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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.
101

Development and Implementation of a Flight Test Program for a Geometrically Scaled Joined Wing SensorCraft Remotely Piloted Vehicle

Aarons, Tyler David 20 January 2012 (has links)
The development and implementation of a flight test program for an unmanned aircraft is a multidisciplinary challenge. This thesis presents the development and implementation of a rigorous test program for the flight test of a Geometrically Scaled Joined Wing SensorCraft Remotely Piloted Vehicle from concept through successful flight test. The design methodology utilized in the development of the test program is presented, along with the extensive formal review process required for the approval of the test plan by the Air Force Research Laboratory. The design, development and calibration of a custom instrumentation package is also presented along with the setup, procedure and results from all testing. Results are presented for a wind tunnel test for air data boom calibration, propulsion system static thrust testing, a bifilar pendulum test for experimental calculation of mass moments of inertia, a static structural loading test for structural design validation, a full taxi test and a successful first flight. / Master of Science
102

Common-Event Network Test-Instrumentation System (CENTS) Program Status Review

Berard, Alfredo, Boolos, Tim, Klein, Lorin D. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The CENTS Program is a Central Test and Evaluation Investment Program (CTEIP) effort conducted by the 46th Test Wing at Eglin Air Force Base, Florida. This project uses advanced internetworking technology to collect data unobtrusively from multiple Line Replaceable Units (LRU's) within an aircraft without the expense of running new wiring. The data is transported to a master network controller using the existing aircraft powerlines at a raw data rate of over 10 Mbits/s. Sensors are integrated into the shells of the LRU's data bus connectors to minimize the number of aircraft modifications required for a test. CENTS began in January 2000 as an OSD CTEIP Sponsored Test Technology Development and Demonstration (TTD&D) project and is currently in Phase 2 of the effort. Phase 1 saw the successful demonstration of the use of MIL-STD-704 power busses to establish a virtual network for data transport. This paper reviews the current status and past achievements of the CENTS TTD&D program as well as describing some immediate potential pay- offs for the Test and Evaluation community in the near-term.
103

A MIL-STD-1553 Multiplex Data Bus Record-All Small Data Acquisition System

Fletcher, T. R. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / MIL-STD-1553 multiplex data buses are commonly used to link complex software-controlled systems in modern aircraft. The software in these aircraft is routinely updated; each update requires flight testing. Also, sophisticated weapons and electronic warfare systems which are integrated into operationally-ready aircraft must be routinely evaluated. The simplest way to perform the required evaluation is to record all the data from the multiplex data buses during an operational flight; these data can then be replayed and examined after the flight. Traditionally, some operational systems had to be disabled or removed from an aircraft to allow installation of a data acquisition system. This paper discusses a MILSTD- 1553 multiplex bus Record-All Small Data Acquisition System (RASDAS) installed in a McDonnell Douglas CF-188 fighter aircraft to record all data from two 1553 multiplex data buses without displacing any operational equipment. The specific requirements and constraints associated with evaluating the integrated systems of a CF-188 aircraft are examined; further, RASDAS implementation in this aircraft type is discussed from planning to flight evaluation.
104

Air Data System Calibration For Military Transport Aircraft Modernization Program

Ozer, Huseyin Erman 01 January 2013 (has links) (PDF)
This thesis presents the calibration processes of the pitot-static system, which is a part of the air data system of a military transport aircraft through flight tests. Tower fly-by method is used for air data system calibration. Altitude error caused by the position of the static port on the aircraft is determined by analyzing the data collected during four sorties with different weight, flap and landing gear configurations. The same data has been used to determine the airspeed measurement error. It has been shown that both the altitude and airspeed errors are within the allowable limits specified by FAR 25. Same method is also used for trailing cone calibration that is used for high altitude test flights for RVSM certification.
105

Concurrent learning for convergence in adaptive control without persistency of excitation

Chowdhary, Girish 11 November 2010 (has links)
Model Reference Adaptive Control (MRAC) is a widely studied adaptive control methodology that aims to ensure that a nonlinear plant with significant modeling uncertainty behaves like a chosen reference model. MRAC methods attempt to achieve this by representing the modeling uncertainty as a weighted combination of known nonlinear functions, and using a weight update law that ensures weights take on values such that the effect of the uncertainty is mitigated. If the adaptive weights do arrive at an ideal value that best represent the uncertainty, significant performance and robustness gains can be realized. However, most MRAC adaptive laws use only instantaneous data for adaptation and can only guarantee that the weights arrive at these ideal values if and only if the plant states are Persistently Exciting (PE). The condition on PE reference input is restrictive and often infeasible to implement or monitor online. Consequently, parameter convergence cannot be guaranteed in practice for many adaptive control applications. Hence it is often observed that traditional adaptive controllers do not exhibit long-term-learning and global uncertainty parametrization. That is, they exhibit little performance gain even when the system tracks a repeated command. This thesis presents a novel approach to adaptive control that relies on using current and recorded data concurrently for adaptation. The thesis shows that for a concurrent learning adaptive controller, a verifiable condition on the linear independence of the recorded data is sufficient to guarantee that weights arrive at their ideal values even when the system states are not PE. The thesis also shows that the same condition can guarantee exponential tracking error and weight error convergence to zero, thereby allowing the adaptive controller to recover the desired transient response and robustness properties of the chosen reference models and to exhibit long-term-learning. This condition is found to be less restrictive and easier to verify online than the condition on persistently exciting exogenous input required by traditional adaptive laws that use only instantaneous data for adaptation. The concept is explored for several adaptive control architectures, including neuro-adaptive flight control, where a neural network is used as the adaptive element. The performance gains are justified theoretically using Lyapunov based arguments, and demonstrated experimentally through flight-testing on Unmanned Aerial Systems.
106

Information system for flight test campaigns: A proposal for a research institution / Sistema de informação para campanhas de ensaios em voo: uma proposta para uma instituição de pesquisa

Fátima Aparecida Pedro 09 April 2014 (has links)
The development of Information Management Strategy is essential for a given organization. For such business the big challenge is to provide adequate information management to improve its efficiency. Flight test business encompasses the execution of experimental test flight on manned aircraft. For such activity information management is vital for risk assessment. A single test flight could produce a large amount of data, therefore the Management Information System (SIG) becomes complex. A SIG model to be used for flight test business is proposed by this dissertation. The adopted model is proposed to provide an efficient information management for the Experimental Flight Test Campaign Executive Process (PECEV). The research process employs an exploratory case study methodology. Such study was executed into a Science and Technology Institution (ICT) that provides experimental flight test services for aerospace research and development. Such institution belongs to an industrial technology cluster located in the metropolitan region of Vale do Paraiba e Litoral Norte in São Paulo, Brazil. The analysis of the current process used to provide flight test services by such institution, employed a documental analysis with qualitative approach. The proposed SIG model was based on the Plan, Do, Check and Act (PDCA) method. Action items were included for process improvement. Based on the proposed model it is expected that this ICT could implement this SIG to allow effective management of PECEV. / O desenvolvimento de uma estratégia de gestão de informações é imprescindível em uma organização. Torna-se um desafio para a organização gerir os recursos de dados, de forma a manter a eficiência de seus serviços. A atividade de ensaios em voo envolve a execução de voos de ensaios em aeronaves tripuladas. A gestão de informações é considerada vital para minimizar os fatores de riscos dessa atividade. Devido ao grande volume de dados proveniente de um único voo de ensaio, os Sistemas de Informações Gerenciais (SIGs) para essa atividade são complexos. Nesta dissertação, é apresentada a proposta de um modelo de SIG para ensaios em voo. O modelo se propõe a apresentar um plano para a gestão das informações do Processo de Execução de Campanhas de Ensaios em Voo (PECEV). A pesquisa apresentada é um estudo de caso, com delineamento exploratório. Foi desenvolvida em uma Instituição de Ciência e Tecnologia (ICT) de pesquisa do setor aeroespacial, que realiza atividades de ensaios em voo. Essa instituição é integrante do parque tecnológico e industrial localizado na Região Metropolitana do Vale do Paraíba e Litoral Norte. Foi elaborada uma análise documental, por meio de uma abordagem qualitativa, para a análise do atual processo de ensaios em voo da ICT. O modelo proposto do SIG foi obtido seguindo o modelo preconizado pelo Procedimento de Gestão para Melhoria de Processos (PDCA). Foram propostas ações para aprimorar o atual processo. A partir do modelo proposto, pressupõe-se que, posteriormente, seja implantado na ICT um SIG que possibilite a gestão eficaz do PECEV.
107

Characterization and Helicopter Flight Test of 3-D Imaging Flash LIDAR Technology for Safe, Autonomous, and Precise Planetary Landing

Roback, Vincent Eric 17 September 2012 (has links)
Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested under the Autonomous Landing and Hazard Avoidance (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GNC) and sensing system based on lidar technology capable of enabling safe, precise human-crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 ?m Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GNC system from around the country into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of human-made geometric hazards. Results show that the maximum operational range goal of 1000m is met and exceeded up to a value of 1200m, that the range precision goal of 8 cm is marginally met, and that the transmitter zoom optics divergence needs to be extended another eight degrees to meet the zoom goal 6° to 24°. Several hazards are imaged at medium ranges to provide three-dimensional Digital Elevation Map (DEM) information. / Master of Science
108

TELEMETRY PROCESSING SYSTEMS DESIGN TRENDS

Yates, James William 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Current changes in the way that large flight test systems are utilized have affected the industry’s methodology in both the early design phases and in the implementation of nextgeneration hardware and software. The reduction of available RF spectrum, the implementation of packet telemetry methods and systems, and a desire to implement commercial-off-the-shelf (COTS) hardware are only some of the considerations that telemetry systems integrators and product houses have to face. This paper describes how test methodology changes affect current large systems design at both government test ranges and at airframe/missile manufacturer test facilities. In addition, consideration is given to the area of increased processing power as it affects hardware and software design, the leveraging of such current and future telecommunications technology as network switch technology and compression, cross utilization, standardized technology, and the movement toward platform-independent software.
109

MIGRATING FROM A VAX/VMS TO AN INTEL/WINDOWS-NT BASED GROUND STATION

Penna, Sergio D., Rios, Domingos B. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Upgrading or replacing production systems is always a very resource-consuming task, in particular if the systems being replaced are quite specialized, such as those serving any Flight Test Ground Station. In the recent past a large number of Ground Station systems were based in Digital’s VAX/VMS architecture. The computer industry then expanded very fast and by 1990 realtime PCM data processing systems totally dependent on hardware and software designed for IBM-PC compatible micro-computers were becoming available. A complete system replacement in a typical Ground Station can take from one to several years to become a reality. It depends on how complex the original system is, how complex the resulting system needs to be, how much resources are available to support the operation, how soon the organization needs it, etc. This paper intends to review the main concerns encountered during the replacement of a typical VAX/VMS-based by an Intel-Windows NT-based Ground Station. It covers the transition from original requirements to totally new requirements, from mini-computers to micro-computers, from DMA to high-speed LAN data transfers, while conserving some key architectural features. This 8-month development effort will expand EMBRAER’s capability in acquiring, processing and archiving PCM data in the next few years at a lower cost, while preserving compatibility with old legacy flight test data.
110

COMMON AIRBORNE INSTRUMENTATION SYSTEM; A FRESH LOOK

Grace, Thomas 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The US Government originally funded the development of the Common Airborne Instrumentation System (CAIS) to address industry-wide compatibility, maintenance, and commonality issues. Although initially targeted for US Department of Defense (DoD) programs, CAIS is also being used throughout the world in many commercial applications. This paper provides a fresh look at the evolution of the CAIS concept starting with some historical background of the CAIS Program, an overview of the CAIS System Architecture and recent trends in the use of “Commercial Off The Shelf (COTS)” products and technology.

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