322,258 research outputs found

    An Integrated Approach Enabling Cross-Domain Simulation of Model-Based E/E-Architectures

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    The increasing complexity of electric/electronic architectures (EEA) in the automotive domain raised the necessity of model-based development processes for the design of such heterogeneous systems, which combine different engineering principles with different viewpoints. High-level simulation is a great means to evaluate the EEA in the concept phase of the design, since it reduces costly real-world experiments. However, model-based EEA design and analysis as well as its simulation are often separate processes in the development lifecycle. In this paper, we present a novel approach that extends state-of-the-art model-based systems engineering principles of EEA by a behavior specification reusing library components. The specification is seamlessly integrated in the development process of a single source EEA model. Therewith, the starting point is the abstract logical function architecture of the EEA. Based on this single source EEA model we synthesize a unified high-level simulation model, which is capable of linking the behavioral model with lower level implementation details of other domains, e.g. the network communication of the underlying hardware topology. This cross-layer simulation enables an early but holistic system’s behavior analysis of the dynamic changes which typically depend on the scenarios applied. Moreover, the integrated approach enables the potential to feedback the simulation results into suitable EEA metrics and benchmarks for further analysis and optimization as well as the seamless traceability of the behavioral specification to requirements and other abstraction layers. A driver assistance system use case demonstrates the proof-of-concept and the benefits of our methodology

    Axiomatic system design : chemical mechanical polishing machine case study

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (p. 205-209).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Axiomatic design is investigated as a design methodology for large or complex system design. Particular considerations of system design are described and the suitability of axiomatic design for such considerations is discussed. Then, tools to enable successful application of axiomatic design to systems are developed. The tools are expressed as theorems for axiomatic system design. The first theorem describes conditions for equivalence of FRs, and helps define the relationships within a design matrix. The second theorem describes a method of using only leaf levels to represent a system, and re-sequencing the design to achieve a decoupled matrix. Therefore, some types of coupling at high levels may be reduced or eliminated. The third theorem defines the decomposition strategy that is necessary to make axiomatic design compatible with object-oriented simulation models that are created starting with the high levels of the decomposition. The fourth and fifth theorems present a new method for considering and increasing system robustness to external noise factors during the conceptual design phase. While techniques for increasing robustness to external noise factors are known, integrating them into axiomatic design has not been shown previously. A case study of the design of a machine tool system for polishing silicon wafers using chemical mechanical polishing (CMP) is presented. The CMP system architecture is decomposed from top level requirements using the principles of axiomatic design, and the theorems developed in this thesis. The CMP system was designed and fabricated at MIT by a team of students, and has demonstrated excellent capability to remove material from the surface of a wafer while offering increased control of the removal profile.by Jason W. Melvin.Ph.D

    Evaluation of e-learning web sites using fuzzy axiomatic design based approach

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    High quality web site has been generally recognized as a critical enabler to conduct online business. Numerous studies exist in the literature to measure the business performance in relation to web site quality. In this paper, an axiomatic design based approach for fuzzy group decision making is adopted to evaluate the quality of e-learning web sites. Another multi-criteria decision making technique, namely fuzzy TOPSIS, is applied in order to validate the outcome. The methodology proposed in this paper has the advantage of incorporating requirements and enabling reductions in the problem size, as compared to fuzzy TOPSIS. A case study focusing on Turkish e-learning websites is presented, and based on the empirical findings, managerial implications and recommendations for future research are offered

    Mathematical and computer modeling of electro-optic systems using a generic modeling approach

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    The conventional approach to modelling electro-optic sensor systems is to develop separate models for individual systems or classes of system, depending on the detector technology employed in the sensor and the application. However, this ignores commonality in design and in components of these systems. A generic approach is presented for modelling a variety of sensor systems operating in the infrared waveband that also allows systems to be modelled with different levels of detail and at different stages of the product lifecycle. The provision of different model types (parametric and image-flow descriptions) within the generic framework can allow valuable insights to be gained

    Radiation Risks and Mitigation in Electronic Systems

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    Electrical and electronic systems can be disturbed by radiation-induced effects. In some cases, radiation-induced effects are of a low probability and can be ignored; however, radiation effects must be considered when designing systems that have a high mean time to failure requirement, an impact on protection, and/or higher exposure to radiation. High-energy physics power systems suffer from a combination of these effects: a high mean time to failure is required, failure can impact on protection, and the proximity of systems to accelerators increases the likelihood of radiation-induced events. This paper presents the principal radiation-induced effects, and radiation environments typical to high-energy physics. It outlines a procedure for designing and validating radiation-tolerant systems using commercial off-the-shelf components. The paper ends with a worked example of radiation-tolerant power converter controls that are being developed for the Large Hadron Collider and High Luminosity-Large Hadron Collider at CERN.Comment: 19 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

    Development and Validation of Functional Model of a Cruise Control System

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    Modern automobiles can be considered as a collection of many subsystems working with each other to realize safe transportation of the occupants. Innovative technologies that make transportation easier are increasingly incorporated into the automobile in the form of functionalities. These new functionalities in turn increase the complexity of the system framework present and traceability is lost or becomes very tricky in the process. This hugely impacts the development phase of an automobile, in which, the safety and reliability of the automobile design should be ensured. Hence, there is a need to ensure operational safety of the vehicles while adding new functionalities to the vehicle. To address this issue, functional models of such systems are created and analysed. The main purpose of developing a functional model is to improve the traceability and reusability of a system which reduces development time and cost. Operational safety of the system is ensured by analysing the system with respect to random and systematic failures and including safety mechanism to prevent such failures. This paper discusses the development and validation of a functional model of a conventional cruise control system in a passenger vehicle based on the ISO 26262 Road Vehicles - Functional Safety standard. A methodology for creating functional architectures and an architecture of a cruise control system developed using the methodology are presented.Comment: In Proceedings FESCA 2016, arXiv:1603.0837

    KEMNAD: A Knowledge Engineering Methodology for Negotiating Agent Development

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    Automated negotiation is widely applied in various domains. However, the development of such systems is a complex knowledge and software engineering task. So, a methodology there will be helpful. Unfortunately, none of existing methodologies can offer sufficient, detailed support for such system development. To remove this limitation, this paper develops a new methodology made up of: (1) a generic framework (architectural pattern) for the main task, and (2) a library of modular and reusable design pattern (templates) of subtasks. Thus, it is much easier to build a negotiating agent by assembling these standardised components rather than reinventing the wheel each time. Moreover, since these patterns are identified from a wide variety of existing negotiating agents(especially high impact ones), they can also improve the quality of the final systems developed. In addition, our methodology reveals what types of domain knowledge need to be input into the negotiating agents. This in turn provides a basis for developing techniques to acquire the domain knowledge from human users. This is important because negotiation agents act faithfully on the behalf of their human users and thus the relevant domain knowledge must be acquired from the human users. Finally, our methodology is validated with one high impact system
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