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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.
251

Leveled flight control of an unmanned underwater vehicle operating in a wave induced environment

Unknown Date (has links)
Autonomous Underwater Vehicle (AUV) depth control methods typically use a pressure sensor to measure the depth, which results in the AUV following the trajectory of the surface waves. Through simulations, a controller is designed for the Ocean Explorer AUV with the objective of the AUV holding a constant depth below the still water line while operating in waves. This objective is accomplished by modeling sensors and using filtering techniques to provide the AUV with the depth below the still water line. A wave prediction model is simulated to provide the controller with knowledge of the wave disturbance before it is encountered. The controller allows for depth keeping below the still water line with a standard deviation of 0.04 and 0.65 meters for wave amplitudes of 0.1-0.25 and 0.5-2 meters respectively and wave frequencies of 0.35-1.0 𝑟𝑎𝑑⁄𝑠𝑒𝑐, and the wave prediction improves the depth control on the order of 0.03 meters. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
252

Nonlinear control of an unmanned amphibious vehicle

Unknown Date (has links)
The DUCKW-Ling is an 8.3 foot long, amphibious water plane area twin hull (SWATH) concept vehicle which is propelled by a pair of crawler tracks on land and dual propellers when water-borne. In its operational zone, the vehicle's dynamics change dramatically as it transitions from being completely water-borne and buoyancy supported to being completely land-borne and track supported. In the water environment, a cascaded, first-order sliding mode controller was used to control the surge and heading of the vehicle, and was capable of having a faster response when compared to using a proportional controller. Additionally, field trials of the DUKW-Ling show the capability of the vehicle to navigate and track predetermined waypoints in both terrestrial and aquatic terrains. In the transitional zone, the electric motor current from the tracks was used as the feedback mechanism to adequately actuate the propellers and tracks in the system as the dynamics of the vehicle change. / by Josâe L. Alvarez. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
253

Optical 2D Positional Estimation for a Biomimetic Station-Keeping Autonomous Underwater Vehicle

Unknown Date (has links)
Underwater vehicles often use acoustics or dead reckoning for global positioning, which is impractical for low cost, high proximity applications. An optical based positional feedback system for a wave tank operated biomimetic station-keeping vehicle was made using an extended Kalman filter and a model of a nearby light source. After physical light model verification, the filter estimated surge, sway, and heading with 6 irradiance sensors and a low cost inertial measurement unit (~$15). Physical testing with video feedback suggests an average error of ~2cm in surge and sway, and ~3deg in yaw, over a 1200 cm2 operational area. This is 2-3 times better, and more consistent, than adaptations of prior art tested alongside the extended Kalman filter feedback system. The physical performance of the biomimetic platform was also tested. It has a repeatable forward velocity response with a max of 0.3 m/s and fair stability in surface testing conditions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
254

A PVDF-based sensing system for automated micro-manipulation.

January 2002 (has links)
Fung, Kar Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 110-114). / Abstracts in English and Chinese. / 摘要 --- p.i / ABSTRACT --- p.ii / ACKNOWLEDGMENTS --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background and Motivation --- p.1 / Chapter 1.2 --- Objective of the project --- p.4 / Chapter 1.3 --- Organization of the thesis --- p.5 / Chapter 2. --- Literature Review --- p.7 / Chapter 2.1 --- Control on Micro-Manipulation --- p.7 / Chapter 2.1.1 --- Visual Feedback Control --- p.8 / Chapter 2.1.2 --- Sensor-Based Feedback Control --- p.9 / Chapter 2.1.3 --- Bilateral Control --- p.9 / Chapter 2.2 --- Force Sensing System on Micro-Manipulation --- p.10 / Chapter 2.3 --- PVDF Sensor --- p.11 / Chapter 2.4 --- Summary of the Literature Review --- p.12 / Chapter 3. --- Micro-Manipulation --- p.14 / Chapter 3.1 --- Introduction of Micro-Manipulation --- p.14 / Chapter 3.2 --- Probe Station --- p.14 / Chapter 3.2.1 --- Micromanipulators --- p.15 / Chapter 3.2.2 --- Microscopes --- p.15 / Chapter 4. --- Piezoelectric Polyvinylidence Fluoride (PVDF) Sensor --- p.16 / Chapter 4.1 --- Charteristic of PVDF Sensor --- p.16 / Chapter 4.1.1 --- Piezoelectric Properties --- p.16 / Chapter 4.1.2 --- Dimensions of the PVDF Sensor --- p.18 / Chapter 4.2 --- Comparison of Piezoelectric Materials --- p.19 / Chapter 5. --- Theoretical Analysis of PVDF Sensor --- p.21 / Chapter 5.1 --- Sensitivity of PVDF Sensor --- p.21 / Chapter 5.2 --- Relationship between the Deflection and the Force of the PVDF --- p.22 / Chapter 5.3 --- Calculation of the Spring Constant K of the PVDF --- p.23 / Chapter 5.4 --- Simulation on the output from the PVDF Sensor --- p.23 / Chapter 6. --- Experimental Analysis of PVDF Sensor --- p.26 / Chapter 6.1 --- Force-Deflection Diagram --- p.26 / Chapter 6.2 --- Frequency Response of the PVDF Sensor --- p.27 / Chapter 7. --- 1-D PVDF-Based Sensing System --- p.30 / Chapter 7.1 --- Original Design of the Sensing System --- p.30 / Chapter 7.1.1 --- Plastic pipe and adapter --- p.31 / Chapter 7.1.2 --- PVDF Sensor --- p.32 / Chapter 7.1.3 --- Probe-tip holder --- p.32 / Chapter 7.2 --- Current Design of the Sensing System --- p.32 / Chapter 7.3 --- Analysis of the Sensing System --- p.34 / Chapter 7.3.1 --- Frequency Response of the Sensing System --- p.34 / Chapter 7.3.2 --- Sensitivity of the Sensing System --- p.41 / Chapter 8. --- Experiments on 1-D PVDF Sensing System --- p.49 / Chapter 8.1 --- Experimental Setup of the 1-D Sensing System --- p.49 / Chapter 8.1.1 --- Programmable Micromanipulator --- p.50 / Chapter 8.1.2 --- Charge Amplifier --- p.51 / Chapter 8.2 --- Calibration of the 1-D Sensing System --- p.53 / Chapter 8.2.1 --- Noise Signal from the system --- p.53 / Chapter 8.2.2 --- Signal from vibration --- p.55 / Chapter 8.3 --- Experimental Results on touching a substrate --- p.60 / Chapter 8.3.1 --- Description --- p.60 / Chapter 8.3.2 --- Results from touching a substrate --- p.62 / Chapter 8.3.3 --- Analysis of the deflection after touched a substrate --- p.67 / Chapter 8.4 --- Experimental Results on touching a micro mirror --- p.68 / Chapter 8.4.1 --- Description --- p.68 / Chapter 8.4.2 --- Results --- p.70 / Chapter 8.5 --- Experimental Results on lifting a mass platform --- p.74 / Chapter 8.5.1 --- Description --- p.74 / Chapter 8.5.2 --- Results --- p.76 / Chapter 9. --- Modification of 1-D Sensing System --- p.79 / Chapter 9.1 --- Design of the system --- p.79 / Chapter 9.2 --- Experimental Setup of the system --- p.80 / Chapter 9.3 --- Experimental Results on lifting a mass platform --- p.81 / Chapter 10. --- 2-D PVDF-Based Sensing System --- p.90 / Chapter 10.1 --- Design of the Sensing System --- p.90 / Chapter 10.2 --- Experimental Setup --- p.91 / Chapter 10.3 --- Calibration of the 2-D Sensing System --- p.92 / Chapter 10.3.1 --- Noise Signal from the system --- p.92 / Chapter 10.4 --- Experiments Results on touching a substrate --- p.94 / Chapter 11. --- Experimental Analysis --- p.97 / Chapter 11.1 --- Data Acquisition --- p.97 / Chapter 11.2 --- Spectrum Analysis of the Experimental Data --- p.101 / Chapter 12. --- Conclusion --- p.103 / Chapter 13. --- Future Work --- p.105 / Chapter 13.1 --- Control of the Sensing System --- p.105 / Chapter 13.2 --- Tele-operation System on force feedback sensing system --- p.107 / Chapter A. --- Appendix --- p.109 / Chapter A. 1 --- Procedures in using probe station --- p.109 / Bibliography --- p.110
255

Structural properties and estimation of delay systems.

Kwong, Raymond Hon-Sing January 1975 (has links)
Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Vita. / Includes bibliographical references. / Ph.D.
256

Finite-state control of uncertain systems.

Jones, Steven Norman January 1978 (has links)
Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / M.S.
257

On the optimal minimum order observer-based compensator and the limited state variable feedback controller.

Lloréns-Ortiz, Baldomero January 1976 (has links)
Thesis. 1976. Elec.E.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Microfiche copy available in Archives and Engineering. / Bibliography: leaves 138-140. / Elec.E.
258

Practical robustness measures in multivariable control system analysis

Lehtomaki, Norman A. (Norman August) January 1981 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Norman August Lehtomaki. / Ph.D.
259

Issues in the digital implementation of control compensators

Moroney, Paul January 1979 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Paul Moroney. / Ph.D.
260

Dynamic routing in an unreliable manufacturing network with limited storage

Hahne, Ellen Louise January 1981 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 231-242. / by Ellen Louise Hahne. / M.S.

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