1,622 research outputs found
Space systems conceptual design: Analysis methods for engineering-team support
No full textThe research can be placed in the framework of designing methods for complex systems focused on the conceptual design phase of the systems’ life-cycle. More specifically, the methods presented in the dissertation belong to the category of Operational Research methods. They aim at the creation of design and analysis tools in support of the engineering team during conceptual design activities. Even though the proposed methods are referred to space-systems applications throughout the dissertation, they are easily extendable also to other engineering applications. This aspect makes the research of great theoretical and practical interest also outside the aerospace industry. A powerful methodology was developed that is typical of more specialist applications (for more detailed design phases) and that is flexible and fast to execute at the same time as required for a conceptual design phase of a complex system.Space Engineering - Astrodynamics and Space MissionsAerospace Engineerin
Tra letteratura e arti figurative: dal Dolce al Ridolfi
No full textVerifica le intersezioni fra tradizione letteraria e arti figurative sulla scorta dei trattati del Dolce e del Ridolfi
Orthogonal-Array based Design Methodology for Complex, Coupled Space Systems
No full textThe process of designing a complex system, formed by many elements and sub-elements interacting between each other, is usually completed at a system level and in the preliminary phases in two major steps: design-space exploration and optimization. In a classical approach, especially in a company environment, the two steps are usually performed together, by experts of the field inferring on major phenomena, making assumptions and doing some trial-and-error runs on the available mathematical models. To support designers and decision makers during the design phases of this kind of complex systems, and to enable early discovery of emergent behaviours arising from interactions between the various elements being designed, the authors implemented a parametric methodology for the design-space exploration and optimization. The parametric technique is based on the utilization of a particular type of matrix design of experiments, the orthogonal arrays. Through successive design iterations with orthogonal arrays, the optimal solution is reached with a reduced effort if compared to more computationally-intense techniques, providing sensitivity and robustness information. The paper describes the design methodology in detail providing an application example that is the design of a human mission to support a lunar base
From my vast repertoire: Guido Altarelli's legacy
No full textWe discuss spin physics, Guido Altarelli's contribution to it, and what we still have to learn. We set out in particular a programme for incorporating constraints from semi-inclusive data into global fits of polarized PDFs, and discuss the need for the EIC to increase the precision and kinematic coverage of current measurements
Complex-systems design methodology for systems-engineering collaborative environment
No full textIn the last decades man-made systems have gained in overall complexity and have become more articulated than before. From an engineering point of view, a complex system may be defined as one in which there are multiple interactions between many different elements of the system and many different disciplines concurring to its definition. However, the complexity seen from the system perspective is only partial. In more general terms complexity does not only regard the system per se, but it is also related to the whole life-cycle management of the system. This encompasses all the activities needed to support the program development from the requirements definition to the verification, validation and operation of the system in the presence of a large number of different stakeholders. These two interrelated views of complexity, being bottom-up in the first case and top-down in the second, both converge to the system defined as an entity formed by a set of interdependent functions and elements that complete one or more functions defined by requirements and specifications. Systems Engineering processes have been increasingly adopted and implemented by enterprise environments to face this increased complexity. The purpose is to pursue time and cost reduction by a parallelization of processes and activities, while at the same time maintaining high-quality standards. From the life-cycle management point of view the tendency has been to rely more and more on software tools to formally applying modelling techniques in support of all the activities involved in the system life-cycle from the beginning to the end. The transition from document-centric to model-centric systems engineering allows for an efficient management of the information flow across space and time by delivering the right information, in the right place, at the right time, and to the right people working in geographically-distributed multi-disciplinary teams. This standardized implementation of model-centric systems engineering, using virtual systems modelling standards, is usually called Model Based Systems Engineering, MBSE. On the other side, looking at the problem from the perspective of the system as a product, the management of complexity is also experiencing a radical modification. The former adopted approach of sequentially designing with separate discipline activities is now being replaced by a more integrated approach. In the Aerospace-Engineering domain, for instance, designing with highly integrated mathematical models has become the norm. Already from the preliminary design of a new system all its elements and the disciplines involved over the entire life-cycle are taken into account, with the objective of reducing risks and costs, and possibly optimizing the performance. When the right people all work as a team in a multi-disciplinary collaborative environment, the MBSE and the Concurrent Engineering finally converge to the definition of the system. The main concern of the engineering activities involved in system design is to predict the behavior of the physical phenomena typical of the system of interest. The development and utilization of mathematical models able to reproduce the future behavior of the system based on inputs, boundary conditions and constraints, is of paramount importance for these design activities. The basic idea is that before those decisions that are hard to undo are made, the alternatives should be carefully assessed and discussed. Despite the favorable environment created by MBSE and Concurrent Engineering for the discipline experts to work, discuss and share knowledge, a certain lack of engineering-tool interoperability and standardized design methodologies has been so far a significant inhibitor, (International Council on Systems Engineering [INCOSE], 2007). The systems mathematical models usually implemented in the collaborative environments provide exceptional engineering-data exchange between experts, but often lack in providing structured and common design approaches involving all the disciplines at the same time. In most of the cases the various stakeholders have full authority on design issues belonging to their inherent domain only. The interfaces are usually determined by the experts and manually fed to the integrated models. We believe that the enormous effort made to conceive, implement, and operate MBSE and Concurrent Engineering could be consolidated and brought to a more fundamental level, if also the more common design analytical methods and tools could be concurrently exploited. Design-space exploration and optimization, uncertainty and sensitivity analysis, and trade off analysis are certainly design activities that are common to all the disciplines, consistently implemented for design purposes at the discipline-domain level. Bringing fundamental analysis techniques from the discipline-domain level to the system-domain level, to exploit interactions and synergies and to enable an efficient trade-off management is the central topic discussed in this chapter. The methodologies presented in this chapter are designed for their implementation in collaborative environments to support the engineering team and the decision-makers in the activity of exploring the design space of complex-system, typically long-running, models. In Section 2 some basic definitions, terminology, and design settings of the class of problems of interest are discussed. In Section 3 a test case of an Earth-observation satellite mission is introduced. This satellite mission is used throughout the chapter to show the implementation of the methods step by step. Sampling the design space is the first design activity discussed in Section 4. Then in Section 5 and Section 6 a general approach to compute sensitivity and to support the engineering team and decision makers with standard visualization tools are discussed. In Section 7 we provide an overview on the utilization of a unified sampling method for uncertainty and robustness analysis. Finally, we conclude the chapter providing some recommendations and additional thoughts in Section
A System Engineering Tool for the Design of Satellite Subsystems
No full textThe conceptual design of a satellite system is a very challenging and crucial engineering problem. The authors have investigated empirical and analogy models for the conceptual design of the subsystems of a satellite developing a multidisciplinary design process that has been implemented into a software SEM, acronym for System Engineering Module. Module because SEM will be incorporated in a more general astrodynamics software developed by ESA; the name of this software is STA, Space Trajectory Analysis. SEM enhances the quality of the design by guiding and advising the user through the process. This paper discusses the fundamental aspects related to the multidisciplinary design process and to the software developed to implement it. The input/output classification and the identified information flow among the subsystems' models pave the way for further development in the direction of automated optimization techniques that could easily be implemented in SE
SYSTEM OF SYSTEMS ANALYSIS OF LOW-COST SMALL-SATELLITES SOLUTIONS FOR END-USER ORIENTED SPACE-BASED SERVICES
No full textThe low-cost exploitation of space has experienced an increasing trend of interest from the scientific community in the last decade. The will of providing reliable space-based services at lower cost dictates for brand-new approaches to space activities, driven by the assessment of different design alternatives to focus the interest on most promising architectures. Objective of the present research is to study the impact of a low-cost non-commercial constellation of small satellites and ground stations in a System of Systems (SoS) scenario. The idea is to integrate the constellation as a complementary distributed system in existing space SoS, exploiting emergent behaviours of this interaction. The interoperability of existing ground and space assets, together with the shift from a product-oriented design to a service-oriented one, addresses the SoS as an end-user oriented architecture. A set of solutions based on the users' requirements and priorities have been evaluated and potential additional services identified. Preliminary analyses focused on how the existing space and ground architectures for science, Earth observation, navigation, and commercial GSM communication could be used as a SoS in support of the identified purpose, and to what extent a low-cost constellation could integrate more expensive payloads already in orbit have been done. Amongst the innovative aspects of the proposed research it is worth mentioning the innovative approach to space SoS evaluation in early stage of design. As an example of the methodology, the development of a new use of GNSS for low-cost atmospheric observation has been assumed as case study, and the implementation of the related technology proposed for the development of a remote sensing nano-satellite constellation
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