the focus for this study. In the aerospace domain there are numerous reported accidents where contributory factors are attributed to pilots’ misunderstanding of automated system configurations, and pilots’ misinterpretation of system behaviour. These problems have occurred as rapid advances in technology have led to an overabundance of ‘useful’ information being presented to the pilot. Currently, the information presented to pilots is often disjointed and distributed across various interfaces where each interface is based on its own design rationale. This creates problems where the pilot either cannot locate information in a timely manner, or misinterprets the available information. There is a need for a systematic design process that deals with meaningfully presenting the abundance of features and interactions of the new technology introduced into the cockpit through the use of existing domain knowledge, structures and strategies drawn from existing pilot training and experience. The thesis is a case study. It shows how a new systematic interface design guidance process was developed by first identifying effective information presentation directly from airforce and airline pilots in their time-critical working environment conducted through observational and empirical studies. The studies provided answers for research questions that were concerned with finding appropriate information presentations for pilots. This resulted in a framework that serves as a guide for the interface designer on how to arrive at, structure and present information to an operator in a cognitively efficient manner. The thesis demonstrates two applications of the design framework, one of which is then evaluated by pilots who demonstrate significantly improved speed and accuracy performance when compared to conventional alphanumerical displays. The applications and limitations of the framework are also discussed.

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Marchiori, Rodolfo Henrique. "Framework Design for System of Systems : A Bottom Up Approach Applied to Search and Rescue Missions." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149607.

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This thesis addresses the complexities in the design of System of Systems, by providing a flexible, case independent method to analyse and rank the alternatives that are capable of performing the desired missions or operations assigned by decision makers. Although its methods involve only low-fidelity models, these proved to be the best choice as the design space created and, consequently, the number of analysis grow explosively with the increase of available options to perform the required tasks. This is due to the combinatory approach used in the generation of the design space. Another goal is to provide a demonstration of possible improvements with the addition of ontologies to the early stages of design, especially when complex solutions are expected. This also diminishes the probability of human error by decreasing the amount of work demanded when adding alternatives or changing their characteristics, displaying again the feasible application of knowledge based and automated solutions to the engineering design process. With these advantages, the flexibility of altering the set of inputs is enhanced, adding to the resilience of the framework, as it can be attached to any available compatible ontology and perform in that specific domain without hindrance. Due to the lack of techniques and the probable cost of these once made available, the evaluation of emergence is not considered in this work, and is not reccomended to be directly done once ready for use, at least not on the full result array. Moreover, the modular implementation of the framework makes the exchange of functions a rather simple task, enabling users to adapt it to their own needs. Some immediate implementations are mentioned to greatly improve the general performance and relevance of results provided.

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Jackson, David Wayne. "Robust aircraft subsystem conceptual architecting." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50202.

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Aircraft subsystems are key components in modern aircraft, the impact and significance of which have been constantly increasing. Furthermore, the architecture selection of these subsystems has overall system-level effects. Despite the significant effects of architecture selections, existing methods for determining the architecture, especially early in design, are similar to the use of traditional point solutions. Currently, aircraft subsystems are rarely examined during the conceptual design phase, despite the fact that this phase has a significant influence on aircraft cost and performance. For this reason, there is a critical need to examine subsystem architecture trades and investigate the design space during the conceptual design of an aircraft. Traditionally, after the aircraft conceptual design phase, subsystems are developed in a process that begins with the point selection of the architecture, then continues with its development and analysis, and concludes in the detailed development of the subsystems. The choice of the point design of the architecture to be developed can be made using simplified models to explore the design space. This method known as conceptual architecting is explored in this dissertation. This dissertation also focuses on bringing actuation subsystem architecture trades into conceptual design because of the significant cost impact of this design phase and the interdependence of vehicle sizing with the subsystems impact on the aircraft. The extent of these interdependencies is examined and found to be significant. As a result, this coupling must be captured to enable better informed decision making. A methodology to examine the design space of aircraft subsystem architectures during the conceptual design of aircraft, while incorporating this coupling, is presented herein and applied specifically to actuation architectures.

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Choi, Taeyun Paul. "A recourse-based solution approach to the design of fuel cell aeropropulsion systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22676.

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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Mavris, Dimitri; Committee Member: German, Brian; Committee Member: Haynes, Comas; Committee Member: Masson, Philippe; Committee Member: Soban, Danielle.

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Yuan, Xin. "Model-based feedback control of subsonic cavity flows - control design." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1158032317.

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Belben, Joel Brian. "ENABLING RAPID CONCEPTUAL DESIGN USING GEOMETRY- BASED MULTI-FIDELITY MODELS IN VSP." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/969.

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The purpose of this work is to help bridge the gap between aircraft conceptual design and analysis. Much work is needed, but distilling essential characteristics from a design and collecting them in an easily accessible format that is amenable to use by inexpensive analysis tools is a significant contribution to this goal. Toward that end, four types of reduced-fidelity or degenerate geometric representations have been defined and implemented in VSP, a parametric geometry modeler. The four types are degenerate surface, degenerate plate, degenerate stick, and degenerate point, corresponding to three-, two-, one-, and zero- dimensional representations of underlying geometry, respectively. The information contained in these representations was targeted specifically at lifting line, vortex lattice, equivalent beam, and equivalent plate theories, with the idea that suitability for interface with these methods would imply suitability for use with many other analysis techniques. The ability to output this information in two plain text formats— comma separated value and Matlab script—has also been implemented in VSP, making it readily available for use. A modified Cessna 182 wing created in VSP was used to test the suitability of degenerate geometry to interface with the four target analysis techniques. All four test cases were easily completed using the information contained in the degenerate geometric types, and similar techniques utilizing different degenerate geometries produced similar results. The following work outlines the theoretical underpinnings of degenerate geometry and the fidelity-reduction process. It also describes in detail how the routines that create degenerate geometry were implemented in VSP and concludes with the analysis test cases, stating their results and comparing results among different techniques.

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Miller, Adam J. "Methodology for Cost Estimation of Systems at a Preliminary Stage of Design." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1344259852.

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Devarakonda, Nagini. "Eco-inspired Robust Control Design for Linear Dynamical Systems with Applications." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313519615.

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Richardson, Matthew. "Mass Estimation through Fusion of Astrometric and Photometric Data Collection with Application to High Area-to-Mass Ratio Objects." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1742.

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This thesis work presents the formulation for a tool developed in MATLAB to determine the mass of a space object from the fusion of astrometric and photometric data. The application for such a tool is to better model the mass estimation method used for high area-to-mass ratio objects found in high altitude orbit regimes. Typically, the effect of solar radiation pressure is examined with angles observations to deduce area-to-mass ratio calculations for space objects since the area-to-mass ratio can greatly affect its orbital dynamics. On the other hand, photometric data is not sensitive to mass but is a function of the albedo-area and the rotational dynamics of the space object. Thus from these two data types it is possible to disentangle intrinsic properties using albedo-area and area-to-mass and ultimately determine the mass of a space object. Three case studies were performed for the different orbit regimes: geosynchronous, highly elliptic, and medium earth orbit. The position states were either initialized with a two line element set or with initial orbit determination methods to simulate data which was run through an unscented Kalman filter to estimate the translational and rotational states of the space object as well as the mass an albedo area. In the geosynchronous and highly elliptic cases the tool was able to accurately predict the mass value to within 5kg of the true value based on a 95% confidence interval which will allow applications to understanding high area-to-mass objects with high certainty.

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Seitz, Timothy M. "Linearizing and Distributing Engine Models for Control Design." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1373728747.

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Yost, Morgan. "An Iteration on the Horizon Simulation Framework to Include .NET and Python Scripting." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1607.

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Modeling and Simulation is a crucial element of the aerospace engineering design pro- cess because it allows designers to thoroughly test their solution before investing in the resources to create it. The Horizon Simulation Framework (HSF) v3.0 is an aerospace modeling and simulation tool that allows the user to verify system level requirements in the early phases of the design process. A low fidelity model of the system that is created by the user is exhaustively tested within the built-in Day-in-the-Life simulator to provide useful information in the form of failed requirements, system bottle necks and leverage points, and potential schedules of operations. The model can be stood up quickly with Extended Markup Language (XML) input files or can be customly created with Python Scripts that interact with the framework at runtime. The goal of the work presented in this thesis is to progress HSF from v2.3 to v3.0 in order to take advantage of current software development technologies. This includes converting the codebase from C++ and Lua scripting to C♯ and Python Scripting. The particulars of the considerations, benefits, and implementation of the new framework are discussed in detail. The simulation data and performance run time of the new framework were compared to that of the old framework. The new framework was found to produce similar data outputs with a faster run time.

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Umaretiya, Jagdish R. "Specifications extraction and synthesis: Their correlations with preliminary design." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185035.

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This report addresses the research applied towards the automation of the engineering design process, in particular the structural design process. The three important stages of the structural design process are: the specifications, preliminary design and the detailed design. An iterative redesign architecture of the structural design process lends itself to automation. The automation of the structural design can improve both the cost and the reliability, and enhance the productivity of the human designers. To the extent that the assumptions involved in the design process are explicitly represented and automatically inforced, the design errors resulting from the violated assumptions can be avoided. Artificial Intelligence (AI) addresses the automation of complex and knowledge-intensive tasks such as the structural design process. It involves the development of the Knowledge Based Expert System (KBES). There are several tools, also known as expert shells, and languages available for the development of knowledge-based expert systems. A general purpose language, called LISP, is very popular among researchers in AI and is used as an environmental tool for the development of the KBES for the structural design process. The resulting system, called Expert-SEISD, is very generic in nature. The Expert-SEISD is composed of the user interface, inference engine, domain specific knowledge and data bases and the knowledge acquisition. The present domain of the Expert-SEISD encompasses the design of structural components such as beams and plates. The knowledge acquisition module is developed to facilitate the incorporation of new capabilities (knowledge or data) for beams, plates and for new structural components. The decision making is an integral part of any design process. A decision-making model suitable for the specifications extraction and the preliminary design phases of the structural design process is proposed and developed based on the theory of fuzzy sets. The methods developed here are evaluated and compared with similar methods available in the literature. The new method, based on the union of fuzzy sets and contrast intensification, was found suitable for the proposed model. It was implemented as a separate module in the Expert-SEISD. A session with the Expert-SEISD is presented to demonstrate its capabilities of beam and plate designs and knowledge acquisition.

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Fulcher, Jared T. "A DESIGN PATHFINDER WITH MATERIAL CORRELATION POINTS FOR INFLATABLE SYSTEMS." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/39.

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The incorporation of inflatable structures into aerospace systems can produce significant advantages in stowed volume to mechanical effectiveness and overall weight. Many applications of these ultra-lightweight systems are designed to precisely control internal or external surfaces, or both, to achieve desired performance. The modeling of these structures becomes complex due to the material nonlinearities inherent to the majority of construction materials used in inflatable structures. Furthermore, accurately modeling the response and behavior of the interfacing boundaries that are common to many inflatable systems will lead to better understanding of the entire class of structures. The research presented involved using nonlinear finite element simulations correlated with photogrammetry testing to develop a procedure for defining material properties for commercially available polyurethane-coated woven nylon fabric, which is representative of coated materials that have been proven materials for use in many inflatable systems. Further, the new material model was used to design and develop an inflatable pathfinder system which employs only internal pressure to control an assembly of internal membranes. This canonical inflatable system will be used for exploration and development of general understanding of efficient design methodology and analysis of future systems. Canonical structures are incorporated into the design of the phased pathfinder system to allow for more universal insight. Nonlinear finite element simulations were performed to evaluate the effect of various boundary conditions, loading configurations, and material orientations on the geometric precision of geometries representing typical internal/external surfaces commonly incorporated into inflatable pathfinder system. The response of the inflatable system to possible damage was also studied using nonlinear finite element simulations. Development of a correlated material model for analysis of the inflatable pathfinder system has improved the efficiency of design and analysis techniques of future inflatable structures.

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Mincolla, Andrea. "Space Systems of Systems Generative Design Using Concurrent MBSE: An Application of ECSS-E-TM-10-25 and the GCD Tool to Copernicus Next Generation." Thesis, KTH, Rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-286332.

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The Concurrent Design Platform 4 (CDP4®) is a collaborative Model-Based Systems Engineering (MBSE) software tool conceived for architecting complex systems. Nevertheless, there are limitations concerning the manageable number of system options. The upcoming Siemens tool for generative engineering, Simcenter™ Studio, is attempting to overcome this limitation by enabling automatic synthesis and evaluation of architecture variants. The motivation for the Generative Concurrent Design (GCD) project as a collaboration between RHEA, Siemens and OHB is to develop a combined prototype of these two tools. This thesis presents a modelling of Copernicus Next Generation (CNG) space component, using generative capabilities in a typical Phase-0 study. It represents the third step of the bottom-up GCD validation process, intended to investigate how architecting differs among “Sub-system”, “Systems” and “Systems of Systems (SoS)”. Therefore, this work provides an architecting strategy which is generalizable for other SoS use-cases and contributes to assess whether extensions to ECSS-E-TM-10-25 are necessary to successfully support GCD.
Concurrent Design Platform 4 (CDP4®) är ett samarbetsverktyg för modellbaserad systemteknik (MBSE) som utformats för att bygga komplexa system. Dock finns det begränsningar vad gäller det antalet hanterbara systemalternativ. Det kommande Siemens-verktyget för generativ teknik, Simcenter™ Studio, försöker övervinna denna begränsning genom att möjliggöra automatisk syntes och utvärdering av arkitekturvarianter. Motivationen för Generative Concurrent Design (GCD) -projektet som ett samarbete mellan RHEA, Siemens och OHB är att utveckla en kombinerad prototyp av verktygen CDP4® och Simcenter™. Detta examensarbete presenterar en modellering av rymdkomponenten Copernicus Next Generation (CNG) med användning av generativa funktioner i en typisk fas-0-studie. Den representerar det tredje steget i GCD-valideringsprocessen nedifrån och upp, avsedd att undersöka hur arkitekturen skiljer sig åt mellan "Sub-system", "Systems" och "Systems of Systems (SoS)". Detta arbete ger därför en arkitektonisk strategi som är generaliserbar för andra SoS-användningsfall och bidrar till att bedöma om förlängningar till ECSS-E-TM-10-25 är nödvändiga för att framgångsrikt stödja GCD.

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McDonough, Laura. "Receptance Based Control of Aeroelastic Systems for Flutter Suppression." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1355500262.

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39

McCrink, Matthew H. "Development of Flight-Test Performance Estimation Techniques for Small Unmanned Aerial Systems." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1449142886.

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40

Burt, Colin. "Design, Fabrication and Test of an Operationally Responsive Aircraft with NIIRS Evaluated Imager." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1087.

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Unmanned Aerial Systems (UAS) are a growing asset. Currently UAS are on the cutting edge with resources being spent developing the capabilities mostly for military use. This project is intended to create a system for non-defense customers. Specifically, the Operationally Responsive Aircraft (ORA) will appeal to academic institutions, individual consumers, future customers new to the UAS industry, as well as anybody trying to get airtime for custom sensors. The system developed in this project utilizes dual aluminum external payload bays attached to a ParkZone Radian aircraft. Each external payload bay can contain approximately 500 $\text{cm}^3$, with a height and width limit of 4.1 cm and 11.0 cm respectively. The custom sensors must weigh less than or equal to 3.2 lbs combined. The external payload bays were designed to hold an imaging payload which produces a composite map of the land surveyed. The system incorporates an Arduino Uno, SD Shield, as well as a CMOS camera and board. The processor saves individual images to an SD card. Once the aircraft has landed, the operator combines the images with Microsoft Research Image Composite Editor to create the composite map. This imaging payload has a NIIRS value of 4.0 +/- 0.4, which is equivalent to identifying a basketball court within a residential environment.

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Patel, Viren Kishor. "SysML Output Interface and System-Level Requirement Analyzer for the Horizon Simulation Framework." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1834.

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Model-Based Systems Engineering in industry has been constantly increasing its presence within the aerospace industry. SysML is one such MBSE tool that shows complex system organization and relationships. The Horizon Simulation Framework is another MBSE tool, created by Cal Poly students, that gives users the ability to run “day-in-the-life” simulations of systems. Finding a way to link these two tools could allow systems engineers to reap the benefits of both. This thesis investigates the background and design process involved with developing the code that can convert an output file generated in SysML, into a format specifically made for the Horizon Simulation Framework. The goal was to create an interface that can allow users to model a system in SysML, and analyze the model and verify system requirements using HSF. Another goal was to expand the capabilities of the Horizon Simulation Framework by designing and develop a module that would allow users to define and analyze system-level requirements. To evaluate the effectiveness of both codes, the Aeolus example case was used. A SysML model of the system was created as the product of another thesis; SysML based CubeSat Model Design and Integration with the Horizon Simulation Framework. The Aeolus SysML model was converted and used as input in an HSF simulation. The SysML model simulation data was compared against those of the original test case. To test the requirement module, system level requirements were formulated within the Aeolus system and run in simulation, providing an analysis of the results. The results of the analysis confirmed a successful conversion of the SysML model into an equivalent HSF model and a successful analysis of system-level requirements.

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42

Chandavarkar, Rohan Vivek. "Eco-inspired Robust Control Design for Linear Time-Invariant systems with Real Parameter Uncertainty." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1373467190.

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43

Hektor, Oskar. "Review of Present Systems and Costs of Conceptual Designs of UAV:s for Humanitarian Relief Missions." Thesis, KTH, Flygdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240955.

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A study of the viabliness of a UAV for humanitarian relief missions has been done. With an aeronautical model fulﬁlling humanitarian logistics has then the manufacture and operational life-cycle costs as well as the present air jurisdiction. In contrast to this has also an evaluation of the empty weight conceptual estimation equation been reviewed and what conditions fairly describes the sizing of a UAV. The study ﬁnds there’s a technical possibility, economic plausibility but a need for legal development. The coeﬃcients which are suﬃcient to estimate the empty weight ratio are the Home built aircrafts and powered sailplane. The study concludes what present oﬀ-the-shelf systems that might be suitable to sustain humanitarian relief missions.
Syftet med den här studien har varit att undersöka möjligheterna för att använda drönare till att leverera humanitär hjälp. Att ge humanitär hjälp innebär att man assisterar stater i att leverera nödvändiga varor och tjänster till områden där den nationella staten behöver assistans för att upprätthålla nödvändiga livsvillkor för befolkningen. Det kan vara att leverera mat och mediciner men även enklare skolmateriel eller liknande. Oftast är orsaken bakom en humanitär insats att det skett någon typ av katastrof, det kan vara både natur och mänskligt skapade katastrofer. Ett exempel på en sådan nylig kris har varit inbördeskriget som rasat i Syrien under större delen av 2010-talet. Ett problem som har dykt upp är att det är svårt att få fram rätt hjälp dit den behövs, speciellt om de civila som har behovet beﬁnner sig i en krigszon. I ett sådant fall är det mycket riskabelt att transportera och leverera humanitär hjälp till de som behöver det. De riskerar att bli skjutna, kidnappade och kapade. Detta skapar både personliga och materiella skador. Frågan blir då om man skulle kunna leverera den hjälpen med drönare, för att minska risken för personskador men också minska eﬀekten för hela hjälpinsatsen om en eller ﬂera av drönare skulle förvinna. Det som komplicerar hela i logistiken är att man måste ta hänsyn till hur personer byter besittning av godsen och hur man veriﬁerar att varje person får just rätt hjälp. Speciellt då värdet av godset i en kris kan bli asymptotiskt högt. För att testa huruvida det är möjligt att använda UAV:er för humanitär hjälp skapades en simuleringsmodell av en drönare. Eftersom det förväntades att ett uppdrag är ungefär 300 km + 300km tur-o-retur övergavs någon typ av helikopterdesign tidigt. Modellen simulerade många uppdrag som bedömdes vara relevanta för en UAV som skulle leverera humanitär hjälp. Utifrån dessa uppdrag bedömdes några av de operativa kostnader som var knutna till uppdragen. Det gäller främst tillverkningskostnader, bränslekostnader samt avgifter som behöver betalas av den som använder luftrummet. Det ﬁnns en bok som är ﬂygplanskonstruktörens bibel (Aircraft Design). Den är skriven av Daniel P. Raymer. Han föreslår där en formel för hur man konceptuellt kan bestämma vikten av ett nytt ﬂygplan. De beﬁntliga planen jämfördes sedan med formeln för att undersöka om dessa också stämde på drönare. Eftersom drönare inte har piloter ombord innebär det att vissa apparater inte behöver ﬁnnas på det ﬂygplanet, vilket kan tänkas ändra hur mycket en UAV estimeras väga jämfört med ett vanligt plan. Studien kommer fram till att det som Raymer har föreslagit verkar för det mesta vara rättvisande även när man designar UAV:er. Avslutningsvis identiﬁeras tre olika drönare som med mer eller mindre modiﬁering skulle kunna användas för humanitära insatser. Dock är, som nämnt tidigare, de ﬂesta UAV:er utvecklade för olika typer av informationssamling. Då ﬂera av dessa apparater inte är lika nödvändiga i en humanitär-logistisk situation är det sannolikt att inköpspriset skulle vara billigare än annars. Slutsatserna är att det nu är tekniskt möjligt att använda drönare för humanitär hjälp, ekonomiskt är det möjligt om än dyrt men juridiskt är det i dagsläget inte möjligt. Juridiken och reglementet för hur avgiftssystemet och luftrummet fungerar behöver utvecklas för att på ett hållbart och säkert sätt integrera autonoma farkoster med beﬁntlig luftfart. Beroende på hur regleringarna av luftrummet förändras, ändras även de ekonomiska förutsättningarna för att använda drönare för att utföra logistiska uppdrag.

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44

Fabbri, Riccardo. "Conceptualization, design & simulation of a small asteroid probe." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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The Asteroid Impact and Deflection Assessment (AIDA), is an upcoming mission resulting from the collaboration of ESA and NASA and aims at assessing the effects of a kinetic impact on an asteroid for the purpose of threat mitigation. In this framework, this research seeks to prove the feasibility of a small lander design able to autonomously land on the secondary object of the asteroid system Didymos. Initially, an overview of the most suitable guidance laws and sensors is provided. This highlighted that some types of proportional navigation guidance laws and the ZEM/ZEV could be good candidates and are therefore further analyzed in the following chapters. Meanwhile, a set of sensors comprising altimeter, camera, Star-Tracker and accelerometers was considered. To assess the effect of the noise affecting the sensors on the translational dynamics of the probe, the system is linearized and studied. This permitted to highlight that the most relevant disturbances are the ones that affect the determination of the LOS rate, hence the readings of camera and star-tracker. Afterward, the deployment is simulated in the details in a simulator, this permitted to determine that a combination of a modified version of the true proportional navigation and ZEM/ZEV provide a good solution in terms of guidance laws. Unfortunately, because of the lack of details characterizing the asteroid model, it was not possible to realistically simulate the ZEM/ZEV. Therefore, it is suggested as the next step of study to carry out further investigation and to develop a simulator able to reach the depth of details required. Finally, a proposed set-up of sensors is delineated and a Monte-Carlo run analyzing the robustness and reliability of this design for the MTPN is reported. The outcome seems to demonstrate that with a very compact and simple design, the probe is capable to autonomously insert itself in a trajectory leading from the deployment location to the target asteroid.

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45

Ashley, Eric. "A System Architecture for Phased Development of Remote sUAS Operation." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2138.

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Current airspace regulations require the remote pilot-in-command of an unmanned aircraft systems (UAS) to maintain visual line of sight with the vehicle for situational awareness. The future of UAS will not have these constraints as technology improves and regulations are changed. An operational model for the future of UAS is proposed where a remote operator will monitor remote vehicles with the capability to intervene if needed. One challenge facing this future operational concept is the ability for a flight data system to effectively communicate flight status to the remote operator. A system architecture has been developed to facilitate the implementation of such a flight data system. Utilizing the system architecture framework, a Phase I prototype was designed and built for two vehicles in the Autonomous Flight Laboratory (AFL) at Cal Poly. The project will continue to build on the success of Phase I, culminating in a fully functional command and control system for remote UAS operational testing.

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Cheney, Liam Jon. "Development of Safety Standards for CubeSat Propulsion Systems." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1180.

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The CubeSat community has begun to develop and implement propulsion systems. This movement represents a new capability which may satisfy mission needs such as orbital and constellation maintenance, formation flight, de-orbit, and even interplanetary travel. With the freedom and capability granted by propulsion systems, CubeSat providers must accept new responsibilities in proportion to the potential hazards that propulsion systems may present. The Cal Poly CubeSat program publishes and maintains the CubeSat Design Specification (CDS). They wish to help the CubeSat community to safety and responsibly expand its capabilities to include propulsive designs. For this reason, the author embarked on the task of developing a draft of safety standards CubeSat propulsion systems. Wherever possible, the standards are based on existing documents. The author provides an overview of certain concepts in systems safety with respect to the classification of hazards, determination of required fault tolerances, and the use of inhibits to satisfy fault tolerance requirements. The author discusses hazards that could exist during ground operations and through launch with respect to hazardous materials and pressure systems. Most of the standards related to Range Safety are drawn from AFSPCMAN 91-710. Having reviewed a range of hypothetical propulsion system architectures with an engineer from Range Safety at Vandenberg Air Force Base, the author compiled a case study. The author discusses many aspects of orbital safety. The author discusses the risk of collision with the host vehicle and with third party satellites along with the trackability of CubeSats using propulsion systems. Some recommendations are given for working with the Joint Functional Component Command for Space (JFCC SPACE), thanks to the input of two engineers who work with the Joint Space Operations Center (JSpOC). Command Security is discussed as an important aspect of a mission which implements a propulsion system. The author also discusses End-of-Life procedures such as safing and de-orbit operations. The orbital safety standards are intended to promote “good citizenship.” The author steps through each proposed standard and offers justification. The author is confident that these standards will set the stage for a dialogue in the CubeSat community which will lead to the formulation of a reasonable and comprehensive set of standards. The author hopes that the discussions given throughout this document will help CubeSat developers to visualize the path to flight readiness so that they can get started on the right foot.

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47

Fern, Lisa C. "A Cognitive Systems Engineering Approach to Developing Human Machine Interface Requirements for New Technologies." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461248106.

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48

D'Anniballe, Alessandro. "Development of a sizing tool for preliminary mission analysis and design of propulsion systems for orbit control of small satellites in LEO -VLEO." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14719/.

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The ever-growing necessity for faster and cheaper access to space, makes the building of artificial satellites to shift more and more towards small measures. The most exemplar case of small satellites is given by the so called CubeSats, i.e. modular satellites practically ‘built in blocks’ of approximately the same size and weight. Such an approach allows to fasten the design and decrease the overall project complexity, but at the same time has many limitations. The main one is equipping the satellites with a propulsion system for the control of their operative orbit. Such a task normally requires a consistent amount of propellant, and so a specific dedicated propulsion system, that weighs consistently (in terms of both mass and volume) on the budget of these small spacecrafts. The present thesis studies the feasibility of providing small satellites with a propulsion system that would enable them to perform orbit control maneuvers all along the mission duration. The concept is to create a computer tool able to carry out a rapid analysis of the satellite mission, for the determination of the needed Δv, and then a preliminary design of the main components of the required propulsion system. Different propulsion technologies can in this way be considered, being then able to do a trade-off to choose the best solution, in terms of mass and performances. Satellite models ranging from nano to mini-sat standard in LEO-VLEO missions of different durations (2, 5 and 7 years) have been used for feasibility simulations, and re-sults show that the use of some propulsion technology is possible to reach the fixed mission goals.

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Ashworth, Geoffrey (Geoffrey John). "Architectural disruption in aerospace." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55202.

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Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 70-71).
Distinctive technology and customer / supplier relationships are currently the primary sources of competitive advantage in the Aerospace industry. Modular Open System Architecture (MOSA) requirements represent a significant disruption to this mode of competition. The United States Department of Defense intends to accelerate the rate of aerospace innovation and inject additional competitiveness into the procurement process through the modularization of its products and effective intellectual property management. This combination of architectural disruption and new customer capabilities has the potential to reduce the industry's opportunity to capture value from innovative technologies or a position as first supplier. Historical examples such as Polaroid and IBM demonstrate the organizational paralysis that often results from disruptions in product architecture. The competitive formula becomes ingrained in the processes, resources, and culture of mature companies and is no longer explicit knowledge, which limits the company's ability to develop the capabilities required to compete in its new environment. Competing in a MOSA environment will require the development of new organizational capabilities such as rapid experimentation, fighting standards wars, and protecting system-level knowledge. Defining the disruptive threat and the foundations of current core competencies will enable firms to develop the organizational capabilities essential for this shift in competitive context.
(cont.) The author will present several historical examples of architectural disruption, a framework for evaluating the disruptive change, and an identification of organizational anchors that may hinder a particular competitor's ability to respond to MOSA. The goal of the thesis is to start a dialogue within an identified incumbent with in hopes of beginning the organizational transformation required to effectively compete in this new era.
by Geoffrey Ashworth.
S.M.

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Chalker, Jack Randolph. "Design and Manipulation of a Power-Generating System with High-Temperature Fuel Cells for Hypersonic Applications." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1567169603256774.

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Dissertations / Theses on the topic 'Aerospace systems design'

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