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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.
201

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

Hjorth, Mattias, Hvittfeldt, Björn January 2002 (has links)
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). 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. 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. 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.
202

Hard Realtime Rapid Prototyping Development Platform / Utvecklingsplattform för snabb framtagning av prototyper för hård realtidsexekvering

Rosenquist, Christer January 2003 (has links)
Matlab Simulink is a commonly used tool in the design process of control systems. To further take advantage of the Matlab Simulink models it is desirable to translate them for realtime use together with the possibility to read/write physical signals. Real-Time Workshop is an extension to Simulink that automatically generates code from a model to a variety of target platforms. RTAI and RTLinux are hard realtime operating systems, making use of Linux. To make automatically generated code run on RTAI and RTLinux an adaptation of the generation of code is necessary. To control, for example, an automotive engine a data acquisition card with an appropriate device driver is required. Comedi, an open source project, provides a number of device drivers for data acquisition cards. The developed system makes use of Simulink, Real-Time Workshop, RTAI or RTLinux, and the standard data acquisition card NI 6035E using a Comedi device driver. The Simulink models may be executed at frequencies up to 50 kHz on ordinary PC hardware. The evaluation of the system consisted of measuring the interrupt latency of the used motherboard's bus, measuring computation times running Simulink models with known complexity, running models developed at Vehicular Systems and a comparison of interfacing Simulink/Real-Time Workshop between RTAI and RTLinux. The recommended realtime operating system is RTAI due to the open source community support of it as a target platform for Real-Time Workshop.
203

Kmitání strojů v průmyslové praxi / Vibration of Production Machines

Hadraba, Petr January 2017 (has links)
The vibration analysis of a production machine is a key factor of its functionality, service life and occupational safety. This work deals with mathematical dynamic modelling and its contribution to the improvement of a mechanical design and mechanism failure prevention. The whole process is presented on the example of a drum cam rotary indexing table and on the example of actuators of multi spindle automatic lathes. The analysis consisted of complex nonlinear models based on basic linear models. It was computed using Matlab, Simulink and MSC ADAMS. Models of these mechanisms were validated with experimental measurements. The results were used for mechanical design improvement and for speed control optimization.
204

Řízení inverzního kyvadla / Inverted pendulum control

Daněk, Petr January 2017 (has links)
This diploma thesis deals with inverse pendulum control. There are described types of inverse pendulums, used power electronics, sensors and their connection to the MF624 control card and to external hardware. Further is described the identification of parameters, including the assembly of a custom algorithm for identification of viscous friction in the pendulum rotary coupling. For identification of moments of inertia are used 3D CAD models, where the thesis describes also use of these models for VRML visualization. The thesis also describes how to build a dynamic model by using Matlab-Simulink and the Simscape-Multibody toolbox. This model is further used in design of the controller using LQR and its simulation testing. The controller is complemented by swing-up algorithm, security elements and MF624 driver interface is designed. The control is tested on a real inverse pendulum assembly and implemented in external hardware.
205

Monitorování stavu mechatronických systémů / Condition monitoring of mechatronic systems

Horňan, Bohdan January 2021 (has links)
This thesis is concerned with condition monitoring and quantitative analysis of synchronous motors. Constantly rising requirements on the reliability of motors develop new methods of predictive diagnostics, which can identify failure conditions in the initial stage. Created mechatronic systems with the implemented failure from pre-prepared PMSM model are tested by unconventional condition monitoring methods. Software solutions of diagnostics and model designs of the mechatronic systems are implemented in MATLAB & Simulink. Part of this work is also a short introduction to the issue with necessary theoretical fundamentals and research of some selected methods of predictive diagnostics.
206

Návrh typu modulace pro prostředí s rušením / Modulation technique design for radio channels with interference

Bělohlávek, Jiří January 2009 (has links)
This thesis concisely describes essential type of modulation technique for transmission of binary signal. In introductory part there are summarized advantages and disadvantages for each described modulation technique. There are described proceeding of modulation and demodulation too. Next part is specialized mainly to determination of incorrect receiving probability. For each modulation technique are calculated theoretical values of bit error rate and compiled graph. In practical part there are described possibilities of Matlab platform for measurement of bit error rate. In implement Simulink there is built model of communication channel with additional AWGN channel. Graphs are constructed from simulation data by the help of model’s control script. On selected modulation technique are inspected various elements which are reacted with graph. In finale part there are compared theoretical and measured values and summarized analysis.
207

Turbo kódy a jejich aplikace / Turbo codes and their applications

Ploštica, Stanislav January 2009 (has links)
This Diploma thesis aims to explain the data coding using turbo codes. These codes belong to the group of error correction codes. We can reach the high efficiency using these codes. The first part describes process of encoding and decoding. There are describes parts of encoder and decoder. Principle of encoding and decoding demonstrate a simple example. The end of this part contains description of two most frequently used decoding algorithms (SOVA and MAP). The second part contains description of computer program that was made for using as teaching aid. This program was created in Matlab GUI. This program enables to browse error correction process step by step. This program contains graphic interface with many options and display results. In the third part is described program created in Matlab Simulink that was implemented into the TMS320C6713 kit and there is description of measuring procedure. For verification of efficiency of turbo codes was measured any parameters. Some of these parameters are: number of decoding iterations, generating polynoms and using of puncturing. The last part contains measured value and result evaluation.
208

Simulace řídicích struktur elektromechanických systémů / Simulation of Electromechanical System Control Structures

Petruška, Ľubomír January 2010 (has links)
Construction of motor models is the main topic of this project. Mathematical characterization of AC machine, permanent magnet synchronous motor, separately-excited DC motor, series-wound DC motor, permanent magnet DC motor, switched reluctance motor is also described. Design of models is based on mathematical description of particular motors. Models are created in Matlab Simulink. Each model is implemented in continuous and also in discrete time variant. Selected models are implemented also on processor from Freescale 56F800E Hybrid Controller family. Each model has individual graphic user interface. Besides motor models, there is description and easy algorithm of Space Vector Modulation. Model of this method is also created. Models are build-up into a library, which can be used for simulations and tests of control structures. Results of models simulations are presented at the end of this project. Simulation of models that are implemented on processor is also made in Matlab Simulink environment and is compared to simulation of models that are implemented directly in Matlab Simulink.
209

Možnosti využití neuronových sítí v síťových prvcích / Potential application of neural networks in network elements

Babnič, Patrik January 2011 (has links)
The goal was to get acquainted with the problems of network elements to describe neural networks that can be used to manage such a feature. The theoretical part deals with the neural networks from their inception to the present. It focuses mainly on the network, witch can be used for management control. These are the two network: Hopfield network and Kohonen network. The practical part deals with the network element model and ist implementation. It contains a practical element model using a neural network, witch is controlled by a network element.
210

Adaptivní OFDM / Adaptive OFDM

Nowak, Dan January 2011 (has links)
The purpose of this paper is to study the possibilities of the OFDM system adaptive modulation. The study presents mechanism for acquiring the necessary data of every frequency subchannel using pilot signals and application of these data for system adjustment. The paper introduces the water-filling principle for subchannel power allocation on the basis of their SNR and adaptive modulation mechanisms for variety of OFDM usage. These mechanisms are implemented into a MATLAB model. The code is then transformed into graphical representation and using USRP2, the signal is transmitted by real world channel.

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