Dissertations / Theses: 'Real-time operating systems'

1

Pinnix, Justin Everett. "Operating System Kernel for All Real Time Systems." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010310-181302.

Full text

Abstract:

PINNIX, JUSTIN EVERETT. Operating System Kernel for All Real Time Systems.(Under the direction of Robert J. Fornaro and Vicki E. Jones.)

This document describes the requirements, design, and implementation of OSKAR, ahard real time operating system for Intel Pentium compatible personal computers.OSKAR provides rate monotonic scheduling, fixed and dynamic priority scheduling,semaphores, message passing, priority ceiling protocols, TCP/IP networking, and globaltime synchronization using the Global Positioning System (GPS). It is intended toprovide researchers a test bed for real time projects that is inexpensive, simple tounderstand, and easy to extend.

The design of the system is described with special emphasis on design tradeoffs made toimprove real time requirements compliance. The implementation is covered in detail atthe source code level. Experiments to qualify functionality and obtain performanceprofiles are included and the results explained.

APA, Harvard, Vancouver, ISO, and other styles

2

Tomiyama, Hiroyuki, Shinya Honda, and Hiroaki Takada. "Real-Time Operating Systems for Multicore Embedded Systems." IEEE, 2008. http://hdl.handle.net/2237/12100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

DeBrunner, Linda Sumners. "Multitasking operating systems for real-time applications." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/104318.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Larsson, Anders. "Fully automatic benchmarking of real-time operating systems." Thesis, University of Skövde, Department of Computer Science, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-172.

Full text

Abstract:

Testing and evaluating the performance of different software solutions is important in order to compare them with each other. Measuring, or benchmark, software is not a trivial task and conducting tests in a real-time environment implicates it further. Still, measuring is the only way to provide useful information, for example, which real-time operating system is best suitable for a specific hardware configuration.

The purpose of this project is to design a benchmark support system, which automatically performs benchmarks of a real-time operating system in a host-target environment. The benchmarks are conducted according to a user-defined specification and the support system also allows a developer to create configurable benchmarks.

The benchmark support system described also allows parameters to increase monotonically within a specified interval during benchmark execution. This is an important feature in order to detect unpredictable behavior of the real-time system.

APA, Harvard, Vancouver, ISO, and other styles

5

Böke, Carsten. "Automatic configuration of real time operating systems and real time communication systems for distributed embedded applications." Paderborn : Heinz-Nixdorf-Inst, 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971712182.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Okyay, Mehmet Onur Aytaç Sıtkı. "A portable real-time operating system for embedded platforms/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/bilgisayaryazilimi/T000477.doc.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Wells, George Clifford. "A study of real-time operating systems for microcomputers." Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1004896.

Full text

Abstract:

This thesis describes the evaluation of four operating systems for microcomputers. The emphasis of the study is on the suitability of the operating systems for use in real-time applications, such as process control. The evaluation was performed in two sections. The first section was a quantitative assessment of the performance of the real-time features of the operating system. This was performed using benchmarks. The criteria for the benchmarks and their design are discussed. The second section was a qualitative assessment of the suitability of the operating systems for the development and implementation of real-time systems. This was assessed through the implementation of a small simulation of a manufacturing process and its associated control system. The simulation was designed using the Ward and Mellor real-time design method which was extended to handle the special case of a real-time simulation. The operating systems which were selected for the study covered a spectrum from general purpose operating systems to small, specialised real-time operating systems. From the quantitative assessment it emerged that QNX (from Quantum Software Systems) had the best overall performance. Qualitatively, UNIX was found to offer the best system development environment, but it does not have the performance and the characteristics required for real-time applications. This suggests that versions of UNIX that are adapted for real-time applications are worth careful consideration for use both as development systems and implementation systems.

APA, Harvard, Vancouver, ISO, and other styles

8

Sepulveda, Florez Daniel Mauricio. "Stress Injection Study on Hard Real-Time Operating Systems." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20261/.

Full text

Abstract:

The automotive software complexity has increased exponentially in the last 30 years. Nowadays, automotive applications are built on top of hard real-time operating system where many tasks are executed. Due to the automotive high integration levels and the time-to-market, software integration and robustness tests should be performed effectively and efficiently. Infineon Technologies for the AURIX 2G microcontroller has integrated a novel hardware architecture to support the Resource Usage Test and the Stress Test. Despite this hardware support, it has never been used before. Then, it is critical to propose a method to efficiently use this structure and to allow the evaluation of the performance and reliability of the chips. This thesis develops a method and a tool that uses stress injection to analyze the performance, robustness values and boundaries of hard real-time systems under different scenarios. The designer is able: i) to configure the embedded debugging hardware architecture to efficiently explore different stress scenarios; ii) to gather information; and to quantify different types of performance and robustness metrics. The method is automated and fully parameterizable. The developed tool in this thesis is called Galenus, it is integrated into the already existing internal debugging environment of Infineon Technologies for the AURIX microcontroller. The stress injection is based on the reduction of the effective performance of a SoC component (e.g., TriCore within AURIX). The stress injection allows to assess the sensitivity of the SoC under different stress scenarios. These scenarios are defined on the offline initial state using formal methods of scheduling theory. Using the stress injection method, the SoC designer can identify possible risk scenarios testing the performance and robustness of the system at runtime. This thesis is based on the stress injection by CPU suspension within two types of software application, RTOS and Bare-metal.

APA, Harvard, Vancouver, ISO, and other styles

9

Patil, Ameet. "Application-specific resource management in real-time operating systems." Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444712.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Adelstein, Frank Nathan. "Network and operating systems support for real-time multimedia /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487862972135428.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Sjöström, Thames Sixten. "Porting a Real-Time Operating System to a Multicore Platform." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-76933.

Full text

Abstract:

This thesis is part of the European MANY project. The goal of MANY is to provide developers with tools to develop software for multi and many-core hardware platforms. This is the first thesis that is part of MANY at Enea. The thesis aims to provide a knowledge base about software on many-core at the Enea student research group. More than just providing a knowledge base, a part of the thesis is also to port Enea's operating system OSE to Tilera's many-core processor TILEpro64. The thesis shall also investigate the memory hierarchy and interconnection network of the Tilera processor. The knowledge base about software on many-core was constrained to investigating the shared memory model and operating systems for many-core. This was achieved by investigating prominent academic research about operating systems for many-core processors. The conclusion was that a shared memory model does not scale and for the operating system case, operating systems shall be designed with scalability as one of the most important requirements. This thesis has implemented the hardware abstraction layer required to execute a single-core version of OSE on the TILEpro architecture. This was done in three steps. The Tilera hardware and the OSE software platform were investigated. After that, an OSE target port was chosen as reference architecture. Finally, the hardware dependent parts of the reference software were modified. A foundation has been made for future development.

APA, Harvard, Vancouver, ISO, and other styles

12

Furht, B., A. Boujarwah, D. Gluch, D. Joseph, D. Kamath, P. Matthews, M. McCarty, R. Stoehr, and R. Sureswaran. "A TOOL FOR PERFORMANCE EVALUATION OF REAL-TIME UNIX OPERATING SYSTEMS." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/612926.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

13

Brinkmeyer, Jay Charles 1960. "A multi-tasking operating system for real-time applications." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276589.

Full text

Abstract:

Presented in this thesis is the design and implementation of a fast, compact, and flexible multi-tasking operating system. This system is designed for use in small computers which must deliver real-time performance in extremely constrained environments. The operating system is implemented in the "C" language to allow portability between different computers systems. A number of useful features are provided which support dynamic task management, message passing, a hierarchial file system, device drivers, and a command line interpreter. Modularized construction enables the user to prune unnecessary system features for specific applications. Presently, the system is operational on a personal computer which is also used for system development. This serves as a realistic environment for testing system response to real-time events.

APA, Harvard, Vancouver, ISO, and other styles

14

Yan, Lin Wu. "A Lightweight Framework for Tracing andVisualizing Real-Time Operating Systems." Thesis, Högskolan Väst, Institutionen för ekonomi och it, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-4428.

Full text

Abstract:

System tracing is a helpful method for engineersand users to know exactly what happens in an operating system,especially in real-time operating systems (RTOS), because forreal-time system, it is normally more difficult to know theperformance of hardware and software than for desktopcomputers. Although this kind of tracing tools already exist forsome commercial RTOS, it is fairly hard to see those tools forsmall or open source RTOS. Moreover, because the structure andimplementation of different RTOS varies, it is rare to find aframework that can easily be ported to those platforms. In thisthesis, a solution is presented to this general tracing problem ondifferent platforms. By using the portable framework, it ispossible to implement tracing component into a real timeoperating system by some simple reconfigurations. This platformportability feature is accomplished by separating the specificplatform logic from the logic of the tracing part. Finally, adeployment of this framwork onto a small open source real-timeoperating system—AtomThreads, running on an AVRATmega1650 – is used as a demonstration of this framework.

APA, Harvard, Vancouver, ISO, and other styles

15

Chen, Bojie. "HUMIDITY SENSOR CIRCUIT USING REAL TIME OPERATING SYSTEM (FREERTOS) KERNEL." UKnowledge, 2014. http://uknowledge.uky.edu/ece_etds/61.

Full text

Abstract:

A humidity sensor can be used to measure the moisture content of the environment. The physical change of the sensor expresses as the change of electrical property like capacitance, resistance, voltage, current, frequency, etc. In order to process these analog signals digitally, microprocessor is involved in the measurement. This thesis presents design of a circuit to measure low moisture levels. The 16-bit RISC mixed signal microcontroller MSP430F249 from Texas Instruments will be used. The circuit has good performance at extremely low humidity levels. Meanwhile, a small real time operating system kernel FreeRTOS, a market leading RTOS from Real Time Engineer Ltd is ported to the microcontroller. The basic concept about FreeRTOS and how to port this RTOS to MSP430F249 microcontrollers will be the topics of this thesis as well.

APA, Harvard, Vancouver, ISO, and other styles

16

Forbes, Harold C. "Operating system principles and constructs for dynamic multi-processor real-time control systems." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8165.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Yankov, Y. Daniel. "Discrete event system modeling of demand responsive transportation systems operating in real time." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002466.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Yankov, Daniel Y. "Discrete Event System Modeling Of Demand Responsive Transportation Systems Operating In Real Time." Scholar Commons, 2008. https://scholarcommons.usf.edu/etd/575.

Full text

Abstract:

Demand responsive transportation is a variable route service of passengers or freight from specific origin(s) to destination(s) in response to the request of users. Operational planning of DRT system encompasses the methods to provide efficient service to the passengers and to the system operators. These methods cover the assignments of vehicles to transportation requests and vehicle routings under various constraints such as environmental conditions, traffic and service limitations. Advances in the information and communication technologies, such as the Internet, mobile communication devices, GIS, GPS, Intelligent Transportation Systems have led to a significantly complex and highly dynamical decision making environment. Recent approaches to DRT operational planning are based on "closed information loop" to achieve a higher level of automation, increased flexibility and efficiency. Intelligent and effective use of the available information in such a complex decision making environment requires the application of formal modeling and control approaches, which are robust, modular and computationally efficient. In this study, DRT systems are modeled as Discrete Event Systems using Finite Automata formalism and DRT real time control is addressed using Supervisory Control Theory. Two application scenarios are considered; the first is based on air-charter service and illustrates uncontrolled system model and operational specification synthesis. The automatic synthesis of centralized and modular supervisors is demonstrated. The second scenario is a mission critical application based on emergency evacuation problem. Decentralized supervisory control architecture suitable for accommodating the real-time contingencies is presented. Conditions for parallel computation of local supervisors are specified and the computational advantages of alternative supervisory control architectures are discussed. Discrete event system modeling and supervisory control theory are well established and powerful mathematical tools. In this dissertation, they are shown to be suitable for expressing the modeling and control requirements of complex and dynamic applications in DRT. The modeling and control approaches described herein, coupled with the mature body of research literature in Discrete Event Systems and Supervisory Control Theory, facilitate logical analysis of these complex systems and provide the necessary framework for development of intelligent decision making tools for real time operational planning and control in a broad range of DRT applications.

APA, Harvard, Vancouver, ISO, and other styles

19

Baldovin, Andrea <1983&gt. "Operating System Contribution to Composable Timing Behaviour in High-Integrity Real-Time Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6597/1/Baldovin_Andrea_tesi.pdf.

Full text

Abstract:

The development of High-Integrity Real-Time Systems has a high footprint in terms of human, material and schedule costs. Factoring functional, reusable logic in the application favors incremental development and contains costs. Yet, achieving incrementality in the timing behavior is a much harder problem. Complex features at all levels of the execution stack, aimed to boost average-case performance, exhibit timing behavior highly dependent on execution history, which wrecks time composability and incrementaility with it. Our goal here is to restitute time composability to the execution stack, working bottom up across it. We first characterize time composability without making assumptions on the system architecture or the software deployment to it. Later, we focus on the role played by the real-time operating system in our pursuit. Initially we consider single-core processors and, becoming less permissive on the admissible hardware features, we devise solutions that restore a convincing degree of time composability. To show what can be done for real, we developed TiCOS, an ARINC-compliant kernel, and re-designed ORK+, a kernel for Ada Ravenscar runtimes. In that work, we added support for limited-preemption to ORK+, an absolute premiere in the landscape of real-word kernels. Our implementation allows resource sharing to co-exist with limited-preemptive scheduling, which extends state of the art. We then turn our attention to multicore architectures, first considering partitioned systems, for which we achieve results close to those obtained for single-core processors. Subsequently, we shy away from the over-provision of those systems and consider less restrictive uses of homogeneous multiprocessors, where the scheduling algorithm is key to high schedulable utilization. To that end we single out RUN, a promising baseline, and extend it to SPRINT, which supports sporadic task sets, hence matches real-world industrial needs better. To corroborate our results we present findings from real-world case studies from avionic industry.

APA, Harvard, Vancouver, ISO, and other styles

20

Baldovin, Andrea <1983&gt. "Operating System Contribution to Composable Timing Behaviour in High-Integrity Real-Time Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6597/.

Full text

Abstract:

The development of High-Integrity Real-Time Systems has a high footprint in terms of human, material and schedule costs. Factoring functional, reusable logic in the application favors incremental development and contains costs. Yet, achieving incrementality in the timing behavior is a much harder problem. Complex features at all levels of the execution stack, aimed to boost average-case performance, exhibit timing behavior highly dependent on execution history, which wrecks time composability and incrementaility with it. Our goal here is to restitute time composability to the execution stack, working bottom up across it. We first characterize time composability without making assumptions on the system architecture or the software deployment to it. Later, we focus on the role played by the real-time operating system in our pursuit. Initially we consider single-core processors and, becoming less permissive on the admissible hardware features, we devise solutions that restore a convincing degree of time composability. To show what can be done for real, we developed TiCOS, an ARINC-compliant kernel, and re-designed ORK+, a kernel for Ada Ravenscar runtimes. In that work, we added support for limited-preemption to ORK+, an absolute premiere in the landscape of real-word kernels. Our implementation allows resource sharing to co-exist with limited-preemptive scheduling, which extends state of the art. We then turn our attention to multicore architectures, first considering partitioned systems, for which we achieve results close to those obtained for single-core processors. Subsequently, we shy away from the over-provision of those systems and consider less restrictive uses of homogeneous multiprocessors, where the scheduling algorithm is key to high schedulable utilization. To that end we single out RUN, a promising baseline, and extend it to SPRINT, which supports sporadic task sets, hence matches real-world industrial needs better. To corroborate our results we present findings from real-world case studies from avionic industry.

APA, Harvard, Vancouver, ISO, and other styles

21

Sheridan-Barbian, Katherine K. "A survey of real-time operating systems and virtualization solutions for space systems." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45256.

Full text

Abstract:

Approved for public release; distribution is unlimited
The Department of Defense and the intelligence community rely on space systems for a broad spectrum of services. These systems operate in highly constrained environments (in terms of space, weight and power), making virtualization and resource sharing a desirable approach. Agencies are actively exploring new architectures, such as those employing virtualization, to support their growing space mission. In this thesis, we review how virtualization architectures claim to support the real-time requirements of their guests. We survey real-time systems and virtualization architectures proposed for use in space systems. Further, we investigate the behaviors of virtualized operating systems using a method of remote network-based fingerprinting with TCP timestamps. Our work provides insights into how guests, both general purpose and real-time, behave in virtualized environments. Our survey work and experimental analysis aim to further understanding of how virtualization can be securely incorporated into space systems.

APA, Harvard, Vancouver, ISO, and other styles

22

Blake, Carl David. "A REAL-TIME MULTI-TASKING OPERATING SYSTEM FOR GENERAL PURPOSE APPLICATIONS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275400.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Bor, Mehmet. "Effective interprocess communication (IPC) in a real-time transputer network." Thesis, Loughborough University, 1994. https://dspace.lboro.ac.uk/2134/33101.

Full text

Abstract:

The thesis describes the design and implementation of an interprocess communication (IPC) mechanism within a real-time distributed operating system kernel (RT-DOS) which is designed for a transputer-based network. The requirements of real-time operating systems are examined and existing design and implementation strategies are described. Particular attention is paid to one of the object-oriented techniques although it is concluded that these techniques are not feasible for the chosen implementation platform. Studies of a number of existing operating systems are reported. The choices for various aspects of operating system design and their influence on the IPC mechanism to be used are elucidated. The actual design choices are related to the real-time requirements and the implementation that has been adopted is described.

APA, Harvard, Vancouver, ISO, and other styles

24

Apte, Manoj Shriganesh. "An operating system architecture and hybrid scheduling methodology for real-time systems with uncertainty." Diss., Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-11102004-152431.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Dhake, Pravin. "A real time operating system based test-bed for autonomous vehicle navigation." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/Dhake_09007dcc803c20b4.pdf.

Full text

Abstract:

Thesis (M.S.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 28, 2007) Includes bibliographical references (p. 86-87).

APA, Harvard, Vancouver, ISO, and other styles

26

Schneider, Jörn [Verfasser]. "Combined Schedulability and WCET Analysis for Real-Time Operating Systems / Jörn Schneider." Aachen : Shaker, 2003. http://d-nb.info/1172610940/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Lindblom, Karl, and Robert Kyrk. "Real Time Communication Platform : Using ARM Cortex M7 and MQTT." Thesis, Karlstads universitet, Avdelningen för datavetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67618.

Full text

Abstract:

Microcontroller platforms are heavily used in embedded solutions adopted in nearly every industry covering a wide range of applications and use cases. In the paper and pulp industry the change prompted by the rising popularity of data decentralisation, big data analysis and machine learning, forces companies to upgrade or renew old platforms used to collect and analyse data. This thesis will evaluate a generation change for a communication platform that collects data from a sensor, its capabilities regarding secure communication over TCP/IP with the possibility to implement an efficient machine-to-machine communication protocol. The main focus of the evaluation is development, implementation and integration of software for the embedded system with a real time operating system using the ARM Cortex M7. Using small open source tools and the powerful ARM core we were able to build a small, flexible, real time system that publishes sensor data over MQTT securely using TCP/IP and TLS.

APA, Harvard, Vancouver, ISO, and other styles

28

Kim, Hyoseung. "Towards Predictable Real-Time Performance on Multi-Core Platforms." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/836.

Full text

Abstract:

Cyber-physical systems (CPS) integrate sensing, computing, communication and actuation capabilities to monitor and control operations in the physical environment. A key requirement of such systems is the need to provide predictable real-time performance: the timing correctness of the system should be analyzable at design time with a quantitative metric and guaranteed at runtime with high assurance. This requirement of predictability is particularly important for safety-critical domains such as automobiles, aerospace, defense, manufacturing and medical devices. The work in this dissertation focuses on the challenges arising from the use of modern multi-core platforms in CPS. Even as of today, multi-core platforms are rarely used in safety-critical applications primarily due to the temporal interference caused by contention on various resources shared among processor cores, such as caches, memory buses, and I/O devices. Such interference is hard to predict and can significantly increase task execution time, e.g., up to 12 commodity quad-core platforms. To address the problem of ensuring timing predictability on multi-core platforms, we develop novel analytical and systems techniques in this dissertation. Our proposed techniques theoretically bound temporal interference that tasks may suffer from when accessing shared resources. Our techniques also involve software primitives and algorithms for real-time operating systems and hypervisors, which significantly reduce the degree of the temporal interference. Specifically, we tackle the issues of cache and memory contention, locking and synchronization, interrupt handling, and access control for computational accelerators such as general-purpose graphics processing units (GPGPUs), all of which are crucial to achieving predictable real-time performance on a modern multi-core platform. Our solutions are readily applicable to commodity multi-core platforms, and can be used not only for developing new systems but also migrating existing applications from single-core to multi-core platforms.

APA, Harvard, Vancouver, ISO, and other styles

29

Nordström, Susanna. "Configurable Hardware Support for Single Processor Real-Time Systems." Licentiate thesis, Mälardalen University, School of Innovation, Design and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-528.

Full text

Abstract:

This thesis describes a further development of a building block for programmable devices in embedded systems handling real-time functionality.

Embedded systems are included in a variety of products within different technical areas such as industrial automation, consumer electronics, automotive industry, and communication-, and multimedia systems. Products ranging from trains and airplanes to microwave ovens and washing machines are controlled by embedded systems.

Programmable devices constitute a part of these embedded systems. Today, a programmable device can include a complete system containing building blocks connected with each other via programs written using a hardware description language. The programmable devices can be programmed and changed over and over again and this flexibility makes it possible to explore how these building blocks can best be designed in relation to system requirements, before final implementation.

This thesis describes a further development of a building block for programmable devices implemented in a non-traditional way, i.e., the implementation is written using both hardware description language and traditional software languages. This new building block handles real-time functionality in a non-traditional way that enables certain benefits, such as increased performance, predictability and less memory consumption. Using a non-traditional implementation also has its drawbacks, and e.g., extensions and adjustments can be hard to handle since modifications are required in both hardware and software programming languages.

The new building block was investigated in order to see how it could be facilitated when used for real-time functionality. The configurability of the block was extended which enables further customization of the building block. This leads to the possibility to use the block within a wider spectrumof applications. It is also possible to reduce the size and cost of the final product since resource usage can be optimized.

Furthermore, a mathematicalmodel estimating resource usage for real-time functionality has been developed. The model enables distinctive trade-offs comparisons, and guidance for system designers, when considering what type of real-time operating system to use in a certain design.

APA, Harvard, Vancouver, ISO, and other styles

30

Swim, Bradley Roy. "Predictable dynamic task scheduling in a hard real-time distributed operating system." Thesis, Staffordshire University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337215.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Böke, Carsten [Verfasser]. "Automatic configuration of real time operating systems and real time communication systems for distributed embedded applications / Heinz-Nixdorf-Institut, Universität Paderborn. Carsten Böke." Paderborn : Heinz-Nixdorf-Inst, 2004. http://d-nb.info/971712182/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Gheith, Ahmed M. "Support for multi-weight object, invocations and atomicity in real-time systems." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/8173.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

McLean, Angus L. M. Thom III. "Real-time distributed simulation analysis : an application of temporal database and simulation systems research." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/9124.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Glover, James Patrick Neil. "Real time simulation and parallel processing in the control of co-operating manipulator systems." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359066.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Fri, Martin, and Jon Börjesson. "Usage of databases in ARINC 653-compatible real-time systems." Thesis, Linköping University, Department of Computer and Information Science, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57473.

Full text

Abstract:

The Integrated Modular Avionics architecture , IMA, provides means for runningmultiple safety-critical applications on the same hardware. ARINC 653 is aspecification for this kind of architecture. It is a specification for space and timepartition in safety-critical real-time operating systems to ensure each application’sintegrity. This Master thesis describes how databases can be implementedand used in an ARINC 653 system. The addressed issues are interpartitioncommunication, deadlocks and database storage. Two alternative embeddeddatabases are integrated in an IMA system to be accessed from multiple clientsfrom different partitions. Performance benchmarking was used to study the differencesin terms of throughput, number of simultaneous clients, and scheduling.Databases implemented and benchmarked are SQLite and Raima. The studiesindicated a clear speed advantage in favor of SQLite, when Raima was integratedusing the ODBC interface. Both databases perform quite well and seem to begood enough for usage in embedded systems. However, since neither SQLiteor Raima have any real-time support, their usage in safety-critical systems arelimited. The testing was performed in a simulated environment which makesthe results somewhat unreliable. To validate the benchmark results, furtherstudies must be performed, preferably in a real target environment.The Integrated Modular Avionics architecture , IMA, provides means for runningmultiple safety-critical applications on the same hardware. ARINC 653 is aspecification for this kind of architecture. It is a specification for space and timepartition in safety-critical real-time operating systems to ensure each application’sintegrity. This Master thesis describes how databases can be implementedand used in an ARINC 653 system. The addressed issues are interpartitioncommunication, deadlocks and database storage. Two alternative embeddeddatabases are integrated in an IMA system to be accessed from multiple clientsfrom different partitions. Performance benchmarking was used to study the differencesin terms of throughput, number of simultaneous clients, and scheduling.Databases implemented and benchmarked are SQLite and Raima. The studiesindicated a clear speed advantage in favor of SQLite, when Raima was integratedusing the ODBC interface. Both databases perform quite well and seem to begood enough for usage in embedded systems. However, since neither SQLiteor Raima have any real-time support, their usage in safety-critical systems arelimited. The testing was performed in a simulated environment which makesthe results somewhat unreliable. To validate the benchmark results, furtherstudies must be performed, preferably in a real target environment.

APA, Harvard, Vancouver, ISO, and other styles

36

Lee, Young Joon. "The real-time implementation of hardware-in-the-loop systems on different RTOS platforms." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/15942.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Baunach, Marcel [Verfasser], and Reiner [Akademischer Betreuer] Kolla. "Advances in Distributed Real-Time Sensor/Actuator Systems Operation - Operating Systems, Communication, and Application Design Concepts - / Marcel Baunach. Betreuer: Reiner Kolla." Würzburg : Universitätsbibliothek der Universität Würzburg, 2013. http://d-nb.info/103163083X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Grobler, Johannes Petrus. "Design and implementation of a high resolution soft real-time timer." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08282007-095022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Johansson, Staffan. "Port of OPC UA to gateway for industrial networks." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-23432.

Full text

Abstract:

HMS Industrial networks is a company that offers communication solutions for automation systems. There exists an abundance of different industrial network technologies and HMS manufactures gateways that translate and allow communication between the different networks.The multiplicity of network technologies introduces problems when it comes to monitoring the processes in an automation system. It is desirable to be able to access the process data through a single network technology and this is what OPC UA is used for. Briefly, OPC UA can be described as an interface for exchange ofprocess data in automation systems. HMS has noticed a rising trend in the interest for OPC UA and therefore wants to investigate the possibility to use OPC UA on their platform, the Anybus X-Gateway. The goal of this thesis has been to port an OPC UA stack, provided by the OPCfoundation, to the HMS operating system running on an Anybus X-Gateway. The port has been successful and has been verified by unit tests and a test application. Thus, a first step towards a complete OPC UA product has been taken. Further, the thesis presents a theoretical summary about real-time operating systems to explain their function and usage.

APA, Harvard, Vancouver, ISO, and other styles

40

Micacchi, Christopher D. D. "An architecture for multi-agent systems operating in solf real-time environments with unexpected events." Waterloo, Ont. : University of Waterloo, 2004. http://etd.uwaterloo.ca/etd/cdmicacc2004.pdf.

Full text

Abstract:

Thesis (MMath)--University of Waterloo, 2004.
"A thesis presented to the University of Waterloo in fulfilment of the thesis requirement for the degree of Master of Mathematics in Computer Science." Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

41

Micacchi, Christopher. "An Architecture For Multi-Agent Systems Operating In Soft Real-Time Environments With Unexpected Events." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/1047.

Full text

Abstract:

In this thesis, we explore the topic of designing an architecture and processing algorithms for a multi-agent system, where agents need to address potential unexpected events in the environment, operating under soft real-time constraints. We first develop a classification of unexpected events into Opportunities, Barriers and Potential Causes of Failure, and outline the interaction required to support the allocation of tasks for these events. We then propose a hybrid architecture to provide for agent autonomy in the system, employing a central coordinating agent. Certain agents in the community operate autonomously, while others remain under the control of the coordinating agent. The coordinator is able to determine which agents should form teams to address unexpected events in a timely manner, and to oversee those agents as they perform their tasks. The proposed architecture avoids the overhead of negotiation amongst agent teams for the assignment of tasks, a benefit when operating under limited time and resource constraints. It also avoids the bottleneck of having one coordinating agent making all decisions before work can proceed in the community, by allowing some agents to work independently. We illustrate the potential usefulness of the framework by describing an implementation of a simulator loosely based on that used for the RoboCup Rescue Simulation League contest. The implementation provides a set of simulated computers, each running a simple soft real-time operating system. On top of this basic simulation we implement the model described above and test it against two different search-and-rescue scenarios. From our experiments, we observe that our architecture is able to operate in dynamic and real-time environments, and can handle, in an appropriate and timely manner, any unexpected events that occur. We also comment on the value of our proposed approach for designing adjustable autonomy multi-agent systems and for specific environments such as robotics, where reducing the overall level of communication within the system is crucial.

APA, Harvard, Vancouver, ISO, and other styles

42

Van, Wyk Frans-Pieter. "Simutaneous real-time object recognition and pose estimation for artificial systems operating in dynamic environments." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/33323.

Full text

Abstract:

Recent advances in technology have increased awareness of the necessity for automated systems in people’s everyday lives. Artificial systems are more frequently being introduced into environments previously thought to be too perilous for humans to operate in. Some robots can be used to extract potentially hazardous materials from sites inaccessible to humans, while others are being developed to aid humans with laborious tasks. A crucial aspect of all artificial systems is the manner in which they interact with their immediate surroundings. Developing such a deceivingly simply aspect has proven to be significantly challenging, as it not only entails the methods through which the system perceives its environment, but also its ability to perform critical tasks. These undertakings often involve the coordination of numerous subsystems, each performing its own complex duty. To complicate matters further, it is nowadays becoming increasingly important for these artificial systems to be able to perform their tasks in real-time. The task of object recognition is typically described as the process of retrieving the object in a database that is most similar to an unknown, or query, object. Pose estimation, on the other hand, involves estimating the position and orientation of an object in three-dimensional space, as seen from an observer’s viewpoint. These two tasks are regarded as vital to many computer vision techniques and regularly serve as input to more complex perception algorithms. An approach is presented which regards the object recognition and pose estimation procedures as mutually dependent. The core idea is that dissimilar objects might appear similar when observed from certain viewpoints. A feature-based conceptualisation, which makes use of a database, is implemented and used to perform simultaneous object recognition and pose estimation. The design incorporates data compression techniques, originally suggested by the image-processing community, to facilitate fast processing of large databases. System performance is quantified primarily on object recognition, pose estimation and execution time characteristics. These aspects are investigated under ideal conditions by exploiting three-dimensional models of relevant objects. The performance of the system is also analysed for practical scenarios by acquiring input data from a structured light implementation, which resembles that obtained from many commercial range scanners. Practical experiments indicate that the system was capable of performing simultaneous object recognition and pose estimation in approximately 230 ms once a novel object has been sensed. An average object recognition accuracy of approximately 73% was achieved. The pose estimation results were reasonable but prompted further research. The results are comparable to what has been achieved using other suggested approaches such as Viewpoint Feature Histograms and Spin Images.
Dissertation (MEng)--University of Pretoria, 2013.
gm2014
Electrical, Electronic and Computer Engineering
unrestricted

APA, Harvard, Vancouver, ISO, and other styles

43

Arumí, Albó Pau. "Real-time multimedia on off-the-shelf operating systems: from timeliness dataflow models to pattern languages." Doctoral thesis, Universitat Pompeu Fabra, 2009. http://hdl.handle.net/10803/7558.

Full text

Abstract:

Els sistemes multimèdia basats en programari capaços de processar àudio, vídeo i gràfics a temps-real són omnipresents avui en dia. Els trobem no només a les estacions de treball de sobre-taula sinó també als dispositius ultra-lleugers com els telèfons mòbils. Degut a que la majoria de processament es realitza mitjançant programari, usant abstraccions del maquinari i els serveis oferts pel sistema operatiu i les piles de llibreries que hi ha per sota, el desenvolupament ràpid d'aplicacions esdevé possible. A més d'aquesta immediatesa i exibilitat (comparat amb les plataformes orientades al maquinari), aquests plataformes també ofereixen capacitats d'operar en temps-real amb uns límits de latència apropiats. Malgrat tot això, els experts en el domini dels multimèdia s'enfronten a un desafiament seriós: les funcionalitats i complexitat de les seves aplicacions creixen ràpidament; mentrestant, els requeriments de temps-real (com ara la baixa latència) i els estàndards de fiabilitat augmenten. La present tesi es centra en l'objectiu de proporcionar una caixa d'eines als experts en el domini que els permeti modelar i prototipar sistemes de processament multimèdia. Aquestes eines contenen plataformes i construccions que reecteixen els requeriments del domini i de l'aplicació, i no de propietats accidentals de la implementació (com ara la sincronització entre threads i manegament de buffers). En aquest context ataquem dos problemes diferents però relacionats:la manca de models de computació adequats pel processament de fluxos multimèdia en temps-real, i la manca d'abstraccions apropiades i mètodes sistemàtics de desenvolupament de programari que suportin els esmentats models. Existeixen molts models de computació orientats-a-l'actor i ofereixen millors abstraccions que les tècniques d'enginyeria del programari dominants, per construir sistemes multimèdia de temps-real. La família de les Process Networks i els models Dataflow basades en xarxes d'actors de processat del senyal interconnectats són els més adequats pel processament de fluxos continus. Aquests models permeten expressar els dissenys de forma propera al domini del problema (en comptes de centrar-se en detalls de la implementació), i possibiliten una millor modularització i composició jeràrquica del sistema. Això és possible perquè el model no sobreespecifica com els actors s'han d'executar, sinó que només imposa dependències de dades en un estil de llenguatge declaratiu. Aquests models admeten el processat multi-freqüència i, per tant, planificacions complexes de les execucions dels actors. Però tenen un problema: els models no incorporen el concepte de temps d'una forma útil i, en conseqüència, les planifiacions periòdiques no garanteixen un comportament de temps-real i de baixa latència. Aquesta dissertació soluciona aquesta limitació a base de descriure formalment un nou model que hem anomenat Time-Triggered Synchronous Dataflow (TTSDF). En aquest nou model les planificacions periòdiques són intercalades per vàries "activacions" temporalment-disparades (time-triggered) de forma que les entrades i sortides de la xarxa de processat poden ser servides de forma regular. El model TTSDF té la mateixa expressivitat (o, en altres paraules, té computabilitat equivalent) que el model Synchronous Dataow (SDF). Però a més, té l'avantatge que garanteix la operativitat en temps-real, amb mínima latència i absència de forats i des-sincronitzacions a la sortida. Finalment, permet el balancejat de la càrrega en temps d'execució entre diferents activacions de callbacks i la paralel·lització dels actors. Els models orientats-a-l'actor no són solucions directament aplicables; no són suficients per construir sistemes multimèdia amb una metodologia sistemàtica i pròpia d'una enginyeria. També afrontem aquest problema i, per solucionar-lo, proposem un catàleg de patrons de disseny específics del domini organitzats en un llenguatge de patrons. Aquest llenguatge de patrons permet el refús del disseny, posant una especial atenció al context en el qual el disseny-solució és aplicable, les forces enfrontades que necessita balancejar i les implicacions de la seva aplicació. Els patrons proposats es centren en com: organitzar diferents tipus de connexions entre els actors, transferir dades entre els actors, habilitar la comunicació dels humans amb l'enginy del dataflow, i finalment, prototipar de forma ràpida interfícies gràfiques d'usuari per sobre de l'enginy del dataflow, creant aplicacions completes i extensibles. Com a cas d'estudi, presentem un entorn de desenvolupament (framework) orientat-a-objectes (CLAM), i aplicacions específiques construïdes al seu damunt, que fan ús extensiu del model TTSDF i els patrons contribuïts en aquesta tesi.
Software-based multimedia systems that deal with real-time audio, video and graphics processing are pervasive today, not only in desktop workstations but also in ultra-light devices such as smart-phones. The fact that most of the processing is done in software, using the high-level hardware abstractions and services offered by the underlying operating systems and library stacks, enables for quick application development. Added to this exibility and immediacy (compared to hardware oriented platforms), such platforms also offer soft real-time capabilities with appropriate latency bounds. Nevertheless, experts in the multimedia domain face a serious challenge: the features and complexity of their applications are growing rapidly; meanwhile, real-time requirements (such as low latency) and reliability standards increase. This thesis focus on providing multimedia domain experts with workbench of tools they can use to model and prototype multimedia processing systems. Such tools contain platforms and constructs that reect the requirements of the domain and application, and not accidental properties of the implementation (such as thread synchronization and buffers management). In this context, we address two distinct but related problems: the lack of models of computation that can deal with continuous multimedia streams processing in real-time, and the lack of appropriate abstractions and systematic development methods that support such models. Many actor-oriented models of computation exist and they offer better abstractions than prevailing software engineering techniques (such as object-orientation) for building real-time multimedia systems. The family of Process Networks and Dataow models based on networks of connected processing actors are the most suited for continuous stream processing. Such models allow to express designs close to the problem domain (instead of focusing in implementation details such as threads synchronization), and enable better modularization and hierarchical composition. This is possible because the model does not over-specify how the actors must run, but only imposes data dependencies in a declarative language fashion. These models deal with multi-rate processing and hence complex periodic actor's execution schedulings. The problem is that the models do not incorporate the concept of time in a useful way and, hence, the periodic schedules do not guarantee real-time and low latency requirements. This dissertation overcomes this shortcoming by formally describing a new model that we named Time-Triggered Synchronous Dataow (TTSDF), whose periodic schedules can be interleaved by several time-triggered activations" so that inputs and outputs of the processing graph are regularly serviced. The TTSDF model has the same expressiveness (or equivalent computability) than the Synchronous Dataow (SDF) model, with the advantage that it guarantees minimum latency and absence of gaps and jitter in the output. Additionally, it enables run-time load balancing between callback activations and parallelization. Actor-oriented models are not off-the-shelf solutions and do not suffice for building multimedia systems in a systematic and engineering approach. We address this problem by proposing a catalog of domain-speciffic design patterns organized in a pattern language. This pattern language provides design reuse paying special attention to the context in which a design solution is applicable, the competing forces it needs to balance and the implications of its application. The proposed patterns focus on how to: organize different kinds of actors connections, transfer tokens between actors, enable human interaction with the dataow engine, and finally, rapid prototype user interfaces on top of the dataow engine, creating complete and extensible applications. As a case study, we present an object-oriented framework (CLAM), and speciffic applications built upon it, that makes extensive use of the contributed TTSDF model and patterns.

APA, Harvard, Vancouver, ISO, and other styles

44

Tshilande, Thinawanga. "Development of real-time orbital propagator software for a Cubesat's on-board computer." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2196.

Full text

Abstract:

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2015.
A precise orbit propagator was developed for implementing on a CubeSat's on-board computer for real-time orbital position and velocity determination and prediction. Knowledge of the accurate orbital position and velocity of a Low Earth Orbit (LEO) Cubesat is required for various applications such as antenna and imager pointing. Satellite motion is governed by a number of forces other than Earth's gravity alone. The inclusion of perturbation forces such as Earth's aspheric gravity, third body attraction (e.g. Moon and Sun), atmospheric drag and solar radiation pressure, is subsequently required to improve the accuracy of an orbit propagator. Precise orbit propagation is achieved by numerically integrating a set of coupled second order differential equations derived from satellite's perturbed equations of motion. For the purpose of this study two numerical integrators were selected: RK4 - Fourth order Runge Kutta method and RKF78 - results from embedding RK7 into RK8. The former is a single-step integrator while the latter is a multi-step integrator. These integrators were selected for their stability, high accuracy and computational efficiency. An orbit propagation software tool is presented in this study. Considering the processing power of Central Processing Unit (CPU) of CubeSat's on-board computer and a trade-off between precision and computational cost, the 10 x 10 and 20 x 20 gravity field models, the Exponential atmospheric model and Jacchia 70 static atmospheric model, were implemented. A 60 x 60 gravity field model is also investigated for reference. For validation purpose the developed software tool results were compared with results from Systems Tool Kit (STK) and Satellite Laser Ranging (SLR) using SUNSAT satellite reference orbit.
National Research Foundation

APA, Harvard, Vancouver, ISO, and other styles

45

Heinig, Andreas [Verfasser], Peter [Akademischer Betreuer] Marwedel, and Hermann [Gutachter] Härtig. "Flexible error handling for embedded real time systems : Operating system and run time aspects / Andreas Heinig. Betreuer: Peter Marwedel. Gutachter: Hermann Härtig." Dortmund : Universitätsbibliothek Dortmund, 2015. http://d-nb.info/1108290477/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Li, Wenming. "Group-EDF: A New Approach and an Efficient Non-Preemptive Algorithm for Soft Real-Time Systems." Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5317/.

Full text

Abstract:

Hard real-time systems in robotics, space and military missions, and control devices are specified with stringent and critical time constraints. On the other hand, soft real-time applications arising from multimedia, telecommunications, Internet web services, and games are specified with more lenient constraints. Real-time systems can also be distinguished in terms of their implementation into preemptive and non-preemptive systems. In preemptive systems, tasks are often preempted by higher priority tasks. Non-preemptive systems are gaining interest for implementing soft-real applications on multithreaded platforms. In this dissertation, I propose a new algorithm that uses a two-level scheduling strategy for scheduling non-preemptive soft real-time tasks. Our goal is to improve the success ratios of the well-known earliest deadline first (EDF) approach when the load on the system is very high and to improve the overall performance in both underloaded and overloaded conditions. Our approach, known as group-EDF (gEDF), is based on dynamic grouping of tasks with deadlines that are very close to each other, and using a shortest job first (SJF) technique to schedule tasks within the group. I believe that grouping tasks dynamically with similar deadlines and utilizing secondary criteria, such as minimizing the total execution time can lead to new and more efficient real-time scheduling algorithms. I present results comparing gEDF with other real-time algorithms including, EDF, best-effort, and guarantee scheme, by using randomly generated tasks with varying execution times, release times, deadlines and tolerances to missing deadlines, under varying workloads. Furthermore, I implemented the gEDF algorithm in the Linux kernel and evaluated gEDF for scheduling real applications.

APA, Harvard, Vancouver, ISO, and other styles

47

Chaturvedi, Vivek. "Leakage Temperature Dependency Aware Real-Time Scheduling for Power and Thermal Optimization." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/870.

Full text

Abstract:

Catering to society’s demand for high performance computing, billions of transistors are now integrated on IC chips to deliver unprecedented performances. With increasing transistor density, the power consumption/density is growing exponentially. The increasing power consumption directly translates to the high chip temperature, which not only raises the packaging/cooling costs, but also degrades the performance/reliability and life span of the computing systems. Moreover, high chip temperature also greatly increases the leakage power consumption, which is becoming more and more significant with the continuous scaling of the transistor size. As the semiconductor industry continues to evolve, power and thermal challenges have become the most critical challenges in the design of new generations of computing systems. In this dissertation, we addressed the power/thermal issues from the system-level perspective. Specifically, we sought to employ real-time scheduling methods to optimize the power/thermal efficiency of the real-time computing systems, with leakage/ temperature dependency taken into consideration. In our research, we first explored the fundamental principles on how to employ dynamic voltage scaling (DVS) techniques to reduce the peak operating temperature when running a real-time application on a single core platform. We further proposed a novel real-time scheduling method, “M-Oscillations” to reduce the peak temperature when scheduling a hard real-time periodic task set. We also developed three checking methods to guarantee the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research from single core platform to multi-core platform. We investigated the energy estimation problem on the multi-core platforms and developed a light weight and accurate method to calculate the energy consumption for a given voltage schedule on a multi-core platform. Finally, we concluded the dissertation with elaborated discussions of future extensions of our research.

APA, Harvard, Vancouver, ISO, and other styles

48

Löser, Jork. "Low-Latency Hard Real-Time Communication over Switched Ethernet." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1138799484082-54477.

Full text

Abstract:

With the upsurge in the demand for high-bandwidth networked real-time applications in cost-sensitive environments, a key issue is to take advantage of developments of commodity components that offer a multiple of the throughput of classical real-time solutions. It was the starting hypothesis of this dissertation that with fine grained traffic shaping as the only means of node cooperation, it should be possible to achieve lower guaranteed delays and higher bandwidth utilization than with traditional approaches, even though Switched Ethernet does not support policing in the switches as other network architectures do. This thesis presents the application of traffic shaping to Switched Ethernet and validates the hypothesis. It shows, both theoretically and practically, how commodity Switched Ethernet technology can be used for low-latency hard real-time communication, and what operating-system support is needed for an efficient implementation.

APA, Harvard, Vancouver, ISO, and other styles

49

Borges, Rodrigo Weissmann. "Aplicabilidade de sistemas operacionais de tempo real (RTOS) para sistemas embarcados de baixo custo e pequeno porte." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/18/18152/tde-09082011-081631/.

Full text

Abstract:

Sistemas embarcados ganham cada vez mais espaço devido ao aumento da demanda por novas funções em equipamentos, às normas regulatórias e às novas necessidades dos consumidores e do mercado. Esse aumento nos requisitos aumenta o tamanho e a complexidade dos softwares embarcados cuja importância cresce significativamente. Sistemas operacionais de tempo real constituem uma ferramenta poderosa para gerenciar a complexidade, facilitar o reuso e aumentar a portabilidade do software e também reduzir o time-to-market. Este trabalho visa avaliar a aplicabilidade de sistemas operacionais de tempo real em sistemas embarcados de baixo custo que utilizam microprocessadores pequenos (8 e 16 bits), avaliando suas características e propondo as melhores alternativas para desenvolvimento de software embarcado. Para o atendimento desta proposta, foi realizado o levantamento de características sobre o desenvolvimento brasileiro de sistemas embarcados, uma análise das características de sistemas de pequeno porte, uma discussão da viabilidade do uso de RTOS e um estudo de caso comparando arquiteturas de software embarcado. Os resultados principais mostram que arquiteturas simplificadas como a Superloop apresentam vantagem sobre os sistemas operacionais devido ao baixo consumo de memória e processamento. Os sistemas operacionais, apesar de propiciarem desenvolvimentos de códigos modulares bem como facilitar o gerenciamento de tempo, são de difícil implementação em microcontroladores pequenos, devido ao seu elevado consumo de memória e processamento. O uso de sistemas operacionais é viável para sistemas de pequeno porte com no mínimo 4 Kbytes de memória RAM e processos com limite de tempo máximo para execução (deadlines) superiores a 1 ms, condições essas que evitam a sobrecarga do microcontrolador. Neste trabalho também é mostrado um retrato do desenvolvimento de embarcados no Brasil.
Embedded systems, more and more are gaining importance, due to the increase of features requested on equipments, the regulatory standards and the costumers and market requirements. This increment on requirements increases the software size and complexity, which importance significantly grows. Real-time operating systems represents a powerful tool to manage the complexity, help the software reuse and improve portability of the software and also reduce the time-to-market. This work aims to analyze the real-time operating systems, verifying their application on low cost embedded systems using small microcontrollers (8 and 16-bit), evaluating their characteristics and propose the best architectures for software development. To attend this proposal, it was performed a survey of Brazilian embedded system development, evaluates the low cost embedded system characteristics, discusses the viability of RTOS usage and performs a comparative study of embedded software architectures. Results show that simplified architectures like the Superloop presents vantages over the operating systems due to their low memory and processing consumption. The operating system, besides helping on time management and code modularity, is difficult to implement in small microcontrollers, due to the high memory and processing consumption. The operating systems are more applicable to small embedded systems with at minimum 4 Kbytes of RAM memory and process with maximum execution time (deadlines) over 1 ms, conditions that do not causes microcontroller overload. In this work is also presented an overview of Brazilian embedded system development.

APA, Harvard, Vancouver, ISO, and other styles

50

Löser, Jork. "Low-Latency Hard Real-Time Communication over Switched Ethernet." Doctoral thesis, Technische Universität Dresden, 2005. https://tud.qucosa.de/id/qucosa%3A24637.

Full text

Abstract:

With the upsurge in the demand for high-bandwidth networked real-time applications in cost-sensitive environments, a key issue is to take advantage of developments of commodity components that offer a multiple of the throughput of classical real-time solutions. It was the starting hypothesis of this dissertation that with fine grained traffic shaping as the only means of node cooperation, it should be possible to achieve lower guaranteed delays and higher bandwidth utilization than with traditional approaches, even though Switched Ethernet does not support policing in the switches as other network architectures do. This thesis presents the application of traffic shaping to Switched Ethernet and validates the hypothesis. It shows, both theoretically and practically, how commodity Switched Ethernet technology can be used for low-latency hard real-time communication, and what operating-system support is needed for an efficient implementation.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Real-time operating systems'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles