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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.
51

An automated virtual tool to compute the entire set of proportional integral derivative controllers for a continuous linear time invariant system

Narasimhan, Bharat 10 October 2008 (has links)
This thesis presents the very practical and novel approach of using the Graphical User Interface (GUI) to compute the entire set of Proportional Integral Derivative (PID) controllers given the transfer function or the frequency response of the system under consideration. Though there is a wide spread usage of PID controllers in the industry, until recently no formal algorithm existed on determining a set of PID values that will stabilize the given system. The industry still relies on algorithms like the Ziegler- Nicholas or ad-hoc approaches in determining the value of PID controllers. Also when it comes to model free approaches, the use of Fuzzy logic and Neural network do not guarantee stability of the system. For a continuous Linear Time Invariant system Bhattacharyya and others have developed an algorithm that determines the entire set of PID controllers given the transfer function or just the frequency response of the system. The GUI has been developed based on this theory. The GUI also evaluates the user input performance specifications and generates a subset of stable controllers given the performance criteria for the system. This thesis presents an approach of automating the computation of entire set of stabilizing Proportional Integral Derivative (PID) controllers given the system transfer function or the frequency response data of the system. The Graphical User Interface (GUI) developed bridges the gap between the developed theory and the industry.
52

A self-contained guidance and targeting algorithm for spacecraft applications

Scarritt, Sara Kathryn 02 October 2012 (has links)
The development of a self-contained, onboard, fully autonomous trajectory guidance tool for spacecraft is presented. To be considered completely autonomous requires the capability to both identify an appropriate startup solution, and then use that solution to target a set of user-defined path and endpoint constraints. To minimize the cost of flight software development and validation, both the generation of the startup solution and the targeting algorithm are designed to be as computationally efficient as possible. This study addresses both the determination of a startup arc and the subsequent targeting process. The first part of the investigation considers the targeting algorithm. Linear targeting through differential corrections is a well-known approach for identifying feasible solutions that meet specified mission and trajectory constraints. However, to date, these methods relied on the assumption that the associated control inputs were impulsive in nature. This research focuses on the theoretical development and numerical validation of a generalized linear targeting algorithm capable of accommodating finite periods of continuous control action for a wide range of applications. Examples are presented to illustrate the general concept and to contrast the performance of this new targeting process against more classical impulsive targeting methods. The second section of the study introduces a novel approach utilizing artificial potential function methods to identify suitable startup solutions. Although common in other types of path planning, these methods have not yet been used for orbital or interplanetary trajectory design, primarily due to their inherent suboptimality. However, results show that this issue can be addressed with relative ease by the targeting algorithm. / text
53

THE DIFFUSION AND ADOPTION OF A TECHNICAL INNOVATION: THE AUTOMATED TELLER MACHINE

Lozano, Marvin Francis, 1950- January 1987 (has links)
No description available.
54

Predictive conditionals, nonmonotonicity and reasoning about the future

Bell, J. January 1988 (has links)
No description available.
55

Control of power electronic devices (FACTS) to enhance power system stability

Oukati Sadegh, Mahmoud January 2003 (has links)
No description available.
56

The facilities automated control and tracking system (FACTS) /

Mouri, Richard I. January 1990 (has links)
Project report (M. Eng.)--Virginia Polytechnic Institute and State University, 1990. / Abstract. Includes bibliographical references (leaves 79-81). Also available via the Internet.
57

Variable sensor system for guidance and navigation of AGVs /

Pancham, Ardhisha. January 2008 (has links)
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2008.
58

Lifelong Visual Localization for Automated Vehicles

Mühlfellner, Peter January 2015 (has links)
Automated driving can help solve the current and future problems of individualtransportation. Automated valet parking is a possible approach to help with overcrowded parking areas in cities and make electric vehicles more appealing. In an automated valet system, drivers are able to drop off their vehicle close to a parking area. The vehicle drives to a free parking spot on its own, while the driver is free to perform other tasks — such as switching the mode of transportation. Such a system requires the automated car to navigate unstructured, possibly three dimensional areas. This goes beyond the scope ofthe tasks performed in the state of the art for automated driving. This thesis describes a visual localization system that provides accuratemetric pose estimates. As sensors, the described system uses multiple monocular cameras and wheel-tick odometry. This is a sensor set-up that is close to what can be found in current production cars. Metric pose estimates with errors in the order of tens of centimeters enable maneuvers such as parking into tight parking spots. This system forms the basis for automated navigationin the EU-funded V-Charge project. Furthermore, we present an approach to the challenging problem of life-long mapping and localization. Over long time spans, the visual appearance ofthe world is subject to change due to natural and man-made phenomena. The effective long-term usage of visual maps requires the ability to adapt to these changes. We describe a multi-session mapping system, that fuses datasets intoiiia single, unambiguous, metric representation. This enables automated navigation in the presence of environmental change. To handle the growing complexityof such a system we propose the concept of Summary Maps, which contain a reduced set of landmarks that has been selected through a combination of scoring and sampling criteria. We show that a Summary Map with bounded complexity can achieve accurate localization under a wide variety of conditions. Finally, as a foundation for lifelong mapping, we propose a relational database system. This system is based on use-cases that are not only concerned with solving the basic mapping problem, but also with providing users with a better understanding of the long-term processes that comprise a map. We demonstrate that we can pose interesting queries to the database, that help us gain a better intuition about the correctness and robustness of the created maps. This is accomplished by answering questions about the appearance and distribution of visual landmarks that were used during mapping. This thesis takes on one of the major unsolved challenges in vision-based localization and mapping: long-term operation in a changing environment. We approach this problem through extensive real world experimentation, as well as in-depth evaluation and analysis of recorded data. We demonstrate that accurate metric localization is feasible both during short term changes, as exemplified by the transition between day and night, as well as longer term changes, such as due to seasonal variation.
59

Security and control of electronic funds transfer specific to a corporate dial-up environment

Gericke, Sydney 15 May 2014 (has links)
M.Comm. (Accounting) / Please refer to full text to view abstract
60

Energy management system for the diagnosis and control of an automatic guided vehicle

Church, Stuart Michael January 2016 (has links)
With the increase in electronic equipment implemented in various systems, as well as the increase in calculating power that these devices offer, designers are being empowered to make use of this power in real-time systems to diagnose and protect the systems themselves. This reasoning is too compounded by the focus on efficiency and safety in the design of complex systems, as well as the increasing expense and sensitivity of the electronic components themselves. With this in mind, this dissertation aims at developing a comprehensive measurement, control and reaction system for the electrical diagnosis and ultimately optimisation of complex electrical and electronic systems. This system will serve as a real-time diagnosis tool, which will enable the real-time diagnosis of various components in an electro-mechanical system, which can then be interpreted to determine the working state of the various components. Another sphere of this project will involve the accurate monitoring of the battery status as well as actively balancing the series connected batteries. The focus on the batteries will seek to prolong the life of the batteries, while being able to squeeze as much capacity out of them. The initial design and testing will be based on an AGV system implemented at VWSA, however a main goal throughout the design process will be modularity, i.e. the ease of implementation of this system in other systems. The key technologies used in the development of this system will still comprise of the components used in the original AGV, however new prototype components sourced from Microcare are used for the battery management system, while current sensors directly connected to the PLC’s analog input ports will be used for the active monitoring of currents distributed through the AGV.

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