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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.
1

Optimalizace odhadu vzdálenosti v bezdrátové ad-hoc síti / Distance Estimation in Wireless Ad-hoc Network

Botta, Miroslav January 2011 (has links)
The work deals with processing of radio received signal strength in IEEE 802.15.4 which communicates in 2.4 GHz ISM band. The signal is processed by the three approximation methods. They are tested for their effectiveness for measuring in different radio environments. Furthermore, the work deals with calculation of the most efficient coefficients for distance calculating by radio transmission fucntions. It defines the issues of such solutions on practical examples. The work also deals with the experimental algorithm for implementing dynamic calibration of the coefficients. It describes the design, processing and verification of this system in practice.
2

Ultra-broadband GaAs pHEMT MMIC cascode Travelling Wave Amplifier (TWA) design for next generation instrumentation

Shinghal, Priya January 2016 (has links)
Ultra-broadband Monolithic Microwave Integrated Circuit (MMIC) amplifiers find applications in multi-gigabit communication systems for 5G and millimeter wave measurement instrumentation systems. The aim of the research was to achieve maximum bandwidth of operation of the amplifier from the foundry process used and high reverse isolation ( < -25.0 dB) across the whole bandwidth. To achieve this, several design variations of DC - 110 GHzMMIC Cascode TravellingWave Amplifier (TWA) on 100 nm AlGaAs/GaAs pHEMT process were done for application in next generation instrumentation and high data transfer rate (100 Gb/s) optical modulator systems. The foundry service and device models used for the design are of the WINPP10-10 process from WIN Semiconductor Corp., Taiwan, a commercial and highly stable process. The cut-off frequency ft and maximum frequency of oscillation fmax for this process are 135 GHz and 185 GHz respectively. Thus, the design was aimed at pushing the ultimate limits of operation for this process. The design specifications were targeted to have S21 = 9.0 to 10.0 ± 1.0 dB, S11 & S22 ≤ -10.0 dB and S12 ≤ -25.0 dB in the whole frequency range. In order to achieve the targeted RF performance, it is imperative to have accurate transistor models over the frequency range of operation, transistor configuration mode and operating bias points. Using smaller periphery transistors results in lower extrinsic & intrinsic input and output capacitances that lead to achieving very wide band performance. Thus, device sizes as small as 2x10 μm were used for the design. A cascode topology, which is a series connection of a common-source and common-gate field effect transistor (FET), was used to achieve large bandwidth of operation, high reverse isolation and high input and output impedance. Using very small periphery devices at cascode bias points posed limitation in the design in terms of accuracy of transistor models under these conditions, specifically at high frequencies i.e., above 50 GHz. One of the major systemrequirements for the application of MMIC ultra-broadband amplifiers in instrumentation is to achieve and maintain high reverse isolation (≤ -25.0 dB) over the whole frequency range of operation which cannot be achieved alone by the cascode topology and new design techniques have to be devised. These twomajor challenges, namely high frequency small periphery FET model modification & development and design technique to achieve high reverse isolation in ultra-broadband frequency range have been addressed in this research.
3

Implementace metod pro měření rychlosti otáčení rotačních strojů na platformě cRIO / Implementation of methods for measurement of rotational speed using cRIO platform

Fábry, Tomáš January 2016 (has links)
This diploma thesis implements methods for a measurement of rotational speed. It is implemented on the Compact RIO platform from National Instruments. Corresponding SW is implemented using the graphical programming language G in LabView environment. Developed system uses two different sensors – incremental encoder and tacho sensor for measurements of rotational speed. Thesis further analysis and implements a method for an encoder nonlinearity determination and for its on-line correction. For used methods, effects adding errors into the measurements are evaluated and quantified.
4

Increasing efficiency in ECU function development for Battery Management Systems

Singh Rajput, Shivaram January 2016 (has links)
In the context of automotive industries today, the focus of ECU function development is always on finding the best possible combinations of control algorithms and parameter. The complex algorithms with broad implementation range requires optimal calibration of ECU parameters to achieve the desired behaviour during the drive cycle of the vehicle. With the growing function complexity of automotive E/E Systems, the traditional approaches of designing the automotive embedded systems are not suitable. In order to overcome the challenge of complexity, many of the leading automotive companies have formed a partnership in order to develop and establish an open industry standard for automotive E/E architecture called AUTOSAR. In this thesis, toolchain for ECU function development following AUTOSAR standard and an efficient measurement and calibration mechanism using XCP on CAN will be investigated and implemented. Two toolchains will be proposed in this thesis, describing their usage in different stages of ECU function development and in calibration. Both these toolchains will be tested to prove its working. / I området utveckling av funktionalitet på elektroniska styrsystem inom bilindustrin idag, ligger fokus på att finna den bästa kombinationen av reglermetoder och styrparametrar. Dessa avancerade system, med breda användningsområden, kräver bästa möjliga injustering av dess kalibrerbara parametrar, för att nå önskat beteende vid användning av fordonet. Det ökande omfånget av funktionskraven på styrsystemen, innebär att sedvanlig metodik för utveckling av dessa system inte är lämplig. För att kunna lösa dessa svårigheter, har de stora inom bilindustrin ingått ett samarbete, där de tillsammans skapat och utvecklar en industristandard för funktionsoch systemutveckling av styrsystem. Standarden kallas AUTOSAR. Denna rapport beskriver hur en kedja av utvecklingsverktyg som följer AUTOSAR-standarden kan användas, för att undersöka och använda en metod för systemövervakning och parameterkalibrering, genom användning av XCP över CAN.
5

Vizuální detekce elektronických součástek / Visual detection of electronic devices

Juhas, Miroslav January 2010 (has links)
This thesis describes application of image processing for precise distance measurement in self acting production of a tip for AFM microscopes. The main goal is to measure distances between assembly parts during fabrication process. The purpose is to acquire a data for self acting assembly line which have to substitute inaccurate and nonrecurring manual assembly process. The assembly process consists of three technological steps. In first two steps the tungsten wire is glued to the cantilever. Distance measurement is necessary in all axes for proper alignment of parts. In third step the sharp tip is etched by KOH solution. The right distance between liquid level and the cantilever must be kept. A camera with high resolution and macro objective is used to acquire an image. Camera image is then calibrated to suppress distortions and scene position with respect to camera position. Length conversion coefficient is also computed. Object recognition and distance measurement is based on standard computer vision methods, mainly: adaptive thresholding, moments, image statistics, canny edge detector, Hough transform… Proposed algorithms have been implemented in C++ using Intel OpenCV library. The final achieved distance resolution is about 10µm per pixel. Algorithm output was successfully used to assembly few test tips.

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