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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.
71

Estimation and Compensation of Load-Dependent Position Error in a Hybrid Stepper Motor / Estimering och kompensering av lastberoende positionsfel i en elektrisk stegmotor

Ronquist, Anton, Winroth, Birger January 2016 (has links)
Hybrid stepper motors are a common type of electric motor used throughout industry thanks to its low-cost, high torque at low speed and open loop positioning capabilities. However, a closed loop control is often required for industrial applications with high precision requirements. The closed loop control can also be used to lower the power consumption of the motor and ensure that stalls are avoided. It is quite common to utilise a large and costly position encoder or resolver to feedback the position signal to the control logic. This thesis has explored the possibility of using a low-cost position sensor based on Hall elements. Additionally, a sensorless estimation algorithm, using only stator winding measurements, has been investigated both as a competitive alternative and as a possible complement to the position sensor. The thesis work summarises and discusses previous research attempts to adequately measure or estimate and control the hybrid stepper motors position and load angle without using a typical encoder or resolver. Qualitative results have been produced through simulations prior to implementation and experimental testing. The readings from the position sensor is subject to noise, owing to its resolution and construction. The position signal has been successfully filtered, improving its accuracy from 0.56° to 0.25°. The output from the sensorless estimation algorithm is subject to non-linear errors caused by errors in phase voltage measurements and processing of velocity changes. However, the dynamics are reliable at constant speeds and could be used for position control.
72

Developing a Graphical Application to Control Stepper Motors with Sensorless Load Detection

Adolfsson, Mattias January 2021 (has links)
For positioning of linear stages in absolute coordinates, there is a general need to find a reference position since the initial one is unknown. This is commonly called homing. To reduce costs and facilitate assembly, homing can be performed without additional sensors, known as sensorless homing. This thesis delves into sensorless homing, specifically with respect to stepper motors, and develops a graphical application for control of them. The commercial technology StallGuard is applied inconjunction with exploration into how it – and sensorless load detectionin general – functions. The resulting graphical application can be used to configure the stepper motors, perform homing using StallGuard, and automatically tune StallGuard to work despite varying conditions. In addition, rudimentary sensorless load detection independent from StallGuard is developed, demonstrating how it could work in practice. Testing shows homing with StallGuard resulting in a position within a ±5μm window in 94% of cases, less than 1/7 the width of an average strand of human hair. Additionally, homing is easily performed with a single button press from the graphical interface, with optional additional configuration available.
73

Vývoj systému řízení astronomického dalekohledu s možností sledování družic / Development of astronomical telescope control system with satellite tracking

Juráň, Jakub January 2018 (has links)
The focus of this thesis is a development of an electronic guiding unit for a mount of an astronomical telescope allowing observations of artificial satellites orbiting the Earth. It contains a theoretical study of methods developed for the description of positions of objects observable on the celestial sphere, including systems used for storage of this information and regaining it in order to point the telescope in a specific direction. The work includes an analysis of the present supply of commercial devices, followed by a detailed description of the design developed here and its components. Finally, there is outline of possibilities of a future development of the system, focusing on software components.
74

Vývoj testovacího přípravku délkového snímače / Development of the testing device for length measurement

Kirchner, Jan January 2018 (has links)
Aim of this thesis is a verification of possibility to measure displacement in small range using sensor based on the principle of strain gauge. For testing purspose, an evaluating unit was designed, made and assembled. This unit contains analog/digital converter, LCD and it has an abbility to move measuring plane using stepper motor. Next part of this thesis is about testing new prototype of strain gauge sensor, including evaluation of results of measuring. The performed measurements were measuring linearity, time stability and repeatability. Based on the results of the measurements, the possibility of using this type of length measuring device was confirmed for further development.
75

Program pro inovaci řídicího systému SORT / Program for inovation of the SORT control system

Šulc, Martin January 2014 (has links)
The analysis for the extension of the control system and proposal of controlling program for surveillance cameras and related theoretical analysis necessary for understanding problems. Proposal communication protocol to access all functions via TCP/IP communication. Subsequent protocol implementation into control program and a programmable controller. Programming application with a user interface for camera control and basic image processing. The program also represents the server for TCP/IP communication with clients over the proposed protocol. The proposed application has to fulfill high pretensions of data streaming from cameras. Extension of the existing control system of the telescope, dome and other systems. The addition of analog measurement and control of digital inputs and outputs. Furthermore, control of stepper motors to control focusers. The embedded communication protocol will be expanded of the new instruction.
76

Dvoukanálový kontrolér krokových motorů / Two channel stepper motor controller

Hýbl, Matouš January 2021 (has links)
Cílem této práce je vývoj dvoukanálového kontroléru krokových motorů. V rámci práce je popsán jak vývoj elektroniky, tak vývoj příslušného software. Elektronika kontrolŕu je založena na mikrokontroléru STM32F405 a driverů krokových motorů vyráběných firmou Trinamic. Pro komunikaci s nadřazenými systémy je implementován protokol CANOpen a sběrnice I\textsuperscript{2}C a USB. Elektronika byla navržena v software KiCAD and využívá čtyřvrstvého plošného spoje a moderních výrobních technologií. Co se týká software, byl vyvinut jak firmware pro mikrokontrolér, tak software pro ovládání kontroléru. Obě části software využívají programovacího jazyka Rust, který se zaměřuje na bezpečnost práce s pamětí, rychlost a zero-cost abstrakce. Sekundárním cílem této práce je ukázat, jak lze tento programovací jazyk s výhodou použít pro programování nízkoúrovňového embedded software. Firmware kontroléru implementuje nezávislé řízení pohybu obou os kontroléru a to jak v rychlostním, tak v pozičním režimu a zároveň implementuje bezpečnostní funkce pro případy selhání komunikace. Výsledný kontrolér by měl být použit v rámcí výzkumné skupiny Robotiky a Umělé Inteligence a studenty na Ústavu Automatizace FEKT VUT.
77

Binokulární vidění / Binocular vision

Brňák, Jan January 2012 (has links)
This masters thesis deals with the physiology of binocular vision people for obtaining two dimensional spatial perception of images with glasses. There are developed theoretical part of the physiology of vision, then writing available methods that are now widespread for obtaining stereoscopic scene. The work also describes shooting dynamic scene using a pair of identical cameras. It focuses mainly on OFF-AXES method and deals with the topic of the settings stereoscopic base. There is also realized a practical part, which works with the capture dynamic scenes using video cameras with a automatic control of cameras distance. Automatic control is performed using the parallel port and a stepper motor. For this purpose it is designed to work in hardware support and a program for mutual communication. Filmed a short movie was screened to a group and those observers evaluated the parameters that were specified in the created poll.
78

Konstrukční řešení mechanismu napínací kladky zkušebního zařízení / Testing Device Idler Pulley Design

Čoček, Jan January 2015 (has links)
The aim of this diploma thesis is the design of automatic tensioning device for regulating forces in driving belts of high-pressure pumps under long-term testing, in collaboration with Bosch Diesel s.r.o. in Jihlava. The paper describes the development of the mechatronic device, from the selection of components, going through the design phase of the automatic electronic device, up to mechanical design and prototype execution. An assessment is made of custom device based on the test in real operations and economic benefits for the client are evaluated in the conslusion.
79

Development of an Optical Scattering Measurement Device / Produktutveckling av ett optiskt mätinstrument

Grünwald, Ida, Gåhlin, Amanda January 2024 (has links)
Optical scattering measurement devices are used to measure light reflection and light scattering from materials, to obtain data of the surface and bulk properties of materials. The measurement data are often used in research and development projects where material requirements are important, also for quality control in manufacturing processes, in different optical simulations and can be used for photorealistic rendering. In this master thesis project conducted at AFRY, a multifunctional team will develop an optical scattering measurement device that aims to collect data more accurately than current devices on the market. This thesis will focus on the mechanical design of the device which consists of the stability and movement of the components, the environment of the measurements and material selection with a focus on performance and sustainability. The optical model that will act as a basis for the development will be a gonioreflectometer consisting of a material sample, sample holder, light source, detector and an environment in which the measurements are conducted. Some of the physical, cognitive and emotional needs of the intended user are efficient use, low risk of misuse, reliable and high precision. A thorough requirement specification was made as a framework for the concept generation. The selected concept provides the movement of the optical components with an angular step enabling the desired optical scattering measurement. The selected stepper motor and gear ratio provides the flexibility of the movement, making it easy for the user to change angular steps of the optical components, enabling both fine and rough measurements. A separating screen was chosen for both concepts in order to avoid light contamination between measurements and the material sample holder resembles a frame that allows for mounting the material sample outside of the device. The mechanical system has a high stability and the material black anodized aluminum further contributes to the sturdiness of the construction. A physical prototype was created to validate the movement, since the movement of the detector and light source will be similar, only the detector movement was prototyped. The prototype showed that the movement of the detector worked in the desired way, hence the construction of the movement is approved. The scope was delimited in consensus with the project members and supervisors due to the time frame, hence there is future work on the device that should be accounted for. In conclusion, the purpose of the project was fulfilled after delimiting the goals and a conceptual solution was created that fulfilled the requirements of the project. / Optiska mätinstrument används för att mäta ljusreflektion och ljusspridning från material, för att erhålla data om materialets yt- och bulkegenskaper. Mätdata används ofta i forsknings- och utvecklingsprojekt där materialkrav är viktiga, även för kvalitetskontroll i tillverkningsprocesser, i olika optiska simuleringar och kan användas för fotorealistisk rendering. I detta examensarbete, genomfört på AFRY, kommer ett multifunktionellt team att utveckla en optisk spridningsmätningsenhet som syftar till att samla in data mer noggrant. Denna avhandling kommer att fokusera på den mekaniska designen av enheten som består av stabiliteten och rörelsen av komponenterna, mätmiljön och materialval med fokus på prestanda och hållbarhet. Den optiska modellen som kommer att ligga till grund för utvecklingen kommer att vara en gonioreflektometer bestående av ett materialprov, provhållare, ljuskälla, detektor och en miljö där mätningarna genomförs. Några av de fysiska, kognitiva och emotionella behoven hos den avsedda användaren är effektiv användning, låg risk för felanvändning, pålitlighet och hög precision. En noggrann kravspecifikation gjordes som en ram för konceptgenereringen. Det valda konceptet möjliggör rörelse av de optiska komponenterna med ett vinkelsteg som tillåter den önskade optiska spridningsmätningen. Den valda stegmotorn och utväxlingen ger flexibilitet i rörelsen, detta bidrar till att det är enkelt för användaren att ändra vinkelstegen för de optiska komponenterna, vilket tillåter både fina och grova mätningar. En avskiljningsskärm valdes för att undvika ljuskontaminering mellan mätningarna och materialprovhållaren liknar en ram där materialprovet monteras utanför enheten. Det mekaniska systemet har en hög stabilitet och materialet svart anodiserad aluminium bidrar till konstruktionens robusthet. En fysisk prototyp skapades för att validera rörelsen, eftersom rörelsen av detektorn och ljuskällan kommer att vara liknande, återskapades endast detektorns rörelse. Prototypen visade att detektorns rörelse fungerade på önskat sätt, därmed godkänns konstruktionen av rörelsen. Projektets mål avgränsades i samförstånd med projektmedlemmarna och handledarna på grund av tidsramen, därmed finns det framtida arbete för mätinstrumentet som bör beaktas. Sammanfattningsvis uppfylldes projektets syfte efter att målen avgränsats och en konceptuell lösning skapades som uppfyllde projektets krav.

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