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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.
221

Trends in Space Shuttle Telemetry Applications

Muratore, John F. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1987 / Town and Country Hotel, San Diego, California / During early manned spacecraft operations, the primary role of ground telemetry systems was data display to flight controllers. As manned spaceflights have increased in complexity, greater demands have been placed on flight controllers to simultaneously monitor systems and replan systems operations. This has led to interest in automated telemetry monitoring systems to decrease the workload on flight controllers. The Mission Operations Directorate at the Lyndon B. Johnson Space Center has developed a five layer model to integrate various monitoring and analysis technologies such as digital filtering, fault detection algorithms, and expert systems. The paper describes the five layer model and explains how it has been used to guide prototyping efforts at Mission Control. Results from some initial expert systems are presented. The paper also describes the integrated prototype currently under development which implements a real time expert system to assist flight controllers in the Mission Control Center in monitoring Space Shuttle communications systems.
222

Validation toolbox for a Physics Engine / Valideringsverktyg för en fysikmotor

Sundling, Emma January 2016 (has links)
Physics engines become more and more common due to the rapid development and increasing demand of simulations. With this comes a need of testing the engine, a way to measure its performance, not only its speed but also its accuracy and stability. The purpose of this thesis has been to create a set of benchmark tests. They aim to check the physical aspects, especially mechanics, of the engine. A strategy and export functions for the test results in order to automate the testing have also been developed. The resulting tests became a beam on piles which analyses constraint stability, an overdetermined system consisting of a static door on multiple hinges, a falling object investigating the accuracy of the integrator, a box on an inclined plane for testing the friction model, a single pendulum as well as a multibody pendulum checking constraint accuracy and energy conservation, the Earth orbiting around the Sun which tests the stability of the integrator and finally a cantilever beam that is a static test of a real scenario. After the tests are performed the results are presented on an HTML-page. A prototype of a Web application is also established as well as a set of scalar tests that can be performed continuously, in order to follow trends or compare the engine's performance from time to time. This thesis was initialized by Algoryx Simulation AB which also provided the engine, AgX Dynamics, with the numerical method called SPOOK. It mainly performed well on all tests. In order to build a fully general toolbox more tests need to be added such as material interactions, scalable test with thousands of bodies, torque tests as well as more complex scenarios, for example a scissor lift and robots. The work can also be extended with more developed export functions, both to the Web and to documents. Hopefully this thesis can be seen as a complement to the earlier efforts done in creating a general set of benchmarks and automation framework for continuous integration and testing. / Fysikmotorer blir mer och mer vanliga på grund av den snabba utvecklingen och efterfrågan på simuleringar. I och med detta ökar också behovet av att testa motorerna och ett sätt att mäta prestandan, inte bara snabbheten utan också noggrannheten och stabiliteten. Syftet med detta examensarbete har varit att skapa ett set av prestandatester. De syftar till att testa de fysikaliska aspekterna av fysikmotorn, särskilt inom mekanik. En strategi och exportfunktioner för testresultaten för att automatisera testningen har också utvecklats. De resulterande testerna blev en balk på pålar som analyserar stabiliteten hos villkoren, ett överbestämt system bestående av en statisk dörr på flera gångjärn, ett fallande objekt som granskar precisionen hos integratorn, en låda på ett lutande plan som testar friktionsmodellen, en enkel pendel samt en flerkropppspendel som kontrollerar villkorsprecisionen och energikonservering, jordens bana runt solen som testar integratorns stabilitet och slutligen en utskjutande balk som är ett statiskt test av ett verkligt fall. När testerna är genomförda presenteras resultaten på en HTML-sida. En prototyp av en webb-applikation har också utvecklats samt ett set med skalära tester som kan utföras kontinuerligt för att följa upp trender och jämföra motorns prestanda över tid. Det här examensarbetet initierades av Algoryx Simulation AB som även tillhandahållit fysikmotorn, AgX Dynamics, med den numeriska metoden SPOOK. Motorn presterade överlag bra på testerna. För att bygga en allmän verktygslåda behövs fler tester så som interaktion mellan material, skalbara tester med tusentals kroppar samt mer komplexa simuleringar, t.ex. en saxlyft och robotar. Arbetet kan också utökas med mer utvecklade exportfunktioner, både mot webben och som dokument. Förhoppningsvis kan detta ses som ett komplement till de tidigare ansträgningar som gjorts för att skapa ett generellt set av prestandatester och ett automatiskt ramverk för kontinuerlig testning.
223

A TOOL FOR PERFORMANCE EVALUATION OF REAL-TIME UNIX OPERATING SYSTEMS

Furht, B., Boujarwah, A., Gluch, D., Joseph, D., Kamath, D., Matthews, P., McCarty, M., Stoehr, R., Sureswaran, R. 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In this paper we present the REAL/STONE Real-Time Tester, a tool for performance evaluation of real-time UNIX operating systems. The REAL/STONE Real-Time Tester is a synthetic benchmark that simulates a typical real-time environment. The tool performs typical real-time operations, such as: (a) reads data from an external source and accesses it periodically, (b) processes data through a number of real-time processes, and © displays the final data. This study can help users in selecting the most-effective real-time UNIX operating system for a given application.
224

THE FABLE OF “REAL-TIME” TELEMETRY DATA MOVEMENT

Gustin, Thomas W. 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents an exciting new concept in real-time information distribution that can be easily integrated into existing and future telemetry reception and data dispersal systems. After briefly examining the evolutionary path and various perceptions of the concept “real-time”, a variety of techniques are explored in achieving the expedient movement of real-time information. Many non-telemetry application environments are now using real-time shared-memory networking techniques to obtain large, highspeed integrated sharing of common information. The phenomenal results are partially attributable to high reliability, extremely low latency, and ease of use. This paper attempts to present various telemetry applications and scenarios with descriptions of benefits achieved by simply changing existing data movement techniques to those using shared-memory networking techniques.
225

Telemetry Ground Station Data Servers for Real-Time Expert Systems

Silagi, Randall L., Friedman, Paul J. 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Expert systems can be of great benefit to analysts, mission controllers, and flight safety officers who must make real-time decisions based upon a myriad of quickly changing parameters. Operators may require extensive training to view a limited parameter set or they can be aided by computers systematically monitoring many parameters. But, even today’s powerful general purpose computers and workstations are limited in their capabilities to monitor (i.e., process) the desired number of parameters. Thus, applications are distributed across multiple platforms. A telemetry ground station front end system (i.e., a real-time data server) that distributes preprocessed data to multiple knowledge stations over standard communications networks is presented.
226

MICROPROCESSOR-BASED DIGITAL CONTROLLER FOR THE ADVANCED TELEMETRY TRACKING SYSTEM

ROSALES, MARCELO V. 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper discusses the design and implementation of a microcomputer system that functions as the central processing unit for performing servo system control, tracking mode determination, operator interface, switching, and logic operations. The computer hardware consists of VMEbus compatible boards that include a Motorola 32-bit MC68020 microprocessor-based CPU board, and a variety of interface boards. The computer is connected to the Radio Frequency system, Antenna Control Unit, azimuth and elevation servo systems, and other systems of the Advanced Transportable Telemetry Acquisition System (TTAS-A) through extensive serial, analog, and digital input/output interfacing. The software platform consists of a commercially-acquired real-time multi-tasking operating system, and in-house developed device drivers and tracking system software. The operating system kernel is written in assembly language, while the application software is written using the C programming language. To enhance the operation of the TTAS-A, software was also developed to provide color graphics, CRT menus, printer listings, interactive real-time hardware/software diagnostics, and a GPIB (IEEE-488 bus) interface for Automated Testing System support.
227

REENGINEERING A TRADITONAL SPACECRAFT CONTROL CENTER

Knauer, Christian, Nötzel, Klaus Ralf 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Deutsche Telekom is operating various communication satellites since 1989. The SCC (spacecraft control center) is located near Frankfurt / Germany. The entire system is based on antenna/RF equipment, baseband and computer software packages running on a computer network of different machines. Due to increased maintenance effort the old baseband system needed to be replaced. This also had effects to the computer system, especially to the M&C. The aim was to design the entire system in a way that the operation effort in costs aspects and human intervention are minimized. This paper shows the successful real world project of reengineering a traditional spacecraft control center (SCC). It is shown how a fifteen year old hardware (baseband system) and software design was replaced by a modern concept during normal operations. The new software packages execute all necessary tasks for spacecraft- and ground station control. The Monitor and Control System (M&C) is a database driven design (FRAMTEC, from CAM Germany).
228

Flight Test: In Search of Boring Data

Hoaglund, Catharine M., Gardner, Lee S. 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The challenge being faced today in the Department of Defense is to find ways to improve the systems acquisition process. One area needing improvement is to eliminate surprises in unexpected test data which add cost and time to developing the system. This amounts to eliminating errors in all phases of a system’s lifecycle. In a perfect world, the ideal systems acquisition process would result in a perfect system. Flawless testing of a perfect system would result in predicted test results 100% of the time. However, such close fidelity between predicted behavior and real behavior has never occurred. Until this ideal level of boredom in testing occurs, testing will remain a critical part of the acquisition process. Given the indispensability of testing, the goal to reduce the cost of flight tests is well worth pursuing. Reducing test cost equates to reducing open air test hours, our most costly budget item. It also means planning, implementing and controlling test cycles more efficiently. We are working on methods to set up test missions faster, and analyze, evaluate, and report on the test data more quickly, including unexpected results. This paper explores the moving focus concept, one method that shows promise in our pursuit of the goal of reducing test costs. The moving focus concept permits testers to change the data they collect and view during a test, interactively, in real-time. This allows testers who are receiving unexpected test results to change measurement subsets and explore the problem or pursue other test scenarios.
229

IN FLIGHT DATA REDUCTION FOR REDUCED BANDWIDTH TRANSMISSION

Hicks, William T. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The desire to acquire large quantities of high speed vibration and acoustic data during aircraft testing is usually satisfied through on-board high speed recording methods. However there is often a need to have some of this data instantly available at the ground station for flight safety and other purposes. A Data Processor (DP) has been developed allowing an airborne data acquisition system to acquire large amounts of wideband analog data, process the data in real-time, and develop reduced bandwidth information from high bandwidth channels. The reduced data can be inserted into a Pulse Code Modulation (PCM) stream and telemetered via a Radio Frequency (RF) link with a potential for a 2000:1 reduction in bandwidth. This on-board processing capability also lends itself to additional tasks such as the generation of a reduced bandwidth marker channel which can flag critical time periods of data activity. This flagging technique can be used to facilitate ground station analysis of specific segments of data, resulting in significant cost and time savings.
230

A NETWORK BASED DISTRIBUTED REAL TIME COMPUTER TELEMETRY SYSTEM

Wu, Wei-Ren, Li, Hua 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / A real time distributed computer telemetry system based on network is described. It is a new generation of open telemetry system in China, which can parallel acquire and process up to 8 data streams of 100bps~3.5Mbps and optimize automatically distribution of processing tasks by using load-balance technique. PCM PSK QPSK PACM may be suitable to the system and the format switched within less than 1 second. The system has been successfully used in the field of aerospace. There are models of automobile, shipboard, airborne as well as ground station for the system. This paper discusses mainly system architecture, performance, principle, and system features.

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