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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

Design of a flexible, landmark-based video tracking system for medium range position measurement

Anders, Frederick J. 05 1900 (has links)
No description available.
2

The low-level guidance of an experimental autonomous vehicle

Pears, Nicholas Edwin January 1989 (has links)
This thesis describes the data processing and the control that constitutes a method of guidance for an autonomous guided vehicle (AGV) operating in a predefined and structured environment such as a warehouse or factory. A simple battery driven vehicle has been constructed which houses an MC68000 based microcomputer and a number of electronic interface cards. In order to provide a user interface, and in order to integrate the various aspects of the proposed guidance method, a modular software package has been developed. This, along with the research vehicle, has been used to support an experimental approach to the research. The vehicle's guidance method requires a series of concatenated curved and straight imaginary Unes to be passed to the vehicle as a representation of a planned path within its environment. Global position specifications for each line and the associated AGV direction and demand speed for each fine constitute commands which are queued and executed in sequence. In order to execute commands, the AGV is equipped with low level sensors (ultrasonic transducers and optical shaft encoders) which allow it to estimate and correct its global position continually. In addition to a queue of commands, the AGV also has a pre-programmed knowledge of the position of a number of correction boards within its environment. These are simply wooden boards approximately 25cm high and between 2 and 5 metres long with small protrusions ("notches") 4cm deep and 10cm long at regular (Im) intervals along its length. When the AGV passes such a correction board, it can measure its perpendicular distance and orientation relative to that board using two sets of its ultrasonic sensors, one set at the rear of the vehicle near to the drive wheels and one set at the front of the vehicle. Data collected as the vehicle moves parallel to a correction board is digitally filtered and subsequently a least squares line fitting procedure is adopted. As well as improving the reliability and accuracy of orientation and distance measurements relative to the board, this provides the basis for an algorithm with which to detect and measure the position of the protrusions on the correction board. Since measurements in three planar, local coordinates can be made (these are: x, the distance travelled parallel to a correction board; and y,the perpendicular distance relative to a correction board; and Ɵ, the clockwise planar orientation relative to the correction board), global position estimation can be corrected. When position corrections are made, it can be seen that they appear as step disturbances to the control system. This control system has been designed to allow the vehicle to move back onto its imaginary line after a position correction in a critically damped fashion and, in the steady state, to track both linear and curved command segments with minimum error.
3

An integrated control system for an Automatic Guided Vehicle (AGV)

Boje, E.P., Kotze, B.J. January 2008 (has links)
Published Article / An immense amount of research is currently, being done on the development and use of Automatic Guided Vehicles (AGVs) in industry. An important component of this research often involves navigation and route-optimization of such AGVs. In this paper the design and control of an AGV, using a stationary control system and a GPS-like navigational system, is discussed. Substantial provision has also been made for the display of operational characteristics of the AGV on the stationary control unit.
4

Etude et mise en oeuvre d'un convoi de véhicules urbains avec accrochage immatériel

Bom, Jonathan 20 July 2006 (has links) (PDF)
Pour résoudre les problèmes lies au trafic important dans les métropoles, de nouvelles alternatives, appelées "Urban Transportation Systems", voient le jour. Celles-ci sont basées sur des véhicules électriques en libre accès. Une fonctionnalité nécessaire de ces systèmes est leur capacité a' se déplacer en convoi. Dans ce manuscrit de thèse, le travail présenté traite de la commande d'un convoi de véhicules urbains. Dans ce mémoire, une modélisation cinématique de type tricycle est adoptée pour représenter le robot mobile. La transformation en système chaîné de ce modèle permet de découpler les commandes latérale et longitudinale. La commande latérale basée sur des techniques de linéarisation exacte, permet d'assurer un suivi de trajectoire avec une tr'es haute précision (puisque les non-linearites du modèle ne sont pas approximées mais au contraire, explicitement prises en compte), indépendamment de la vitesse du robot. La loi de commande longitudinale, basée également sur des techniques de linéarisation exacte, suit une stratégie de commande globale : l''état du convoi est pris en compte, et non pas seulement l'état du véhicule situe immédiatement devant. En fait, le comportement du convoi est étudié à travers les états du leader et du véhicule précédent. L'écart inter-vehicules a réguler est choisi égal à la distance curviligne parcourue le long d'un chemin de référence, ce qui permet d'assurer un comportement cohérent du convoi, y compris lors du suivi de trajectoires a' forte courbure. Afin de prodiguer un confort suffisant aux passagers et d'assurer un fonctionnement en toute sécurité, des fonctions de supervision sont greffées aux lois de commande nominales, d'écrites ci-dessus. Ce module de supervision, nomme "Monitoring", gère également l'insertion ou la désinsertion de véhicules au sein du convoi. Des expérimentations, portées sur des voitures urbaines réelles, nommées Cycabs, permettent de valider les performances de la commande. Pour cela, les véhicules sont équipes d'une communication sans fil de type WiFi. Deux modalités capteurs ont 'et'e envisagées pour localiser les véhicules : principalement un capteur RTK-GPS (Real Time Kinematic Global Positioning System), mais également un système de vision monoculaire.
5

Návrh mezioperační dopravy ve výrobním podniku podle principů Průmyslu 4.0 / Design of inter-operational transport in a manufacturing company according to the Industry 4.0 concept

Mravec, Roman January 2021 (has links)
Based on the description and definition of technology and processes falling within the vision of the fourth industrial revolution with the aim of creating intelligent factories, this diploma thesis deals with the principles of the Industry 4.0 concept in Hilti's production plant with a focus on transport and supply of production equipment. The aim of the work is to create a comprehensive proposal that takes into account all the necessary aspects associated with upgrading the existing state of inter-operational transport in a particular production line to fully automated, flexible and autonomous transport of materials and products in the context of Industry 4.0. A prerequisite for creating a design is the connection of automatically guided vehicles (AGVs) serving individual transport orders. The selection of the vehicle was made taking into account the safety of movement, the method of charging, the system and network integrity of existing and proposed technologies and components. The intention is not only to automate the inter-operational service, but also on the basis of the created automation concept, the ability to autonomously procure the flow of material and products. The mathematical calculation of capacity planning in the production line helped to determine the total load and the number of vehicles needed for continuous procurement of transport requirements. The result of the design part is also the design of specific transport routes and transport conditions that AGV vehicles must comply with in order to maintain a high level of safety. Transparency and a constant overview of transported products is provided by the presented scheme for identification of production batches, Auto-ID system. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal due to high labor costs.

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