published_or_final_version / abstract / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

With the number of deaths, commute time, and injuries constantly rising due to human driving errors, it’s time for a new transportation system, where humans are no longer involved in driving decisions and vehicles are the only machine that decide the actions of a vehicle. To accomplish a fully autonomous world, it’s important for vehicles to be able to communicate instantly and report their movements in order to reduce accidents. This paper discusses four approaches to vehicle to vehicle communication, as well as the underlying standards and technology that enable vehicles to accomplish communicating.

The present study consists of a full translation and analysis of the three main versions of the Section on Law and State, a chapter on Tibetan imperial law and administration found in the mid-16th century Mkhas pa'i dga' ston by Dpa'-bo Gtsuglag Phreng-ba, and in the Rgya bod kyi chos 'byung rgyas pa of Mkhas-pa Lde'u and the Chos 'byung chen po bstan pa'i rgyal mtshan of Lde'u Jo-sras, which both date to the mid to late-13th century. While the post-dynastic Tibetan historical tradition attributes this entire body of legal and administrative reforms to Emperor Srong-btsan Sgam-po (c.605-649), the individual legal and administrative catalogues contained in the Section on Law and State, when subjected to close analysis, can be dated to several different periods. The principal aim of this analysis is to underline the early Tibetan antecedents for the catalogues contained in the Section on Law and State. By relating the catalogues of the Section on Law and State to Old Tibetan sources, this analysis describes in detail the legal and administrative practices of the Tibetan Empire (c.600-c.850). Among the topics covered by this analysis are historical geography and the 'nationalisation' of clan territory, social stratification, technological innovation and legal culture. The Section on Law and State is not limited solely to law and administration, however, and also offers insights regarding cultural institutions such as religious practices and Tibetan funerary culture. Taken together, the scattered and fragmentary catalogues that make up the Section on Law and State, many of which ultimately derive from manuals and official records from the imperial period, constitute a rare juridical corpus of the Tibetan Empire. As such, it furnishes important and detailed information about the legal and administrative culture of the Tibetan Empire, and constitutes a fundamental source for Tibetan social history. The preservation of such documents within Tibet's postdynastic religious histories underlines the persistence of Tibetan political theory, according to which divine rulers, Buddhist or otherwise, must govern according to the just traditions of their forebears.

Este trabalho teve por objetivo o desenvolvimento de um sistema de controle de navegação para um veículo autônomo utilizando lógica difusa. Atribui-se o nome de SNAT (Sistema de navegação-autônoma para um triciclo). O sistema é responsável pela automatização do processo de navegação de um veículo de testes monitorado e controlado de uma base remota mediante enlace de telemetria de dados. O usuário do sistema, pela tela principal da aplicação indica os pontos a seguir, cada um destes é referenciado pela sua latitude e longitude no mapa. Uma vez iniciada a navegação, o sistema de controle recebe periodicamente pacotes de dados da posição e direção do veículo; estes dados são processados pelo controlador difuso que gera os comandos para atuação sobre o veículo. O controlador difuso traduz as expressões qualitativas, comuns na comunicação humana em valores numéricos que representam a direção e a velocidade para manter ou corrigir a navegação do veículo de testes pelo rumo desejado. Nesta dissertação são apresentados diversos aspectos do desenvolvimento do controlador de navegação difusa, os mecanismos de comunicação e acionamento do veículo de uma base remota e os testes realizados que mostram os resultados do SNAT controlando automaticamente a navegação do veículo de testes. / This work had as a goal the development of a fuzzy logic based navigation control system for an autonomous vehicle. The developed control system was named SNAT (from the equivalent in portuguese of autonomous navigation system for a tricycle). The system controls and monitors the navigation of the vehicle from a remote base station using a telemetry data link. The user indicates, using a developed application, the navigation waypoints, referencing them by their latitude and longitude coordinates in a map. When the navigation starts, the system receives periodically data packets indicating the position and direction of the vehicle, these data are processed by the fuzzy control which returns commands to actuate over the vehicle. The fuzzy control translates qualitative expressions, common in human communication, into numerical values that represent the speed and the direction to keep the vehicle as near as possible to the desired navigation route. Many development aspects of the fuzzy controller and of the communication and actuation over the vehicle from the remote base are presented. Also are presented some results of the control system over navigation of the vehicle, which demonstrate that the system operates in a quite satisfactory manner.

Este trabalho teve por objetivo o desenvolvimento de um sistema de controle de navegação para um veículo autônomo utilizando lógica difusa. Atribui-se o nome de SNAT (Sistema de navegação-autônoma para um triciclo). O sistema é responsável pela automatização do processo de navegação de um veículo de testes monitorado e controlado de uma base remota mediante enlace de telemetria de dados. O usuário do sistema, pela tela principal da aplicação indica os pontos a seguir, cada um destes é referenciado pela sua latitude e longitude no mapa. Uma vez iniciada a navegação, o sistema de controle recebe periodicamente pacotes de dados da posição e direção do veículo; estes dados são processados pelo controlador difuso que gera os comandos para atuação sobre o veículo. O controlador difuso traduz as expressões qualitativas, comuns na comunicação humana em valores numéricos que representam a direção e a velocidade para manter ou corrigir a navegação do veículo de testes pelo rumo desejado. Nesta dissertação são apresentados diversos aspectos do desenvolvimento do controlador de navegação difusa, os mecanismos de comunicação e acionamento do veículo de uma base remota e os testes realizados que mostram os resultados do SNAT controlando automaticamente a navegação do veículo de testes. / This work had as a goal the development of a fuzzy logic based navigation control system for an autonomous vehicle. The developed control system was named SNAT (from the equivalent in portuguese of autonomous navigation system for a tricycle). The system controls and monitors the navigation of the vehicle from a remote base station using a telemetry data link. The user indicates, using a developed application, the navigation waypoints, referencing them by their latitude and longitude coordinates in a map. When the navigation starts, the system receives periodically data packets indicating the position and direction of the vehicle, these data are processed by the fuzzy control which returns commands to actuate over the vehicle. The fuzzy control translates qualitative expressions, common in human communication, into numerical values that represent the speed and the direction to keep the vehicle as near as possible to the desired navigation route. Many development aspects of the fuzzy controller and of the communication and actuation over the vehicle from the remote base are presented. Also are presented some results of the control system over navigation of the vehicle, which demonstrate that the system operates in a quite satisfactory manner.

Autonomous forklift handling systems is one of the most interesting research in the last decades. While research fields such as path planning and map building are taking the most significant work for other type of autonomous vehicles, detecting objects that need to move and picking it up becomes one of the most important research fields in autonomous forklifts field. We in this research had provided an algorithm for detecting paper reels accurate position in paper reels warehouses giving a map of the warehouse itself. Another algorithm is provided for giving the priority of papers that want to be picked up. Finally two algorithms for choosing the most appropriate direction for picking the target reel and for choosing the safest path to reach the target reel without damage it are provided. While working on the last two algorithms shows very nice results, building map for unknown stake of papers by accumulating maps over time still tricky. In the following pages we will go in detail by the steps that we followed to provide these algorithms started from giving an over view to the problem background and moving through the method that we used or we developed and ending by result and the conclusion that we got from this work.

published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / toc / Earth Sciences / Master / Master of Philosophy

Adaptive path planning of an autonomous marine vehicle (surface or subsurface) in the role of a communication and navigation aid (CNA) for multiple autonomous underwater vehicles (AUVs) for survey missions is studied. This path planning algorithm can be run before deployment, based on the planned paths of the survey AUVs, or underway, based on information transmitted by the survey AUVs. The planner considers the relative depth of the CNA and survey AUVs (not previously done) allowing the CNA to better aid survey AUVs that maintain a set distance over the ocean floor while surveying. Results are presented from simulations and in-water trials for both pre-deployment and underway planning modes, the latter being preferred since it can adapt to the survey AUV path during the mission. The necessity of bounding the distance between the CNA and any survey AUV in order to bound survey AUV position error is also described.