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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.
171

Datorstödd implementering med hjälp av Xilinx System Generator / Computer Aided Implementation using Xilinx System Generator

Eriksson, Henrik January 2004 (has links)
The development in electronics increases the demand for good design methods and design tools in the field of electrical engeneering. To improve their design methods Ericsson Microwave Systems AB is interested in using computer tools to create a link between the specification and the implementation of a digital system in a FPGA. Xilinx System Generator for DSP is a tool for implementing a model of a digital signalprocessing algorithm in a Xilinx FPGA. To evaluate Xilinx System Generator two testcases has been designed. The testcases are selected to represent the FPGA designs made at Ericsson Microwave Systems. The testcases show that Xilinx System Generator can be used to effectivly implement a model made in Simulink in a FPGA from Xilinx. The result of the implementation is comparable to the implementation of VHDL code written by hand. The use of tools for implementation of a model in hardware cause change in the design methods used at Ericsson Microwave Systems. The higher level of abstraction introduced by System Generator results in the design decisions made at system level having a higher impact on the final realization.
172

Rekursiv greyboxidentifiering av drivsystem i industrirobot.

Eriksson, Petter January 2006 (has links)
In modern industrial robots the components in the transmission contain nonlinearities. These nonlinearities need to be to estimated either for better control or to use the parameters for diagnosis of the system. There is a lot of work done within system identification and mainly within the field of iterative parameter estimation. This thesis considers recursive grey-box identification for a nonlinear model of the transmission in an industrial robot. The nonlinearities that are identified are friction, spring stiffnes, hysteresis and backlash. These nonlinearities are a part of the models that are presented in this thesis. Apart from models there is a need for some sort of algorithm for the identification and some different recursive algorithms are presented. The main subject of this thesis is the identification of parameters and the excitation signals needed for the identification of each parameter. The models and algorithms presented in this thesis work in a principle point of view. Despite this they work in varying extent for the different types of parameters. Estimation of linear and nonlinear friction and linear spring stiffnes works relatively well. Nonlinear spring stiffnes and hysteresis have not been possible to estimate. Backlash which is estimated with a hybrid variant of a RPEM which is not fully recursive works best. When it is not possible to identify the parameters suggestions on other solutions are given, such as for example extension of the model, use of other algorithms or optimization of the excitation signal.
173

Transmission Modeling with Simulink and FPGA implementation of 3072-point FFT for the Homeplug AV system

Sun, Wei-Cheng 20 July 2011 (has links)
The rapid growth of communication technology with the success of internet, has brought huge profits and great convenience to our daily life. Computer networks can be built using either wired or wireless technologies. It will be an important issue that how to select a medium for the transmission. Wired Ethernet has been the traditional choice in most of the networks. However, it has to deploy the Ethernet wires. For the wired internet networks, the power line communication (PLC) technology will be an alternative choice. In this wire-line communication system, the power line network is used as the transmission medium. Therefore, computer networks can work on the existing power line system. No extra new transmission infrastructure is needed. So far, several PLC standards are available, shch as X-10, CEBus(Consumer Electronic Bus), Echonet and Homeplug. This thesis studies the Homeplug AV specification developed by the Homeplug powerline Alliance. By employing MATLAB/Simulink, we build up a PLC baseband transmission model and simulation platform. We carry out the Homeplug AV baseband transmission performance in system level on this platform. The Homeplug AV adopts 3072-point FFT which is not the power of two. It will be a challenge to design the 3072-point FFT processor. Here, we use Xilinx System Generator to design and implement the 3072-point FFT processor. The function verification of the implemented 3072-point FFT processor for Homeplug AV system is carried out by simulation.
174

Simulation Of A 1-d Muscle Model In Simulink

Zeren, Zekai Uygur 01 December 2007 (has links) (PDF)
The most basic property of a muscle is its ability to contract and produce force when stimulated. A muscle is mainly composed of cells consisting of myofibrils with its basic unit called as a sarcomere. A sarcomere is composed of actin and myosin responsible for the muscle contraction. The Hill-type muscle model is the most commonly used model to simulate the behavior of a muscle. A muscle can produce its maximum force at isometric conditions. The level of force produced in the muscle is determined by the the frequency of the signals from the CNS. The force production is also a function of force-muscle current velocity and force-muscle current length relations. A muscle contains two types of sensors / i.e. muscle spindle and golgi tendon organ, which give rise to the feedback control of the muscle length and muscle contraction velocity. In this study a 1-D model of a muscle is formed step by step in Simulink. In the models the muscle mechanics has been investigated and the results are compared with the previous works.
175

Sim2spice, a tool for compiling simulink designs on FPAA and applications to neuromorphic circuits

Petre, Csaba 18 November 2009 (has links)
Analog circuit technology is of vital importance in today's world of electronic design. Increasing prevalence of mobile electronics necessitates the search for solutions which offer high performance given tight constraints on power and chip area. Field programmable arrays utilizing floating-gate technology are one possible solution to analog design. It offers the advantages of analog processing with the additional advantage of reconfigurability, giving the designer the ability to test new analog designs without costly and time-consuming fabrication and test cycles. In this work, a new interface for FPAA's is demonstrated called Sim2spice, with which users can design signal processing systems in Matlab Simulink and compile them to SPICE circuit netlists. These netlists can be further compiled with a tool called GRASPER to a switch list for programming on an FPAA chip. Example library elements are shown, along with some compiled systems such as filters and vector-matrix multipliers. One particularly compelling application of reconfigurable analog design is the field of neuromorphic circuits, which aims to reproduce the basic functional characteristics of biological neurons and synapses in analog integrated circuit technology. Simulink libraries have been built to allow designers to build neuromorphic systems on several FPAAs that have been developed expressly for the purpose of building neurons and connecting them in networks with synapses. Several possible dynamically learning synapses have also been explored.
176

Modelling an RF Converter in Matlab / Modellering av en radarvarningsmottagare i Matlab

Hjorth, Mattias, Hvittfeldt, Björn January 2002 (has links)
<p>Radar warning systems are life saving equipment in modern fighter aircraft. It is therefore vital that the system can tell the difference between a threat genuine frequency) and a false signal (spurious frequency). </p><p>This thesis presents a model aimed at predicting the frequencies and other parameters in the RF converter of the radar warning system. The components of the RF converter have been studied, measured, and modelled. The modelling tool has been the Simulink toolbox for Matlab. </p><p>Extreme accuracy has been sacrificed in order to make the model easy to use for the working engineer. Instead, this model presents a rough estimate of some of the most important properties of the radar warning system with just a few data sheet figures as input.</p><p>The simulation results are satisfactory as a whole. Simulink is the limiting factor in the implementation of the model. Significantly improved results can probably be obtained by working in another software environment.</p>
177

Modelling of the stabilizationsystem in the gunners sight on MBT 122 / Modellbygge av stabiliseringssystem för skyttens sikte i stridsvagn 122

Johansson, Tomas January 2002 (has links)
<p>AerotechTelub bedriver, på uppdrag av den svenska försvarsmakten, en så kallad tech-transfer process eller tekniköverföringsprocess för den från Tyskland inköpta stridsvagnen Leopard 2 (svensk beteckning; strv 122). Syftet med processen är bland annat att säkerställa att den kunskap som behövs för att hålla stridsvagnen i drift. Uppgiften är att studera erhållna dokument och ritningar för stridsvagnens siktessystem. Med hjälp av dessa har en modell av systemet som stabiliserar siktet byggts upp i Matlab och Simulink. </p> / <p>Aerotechtelub is conducting a so called tech-transfer process of the German purchased main battle tank Leopard 2 (Swedish designation Strv 122). The main purpose of the process is to guarantee that the knowledge that is required to keep the tank in operation. The task is to study the obtained documents and schematics concerning the bore sight system of the tank.</p>
178

Modellering av ett OFDM system för IEEE 802.11a med hjälp av Xilinx blockset / Modelling of an OFDM system for IEEE 802.11a using the Xilinx blockset

Botvidzon, Johan January 2002 (has links)
<p>Kraven på dagens trådlösa förbindelser kommer hela tiden att öka och med detta följer även högre krav på nya produkter som kan tillgodose de ökade kraven. För att göra processen från idé till produkt snabbare krävs enkla verktyg för att snabbt kunna gå från den formulerade standarden till en hårdvaruprototyp. Detta arbete har använt sig av ett av dessa verktyg som idag finns tillgängliga, Xilinx System Generator for DSP 1.1, för att ta fram sändare och mottagare för en del av den trådlösa standarden IEEE 802.11a. Arbetet ger en beskrivning av hur sändare och mottagare är uppbyggda samt även synpunkter på System Generator och beskrivningar av problem som uppstod under arbetet. </p> / <p>The demands on todays wireless communications will continue to increase and with this follows a demand for shorter and shorter development times for the products that are going to satisfy this demand. To accomplish this shorter development time simple tools for going from the formulated standard to a hardware prototype is needed. This work uses one of these tools today available, Xilinx System Generator for DSP 1.1, to develop a transmitter and a reciever for a part of the wireless standard IEEE 802.11a. The work gives a description of the building blocks of the transmitter and the reciever but also some views on System Generator and descriptions of problems that were encountered during the work.</p>
179

Modeling and simulation of distribution system components in anticipation of a smarter electric power grid

Toliyat, Amir 11 July 2011 (has links)
Successful development of the electric power grid of the future, hereinafter referred to as a smart grid, implicitly demands the capability to model the behavior, performance, and cost of distribution-level smart grid components. The modeling and simulation of such individual components, together with their overall interaction, will provide a foundation for the design and configuration of a smart grid. It is the primary intent of this thesis, to provide a basic insight into the energy transfer of various distribution-level components by modeling and simulating their dynamic behavior. The principal operations of a smart grid must be considered, including variable renewable generation, energy storage, power electronic interfaces, variable load, and plug-in electric vehicles. The methodology involves deriving the mathematical equations of components, and, using the MATLAB/Simulink environment, creating modules for each component. Ultimately, these individual modules may be connected together via a voltage interface to perform various analyses, such as the treatment of harmonics, or to acquire an understanding of design parameters such as capacity, runtime, and optimal asset utilization. / text
180

Supporting multidisciplinary analysis using system architectures in SysML

Branscomb, Jaclyn Marie 30 May 2012 (has links)
To develop competitive vehicles with ever increasing complexity, automotive designers need to improve their ability to explore a broad range of system architectures efficiently and effectively. Whereas traditional vehicle systems are based upon internal combustion (IC) engines, today’s environmentally conscious vehicle manufacturers must consider alternatives to the IC engine-only systems such as hybrid or electric systems. To help the engineers to model these multiple alternatives, it would be ideal to start from a base vehicle architecture. To design a good vehicle, it is necessary for each of these system architectures to be analyzed from a variety of attributes including performance, fuel economy, or even thermal behavior. Creating the necessary analysis models for each system architecture would be time-consuming, expensive, and could be error prone. To aid in overcoming such challenges, we have developed an approach for supporting the generation of subsystem model templates to support the integration of analysis models. The approach is based on formally modeling the system architecture in the Systems Modeling Language (OMG SysML) and then using model transformations to generate stubs for corresponding analysis models in Modelica and Simulink. In this manner, we assist designers in managing large systems with multiple analyses, ensuring that the systems remain consistent, and enabling the reuse of generic architectures through specialization and redefinition. The starting point is a reference architecture, called the Vehicle Model Architecture or VMA, in which all the key subsystems and interactions between subsystems are formally modeled. In addition, we have created a generic template that is a specialized version of the VMA. This specialized template can then be adapted by the systems engineer to represent a specific vehicle program. In addition, pre-defined, generic analysis templates can be redefined for the specific vehicle program under analysis. The SysML VMA system model is transformed through two model transformations, one that translates the physical portion of the system to Modelica, and one that transforms the logical controls portion of the system to Simulink. By automating these transformations and reusing a set of fixed templates for further specialized architectures, this approach helps to manage the complexity, reduces modeling time by enabling system model reuse. The entire approach taken in this thesis has been named the Vehicle Architecture Modeling Framework, VAMF, which includes the SysML VMA, the corresponding analysis templates, and the tools developed to support this approach. Throughout this thesis, the specific (fictitious) vehicle program “C100” and a 0-to-100 kph performance analysis test are used as examples for demonstration.

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