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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.
11

Mechanical Dynamics of a Sensorless PMSynRel Drive

Yu, Yingbei January 2013 (has links)
Hybrid electric vehicle (HEV) concept has, combining conventional internal combustion engines and electric drives, gained more and more interest due to its environmental friendly features. A PMSynRel based electric drive is considered as a good option due to its high torque density and high efficiency. To reduce the overall cost of HEVs, the position resolvers can be replaced by Hall-sensors or using sensorless control. However, the dynamics of such electric drives may be degraded. The main objective of this MSc project is to develop torque dynamics of such electric drives when operating with/without a position sensor. The developed torque dynamic can be used to analyze the limits of hall senor/sensorless strategy when, e.g. anti-oscillation control isrequired. The torque dynamic is presented as a matrix based transfer function extracted from the speed responses and torque responses using Identification Tool Box in Matlab. Firstly, the transfer function was derived by means of simulations in both time and frequency domains. Secondly, similar procedures were applied to extract the transfer functions based on the experimental results.
12

Realization of a serially-linked haptic device / Framtagning av en serielänkad haptisk enhet

Massoumzadeh, Ramtin January 2017 (has links)
Spatial haptic interfaces have existed for more than 20 years but have not been widespread despite promising applications. The few devices found in the market as of today are either considered costly, of higher quality and produced in smaller series or mass-produced and cheap, but of lower quality. This thesis aims to develop a new serially-linked everyday haptic desktop product under the project name Polhem. It aims to be based on the previous efforts of WoodenHaptics and AluHaptics, developed by Forsslund et al. The electronics and control software is shared between the WoodenHaptics, the AluHaptics as well as the Polhem designed and manufactured in this project. Polhem is capable of delivering forces in 3 DOF and its manipulandum is trackable in 6 DOF. Polhem is designed so as to eliminate problems related to angular tracking technologies currently used in some higher-end haptic devices. / Spatiala haptiska gränssnitt har existerat i mer än 20 år men har trots sina lovande applikationer inte varit tillgänglig i någon större utsträckning. De få enheter som finns på marknaden i dagsläget anses antingen vara dyra, av högre kvalitet och produceras i mindre serier eller massproducerade och billiga, men av lägre kvalitet. Denna avhandling syftar till att utveckla en ny serielänkad haptisk produkt under projektnamnet Polhem. Polhem syftar till att baseras på de föregående enheterna WoodenHaptics och AluHaptics, som utvecklats av Forsslund et al. Elektroniken och reglermjukvaran delas mellan WoodenHaptics, AluHaptics och Polhem. Polhem kan leverera krafter i 3 frihetsgrader och dess manipulandum kan spåras i 6 frihetsgrader. Polhem är utformad så att den eliminerar problem relaterade till äldre vinkelspårningsteknologi som för närvarande används i många högpresterande haptiska enheter
13

Electric Load Driven Longboard / Elektrisk lastdriven longboard

ANDERSSON, JOHAN, HÖGLUND, RICKARD January 2020 (has links)
This bachelor’s thesis aims to show an extensive overview of all the parts that build up an electric load driven longboard and see if a load controlled longboard can be seen as a safe, comfortable and convenient alternative to the more common remote controlled longboard. The thesis will also answer how weight can be measured on a longboard in the most effective way, what the most comfortable riding technique is and what a good motor-battery configuration to be able to travel at 30 km/h and 10 km would be. The longboard measures the weight distribution with load cells located between the deck and the trucks. An Arduino translates the input from the load cells to a certain speed and then sends it to an ODrive which controls a BLDC motor that is powered by two LiPo batteries. The results show that a load controlled longboard can very well be seen as a good alternative if right riding technique is used. The best technique is when the longboard accelerates when the rider tilts and keeps a constant speed when the rider stands straight. The best way to measure the weight is to fasten the trucks with hinges which lets the load cells register weight without anything interfering. Not all tests could be done because of Covid-19 but a measured top speed of 15 km/h with a high gear ratio is a promising result for the future when more suitable gear ratios will be tested to try to reach the goal of 30 km/h. / Det här kandidatexamensarbetet strävar efter att visa en omfattande överblick på alla delar som bygger upp en elektrisk lastdriven longboard och se om en laststyrd longboard kan ses som ett säkert, komfortabelt och behändigt alternativ till den vanligare radiostyrda longboarden via handkontroll. Det här arbetet kommer också svara på hur vikt kan mätas på en longboard på ett så effektivt sätt som möjligt, vad som är den mest bekväma åkstilen och vad är en bra motor-batteri konfiguration för att kunna åka i 30 km/h och nå 10 km skulle vara. Longboarden mäter viktfördelningen med lastceller som är placerade mellan brädan och truckarna. En Arduino omvandlar indatan från lastcellerna till en specifik hastighet som den sedan skickar till en ODrive som kontrollerar en borstlös likströmsmotor som i sin tur är driven av två LiPo batterier. Resultaten visar att en laststyrd longboard kan mycket väl ses som ett bra alternativ om rätt åkstil används. Den bästa stilen är att longboarden accelererar när åkaren lutar sig och håller en konstant hastighet när åkaren står rakt. Det bästa sättet att mäta vikt är att montera truckarna på gångjärn som låter lastcellerna mäta vikt utan att något stör. Alla tester kunde inte utföras på grund av Covid-19 men en uppmätt topphastighet på 15 km/h med en hög utväxling är ett lovande resultat för framtiden när lämpligare utväxlingar kommer testas för att försöka nå målet på 30 km/h.
14

Robot řízený mikroprocesorovou jednotkou PIC / Robot Controlled by PIC Microprocessor Unit

Heřman, Petr January 2015 (has links)
This thesis describes design of a cheap robot. It includes implementation of firmware of low level control unit based on microcontroller PIC. The firmware drives motors, gains sensors data and communicates with the high level control unit. Furthermore the thesis presents realisation of connection to the robotic operation system ROS and its standard structures allowing usage of existing packages for the robot teleoperation and displaying sensor data on the remote computer. The thesis finally reports experiments with the robot. The constructed prototype is the model of the robotic lawn mower, however the whole solution has universal usage.
15

Ověření funkce bezkontaktního snímače hladiny paliva v palivové nádrži / Testing and calibration of fuel level gauge

HAIKL, Petr January 2013 (has links)
This work inkluse measurement principles for measuring liquid level in tanks with a focus on fuel. Are described most frequently used types of liquid level sensors, focusing on fuel. The work inkluse design chosen technical solutions fuel level sensor and its technical implementation, including the technical implementation and verification of its functionality and calibration.

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