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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.
101

Robot pro stolní tenis / Table tennis robot

Nguyen, Thuc Tuyen January 2013 (has links)
This diploma thesis deals with designing and manipulating a robot for training table tennis. Robot's mechanical construction is based on aluminium profiles supported by various standardized assembly units, such as rotating bearings, plain bearings, threaded rods... The front-end part of the robot, which requires better deformation property and lighter weight, was made from ABS material using 3D rapid prototyping technology. The design of the robot allows its body to rotate around three axises. Thanks to the high dynamical ability, robot can be set to throw balls to various places on the playing table, with different types of ball spin. Balls will be shot out by two rubber wheels, which are attached to two electrical DC motors. By driving the speed of the two motors, we can control the speed of the ball, as well as speed of its spin. All robot's activities are driven by an embedded system designed using microcontroller ATMega128. A firmware for controlling robot's function was writen and flashed into the microcontroller. End-users might communicate with the robot via a system of buttons and a text LCD display. The built robot was tested and it has shown its ability to throw balls to 6 different places of the playing table, at different speeds, with different types of ball spin, and different spin speed, according to the parameters set by user.
102

Návrh zařízení pro Power HIL simulaci stejnosměrného motoru / Design of unit for Power HIL simulation of DC motor

Chalupa, Jan January 2014 (has links)
This thesis deals with analysis and implementation of Power-HIL system that is designed to simulate real DC motor with comutator and permanent magnets. For problem analysis were used simulations of real components in Matlab / Simulink. The electronic parts of system were simulated with using the SimElectronic library. Idividual hardware components were designed according to simulation results. The outcome of this thesis is a power electronic simulator of real DC motor, which is implemented on dSPACE platform. The system allows software to setup parameters and behavior of simulated motor. The final system can be used for testing DC motor ECU (electronic control units).
103

Návrh řídicího algoritmu pro elektromechanický aktuátor s výrazným suchým třením / Design of controller for electromechanical actuator with significant dry friction

Veselý, Antonín January 2015 (has links)
This work deals with identification of systems with high dry friction and/or return spring. Identified models are optimised by Parameter Estimation toolbox. Because friction and return spring have negative influence in control systems, models are used as compensators in control loop. Also effect of parameters variation is investigated in this paper.
104

Development and Implementation of a Search and Locate Actuator System

Macías Cubeiro, Rosa January 2012 (has links)
Over the last years, electrical roads have emerged as a cost effective and environmentally friendly solution towards a transportation system with less dependency on fossil fuels. This thesis presents the design of a search and locate system for road-bound conductive electrical roads with position control in two axes. The system is intended to find and follow the position of an electrified rail. The actuator system constitutes a firm groundwork for further research and development in this field. A laboratory test set up has been designed and both hardware and software parts have been constructed. The control of the system uses the CompactRIOTM technology from National Instruments. Results from the practical evaluation suggest that the non-linear characteristic of the system and the lack of direct position feedback from the motor rotation are the main causes of a non-accurate position control. Future development steps should focus on improving the mechanical design and include encoder feedback for the control loop as well as absolute automatic control with the incorporation of rail sensors.
105

Automatic Torque Control for Bicycle Driven Brushless DC (BLDC) Generator

Müller, Luke, Sjöström, Kasper January 2021 (has links)
This work was carried out on behalf of Science Safari. Science Safari wants to create a product that facilitates the understanding of how much physical work is required to create electrical energy. This is done by cranking the pedals of a bicycle. The purpose of this work is to create a control unit that keeps the torque required to crank the pedals close to constant. The torque can be kept constant by creating a variable load for the generator, in this case, a pulse modulated JFET is used. The output of the current sensor and the Hall-effect sensor are used to calculate the required resistance of the JFET to keep constant torque. All this is controlled via a Raspberry Pi 3 Model B (RPi) which also shows real-time values on a display. The functionality of the sensors and JFET has largely been completed, but the assembly of all components is lacking in this work. / Detta arbete är utfört i uppdrag av Science Safari. Science Safari vill skapa en produkt som underlättar förståelsen av hur mycket fysiskt arbete som krävs för att skapa elektrisk energi. Detta genom att användaren vevar på en cykels pedaler för hand. Syftet med detta arbete är att skapa en styrenhet som ungefär håller ett konstantvridmomentet på en cykels pedaler. Vridmomentet kan hållas konstant genom att skapa en variabel last till generatorn, med hjälp av en pulsmodulerad JFET. För att beräkna vilken resistans JFETen ska ha för att hålla konstant vridmoment används en strömsensor och en Hall-effect sensor. Allt detta styrs via en Raspberry Pi 3 ModelB som även visar värden i realtid på en display. Funktionaliteten av sensorerna och JFET har till stor del färdigställts men sammansättning av alla komponenter saknas i detta arbete.
106

An Investigation of the Ward Leonard System for Use in a Hybrid or Electric Passenger Vehicle

Telford, Cody L. 18 April 2012 (has links) (PDF)
Since the early 1900's demand for fuel efficient vehicles has motivated the development of electric and hybrid electric vehicles. Unfortunately, some components used in these vehicles are expensive and complex. Today's consumer electric vehicles use dangerously high voltage,expensive electronic controllers, complex battery management systems and AC motors. The goal of this research at BYU is to increase safety by lowering the operating voltage and decrease cost by eliminating expensive controllers and decrease the number of battery cells. This paper specifically examines the use of a Ward Leonard Motor Control system for use in a passenger vehicle. The theory of the Ward Leonard system as an Infinitely Variable Transmission (IVT) is presented along with its history and past uses. Analogous systems are presented and similarities made in an attempt to enlighten designers to a broader design approach to increase safety and decrease cost of an electric or hybrid electric vehicle. The results of this research include a characterization of the Ward Leonard system as an IVT for use in an electric or hybrid (EV or HEV) passenger vehicle. These results include a study of past uses of the Ward Leonard system and what method is now used as a replacement. The theory of the Ward Leonard system and it operation is explained to an extent that someone not familiar with electronics can understand its working principles. A Control Factor metric was developed as a result of this research to measure the Ward Leonard System's ability to reduce the size of the electronic controller for application in an EV or HEV. The potential cost reduction of the electronic controller that would be used to control the Ward Leonard System compared with current EV and HEV vehicles was also research and identified. A bench top model of the Ward Leonard system was tested validating the Control Factor metric. The Ward Leonard system is capable of reducing the controller size by 77% and potentially reducing its cost by 68% or more. This work also provides performance characteristics for automotive designers and offers several design alternatives for EV and HEV architectures allowing the reduction of high voltage, the use of AC inverters, AC motors, expensive controllers and high cell count battery packs.
107

Best PAL : Ball Exercise Sound Tracking PAL / Best PAL : Ljudlokaliserande smart bollplank för individuell fotbollsträning

Hellberg, Joakim, Sundkvist, Axel January 2018 (has links)
The PAL (Practise and Learn) Original is a ball board consisting of three wooden boards placed in a triangle, developed to practise football players’ passing ability and first touch. The former Swedish international footballer Jessica Landström observed that these ball boards can, if they are improved, help footballers to develop even more skills while practicing alone. Landstr¨om’s idea was to put lamps on top off the ball boards which light up when a certain ball board expects to receive a pass. This would force the player to look up instead of looking at the ball and hence improve their vision. We concluded that speaking also is important within football. So our objective became to follow up on the development of the simple PAL Original to a ball board which rotates towards a sound source. We wanted to achieve this without configuring the PAL Original’s construction. With the purpose of executing the idea we needed to estimate the angle between a sound source and a face of the ball board, rotate the ball board with an electric motor, communicate wirelessly between units and detect a ball hit when the ball board receives a pass. The final prototype consists of two systems, one system executing the sound source localization and rotation and the other system executing the detection of ball hit and wireless communication. The first system uses time difference of arrival (TDOA) between incoming sound for three sound sensors to calculate an angle, which in turn is communicated to a DC motorthat executes the rotation. The other system combines an LED to light up when a pass is expected, an accelerometer to detect a pass, and radio transceivers to communicate with each other. When at least three of these devices are used a randomizing algorithm decides which one should light its LED next when the first one detects a pass. / PAL (Practice and Learn) Original är ett bollplank bestående av tre träskivor placerade i en triangel, utvecklad för att träna fotbollsspelares passningsförmåga och första touch. Jessica Landström, landslagsmeriterad fotbollsspelare, insåg att dessa bollplank kan utvecklas till att hjälpa fotbollsspelare att träna ännu fler områden vid indviduell träning. Landströms ursprungliga idé var att placera en lampa på bollplanket som lyser upp när den förväntar sig en passning, detta för att tvinga spelaren att titta upp istället för att titta på bollen, och därigenom träna spelarens spelförståelse. Vi drog slutsatsen att det också är mycket viktigt med kommunikation i fotboll. Vårt mål blev därför att vidareutveckla PAL Original till ett bollplank som roterar en sida mot en ljudkälla. Vi ville uppnå detta så att det är kompatibelt med PAL Original utan att ändra dess konstruktion. För att genomföra detta behövde vi alltså uppskatta vinkeln mellan en ljudkälla och en sida av det triangulära bollplanket, rotera bollplanket med en motor, kommunicera trådlöst och detektera när bollplanket mottar en passning. Den slutliga prototypen består av två system, ett system som utför lokalisering av ljudkälla samt rotation och ett system som utför detektering av bollträff samt hanterar trådlös kommunikation. Det första systemet utnyttjar tidsskillnad för ankomst, TDOA (Time Difference of Arrival), mellan inkommande ljud till tre ljudsensorer för att beräkna en vinkel, som i sin tur kommuniceras till en likströmsmotor som utför rotationen. Det andra systemet kombinerar en lysdiod som lyser när en passning förväntas, en accelerometer för att detektera att passning mottagits och radiosändare samt mottagare för trådlös kommunikation. När minst tre sådana enheter används, bestämmer en slumpgenerator vilken enhet som ska tända sin lysdiod när den första detekterar en passning.
108

Best PAL : Ball Exercise Sound Tracking PAL / Best PAL : Ljudlokaliserande smart bollplank för individuell fotbollsträning

Sundkvist, Axel, Hellberg, Joakim January 2018 (has links)
The PAL (Practise and Learn) Original is a ball boardconsisting of three wooden boards placed in a triangle, developedto practise football players’ passing ability and firsttouch. The former Swedish international footballer JessicaLandstr¨om observed that these ball boards can, if they areimproved, help footballers to develop even more skills whilepracticing alone. Landstr¨om’s idea was to put lamps on topoff the ball boards which light up when a certain ball boardexpects to receive a pass. This would force the player tolook up instead of looking at the ball and hence improvetheir vision.We concluded that speaking also is important withinfootball. So our objective became to follow up on the developmentof the simple PAL Original to a ball board whichrotates towards a sound source. We wanted to achieve thiswithout configuring the PAL Original’s construction.With the purpose of executing the idea we needed toestimate the angle between a sound source and a face ofthe ball board, rotate the ball board with an electric motor,communicate wirelessly between units and detect a ball hitwhen the ball board receives a pass.The final prototype consists of two systems, one systemexecuting the sound source localization and rotation andthe other system executing the detection of ball hit andwireless communication.The first system uses time difference of arrival (TDOA)between incoming sound for three sound sensors to calculatean angle, which in turn is communicated to a DC motorthat executes the rotation.The other system combines an LED to light up whena pass is expected, an accelerometer to detect a pass, andradio transceivers to communicate with each other. Whenat least three of these devices are used a randomizing algorithmdecides which one should light its LED next whenthe first one detects a pass. / PAL (Practice and Learn) Original är ett bollplankbestående av tre träskivor placerade i en triangel, utveckladför att träna fotbollsspelares passningsförmåga och förstatouch. Jessica Landström, landslagsmeriterad fotbollsspelare,insåg att dessa bollplank kan utvecklas till att hjälpafotbollsspelare att träna ännu fler områden vid indviduellträning. Landströms ursprungliga idé var att placeraen lampa på bollplanket som lyser upp när den förväntarsig en passning, detta för att tvinga spelaren att titta uppistället för att titta på bollen, och därigenom träna spelarensspelförståelse.Vi drog slutsatsen att det också är mycket viktigt medkommunikation i fotboll. Vårt mål blev därför att vidareutvecklaPAL Original till ett bollplank som roterar en sidamot en ljudkälla. Vi ville uppnå detta så att det är kompatibeltmed PAL Original utan att ändra dess konstruktion.För att genomföra detta behövde vi alltså uppskattavinkeln mellan en ljudkälla och en sida av det triangulärabollplanket, rotera bollplanket med en motor, kommuniceratrådlöst och detektera när bollplanket mottar en passning.Den slutliga prototypen består av två system, ett systemsom utför lokalisering av ljudkälla samt rotation ochett system som utför detektering av bollträff samt hanterartrådlös kommunikation.Det första systemet utnyttjar tidsskillnad för ankomst,TDOA (Time Difference of Arrival), mellan inkommandeljud till tre ljudsensorer för att beräkna en vinkel, som i sintur kommuniceras till en likströmsmotor som utför rotationen.Det andra systemet kombinerar en lysdiod som lysernär en passning förväntas, en accelerometer för att detekteraatt passning mottagits och radiosändare samt mottagareför trådlös kommunikation. När minst tre sådana enheteranvänds, bestämmer en slumpgenerator vilken enhet somska tända sin lysdiod när den första detekterar en passning.
109

Investigation for the development of a new electric control unit for customized trucks

Liu, Yusen January 2019 (has links)
Customized truck is a relevant and high-profit part of Scania’s market. Nowadaysdesigners do not have a self-developed electric control unit for introducing non-standardfunctionality. This thesis is intended to investigate the specification of a new system andan approach to implement it in current truck’s electrical system. The adopted methodsin this research are systems analysis, functional specification, HW & SW research andcomparison and validation test of prototype system. The results obtained in this researchinclude the potential functions and corresponding requirement specification, 5 types ofhardware alternatives and 2 recommended software platform. Their feasibility is verifiedby a prototype system with 2 typical functions, control the motor of inward sliding doorand combine the communication of different system. 3 recommended schemes and 2 directionsfor future research are given in the end. Based on investigation results, developersare able to know new system’s specification preliminarily, understand the architectural requirementsand suitable tools and materials for implementation. This research will helpto improve Scania’s truck’s electrical system and product manufacturing in the future. / Specialfordon utgör en viktig och betydande del av Scanias produkter. Dagens de-signer har inte tillgång till en egenutvecklad styrenhet för att introducera icke standardiserade funktioner. Detta examensarbete fokuserar på att undersöka ett nytt system och hur det skulle implementeras i den redan existerande lastbilens elektriska system. De behandlade ämnena i arbetet är systemanalys, funktionsanalys, hårdvaruspecifikation, mjukvara samt validering och utvärdering i form av byggnation och testning av en prototyp. Resultatet som erhållits i denna rapport inkluderar potentiella funktioner och motsvarande kravspecifikation, fem typer av hårdvara och tvårekommenderade mjukvaruplattformar. Reliabiliteten av dessa valideras med en prototyp med två typiska funktioner, kontrolleraen motor på en elektrisk dörr samt kombinera kommunikationen av olika system. Trealternativa lösningar samt två alternativ till framtida studier rekommenderas i slutet av rapporten. Baserat på resultaten har utvecklare möjlighet till en preliminär specifikation,förståkrav påarkitektur, användbara verktyg och material för implementation. Dennarapport kommer att underlätta förbättring av Scanias elektriska system och utveckling iframtiden.
110

Actuator Modeling and Control For a Three Degrees of Freedom Differential Thrust Control Testbed

Garimella, Suresh January 2007 (has links)
No description available.

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