The minimum-time for a robot arm has been a longstanding and unsolved problem of considerable interest. We present a general solution to this problem that involves joint-space tesselation, a dynamic time-scaling algorithm, and graph search. The solution incorporates full dynamics of movement and actuator constraints, and can be easily extended for joint limits and work space obstacles, but is subject to the particular tesselation scheme used. The results presented show that, in general the optimal paths are not straight lines, bit rather curves in joint-space that utilize the dynamics of the arm and gravity to help in moving the arm faster to its destination. Implementation difficulties due to the tesselation and to combinatorial proliferation of paths are discussed.

A contribuição desta pesquisa é dada através do dimensionamento dos impactos efetivos das rodovias, através da ampliação das áreas de influência para além das faixas lineares, acrescentando a avaliação da sensibilidade ambiental das bacias hidrográficas para a otimização do traçado de empreendimentos rodoviários. Foi produzida uma abordagem ordenada e sistemática das relações de causa e conseqüência nas bacias, integrando os impactos da rodovia TO-247, interligando as sedes municipais Lagoa do Tocantins e Mateiros. As sub-bacias da região da área do estudo foram classificadas mediante metodologia para estimativa de produção e transporte de sedimentos, em ambiente ArcGis ArcInfo, onde foi aplicado modelo derivado da Equação Universal da Perda de Solos (Universal Soil Loss Equation – USLE) adaptado de Wischmeier e Smith (1978) e da Relação de Distribuição de Sedimentos (Sediment Delivery Ratio – SDR) proposto por Ferro e Minacapilli (1995). Os resultados possibilitaram a classificação das sub-bacias conforme a porcentagem estimativa de carga de sedimentos que potencialmente viria a assorear os cursos d’água mediante a modificação do seu uso pela ocupação do solo induzida pela rodovia. Os critérios relevantes à definição do traçado da rodovia foram divididos em três: (1) aspectos ambientais, (2) aspectos construtivos e (3) aspectos socioeconômicos, tendo sido parametrizados através do uso de Sistema de Informação Geográfica com algoritmos em ambiente raster, na definição de caminhos de mínimo custo. A otimização da rota proposta sugere a adição de ganhos na orientação dos tomadores de decisão, como a inserção da rodovia TO-247 em bacias com menor nível de restrição de relação de aporte de sedimentos, redução das travessias sobre áreas protegidas, diminuição das obras de arte (bueiros e pontes) e da execução de cortes e aterros, incluindo a possibilidade de melhoria dos acessos aos pontos turísticos de interesse para o desenvolvimento regional. A incorporação de condicionantes hidrológicas através da classificação das bacias quanto a produção e transferência dos sedimentos destacou a principal novidade que foi a definição da área de influência delimitada pelos impactos ambientais de projetos rodoviários para os limites das bacias, podendo contribuir com o planejamento de estradas indutoras de desenvolvimento. / The contribution of this research is given by the design of effective impacts of highways, through the expansion of the influence areas beyond the linear tracks, adding the assessment of the environmental sensitivity of watersheds in order to optimize the layout of road projects. It was produced an orderly and systematic approach of the cause and consequence relations in the watersheds incorporating in it the TO-247 highway impacts, linking the cities of Mateiros and Lagoa do Tocantins. The watersheds in the region of the study area were classified using methodology for estimating production and transport of sediment in ArcGIS ArcInfo environment. It was applied the equation model derived from the Universal Soil Loss Equation - USLE adapted from Wischmeier and Smith (1978) and the Sediment Delivery Ratio - SDR according to what is proposed by Ferro and Minacapilli (1995). Those results allowed the classification of watersheds according to the percentage estimate of sediment load that would potentially silting up the waterways through modification of their usage by land use induced by the highway. The relevant criteria to define the highway route were divided into three: (1) environmental, (2) construction and (3) socioeconomic aspects, which have been parameterized by using Geographic Information System with algorithms in raster environment into the definition of low cost paths. The optimization of the route proposal in TO-247 suggests adding profit in orientation of decision makers, such as entering the highway in watersheds with lower levels of restriction regarding the amount of sediment, reduction of crossings on protected areas, reduction of culverts and bridges and the implementation of sections and embankments, including the possibility of improved access to interest tourist points for regional development. The incorporation of hydrological conditions through the classification of river watersheds as the production and transfer of sediments, which highlighted the main novelty, was the expansion circumscription of the influence area bounded by the environmental impacts of road projects for the limits of the watersheds, which may contribute to the planning of roads inducing development.

A contribuição desta pesquisa é dada através do dimensionamento dos impactos efetivos das rodovias, através da ampliação das áreas de influência para além das faixas lineares, acrescentando a avaliação da sensibilidade ambiental das bacias hidrográficas para a otimização do traçado de empreendimentos rodoviários. Foi produzida uma abordagem ordenada e sistemática das relações de causa e conseqüência nas bacias, integrando os impactos da rodovia TO-247, interligando as sedes municipais Lagoa do Tocantins e Mateiros. As sub-bacias da região da área do estudo foram classificadas mediante metodologia para estimativa de produção e transporte de sedimentos, em ambiente ArcGis ArcInfo, onde foi aplicado modelo derivado da Equação Universal da Perda de Solos (Universal Soil Loss Equation – USLE) adaptado de Wischmeier e Smith (1978) e da Relação de Distribuição de Sedimentos (Sediment Delivery Ratio – SDR) proposto por Ferro e Minacapilli (1995). Os resultados possibilitaram a classificação das sub-bacias conforme a porcentagem estimativa de carga de sedimentos que potencialmente viria a assorear os cursos d’água mediante a modificação do seu uso pela ocupação do solo induzida pela rodovia. Os critérios relevantes à definição do traçado da rodovia foram divididos em três: (1) aspectos ambientais, (2) aspectos construtivos e (3) aspectos socioeconômicos, tendo sido parametrizados através do uso de Sistema de Informação Geográfica com algoritmos em ambiente raster, na definição de caminhos de mínimo custo. A otimização da rota proposta sugere a adição de ganhos na orientação dos tomadores de decisão, como a inserção da rodovia TO-247 em bacias com menor nível de restrição de relação de aporte de sedimentos, redução das travessias sobre áreas protegidas, diminuição das obras de arte (bueiros e pontes) e da execução de cortes e aterros, incluindo a possibilidade de melhoria dos acessos aos pontos turísticos de interesse para o desenvolvimento regional. A incorporação de condicionantes hidrológicas através da classificação das bacias quanto a produção e transferência dos sedimentos destacou a principal novidade que foi a definição da área de influência delimitada pelos impactos ambientais de projetos rodoviários para os limites das bacias, podendo contribuir com o planejamento de estradas indutoras de desenvolvimento. / The contribution of this research is given by the design of effective impacts of highways, through the expansion of the influence areas beyond the linear tracks, adding the assessment of the environmental sensitivity of watersheds in order to optimize the layout of road projects. It was produced an orderly and systematic approach of the cause and consequence relations in the watersheds incorporating in it the TO-247 highway impacts, linking the cities of Mateiros and Lagoa do Tocantins. The watersheds in the region of the study area were classified using methodology for estimating production and transport of sediment in ArcGIS ArcInfo environment. It was applied the equation model derived from the Universal Soil Loss Equation - USLE adapted from Wischmeier and Smith (1978) and the Sediment Delivery Ratio - SDR according to what is proposed by Ferro and Minacapilli (1995). Those results allowed the classification of watersheds according to the percentage estimate of sediment load that would potentially silting up the waterways through modification of their usage by land use induced by the highway. The relevant criteria to define the highway route were divided into three: (1) environmental, (2) construction and (3) socioeconomic aspects, which have been parameterized by using Geographic Information System with algorithms in raster environment into the definition of low cost paths. The optimization of the route proposal in TO-247 suggests adding profit in orientation of decision makers, such as entering the highway in watersheds with lower levels of restriction regarding the amount of sediment, reduction of crossings on protected areas, reduction of culverts and bridges and the implementation of sections and embankments, including the possibility of improved access to interest tourist points for regional development. The incorporation of hydrological conditions through the classification of river watersheds as the production and transfer of sediments, which highlighted the main novelty, was the expansion circumscription of the influence area bounded by the environmental impacts of road projects for the limits of the watersheds, which may contribute to the planning of roads inducing development.

A contribuição desta pesquisa é dada através do dimensionamento dos impactos efetivos das rodovias, através da ampliação das áreas de influência para além das faixas lineares, acrescentando a avaliação da sensibilidade ambiental das bacias hidrográficas para a otimização do traçado de empreendimentos rodoviários. Foi produzida uma abordagem ordenada e sistemática das relações de causa e conseqüência nas bacias, integrando os impactos da rodovia TO-247, interligando as sedes municipais Lagoa do Tocantins e Mateiros. As sub-bacias da região da área do estudo foram classificadas mediante metodologia para estimativa de produção e transporte de sedimentos, em ambiente ArcGis ArcInfo, onde foi aplicado modelo derivado da Equação Universal da Perda de Solos (Universal Soil Loss Equation – USLE) adaptado de Wischmeier e Smith (1978) e da Relação de Distribuição de Sedimentos (Sediment Delivery Ratio – SDR) proposto por Ferro e Minacapilli (1995). Os resultados possibilitaram a classificação das sub-bacias conforme a porcentagem estimativa de carga de sedimentos que potencialmente viria a assorear os cursos d’água mediante a modificação do seu uso pela ocupação do solo induzida pela rodovia. Os critérios relevantes à definição do traçado da rodovia foram divididos em três: (1) aspectos ambientais, (2) aspectos construtivos e (3) aspectos socioeconômicos, tendo sido parametrizados através do uso de Sistema de Informação Geográfica com algoritmos em ambiente raster, na definição de caminhos de mínimo custo. A otimização da rota proposta sugere a adição de ganhos na orientação dos tomadores de decisão, como a inserção da rodovia TO-247 em bacias com menor nível de restrição de relação de aporte de sedimentos, redução das travessias sobre áreas protegidas, diminuição das obras de arte (bueiros e pontes) e da execução de cortes e aterros, incluindo a possibilidade de melhoria dos acessos aos pontos turísticos de interesse para o desenvolvimento regional. A incorporação de condicionantes hidrológicas através da classificação das bacias quanto a produção e transferência dos sedimentos destacou a principal novidade que foi a definição da área de influência delimitada pelos impactos ambientais de projetos rodoviários para os limites das bacias, podendo contribuir com o planejamento de estradas indutoras de desenvolvimento. / The contribution of this research is given by the design of effective impacts of highways, through the expansion of the influence areas beyond the linear tracks, adding the assessment of the environmental sensitivity of watersheds in order to optimize the layout of road projects. It was produced an orderly and systematic approach of the cause and consequence relations in the watersheds incorporating in it the TO-247 highway impacts, linking the cities of Mateiros and Lagoa do Tocantins. The watersheds in the region of the study area were classified using methodology for estimating production and transport of sediment in ArcGIS ArcInfo environment. It was applied the equation model derived from the Universal Soil Loss Equation - USLE adapted from Wischmeier and Smith (1978) and the Sediment Delivery Ratio - SDR according to what is proposed by Ferro and Minacapilli (1995). Those results allowed the classification of watersheds according to the percentage estimate of sediment load that would potentially silting up the waterways through modification of their usage by land use induced by the highway. The relevant criteria to define the highway route were divided into three: (1) environmental, (2) construction and (3) socioeconomic aspects, which have been parameterized by using Geographic Information System with algorithms in raster environment into the definition of low cost paths. The optimization of the route proposal in TO-247 suggests adding profit in orientation of decision makers, such as entering the highway in watersheds with lower levels of restriction regarding the amount of sediment, reduction of crossings on protected areas, reduction of culverts and bridges and the implementation of sections and embankments, including the possibility of improved access to interest tourist points for regional development. The incorporation of hydrological conditions through the classification of river watersheds as the production and transfer of sediments, which highlighted the main novelty, was the expansion circumscription of the influence area bounded by the environmental impacts of road projects for the limits of the watersheds, which may contribute to the planning of roads inducing development.

Les chantiers de construction contiennent plusieurs installations. Celles-ci sont susceptibles d’être endommagées par des incidents liés aux risques naturels ou technologiques comme les incendies, les explosions, les ondes de souffles, etc. Ces incidents peuvent avoir des conséquences néfastes sur l’ensemble du processus de construction, ce qui pourrait entrainer des accidents graves ayant un impact majeur sur la productivité des employés, le temps global du projet, sa qualité et son budget. Par conséquent les gestionnaires et les planificateurs du projet doivent adopter et développer des approches novatrices capables de faire face aux risques naturels potentiels, de minimiser leurs conséquences et de faciliter l’évacuation du site en cas de danger. Une de ces approches consiste à optimiser l’aménagement des chantiers de construction. En général, la réduction des dommages résultants de risques naturels ou technologiques est encore un défi scientifique.Dans cette thèse, deux modèles (déterministe et probabiliste) sont développés pour minimiser les risques au sein d’un chantier. La méthode adoptée pour le développement de ces deux modèles consiste en :• La modélisation des éléments du chantier, par exemple : le générateur électrique, les bureaux et les entrepôts de matériaux, sont modélisés en 2D, pour agir en tant que source d’aléa et/ou cible vulnérable potentielle.• La modélisation de l’aléa : elle montre l’interaction des aléas entre les composants du chantier.• La modélisation de la vulnérabilité : elle représente la faiblesse potentielle des cibles sur l’aléa généré par chaque source.• La définition de la fonction d’utilité : elle vise à offrir une disposition optimisée avec un minimum de risque total sur le chantier. L’algorithme à évolution différentielle est adopté pour exécuter le processus d’optimisation.D’une part, dans le modèle déterministe, nous utilisons le principe de la syntaxe spatiale pour étudier l’impact des configurations spatiales dans l’évaluation du risque sur le chantier. Par conséquent, comme le processus d’évacuation est pris en compte dans l’estimation du risque, le risque réel est amplifié en utilisant le facteur de pénalité appelé « profondeur moyenne ». L’algorithme de Dijkstra est appliqué sur un modèle déterministe afin de trouver les chemins les plus sûrs (chemins de moindre risque) pour évacuer les sites à partir de chaque position sur le chantier vers les lieux sûrs afin de diminuer les pertes humaines et matérielles.D’autre part, le modèle probabiliste suppose que le risque est composé de la défaillance individuelle de chaque installation sur le chantier de construction. La simulation numérique est utilisée pour trouver la distribution de probabilités des défaillances pour l’ensemble du site.Les fonctionnalités d’un SIG (Système d’Information Géographique) ont été utilisées pour présenter les données sous forme de cartes, pour produire des cartes spatiales de risque sur le chantier de construction, pour mettre en œuvre l’algorithme de Dijkastra et pour l’analyse du coût le plus faible.A titre indicatif, les modèles proposés sont utilisés dans un cas d’étude comprenant plusieurs installations. Dans le modèle déterministe, toutes ces installations agissent comme des sources d’aléa et des cibles vulnérables, en même temps, dans le modèle probabiliste, quelques-unes de ces installations agissent comme des sources d’aléa et toutes comme des cibles vulnérables. Les résultats obtenus montrent que les modèles proposés sont efficaces en raison de leur capacité à générer une disposition optimale du site avec un environnement de travail plus sûr. En outre, les modèles obtenus sont capables de mettre en évidence les zones les plus risquées d’un chantier, de générer les chemins d’évacuation les moins risqués, ce qui permettra de minimiser les blessures graves et les victimes en cas d’urgence / Construction sites contain several supporting facilities that are required to complete construction activities. These facilities are susceptible to damage due to the occurrence of natural or technological hazards such as fire, explosion, blast wave, and so on. These may cause adverse consequences for the whole construction process, which in turn lead to fatal accidents that have a major impact on worker and employee productivity, project completion time, project quality and project budget. Therefore, project planners must adopt and develop innovative approaches able to face the occurrence of potential hazards, minimize their consequences, and facilitate the evacuation of the site in case of their occurrence. One of these approaches is optimizing construction site layout. In general, generating construction site layout able minimizing risk resulting from natural or technological hazards is still a scientific challenge.In the present research, two proposed model (deterministic and probabilistic) are developed to minimize the risks within a construction site. The common methodology adopted to develop these two models consists of:• Modeling construction site components, for instance; electric generator, offices and material storages, in a 2D layout, to act as either hazardous source or potential target or both at the same time.• Modeling hazard: it shows the hazard interaction among site components and the attenuation of hazard.• Modeling vulnerability: it represents the potential weakness of whole targets to the hazard generated from each source.• Defining the utility function: it aims to afford an optimized site layout with minimum total risk in the construction site. The differential evolution algorithm is adopted to run optimization process.Particularly, in the deterministic model, we use space syntax principle in order to realize the impact of space configurations in evaluating the risk in the construction site. Therefore, as the evacuation process is considered in estimating the risk, the actual risk is amplified by utilizing penalty factor called mean depth. Furthermore, Dijkstra’s algorithm is run on deterministic model to find the safest paths (least risk paths) for evacuating sites from any position on the construction site towards the safe places in order to diminish losses and fatalities. On the other hand, the framework utilized to develop a probabilistic model assumed that the risk is combined of the individual failure of each facility within a construction site. Moreover, the numerical simulation is performed to find the probabilistic distribution of failure for the whole site.Geographic information system (GIS) capabilities were exploited, in this research, to present data in maps format, generate the spatial risk map in the construction site, and implement the Dijkstra’s algorithm and least-cost path analysis.For illustration purposes, the proposed models are employed in a case study consisting of several facilities. In the deterministic model, all of these facilities act as hazardous sources and potential targets, at the same time, while, in a probabilistic model, only three of these facilities act as fire hazardous sources, whereas, all of them are potential targets. The results revealed that the proposed models are efficient due to their capability of generating site layout with the safer work environment. In addition, the model is capable of highlighting the riskiest areas within a construction site. Moreover, the proposed models are able to generate paths through least-risk zones, which will minimize the serious injuries and victims in cases of emergencies

Various unmanned missions deploy vehicles such as missiles, torpedoes, ground robots, and unmanned aerial vehicles. Guidance strategies for these vehicles aim to intercept a target point and satisfy additional objectives such as specifications on impact angle and interception time. Certain impact angles are crucial for a greater warhead effectiveness, and minimizing the interception time is important for vehicles with limited endurance time and for reducing the probability of detection. This thesis considers the time-optimal impact angle constrained guidance problem for interception of moving targets. In the first part of the thesis, a Dubins paths–based guidance methodology for minimum-time lateral interception of a moving and non-maneuvering target is designed. The existence and the time-optimality of the paths are established for impact angle constrained interception of moving targets. The capture regions are analyzed and a classification of the initial geometries is developed for deducing the time-optimal path type. The corresponding guidance command for optimal interception can be generated from the information of initial engagement geometry and target’s speed. In the next part of the thesis, the concept of equivalent virtual target is introduced to address the problem of impact along a general direction. An algorithm is developed to obtain the optimal interception point for generalized interception scenarios. A proof of convergence is presented for the proposed algorithm. Achieving different impact angles, the interceptor often takes sharp turns. Following such curved trajectories, the interceptor may fail to keep the target inside the seeker field-of-view. In the next part of the thesis, the field-of-view characteristics of the proposed optimal guidance strategies are analyzed. Closed-form expressions are derived for the interceptor’s look-angle to the target. Satisfying field-of-view condition at endpoints of the path segments that constitute the optimal path is proven to guarantee target motion inside the field-of-view throughout the engagement. The stationary target case is also analyzed as a specific scenario. The last part of the thesis presents a method to extend the proposed guidance strategies to maneuvering target scenarios.