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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Active Interaction Complexity  in Systems Engineering / Aktiv Interaktionskomplexitet inom Systemteknik

Haribabu, Aravind Saravanan January 2019 (has links)
The master's thesis describes how complexity measurement can enhance product development or design processes in collaboration with Scania CV AB. Scania has a strong track record in vehicle modularization and thus wanted to investigate the possibility of using complexity measures when architecting, developing, and maintaining complex engineering products such as electrified or self-driving trucks and buses to gain various types of benefits. The section YMPI at Scania, where the project is conducted, had, however, little experience in complexity measurements wants to identify and investigate which complexity measure effectively captures the complexity of a complex system. A fairly complicated industrial case of a conceptual Battery Electric Vehicle (BEV) variant was utilized to demonstrate the newly proposed complexity metric methodology and demonstrate its ability to determine the technical complexity of a system. As a result, the thesis author found a specific case study at Scania and used appropriate methodologies to determine the complexity of the chosen subsystem using the newly proposed complexity measure. This was done by adapting the DSM (Design Structure Matrix) before clustering it with the IGTA++ clustering algorithm. The proposed complexity metric yields a higher complexity number when compared to the traditional product complexity metric.  Another purpose of the thesis was to answer the research questions and conduct a literature review in the field of Model Based System Engineering and product architecting to define the state-of-the-art. The thesis concludes that the newly proposed complexity metric, when implemented on the chosen subsystem, yields a higher complexity number when compared to the number obtained from product complexity, implying that including the directions of an interaction between the components and taking into account the active interacting components improves the accuracy of the complexity measure.  Therefore, it is recommended to Scania to use this proposed method to find the complexity of the system and to compare how the system gets complex when incorporating new technologies or modifying the system or product architecture, as well as to utilize this as a safety and a performance factor for a system. / I examensarbetet beskrivs hur komplexitetsmätning kan förbättra produktutvecklings- eller designprocesser i samarbete med Scania CV AB. Scania har en stark erfarenhet av fordonsmodularisering och önskade därför undersöka möjligheten att använda komplexitetsmått för arkitektur, utveckling och underhåll av komplexa tekniska produkter som elektrifierade eller självkörande lastbilar och bussar för att få olika typer av fördelar. Sektionen YMPI på Scania, där projektet genomförs, hade dock lite erfarenhet av komplexitetsmått och sökte identifiera och undersöka vilket komplexitetsmått som effektivt fångar komplexiteten hos ett komplext system. Ett ganska komplicerat industriellt fall av en konceptuell variant av ett elektriskt batterifordon (BEV) användes för att demonstrera den nyligen föreslagna metoden för komplexitetsmätning och för att visa dess förmåga att fastställa ett systems tekniska komplexitet. Som ett resultat av detta hittade avhandlingsförfattaren en specifik fallstudie hos Scania och använde lämpliga metoder för att bestämma komplexiteten hos det valda delsystemet med hjälp av det nyligen föreslagna komplexitetsmåttet. Detta gjordes genom att anpassa DSM (Design Structure Matrix) innan den klustrades med klusteralgoritmen IGTA++. Det föreslagna komplexitetsmåttet ger ett högre komplexitetstal jämfört med det traditionella produktkomplexitetsmåttet.  Ett annat syfte med avhandlingen var att besvara forskningsfrågorna och genomföra en litteraturstudie inom området modellbaserad systemteknik och produktarkitektur för att definiera den senaste tekniken. I avhandlingen dras slutsatsen att det nyligen föreslagna komplexitetsmåttet, när det tillämpas på det valda delsystemet, ger ett högre komplexitetstal jämfört med det tal som erhålls från produktkomplexitet, vilket innebär att om man inkluderar riktningarna för en interaktion mellan komponenterna och tar hänsyn till de aktiva interagerande komponenterna förbättras komplexitetsmåttets noggrannhet.  Därför rekommenderas Scania att använda den föreslagna metod för att fastställa systemets komplexitet och jämföra hur systemet blir mer komplext när ny teknik införlivas eller när system- eller produktarkitekturen ändras, samt att använda detta som en säkerhets- och prestandafaktor för ett system.
12

Architecting aircraft power distribution systems via redundancy allocation

Campbell, Angela Mari 12 January 2015 (has links)
Recently, the environmental impact of aircraft and rising fuel prices have become an increasing concern in the aviation industry. To address these problems, organizations such as NASA have set demanding goals for reducing aircraft emissions, fuel burn, and noise. In an effort to reach the goals, a movement toward more-electric aircraft and electric propulsion has emerged. With this movement, the number of critical electrical loads on an aircraft is increasing causing power system reliability to be a point of concern. Currently, power system reliability is maintained through the use of back-up power supplies such as batteries and ram-air-turbines (RATs). However, the increasing power requirements for critical loads will quickly outgrow the capacity of the emergency devices. Therefore, reliability needs to be addressed when designing the primary power distribution system. Power system reliability is a function of component reliability and redundancy. Component reliability is often not determined until detailed component design has occurred; however, the amount of redundancy in the system is often set during the system architecting phase. In order to meet the capacity and reliability requirements of future power distribution systems, a method for redundancy allocation during the system architecting phase is needed. This thesis presents an aircraft power system design methodology that is based upon the engineering decision process. The methodology provides a redundancy allocation strategy and quantitative trade-off environment to compare architecture and technology combinations based upon system capacity, weight, and reliability criteria. The methodology is demonstrated by architecting the power distribution system of an aircraft using turboelectric propulsion. The first step in the process is determining the design criteria which includes a 40 MW capacity requirement, a 20 MW capacity requirement for the an engine-out scenario, and a maximum catastrophic failure rate of one failure per billion flight hours. The next step is determining gaps between the performance of current power distribution systems and the requirements of the turboelectric system. A baseline architecture is analyzed by sizing the system using the turboelectric system power requirements and by calculating reliability using a stochastic flow network. To overcome the deficiencies discovered, new technologies and architectures are considered. Global optimization methods are used to find technology and architecture combinations that meet the system objectives and requirements. Lastly, a dynamic modeling environment is constructed to study the performance and stability of the candidate architectures. The combination of the optimization process and dynamic modeling facilitates the selection of a power system architecture that meets the system requirements and objectives.
13

A process for function based architecture definition and modeling

Armstrong, Michael James 01 April 2008 (has links)
Developments in electric technologies have the potential to increase the efficiency and performance of commercial aircraft. However, without proper architecture innovation, technology developments at the subsystem level are not sufficient to ensure successful integration. Adaptations to existing architectures work well when trades are made strictly between equivalent systems which fulfill and induce the same functional requirements. However, this approach does not provide the architect with adequate flexibility to integrate technologies with differing functional and physical interfaces. Architecture redefinition is required for proper implementation of non-traditional and innovative architectural elements. A function-based process for innovative architecture design was developed to provide flexibility in the definition of candidate architectural concepts. Tools and methods were developed which facilitate the definition and exploration of a function-based architectural design space. These include functional decomposition, functional induction, dynamic morphology, adaptive functional mapping, reconfigurable mission definition, and concept level system installation. The Architecture Design Environment (ADEN) was built to integrate these tools and to facilitate the definition of physics-based models in evaluating the performance of candidate architectures. Using functions as the foundation of this process assists in mitigating assumptions which traditionally govern architecture structures and offers a promising approach to architecting through flexible conceptualization and integration. This toolset provides the framework wherein knowledge from conceptual, preliminary, and detailed design efforts can be linked in the definition of revolutionary architectures.
14

Autonomie et reconfiguration des systèmes de systèmes tactiques / Autonomy and reconfiguration of tactical systems of systems

Ludwig, Marie 24 October 2013 (has links)
La complexité croissante des Systèmes de Systèmes et autres grandes fédérations d’acteurs pose de nouvelles problématiques de conception et de réalisation. Cette complexité, induite par des structures de management toujours plus sophistiquées et un cycle de vie long, doit être maîtrisée au plus tôt dans la conception des entreprises. Cette maîtrise permet à l’ensemble des intervenants au cours du cycle de vie d’une entreprise d’identifier ses points clés et de prendre confiance en sa capacité à atteindre ses objectifs. En particulier, il importe de savoir estimer les capacités de l’entreprise à s’adapter à des situations imprévues ou exceptionnelles afin d’assurer ses missions en toutes circonstances. En réaction, de nouvelles démarches d’ingénierie émergent. Elles s’appuient sur la modélisation et la simulation de l’architecture de ces systèmes aux différents stades de leur développement et de leur fonctionnement. Dans le cadre d’une de ces démarches nommée IDEA, nous avons enrichi le langage de description d’architecture avec des concepts et des mécanismes ayant pour but d’adresser l’adaptabilité et des capacités de reconfiguration des entreprises. Ces apports ont été expérimentés avec succès par prototypage et dans des contextes d’affaires industrielles. / As the complexity of large civilian and military Systems of Systems and system federations increases, new system architecture and engineering challenge emerge. This complexity is mainly due to intricate management structures and a long lifecycle, and needs to be mastered from the early stages of architecting. All engineering stakeholders need to identify the key aspects of the enterprise and gain confidence in its ability to fulfill its missions. To ensure that the enterprise is able to satisfy its objectives despite evolving situations, there is a need to focus on its capability to adapt through reconfiguration. New engineering approaches emphasize architecture modelling and simulation to tackle the complexity of the enterprise in all stages of its lifecycle in a flexible and global way. In the context of such an approach named IDEA, we updated the architecture description language to include concepts and mechanisms dedicated to the adaptability and reconfiguration of the enterprise. We also focused on ensuring model consistency. The results were experimented through prototyping and application on industrial affairs.
15

Development of a lumped parameter model of an aerospace pump for condition monitoring purposes

Mkadara, Geneviève, Maré, Jean-Charles 25 June 2020 (has links)
This paper presents the development of a helicopter axial piston pump model with condition monitoring in mind. Industrial constraints and needs ask for modelling with a lumped-parameter approach and require model architecture to be addressed with care. The aim of the proposed model is to assess the merits of pump leakage monitoring through measurement of case pressure. Once reviewed the state of the art in pump modelling, the slipper/swashplate interface is taken as an example to propose and implement in Simcenter AMESim a variable gap height model. The simulation results show that commonly used lumped-parameter models overestimate leakage. It also points out that average leakage at slipper may reverse at high pump displacement.
16

PLANT LEVEL IIOT BASED ENERGY MANAGEMENT FRAMEWORK

Liya Elizabeth Koshy (14700307) 31 May 2023 (has links)
<p><strong>The Energy Monitoring Framework</strong>, designed and developed by IAC, IUPUI, aims to provide a cloud-based solution that combines business analytics with sensors for real-time energy management at the plant level using wireless sensor network technology.</p> <p>The project provides a platform where users can analyze the functioning of a plant using sensor data. The data would also help users to explore the energy usage trends and identify any energy leaks due to malfunctions or other environmental factors in their plant. Additionally, the users could check the machinery status in their plant and have the capability to control the equipment remotely.</p> <p>The main objectives of the project include the following:</p> <ul> <li>Set up a wireless network using sensors and smart implants with a base station/ controller.</li> <li>Deploy and connect the smart implants and sensors with the equipment in the plant that needs to be analyzed or controlled to improve their energy efficiency.</li> <li>Set up a generalized interface to collect and process the sensor data values and store the data in a database.</li> <li>Design and develop a generic database compatible with various companies irrespective of the type and size.</li> <li> Design and develop a web application with a generalized structure. Hence the database can be deployed at multiple companies with minimum customization. The web app should provide the users with a platform to interact with the data to analyze the sensor data and initiate commands to control the equipment.</li> </ul> <p>The General Structure of the project constitutes the following components:</p> <ul> <li>A wireless sensor network with a base station.</li> <li>An Edge PC, that interfaces with the sensor network to collect the sensor data and sends it out to the cloud server. The system also interfaces with the sensor network to send out command signals to control the switches/ actuators.</li> <li>A cloud that hosts a database and an API to collect and store information.</li> <li>A web application hosted in the cloud to provide an interactive platform for users to analyze the data.</li> </ul> <p>The project was demonstrated in:</p> <ul> <li>Lecture Hall (https://iac-lecture-hall.engr.iupui.edu/LectureHallFlask/).</li> <li>Test Bed (https://iac-testbed.engr.iupui.edu/testbedflask/).</li> <li>A company in Indiana.</li> </ul> <p>The above examples used sensors such as current sensors, temperature sensors, carbon dioxide sensors, and pressure sensors to set up the sensor network. The equipment was controlled using compactable switch nodes with the chosen sensor network protocol. The energy consumption details of each piece of equipment were measured over a few days. The data was validated, and the system worked as expected and helped the user to monitor, analyze and control the connected equipment remotely.</p> <p><br></p>

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