| 1. |
- Munjulury, Raghu Chaitanya
(författare)
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Knowledge-Based Integrated Aircraft Design : An Applied Approach from Design to Concept Demonstration
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The design and development of new aircraft are becoming increasingly expensive and timeconsuming. To assist the design process in reducing the development cost, time, and late design changes, the conceptual design needs enhancement using new tools and methods. Integration of several disciplines in the conceptual design as one entity enables to keep the design process intact at every step and obtain a high understanding of the aircraft concepts at early stages.This thesis presents a Knowledge-Based Engineering (KBE) approach and integration of several disciplines in a holistic approach for use in aircraft conceptual design. KBE allows the reuse of obtained aircrafts’ data, information, and knowledge to gain more awareness and a better understanding of the concept under consideration at early stages of design. For this purpose, Knowledge-Based (KB) methodologies are investigated for enhanced geometrical representation and enable variable fidelity tools and Multidisciplinary Design Optimization (MDO). The geometry parameterization techniques are qualitative approaches that produce quantitative results in terms of both robustness and flexibility of the design parameterization. The information/parameters from all tools/disciplines and the design intent of the generated concepts are saved and shared via a central database.The integrated framework facilitates multi-fidelity analysis, combining low-fidelity models with high-fidelity models for a quick estimation, enabling a rapid analysis and enhancing the time for a MDO process. The geometry is further propagated to other disciplines [Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA)] for analysis. This is possible with an automated streamlined process (for CFD, FEM, system simulation) to analyze and increase knowledge early in the design process. Several processes were studied to streamline the geometry for CFD. Two working practices, one for parametric geometry and another for KB geometry are presented for automatic mesh generation.It is observed that analytical methods provide quicker weight estimation of the design and when coupled with KBE provide a better understanding. Integration of 1-D and 3-D models offers the best of both models: faster simulation, and superior geometrical representation. To validate both the framework and concepts generated from the tools, they are implemented in academia in several courses at Linköping University and in industry
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| 2. |
- Jouannet, Christopher, 1974-, et al.
(författare)
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Aerodynamic database of a subscale demonstrator
- 2017
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Ingår i: 35th AIAA Applied Aerodynamics Conference. - Reston, VA, USA : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)abstract
- This paper reports the current status of a joint Swedish-Brazilian research project aiming at exploring sub scale flight testing. A 13% scale fighter aircraft is used as a test bench for developing methods and procedures for data acquisition. This paper will present an aerodynamic database as a partial result of the collaborative project.
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| 3. |
- Jouannet, Christopher, et al.
(författare)
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Design and Flight Testing of a Solar Powered Aircraft, a Student Challenge
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The presented work considers designing, building and flight testing a solar poweraircraft as a student project. The goal is to allow student to participate in an aircraft projectfrom design to flight test in order to acquire aircraft design knowledge from theoretical andpractical means. A first theoretical part consists of creating a sizing program for studyingdifferent concepts. Then the gathered knowledge will result in the realization of a flyingdemonstrator. This was realized during a student project over a 5 month period
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| 4. |
- Knöös Franzén, Ludvig, 1990-, et al.
(författare)
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A Breakdown of System of Systems Needs Using Architecture Frameworks, Ontologies and Description Logic Reasoning
- 2021
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Ingår i: Aerospace. - : MDPI. - 2226-4310. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Aerospace systems are connected with the operational environment and other systems in general. The focus in aerospace product development is consequently shifting from a singular system perspective to a System-of-Systems (SoS) perspective. This increasing complexity gives rise to new levels of uncertainty that must be understood and managed to produce aerospace solutions for an ever-changing future. This paper presents an approach to using architecture frameworks, and ontologies with description logic reasoning capabilities, to break down SoS needs into required capabilities and functions. The intention of this approach is to provide a consistent way of obtaining the functions to be realized in order to meet the overarching capabilities and needs of an SoS. The breakdown with an architecture framework results in an initial design space representation of functions to be performed. The captured knowledge is then represented in an ontology with description logic reasoning capabilities, which provides a more flexible way to expand and process the initial design space representation obtained from the architecture framework. The proposed approach is ultimately tested in a search and rescue case study, partly based on the operations of the Swedish Maritime Administration. The results show that it is possible to break down SoS needs in a consistent way and that ontology with description logic reasoning can be used to process the captured knowledge to both expand and reduce an available design space representation.
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| 5. |
- Knöös Franzén, Ludvig, 1990-, et al.
(författare)
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A System of Systems Approach for Search and Rescue Missions
- 2020
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Konferensbidrag (refereegranskat)abstract
- System-of-Systems Engineering (SoSE) has become a constantly growing field within product development for complex systems. Systems are becoming more and more connected with other systems and the operational environment in general. This takes the development process to new levels of complexity where high degrees of uncertainties are expected due to ever occurring changes in the operational environment, and other external factors such as politics, economy, and technology. This creates a need of being able to understand the influence of changes early in the development process and to facilitate the systems? perseverance. The focus of the development shifts from fulfilling specific requirements, to being able to meet needs and deliver capabilities over time. Additionally, modeling and simulation for complex systems and System-of-Systems (SoS) becomes a valued alternative to the economically prohibited and almost impossible prototype testing. In consideration of this problem, the presented work introduces a method for both modeling and simulation of a SoS. The method uses ontology with description logic reasoning to derive and narrow down a SoS design space which is further analyzed using Agent Based Simulation (ABS). A Search and Rescue (SAR) scenario is used as a case study to test the method. Measures of Effectiveness (MoE), based on the time it takes to find a rescue subject and the cost of doing so, are used to evaluate the SoS performances. The presented method is envisioned to be used early in the development of complex systems and SoS to increase the overall understanding of them.
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| 6. |
- Knöös Franzén, Ludvig, 1990-
(författare)
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A System of Systems View in Early Product Development : An Ontology-Based Approach
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The concept of system-of-systems is becoming increasingly common and relevant in many engineering applications. Today’s highly interconnected world entails that more and more systems have dependencies on other systems. This increasing number of interdependencies results in new levels of complexity that must be managed in the early development of new products. Different viewpoints must also be handled to understand the many layers of a system-of-systems and its surrounding context. An ever-changing future results in uncertainty about the operational environment but also other aspects, such as available technologies, which complicates the matter even further. Traditional approaches for early product development can be used to some extent, but the complexity, scale and sheer number of interconnections in system-of-systems require a holistic perspective to obtain an early understanding of the problem, design spaces, and multiple aspects involved. This dissertation aims to present a method that has been developed to address the demand for a more holistic system-of-systems view in early product development. Overall, the method consists of four parts that together show how design spaces for system-of-systems can be generated and later processed to find suitable solutions. Search and rescue operations have been used as examples of system-of-systems throughout this work and in the development of the presented method. The first two parts of the method are based on architecture frameworks and ontologies with description logic reasoning capabilities. An architecture framework is here used to break down system-of-system needs into functions to be fulfilled by constituent systems. Ontologies are thereafter used to represent the outcome and the resulting system-of-system design spaces with involved entities and their relationships. Description logic reasoning can subsequently be used to process the available design spaces and suggest suitable system-of-system solutions. The last two parts of the method build upon a concept exploration and estimation approach, together with visual analytics. The approach illustrates how individual system concepts can be estimated from an ontology-represented design space, and how visual analytics can be used to explore different system-of-system viewpoints at an early stage. Based on the outcomes of the presented method, this dissertation contributes a holistic take on early product development from a system-of-systems perspective.
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| 7. |
- Knöös Franzén, Ludvig, 1990-
(författare)
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An Ontological and Reasoning Approach to System of Systems
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- System-of-Systems (SoS) are all around us and are becoming more common in today’s highly interconnected world. Systems are connected with other systems and have strong dependencies with their operational environments. This leads to an increased level of complexity and risk during product development. A holistic view, and an SoS perspective, is consequently needed in order to develop an early understanding of the available design spaces for new system solutions. This thesis suggests a method that has been developed for this purpose, and to meet the demand for a more holistic product development. Overall, the method consists of two correlated approaches that show how a design space for SoSs can be generated and later processed with, for example, design space reductions. Search and Rescue (SAR) operations have been used as examples of typical SoSs throughout this work and in the development of the presented method. An architecture framework has been used to introduce a standardized and consistent way of understanding the relationships that exist between needs, capabilities and functions. This approach can consequently be used to generate a design space of functions to be performed to meet the overarching needs of an SoS. The second approach has been based on ontology and description logic reasoning. Ontology has here been used to represent an SoS design space with, for example, available SAR assets and their relationships with the operational environment. An SoS representation in an ontology model introduces additional expressiveness and the design space processing capabilities needed for a holistic design process and product development. Based on these results, this thesis and its suggested method and approaches contribute to holistic product development from an SoS perspective.
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| 8. |
- Knöös Franzén, Ludvig, 1990-, et al.
(författare)
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An Ontological Approach to System of Systems Engineering in Product Development
- 2019
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Ingår i: Linköping Electronic Conference Proceedings 162 (2019). - Linköping : Linköping University Electronic Press. - 9789175190068 ; , s. 35-44
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Konferensbidrag (refereegranskat)abstract
- This paper presents an approach to system-of-systems engineering for product development with the use of ontology. A proposed method for building as well as using ontology to generate and explore system-of-systems design spaces based on identified system-of-system needs is presented. The method is largely built to cover the first levels of related work, where a process for system of systems in the context of product development is introduced. Within this work, it is shown that scenarios for a system-of-systems can be used to identify needs and subsequently the system-of-systems capabilities that fulfils them. The allocation of capabilities to possible constituent systems is used to show the available design space. The proposed method of this paper therefore addresses these initial challenges and provides a framework for approaching the system-of-systems design space creation using ontology. A case study is used to test the method on a fictitious search and rescue scenario based on available resources and information from the Swedish Maritime Administration. The case study shows that a representation of a system-of-systems scenario can be created in an ontology using the method. The ontology provides a representation of the involved entities from the fictitious scenario and their existing relationships. Defined ontology classes containing conditions are used to represent the identified needs for the system-of-systems. The invocation of a description logic reasoner is subsequently used to classify and create an inferred ontology where the available system-of-systems solutions are represented as sub-classes and individuals of the defined classes representing the needs. Finally, several classes representing different possible system-of-systems needs are used to explore the available design space and to identify the most persistent solutions of the case study.
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| 9. |
- Knöös Franzén, Ludvig, 1990-, et al.
(författare)
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Ontology-Represented Design Space Processing
- 2021
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Ingår i: AIAA AVIATION 2021 Forum, August 2-6, 2021, VIRTUAL EVENT. - USA : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)abstract
- This paper presents a method for generating a design space intended for aircraft design with the use of ontologies. Aircraft design, seen from a System-of-Systems (SoS) perspective, gives an idea of the complicated relationships and complexities that need to be managed and understood to develop suitable systems for an ever-changing future. Holistic SoS analyzes are used to investigate customer and stakeholder needs that then can be broken down into capabilities and subsequently functions to be performed by involved Constituent Systems (CS), sub-systems and system elements. Ontologies with description logic reasoning capabilities are then used to represent the outcome of the breakdown. An ontology development and integration process can afterwards be used to merge different ontologies together and by that map the derived functions to means that can implement them. This results in an available SoS design space that can be further processed using a description logic reasoner. The outcome of the proposed method is a reduced available design space of functions to be performed and their respective design alternatives. Search and Rescue (SAR) operations based on the Swedish Maritime Administration (SMA) are used as a case study to test the proposed method and to illustrate how it can be utilized. At the end, a design space of alternatives for a new type of search aircraft is generated with ontology and description logic reasoning.
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| 10. |
- Lundström, David, et al.
(författare)
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Subscale Flight Testing of a Generic Fighter Aircraft
- 2016
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Ingår i: Proceedings of the 30th Congress of the International Council of the Aeronautical Sciences (ICAS). - Bohn : International Council of the Aeronautical Sciences. - 9783932182853
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Konferensbidrag (refereegranskat)abstract
- Recent technological advances in mechatronics enhance the possibilities of utilizing subscale flight testing as a tool in the development of aircraft. This paper reports the current status of a joint Swedish-Brazilian research project aiming at exploring these possibilities. A 13\% scale fighter aircraft is used as a test bench for developing methods and procedures for data acquisition. The aircraft is equipped with an instrumentation system assembled from off the shelf components as well as open source hardware and software.
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