1,656 research outputs found
A traffic-aware electric vehicle charging management system for smart cities
© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The expected increase in the number of electric vehicles (EVs) in the coming years will contribute to reducing CO2 pollution in our cities. Currently, EVs' users may suffer from distress due to long charging service times and overloaded charging stations (CSs). Critical traffic conditions (e.g., traffic jams) affect EVs' trip time (TT) towards CSs and thus influence the total trip duration. With this concern, Intelligent transport systems (ITS) and more specifically connected vehicle technologies, can leverage an efficient real-time EV charging service by jointly considering CSs status and traffic conditions in the city. In this work, we propose a scheme to manage EVs' charging planning, focusing on the selection of a CS for the energy-requiring EV. The proposed scheme considers anticipated charging slots reservations performed through a vehicular ad hoc network (VANET), which has been regarded as a cost-efficient communication framework. In specific, we consider two aspects: 1) the EV's total trip time towards its destination considering an intermediate charging at each candidate CS, and 2) the communication delay of the VANET routing protocol. First, in order to estimate the EV's total trip time, our CS selection scheme takes into account the average road speed, traffic lights, and route distance, along the path of the EV. The optimal CS that produces the minimum total charging service time (including the TT) is suggested to that energy-requiring EV. Then, we introduce two communication modes based on geographical routing protocols for VANETs to attain an anticipated charging slot reservation. Simulation results show that with our charging scheme EVs' charging service time is reduced and more EVs are successfully charged.Peer ReviewedPostprint (author's final draft
Adoption of vehicular ad hoc networking protocols by networked robots
This paper focuses on the utilization of wireless networking in the robotics domain. Many researchers have already equipped their robots with wireless communication capabilities, stimulated by the observation that multi-robot systems tend to have several advantages over their single-robot counterparts. Typically, this integration of wireless communication is tackled in a quite pragmatic manner, only a few authors presented novel Robotic Ad Hoc Network (RANET) protocols that were designed specifically with robotic use cases in mind. This is in sharp contrast with the domain of vehicular ad hoc networks (VANET). This observation is the starting point of this paper. If the results of previous efforts focusing on VANET protocols could be reused in the RANET domain, this could lead to rapid progress in the field of networked robots. To investigate this possibility, this paper provides a thorough overview of the related work in the domain of robotic and vehicular ad hoc networks. Based on this information, an exhaustive list of requirements is defined for both types. It is concluded that the most significant difference lies in the fact that VANET protocols are oriented towards low throughput messaging, while RANET protocols have to support high throughput media streaming as well. Although not always with equal importance, all other defined requirements are valid for both protocols. This leads to the conclusion that cross-fertilization between them is an appealing approach for future RANET research. To support such developments, this paper concludes with the definition of an appropriate working plan
Electric Power Allocation in a Network of Fast Charging Stations
In order to increase the penetration of electric vehicles, a network of fast
charging stations that can provide drivers with a certain level of quality of
service (QoS) is needed. However, given the strain that such a network can
exert on the power grid, and the mobility of loads represented by electric
vehicles, operating it efficiently is a challenging problem. In this paper, we
examine a network of charging stations equipped with an energy storage device
and propose a scheme that allocates power to them from the grid, as well as
routes customers. We examine three scenarios, gradually increasing their
complexity. In the first one, all stations have identical charging capabilities
and energy storage devices, draw constant power from the grid and no routing
decisions of customers are considered. It represents the current state of
affairs and serves as a baseline for evaluating the performance of the proposed
scheme. In the second scenario, power to the stations is allocated in an
optimal manner from the grid and in addition a certain percentage of customers
can be routed to nearby stations. In the final scenario, optimal allocation of
both power from the grid and customers to stations is considered. The three
scenarios are evaluated using real traffic traces corresponding to weekday rush
hour from a large metropolitan area in the US. The results indicate that the
proposed scheme offers substantial improvements of performance compared to the
current mode of operation; namely, more customers can be served with the same
amount of power, thus enabling the station operators to increase their
profitability. Further, the scheme provides guarantees to customers in terms of
the probability of being blocked by the closest charging station. Overall, the
paper addresses key issues related to the efficient operation of a network of
charging stations.Comment: Published in IEEE Journal on Selected Areas in Communications July
201
Towards a network management solution for vehicular delay-tolerant networks
Vehicular networks appeared as a new communication solution where vehicles act as a communication infrastructure, providing data communications through vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communications. Vehicular Delay-Tolerant Networks (VDTNs) are a new disruptive network architecture assuming delay tolerant networking paradigm where there are no end-to-end connectivity. In this case the incial node transmits the data to a closed node, the data will be carried by vehicles, hop to hop until the destination.
This dissertation focuses on a proposal of a network management solution, based standard protocol Simple Network Management Protocol (SNMP) to VDTN networks. The developed solution allows control a VDTN netowork through a Network Management System (NMS) with the objective to detect and, if it’s possible, anticipate, possible errors on network.
The research methodology used was the prototyping. So, it was built a network management module to the laboratorial prototype, called VDTN@Lab. The system built include a MIB (Management Information Base) placed in all vehicular network nodes. The solution was built, demonstrated, validated and evaluated their performance, being ready for use.As redes veiculares foram desenhadas para permitir que os veículos possam
transportar dados criando assim um novo tipo de redes, caracterizando-se por dois tipos de
comunicação: comunicações veículo-para-veículo (V2V) ou comunicações veículo-parainfra-estrutura (V2I). Redes veiculares intermitentes (do Inglês Vehicular Delay-Tolerant
Networks - VDTNs) surgiram como uma nova arquitectura de rede de dados onde os
veículos são utilizados como infra-estruturas de comunicação. As VDTNs caracterizam-se
por serem redes veiculares baseadas no paradigma de comunicações intermitentes. Nas
redes VDTN não existe uma ligação permanente extremo a extremo entre o emissor e o
receptor. Neste caso, o nó inicial transmite os dados para um nó que esteja junto dele e
assim sucessivamente, os dados vão sendo transportados pelos veículos, salto a salto até
ao destinatário final.
Esta dissertação centra-se na proposta de uma solução de gestão de rede, baseada
no protocolo estandardizado Simple Network Management Protocol (SNMP) para redes
VDTN. A solução construída permite controlar uma rede VDTN através de um sistema de
gestão de rede (do Inglês Network Management System - NMS) com o objectivo de
detectar e, se possível antecipar, possíveis erros na rede.
A metodologia de investigação utilizada foi a prototipagem. Assim, foi construído
um módulo de gestão de redes para o protótipo laboratorial, chamado VDTN@Lab. O
sistema construído inclui uma MIB (Management Information Base) que é colocada em
todos os nós de uma rede veicular, tanto fixos como móveis. A solução foi construída,
demonstrada, validade e avaliado o seu desempenho, estando assim pronta para ser
utilizada
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