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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

A method for concurrently optimising the weight and response of wound field direct current motors.

El Aker, Mounzer Nizar January 2004 (has links)
Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / Compact, lightweight and responsive direct current (DC) motors are desirable in industries requiring precise control operations such as those using robotic and micro-robotic devices. Permanent magnet (PM) motors have been used exclusively in these industries, in recent years, because they meet these requirements. However, their speed range and output torque are limited compared to wound field direct current (WF DC) motors and this renders them far less effective than WF DC motors in terms of handling load disturbances. So far, only one study by Reyer and Papalambros (1999) has investigated a method for concurrently optimising the weight and response of WF DC motors with, in this case, proportional, integral and derivative (PID) controllers. However, the documentation provided in their study suggests that their optimised WF motor was defective in terms of efficiency, speed and shape. The aim of the present study was to develop Reyer and Papalambros's method in a way that overcomes the problems that arose. To do this, first an investigation into Reyer and Papalambros's mathematical model was conducted, and their equality and inequality equations have been modified. Second, their optimisation model has been represented by its transfer functions. Third, their model's parameters and variables have been reconsidered. Finally, the WF motor/controller system was discretely optimised. Following these developments, the new method was used to optimise the weight and response of a motor/controller system capable of driving a 6 Nm torque in MATLAB to illustrate the developed method and compare its outcome with that achieved by Reyer and Papalambros in 1999. The comparison indicated that the method developed here is superior and the weight and response of the system optimised by this current study outperforms the one developed by Reyer and Papalambros. To confirm the validity of the developed weight optimisation model, the weight of a 50 watt WF DC prototype motor was partially optimised experimentally. This resulted in the weight of this motor being successfully reduced. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1104468 / Thesis (M.Eng.Sc.) -- University of Adelaide, School of Mechanical Engineering, 2004
2

Investigation of cochlear disturbance induced during surgical intervention

Zhang, Yu January 2018 (has links)
Hearing loss is a common impairment or disability for human beings, and is impacting an increasing amount of people, augmented by the growing aging population around the globe. Cochlear implantation, as one of the most effective ways to restore hearing, can only applied to profoundly deaf patients at the moment. In order to expand the group of people who can benefit from cochlear implantation to those with less severe hearing loss, endeavours need to be made to best preserve residual hearing and minimise trauma induced during cochlear implantation surgery. In this thesis, the disturbance induced in the cochlea, i.e. the acoustic and mechanical energy transmitted into the cochlea, during cochleostomy drilling is studied - as well as establishing a comparison between a manually guided conventional technique and a manually supported tissue guided robotic drilling technique. The results show that by changing surgical techniques and how they are applied can have a significant impact on levels of disturbance induced - robotic-aided approach induced lower level of equivalent SPL for up to 86% of the time and can be as much as 39 dB lower than that generated by conventional surgical drilling. This work is timely because trauma is an important consideration to clinicians and health care providers. Cochleostomy is one of the major and most disruptive surgical process during cochlear implantation. With the increasing amount of cochlear implant electrode array designs that are shorter and less intrusive, and the increasing demand of electric-acoustic stimulation via cochlear implant to better resemble the human auditory system, the approach to reduce disruption during cochleostomy drilling is highly relevant to the progression in the hearing care industry and the benefits of the growing hearing impairment community.
3

Geração e otimização de trajetórias de um manipulador robótico utilizando algoritmos genéticos

Nunes, Luiz Eduardo Nicolini do Patrocínio [UNESP] 05 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-05Bitstream added on 2014-06-13T20:06:00Z : No. of bitstreams: 1 nunes_lenp_dr_guara.pdf: 1711475 bytes, checksum: 1ea89d3a534a0a1530a9ef0a0ba7cb3e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho trata da geração e otimização de trajetórias de um manipulador robótico planar (2D) de três graus de liberdade, num ambiente livre de obstáculos. Visto que a cinemática inversa de braços robóticos é um problema complexo que, em geral, geram múltiplas soluções, otimizam-se, aqui, estas soluções através de algoritmos genéticos (AGs). A função de avaliação do AG tem caráter multi-objetivo, de forma a minimizar os deslocamentos angulares e obter de forma precisa a posição da garra, usando funções desenvolvidas para o ambiente Matlab, tais como, GAOT e PLANMANT, devido a sua facilidade de programação e geração de gráficos. A seguir, foram obtidos resultados através de programa desenvolvido em linguagem C, utilizando a biblioteca GAUL, e tem-se avaliado o desempenho computacional de processamento. E finalmente, para a validação experimental deste estudo, tem-se implementado este procedimento em um manipulador robótico Robix RCS-6 de configuração similar ao modelo simulado. Os resultados mostram que o método implementado é eficiente, computacionalmente rápido e viável em aplicações reais. / This work treats of the generation and optimization of trajectories for a planar robotic manipulator (2D) of three degrees of freedom, in free environment obstacles. Since the inverse kinematics of robotic arms are a complex problem that, generally, generate multiple solutions, here are optimized these solutions through genetic algorithms (AGs). The evaluation function of the AG has multi-objective character which minimize the angular displacements and the positional errors, being used functions developed for the Matlab environment, such as, GAOT and PLANMANT, due its compliance of programming and graphics generation. Immediately, results were obtained through program developed in language C, using the GAUL library. The computational processing performance has been evaluated. And finally, for the experimental validation of this study, has been implemented this procedure in a robotic manipulator Robix RCS-6 of similar configuration to the simulated model. The results show that the implemented method is efficient, and computationally fast and viable in real applications. KEYWORDS: Robotic manipulator, Optimal trajectory, Inverse kinematics, Genetic algorithm.
4

THE ATIS INSTRUCTION SET FOR COMMUNICATION WITH ROBOTIC ASTRONOMICAL TELESCOPES

Seeds, Michael A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Astronomers now communicate over Internet with robotic astronomical telescopes using a specially designed instruction set. ATIS, Automatic Telescope Instruction Set, is designed to communicate specific, technical instructions to a robotic telescope, facilitate data retrieval and analysis, support a wide range of data formats, and also convey preference information that describe the astronomers general needs for data acquisition. Over a dozen telescopes now use ATIS and more are under construction.
5

Automated off-line programming and force control in robotics

Dailly, C. January 1986 (has links)
No description available.
6

On the design and development of a modular tactile sensing system

Gelaky, R. January 1989 (has links)
No description available.
7

Model reference adaptive control of two axes hydraulic manipulator

Almeida, Fernando Gomes de January 1993 (has links)
No description available.
8

Vision monitoring systems in arc welding

Clark, Stephen January 1988 (has links)
No description available.
9

Application of an electro-rheological twin clutch mechanism to robot arm positioning

Tan, Kim Piew January 2001 (has links)
No description available.
10

Development of a magnetoresistive shear and normal force tactile sensor and its hierarchical test environment

Adl, Payman January 1992 (has links)
No description available.

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