A Global Path Planning Algorithm Based on Bidirectional SVGA

For path planning algorithms based on visibility graph, constructing a visibility graph is very time-consuming. To reduce the computing time of visibility graph construction, this paper proposes a novel global path planning algorithm, bidirectional SVGA (simultaneous visibility graph construction and path optimization by A⁎). This algorithm does not construct a visibility graph before the path optimization. However it constructs a visibility graph and searches for an optimal path at the same time. At each step, a node with the lowest estimation cost is selected to be expanded. According to the status of this node, different through lines are drawn. If this line is free-collision, it is added to the visibility graph. If not, some vertices of obstacles which are passed through by this line are added to the OPEN list for expansion. In the SVGA process, only a few visible edges which are in relation to the optimal path are drawn and the most visible edges are ignored. For taking advantage of multicore processors, this algorithm performs SVGA in parallel from both directions. By SVGA and parallel performance, this algorithm reduces the computing time and space. Simulation experiment results in different environments show that the proposed algorithm improves the time and space efficiency of path planning

Conception d’entrepôt : sélection des équipements de manutention et d'entreposage

RÉSUMÉ : L’entreposage est une activité nécessaire tout au long du cycle de vie d’un produit. Il est entreposé plusieurs fois dans la chaîne logistique sous forme de matières premières. Il est ensuite entreposé durant le processus de fabrication sous différentes formes (pièce, sous-ensemble, produit fini). Il est finalement entreposé en tant que produit fini chez les intervenants de distribution (grossistes, détaillants, etc.) avant d’être livré chez le consommateur. Le produit séjourne durant une bonne partie de sa vie dans les entrepôts sous toutes ses formes. Les coûts logistiques pèsent sur les entreprises. Ils peuvent être réduits en améliorant par exemple le processus de sélection des équipements logistiques. Il n'est pas toujours nécessaire de disposer d'équipements de manutention et d'entreposage coûteux et hautement automatisés. Selon la littérature du domaine, les concepteurs d’entrepôt et d’usine ont besoin d'outils d'aide à la décision pour choisir l'équipement convenable. L'équipement convenable désigne l'équipement le plus approprié à une opération spécifique de manutention ou d’entreposage de charges. Il possède les caractéristiques techniques requises et respecte les contraintes d'exploitation et d'environnement tout en étant rentable. Une revue de littérature regroupant 74 articles publiés entre 1985 et 2017 et traitant la sélection des équipements de manutention et d’entreposage est réalisée. Elle porte sur cinq différents aspects : buts ou problèmes abordés dans la sélection des équipements de manutention et d’entreposage; données d’entrée; méthodes de sélection; applications des solutions proposées; et validation des propositions. Elle a permis de mettre en évidence ce qui est accompli dans ce domaine jusqu’à aujourd’hui et élaborer des recommandations de recherche. À partir de ces recommandations, différentes contributions sont faites dans cette thèse. Une large collecte de données sur les systèmes d’entreposage destinés aux charges palettisées a été faite pour réaliser leurs fiches techniques. Un système d’entreposage est un équipement d’entreposage couplé à un équipement de manutention. Une validation de ces fiches techniques par l’entreprise Équipement BONI a été obtenue. Une méthodologie de sélection des systèmes d’entreposage destinés aux charges palettisées est proposée. Une extraction automatique de règles de sélection des systèmes desdits systèmes d’entreposage destinés aux charges palettisées est réalisée. Une méthodologie de sélection des équipements d’entreposage destinés aux petites charges est aussi proposée. Finalement, une évaluation du processus de sélection des équipements de manutention et d’entreposage dans un contexte 4.0 est réalisée. Différentes techniques et méthodes ont été adaptées pour réaliser ces contributions. Le raisonnement en logique floue est adopté afin de contourner le problème d’incertitude et d’imprécision des données. Les techniques et méthodes d’intelligence artificielle sont exploitées telles que le système basé sur la connaissance de la famille des systèmes experts et l’algorithme de classification de type apprentissage machine C4.5. Les méthodes d’aide à la décision multicritère à savoir FTOPSIS et AHP sont aussi adaptées aux différents problèmes. Les propositions de cette thèse sont pour la plupart des premiers essais dans ce domaine. Les défauts de la charge palettisée sont tenus compte lors de la sélection des systèmes d’entreposage destinés aux charges palettisées aux côtés des autres critères pour la première fois dans la littérature. Les défauts de la charge palettisée sont : défauts de construction; défauts de forme; défauts d’occupation de la surface de la palette; autres types de défauts; défauts d’emballage des colis et état de la palette. L’application des techniques d’exploration de données (Data mining) au problème de sélection des systèmes d’entreposage destinés aux charges palettisées est aussi une première tentative. La contextualisation de la sélection des équipements de manutention et d’entreposage dans l’ère de la quatrième révolution industrielle indique l’aspect évolutif des problèmes logistiques. Les travaux de cette thèse pourront servir d’inspiration à d’autres efforts de recherche pour contribuer davantage à améliorer les outils d’aide à la décision destinés aux concepteurs d’entrepôt et d’usine. Une mise à jour continue des bases de données est nécessaire afin d’intégrer les avancements technologiques. Les méthodologies de sélection proposées pourraient être programmées en langage informatique afin d’automatiser les processus.----------ABSTRACT : Warehousing is a necessary activity throughout the life cycle of a product. The product is warehoused as a raw material at the supplier or at different locations during the supply chain. It is then warehoused during the production process in various forms (part, sub-assembly, finished product). It is finally warehoused as a finished product in different locations (wholesalers, retailers, etc.) before being delivered to the consumer. The product stays in warehouses during a considerable part of its life. Logistics costs represent a significant percentage of a manufactured product’s total cost. To reduce costs, savings in logistics equipment could be found. This is possible with an efficient equipment selection. Costly, highly automated material handling equipment or warehousing equipment is not always necessary. According to the literature of the field, warehouse or plant designers need decision aid tools to better select suitable equipment. Suitable equipment refers to the most appropriate equipment for a material handling or warehousing operation, and it possesses the required technical characteristics and respects the operation and environmental constraints while being cost effective. A literature review including a selection of 74 papers published between 1985 and 2017 and addressing the material handling equipment selection is realized. It covers five different aspects: aims or issues addressed in the selection of material handling and warehousing equipment; input data; methods for selecting; applications of proposed solutions; and validation of proposals. It enabled us to know what has been done up to now in this field and make further research suggestions. Based on these suggestions, different contributions are made in this thesis. A widespread collection of data on warehousing systems designed for palletized loads is made to elaborate their technical data sheets. A warehousing system is a warehousing equipment coupled with material handling equipment. These technical data sheets have been validated by Equipment BONI Inc. A methodology for the selection of warehousing systems designed for palletized loads is proposed. Rules for the selection of warehousing systems designed for palletized loads are automatically extracted. A methodology for the selection of warehousing equipment designed for small loads is proposed. Finally, an evaluation of the selection process of material handling and warehousing equipment in a 4.0 environment is realized

Motion Planning

Motion planning is a fundamental function in robotics and numerous intelligent machines. The global concept of planning involves multiple capabilities, such as path generation, dynamic planning, optimization, tracking, and control. This book has organized different planning topics into three general perspectives that are classified by the type of robotic applications. The chapters are a selection of recent developments in a) planning and tracking methods for unmanned aerial vehicles, b) heuristically based methods for navigation planning and routes optimization, and c) control techniques developed for path planning of autonomous wheeled platforms

Portable Computer Technology (PCT) Research and Development Program Phase 2

The subject of this project report, focused on: (1) Design and development of two Advanced Portable Workstation 2 (APW 2) units. These units incorporate advanced technology features such as a low power Pentium processor, a high resolution color display, National Television Standards Committee (NTSC) video handling capabilities, a Personal Computer Memory Card International Association (PCMCIA) interface, and Small Computer System Interface (SCSI) and ethernet interfaces. (2) Use these units to integrate and demonstrate advanced wireless network and portable video capabilities. (3) Qualification of the APW 2 systems for use in specific experiments aboard the Mir Space Station. A major objective of the PCT Phase 2 program was to help guide future choices in computing platforms and techniques for meeting National Aeronautics and Space Administration (NASA) mission objectives. The focus being on the development of optimal configurations of computing hardware, software applications, and network technologies for use on NASA missions

VLSI Design

This book provides some recent advances in design nanometer VLSI chips. The selected topics try to present some open problems and challenges with important topics ranging from design tools, new post-silicon devices, GPU-based parallel computing, emerging 3D integration, and antenna design. The book consists of two parts, with chapters such as: VLSI design for multi-sensor smart systems on a chip, Three-dimensional integrated circuits design for thousand-core processors, Parallel symbolic analysis of large analog circuits on GPU platforms, Algorithms for CAD tools VLSI design, A multilevel memetic algorithm for large SAT-encoded problems, etc

Scalable and Extensible Augmented Reality with Applications in Civil Infrastructure Systems.

In Civil Infrastructure System (CIS) applications, the requirement of blending synthetic and physical objects distinguishes Augmented Reality (AR) from other visualization technologies in three aspects: 1) it reinforces the connections between people and objects, and promotes engineers’ appreciation about their working context; 2) It allows engineers to perform field tasks with the awareness of both the physical and synthetic environment; 3) It offsets the significant cost of 3D Model Engineering by including the real world background. The research has successfully overcome several long-standing technical obstacles in AR and investigated technical approaches to address fundamental challenges that prevent the technology from being usefully deployed in CIS applications, such as the alignment of virtual objects with the real environment continuously across time and space; blending of virtual entities with their real background faithfully to create a sustained illusion of co- existence; integrating these methods to a scalable and extensible computing AR framework that is openly accessible to the teaching and research community, and can be readily reused and extended by other researchers and engineers. The research findings have been evaluated in several challenging CIS applications where the potential of having a significant economic and social impact is high. Examples of validation test beds implemented include an AR visual excavator-utility collision avoidance system that enables spotters to ”see” buried utilities hidden under the ground surface, thus helping prevent accidental utility strikes; an AR post-disaster reconnaissance framework that enables building inspectors to rapidly evaluate and quantify structural damage sustained by buildings in seismic events such as earthquakes or blasts; and a tabletop collaborative AR visualization framework that allows multiple users to observe and interact with visual simulations of engineering processes.PHDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/96145/1/dsuyang_1.pd

Development and Evaluation of Interactive Courseware for Visualization of Graph Data Structure and Algorithms

The primary goal of this dissertation was to develop and pilot test interactive, multimedia courseware which would facilitate learning the abstract structures, operations, and concepts associated with graph and network data structures in Computer Science. Learning objectives and prerequisites are presented in an introduction section of the courseware and a variety of learning activities are provided including tutorials, animated demonstrations, interactive laboratory sessions, and self-tests. Courseware development incorporated principles and practices from software engineering, instructional design, and cognitive learning theories. Implementation utilized an easy-to-use authoring tool, NeoBook Professional (1994), to create the overall framework and the user interfaces, and Microsoft QuickBASIC 4.5 (1990) to program the interactive animated demonstrations and laboratory exercises. A major emphasis of the courseware is the use of simple interactive, animated displays to demonstrate the step-by-step operation of graph and network algorithms such as depth-first traversal, breadth-first traversal, shortest path, minimum sparring tree and topological ordering