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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

Méthodes de résolution exactes pour le problème de routage de véhicules avec fenêtres de temps et routes multiples / Exact methods to solve the Multi-Trip Vehicle Routing Problem with Time Windows

Hernandez, Florent 26 November 2010 (has links)
Le problème de routage de véhicules avec fenêtres de temps et routes multiples (MTVRPTW) est une généralisation du problème de routage de véhicules avec fenêtres de temps (VRPTW). Dans le MTVRPTW, on autorise un véhicule à effectuer plusieurs routes durant une période de planification, ce qui permet d'optimiser les transports lorsque le nombre de véhicules est limité et peu élevé. Nous proposons dans cette thèse la première méthode exacte permettant de résoudre ce problème. Notre modélisation prend la forme d'un problème de couverture des clients dont les variables sont des routes. Des contraintes d'exclusion mutuelle expriment la disponibilité des véhicules. Nous utilisons la Génération de Colonnes, avec un sous-problème effectuant, par programmation dynamique, une recherche de plus court chemin élémentaire contraint en ressources. Notre méthode de programmation dynamique tient compte des dépendances de plusieurs ressources grâce à la notion de label représentatif, et est ainsi plus efficace qu'une approche classique. La méthode de Génération de Colonnes est incluse dans un schéma de Branch and Price composé de deux types de branchement, l'un basé sur les arcs, l'autre sur la résolution d'un VRPTW. Nous avons mis en place diverses méthodes accélératrices spécifiques du MTVRPTW. Nous donnons les résultats de l'algorithme sur les instances de Solomon. Des résultats issus de méthodes exactes étaient disponibles dans la littérature pour le MTVRPTW avec durée limite sur les routes. Nous avons proposé un nouvel algorithme plus performant, et basé sur nos méthodes, pour cette variante du problème. / The multi-trip vehicle routing problem with time windows (MTVRPTW) is a generalization of the vehicle routing problem with time windows (VRPTW). In the MTVRPTW, one vehicle can perform several trips during a planning period. This allows optimizing the transport when the number of vehicles is limited and small.We propose here the first exact method for solving this problem.Our model is designed as a coverage problem for customers where the variables are trips. Mutual exclusion constraints express the availability of vehicles. We use a column generation scheme in which the sub-problem is an elementary shortest path problem with resource constraints (ESPPRC). Our dynamic programming method for ESPPRC takes into account dependencies of several resources through the concept of representative label. It is thus more efficient than a conventional approach. The column generation method is included in a Branch and Price scheme with two types of branching. One is based on arc selection, and the other on solving a VRPTW. We have implemented various accelerating methods which are specific to MTVRPTW. We give the results of our algorithm on Solomon instances.Results from exact methods were available in the literature for the MTVRPTW with time limit on the trips. We proposed a new and more efficient algorithm, based on our methods, to solve this variant of the problem.
2

Vehicle Routing for City Logistics / OPTIMISATION DE TOURNEES DE VEHICULES POUR LA LOGISTIQUE URBAINE

Cattaruzza, Diego 27 March 2014 (has links)
Le transport de marchandises dans les zones urbaines est un sujet important de nos jours. Le transport est une activité vitale pour les villes, mais implique pollution, congestion, accidents. La logistique urbaine vise à optimiser les processus logistiques et de transports urbains en tenant compte des aspects environnementaux et sociaux. Cette thèse traite de cette thématique et fait partie du projet MODUM.MODUM vise à étudier un système de livraison basé sur des centres de distribution urbains. Nous présentons une classification et une analyse des mouvements de marchandises et des problèmes de tournées de véhicules (VRP) associés.La deuxième partie propose une revue complète des travaux de recherche traitant des problème VRP avec excursions multiples (MTVRP). Le MTVRP est une extension du VRP où les véhicules sont autorisés à effectuer plusieurs tournées. Nous proposons une heuristique pour le MTVRP qui est par la suite adaptée pour un problème plus riche, le MTVRP avec fenêtres de temps et dates de disponibilité. Il s'agit d'une variante du MTVRP où à chaque client est associée une fenêtre de temps et à chaque marchandise une date de disponibilité qui représente l'instant où elle devient disponible au dépôt.Par la suite, nous étudions une variante du MTVRP où les marchandises sont classées par types de produits qui ne peuvent pas être transportés dans le même véhicule. Une analyse est effectuée pour montrer l’avantage des tournées multiples pour le problème de dimensionnement des flottes.Enfin, nous décrivons le problème de tournées qui se pose dans MODUM et le simulateur qui est développé pour évaluation du système. / Transportation of merchandise in urban areas has become an important nowadays topic. In fact, transportation is a vital activity for each city, but entail pollution, congestion, accidents.City logistics aims at optimizing the whole urban logistics and transportation process, taking into account environmental and social aspects. This thesis, that is part of the MODUM project, finds its location in this area of research. In particular, MODUM aims at studying a delivery system based on City Distribution Centers.We first present a classification and an analysis of urban good movements and routing problems peculiar to metropolitan areas. A second survey proposes a complete collection of articles that has been done on the Multi Trip Vehicle Routing Problem (MTVRP). The MTVRP is an extension of the Vehicle Routing Problem (VRP) where vehicles are allowed to perform several trips.We propose an efficient heuristic for the MTVRP that is, in a subsequent step, adapted to a new routing problem, the MTVRP with Time Windows and Release Dates (MTVRPTWR). It is a variant of the MTVRP where each customer is associated with a time window and each merchandise is associated with a release date that represents the instant it becomes available at the depot.We, then, study a variant of the MTVRP where goods belong to different commodities that cannot be transported at the same time by the same vehicle. An analysis is conducted on the benefits of the multi-trip aspect in fleet dimensioning problems.Finally we describe the complex routing problem that arises in MODUM and the simulator that is developed to evaluate the performances of the system.
3

Modelagem e meta-heurísticas para o problema de roteamento de veículos com janelas de tempo, múltiplos entregadores e múltiplas viagens em uma empresa de distribuição de bebidas

Souza Neto, José Ferreira de 21 March 2016 (has links)
Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-10-06T17:59:08Z No. of bitstreams: 1 DissJFSN.pdf: 5729965 bytes, checksum: 946688f479f7780db197fa49b4b4c853 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:51:08Z (GMT) No. of bitstreams: 1 DissJFSN.pdf: 5729965 bytes, checksum: 946688f479f7780db197fa49b4b4c853 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:51:14Z (GMT) No. of bitstreams: 1 DissJFSN.pdf: 5729965 bytes, checksum: 946688f479f7780db197fa49b4b4c853 (MD5) / Made available in DSpace on 2016-10-20T13:51:20Z (GMT). No. of bitstreams: 1 DissJFSN.pdf: 5729965 bytes, checksum: 946688f479f7780db197fa49b4b4c853 (MD5) Previous issue date: 2016-03-21 / Não recebi financiamento / Vehicle routing problems occur in many practical situations where the pickup and/or delivery of goods is required. In this context, the present research aims to contribute to the study of logistic operations that arise in companies that deliver products on a regular basis to customers in densely populated urban areas. The problem consists in designing minimal cost daily routes serving the maximal number of customers. To this end, the crew of each vehicle comprise multiple deliverymen as means to reduce service times. Based on a case study in a drinks producer and distributor in the state of São Paulo, it is proposed a mixed integer linear programming model that comprise costs with own and chartered vehicles and the number of deliverymen, and various operational constraints such as time windows in customers, multiple daily trips, time limitations for the circulation of some vehicle types in specific areas, compatibility between vehicles and customers, maximum load in each vehicle, maximum route time and minimum load for the realization of a second trip. Results obtained by solving the model with real instances through exact (branch&cut), heuristic (constructive, local search, GRASP and Simulated Annealing) and hybrid (GRASP and branch&cut) approaches demonstrate the good quality of the generated solutions, and indicate the potential of application of some of these methods in practice. / Problemas de roteamento de veículos ocorrem em diversas situações práticas onde se faz necessária a distribuição e/ou coleta de produtos. Nesse contexto, a presente pesquisa visa o estudo das operações logísticas presentes em empresas que entregam produtos em base regular a clientes localizados em áreas urbanas de alta densidade demográfica. O problema consiste na obtenção de rotas de mínimo custo visando o atendimento do maior número de clientes da carteira diária. Para tal, a tripulação de cada veículo pode contemplar múltiplos entregadores para redução dos tempos de serviço. Com base em um estudo de caso em uma distribuidora de bebidas do interior do Estado de São Paulo, é proposto um modelo de programação linear inteira mista que considera custos com frota própria e fretada e com o número de entregadores, e diversas restrições operacionais, tais como janelas de tempo em clientes, múltiplas viagens diárias, limitações de horários de circulação de tipos de veículos, compatibilidade entre veículos e clientes, capacidade máxima de carga a ser transportada em cada veículo, tempo máximo de rota e carga mínima para realização da segunda viagem. Resultados da resolução do modelo para instâncias reais por meio de abordagens exatas (branch&cut), heurísticas (construtiva, busca local, GRASP e Simulated Annealing) e híbrida (GRASP e branch&cut), demonstram a boa qualidade das soluções geradas, e evidenciam o potencial de uso dessas metodologias na prática.

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