7,927 research outputs found

    A Conceptual Framework for Analysis of System Safety Interoperability of United States Navy\u27s Combat Systems

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    Today\u27s political and military reality requires the optimal use of our legacy systems. The objective is to maximize the effectiveness of our operations by efficient allocation, placement and the use of our forces and war-fighting systems. The synergism drawn from the capabilities of the legacy complex systems enables today\u27s war-fighting needs to be met without substantial increase in cost or resources. This synergism can be realized by the effective integration and interoperation of legacy systems into a larger, more complex system of systems. However, the independently developed legacy systems in this new tactical environment often have different data types, languages, data modeling, operating systems, etc. These differences are impediments to the requirement for interoperability, and can create an environment of confusion, misinformation and certainly un-interoperability, hence hinder the safe interoperation of the metasystem and potentially increase the risk for mishaps. Safe interoperability capability assures that the mission objectives are achieved not only effectively but also safely. The System Safety Interoperability Framework (SSIF) introduced in this dissertation provides the framework for the engineering community to evaluate, from system safety perspective, the interoperability issues between multiple complex systems in the U.S. Navy\u27s system of systems context. SSIF characterization attributes are System of Systems (SoS) tactical environment, SoS Engineering, SoS Safety Engineering, and Safety Critical Data. SSIF is applied to AEGIS Ballistic Missile Defense 3.0 Program to explore and analyze the safety interoperability issues in the overall system, by which the SSIF is further validated as an effective approach in analyzing the safe interoperability capability in Navy\u27s combat systems

    Unmanned Aerial Systems Research, Development, Education and Training at Embry-Riddle Aeronautical University

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    With technological breakthroughs in miniaturized aircraft-related components, including but not limited to communications, computer systems and sensors and, state-of-the-art unmanned aerial systems (UAS) have become a reality. This fast growing industry is anticipating and responding to a myriad of societal applications that will provide either new or more cost effective solutions that previous technologies could not, or will replace activities that involved humans in flight with associated risks. Embry-Riddle Aeronautical University has a long history of aviation related research and education, and is heavily engaged in UAS activities. This document provides a summary of these activities. The document is divided into two parts. The first part provides a brief summary of each of the various activities while the second part lists the faculty associated with those activities. Within the first part of this document we have separated the UAS activities into two broad areas: Engineering and Applications. Each of these broad areas is then further broken down into six sub-areas, which are listed in the Table of Contents. The second part lists the faculty, sorted by campus (Daytona Beach---D, Prescott---P and Worldwide--W) associated with the UAS activities. The UAS activities and the corresponding faculty are cross-referenced. We have chosen to provide very short summaries of the UAS activities rather than lengthy descriptions. Should more information be desired, please contact me directly or alternatively visit our research web pages (http://research.erau.edu) and contact the appropriate faculty member directly

    Nonlinear attitude control design and verification for a safe flight of a small-scale unmanned helicopter

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    Autonomous small unmanned helicopter systems have been widely studied in the last decades. These systems are extremely agile due to their energy efficiency, overall costs and high levels of maneuverability compared to manned helicopters. This allows them to be used in urban environments for different applications such as search and rescue, aerial stunts for movie industry, fire fighting, surveillance, etc. Such applications require the control system to be robust and safe since a fault may lead to environmental damage and endangering human life. For reasons of the very high safety requirements, in this paper we propose a robust control design and also introduce formal verification of control for small-scale unmanned helicopters. The controller proposed is based on dynamic inversion control for a 3-DOF (degree-of-freedom) attitude dynamics while taking into account the system modelling uncertainty with variable payloads and external disturbances of wind. An invariant set called control-enabled-set is defined for flight envelope, which represents the dynamical state vectors comprised of the attitude and rotation rates, for which the stable control of the craft is feasible with our control scheme. Then the controller is verified using formal methods represented by MetiTarski automated theorem prover to ensure controller stability and robustness. Our approach also paves the way to the possibility that the autopilot system monitors whether it is getting near the boundary of its flight envelope, in which case it can propose or plan and execute an emergency landing to a safe location

    A systems approach to reducing utility billing errors

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    Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; in conjunction with the Leaders for Global Operations Program at MIT, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 63-64).Many methods for analyzing the possibility of errors are practiced by organizations who are concerned about safety and error prevention. However, in situations where the error occurrence is random and difficult to track, the rate of errors at a particular instant in time is not a practical metric of hazardous conditions (or whether a system may be vulnerable to errors). Qualitative indicators (such as stress levels) that are easier to observe, but difficult to measure, may be linked to the dynamic behavior of quantitative indicators that are easier to measure using System Dynamics models. In this work, we propose a method to find an appropriate metric for error analysis, by determining the direct quantitative triggers associated with the qualitative indicators of hazardous conditions. A System Dynamics model is generated for determining the measurable quantitative indicator behaviors linked to more apparent qualitative factors for determining the health of a system. Used in concert with other system methodologies, it gives insight into triggers and policies for developing and implementing improvement processes. The context of this research is in reducing billing errors at a utility company which for confidentiality reasons we refer to as United Energy. We use several system methodologies including System Dynamics and Safety System Analysis, to assess the billing operation system and process, to develop a project management plan for the development and implementation of a tool to reduce billing errors.by Nori Ogura.S.M.M.B.A

    Towards an integrated tool support for the analysis of IOPT Nets using the Spin Model Checker

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    This paper presents a model translation to allow automatic simulation and verification of controller models for cyber-physical systems. The models are constructed using IOPT nets, a non-autonomous Petri nets class. Those models are then translated into Promela models to be executed by the Spin model checker, a widely used open-source software verification tool. Three illustrative examples are presented: one autonomous model and two non-autonomous models. As future work, it is foreseen the integration with the freely available IOPT-Tools framework

    Deep Underground Science and Engineering Laboratory - Preliminary Design Report

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    The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations
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