Traffic Modeling of a Cooperative Charge While Driving System in a Freight Transport Scenario

The aim of this paper is to present a research study on a traffic model developed for analysing the performance of the wireless inductive systems for charging while driving (CWD) fully electric vehicles (FEVs) from both traffic and energy points of view. The design assumptions of the developed traffic model are aimed to simulate in particular a freight distribution service in a fully cooperative traffic environment. In this case, the CWD service could be used to guarantee the minimum state of charge (SOC) of the batteries at the arrival to the depot that allows the vehicles to shortly start with further activities. In this way, the fleet manager could avoid wasting time for the stationary recharge, thus increasing the level of service of the freight distribution. The CWD system is applied to a multilane ring road with several intermediate on-ramp entrances, where the slowest lane is reserved for the charging activities, when authorized vehicles are present. A specific traffic model has been developed and implemented adopting a mesoscopic approach, where vehicle energy needs and charging opportunities affect drivers’ behavior. Overtaking maneuvers, as well as new entries in the CWD lane of vehicles which need to charge, have been modeled by taking into account a fully cooperative driving system among vehicles which manages an adequate gap between consecutive vehicles. Finally, a speed control strategy in which vehicles can be delayed to create an empty time-space slot in the CWD lane, is simulated at a defined node. This type of control, though is simulated to allow extraordinary maintenance operations, which may require a free charging zone for a given time slot, could also be applied to support merging maneuvers for on ramp vehicles

"Charge while driving" for electric vehicles: road traffic modeling and energy assessment

The aim of this research study is to present a method for analyzing the performance of the wireless inductive charge-while-driving (CWD) electric vehicles, from both traffic and energy points of view. To accurately quantify the electric power required from an energy supplier for the proper management of the charging system, a traffic simulation model is implemented. This model is based on a mesoscopic approach, and it is applied to a freight distribution scenario. Lane changing and positioning are managed according to a cooperative system among vehicles and supported by advanced driver assistance systems (ADAS). From the energy point of view, the analyses indicate that the traffic may have the following effects on the energy of the system: in a low traffic level scenario, the maximum power that should be supplied for the entire road is simulated at approximately 9 MW; and in a high level traffic scenario with lower average speeds, the maximum power required by the vehicles in the charging lane increases by more than 50 %

The influence of time windows on the costs of urban freight distribution services in city logistics applications

In freight distribution services a required quality level may have a relevant effect on transportation costs. For this reason an evaluation tool is useful to compare different service settings and support the decision, on the base of quantitative indicators. This paper proposes a method for cost evaluation in this context and presents an application to a case study concerning a freight distribution service, which operates on a wide road network having a city centre, a peripheral urban area and a peri-urban rural zone. A simulation method is proposed to obtain real-life scenarios in order to test the method and its indicators. The performance of each indicator has been evaluated in an experimental context to produce realistic test cases, using a trip planning tool and a demand generator. First, the behaviour of the indicators is analysed with regard to the time windows width planned for the service. Then, their ability in estimating the total transportation cost to satisfy all the requests, under different time period profiles, is shown. The results confirm the ability of the set of indicators to predict with a good approximation the transportation costs and therefore to be used in supporting the service quality planning decision

Estimating charging demand by modelling EV drivers' parking patterns and habits

The diffusion of battery electric vehicles (BEVs) requires a proper charging infrastructure to supply users the chance to charge their vehicles according to energy, time, and space needs. Thus, city planners and stakeholders need decision support tools to estimate the impacts of potential charging activities and compare alternative scenarios. The paper proposes a modelling approach to represent parking activities in urban areas and obtain key indicators of the electric energy required. The agent-based model reproduces the dynamics of user parking and assesses the impacts on the electricity grid during the day. Since the focus is on parking activities, no detailed data on vehicle trips are required to apply the standard demand modelling approach, which would require Origin-Destination matrices to simulate traffic flows on the road network. Preliminary results concerning the city of Turin are presented for simulated scenarios to identify zones where charging demand can be critical and peak events in electric power over the day. The model is designed to be scalable for all European cities because, as the case study shows, it uses available data. The results obtained can be used for the design of charging infrastructure (power and type) by zones

Evoluzione dell'auto verso l'autonomia: collocazione storico-evolutiva, motivazioni ed effetti sulla sicurezza

Intervento di sintesi sull'evoluzione dell'auto verso l'autonomia: dopo la collocazione evolutiva dell'innovazione e dell'automazione nella storia dell'automobile, vengono esposte le motivazioni per l'introduzione della guida assistita, forse un domani dell'autonomia integrale, con gli effetti attesi sulla sicurezza stradale

Freight distribution performance indicators for service quality planning in large transportation networks

This paper studies the use of performance indicators in routing problems to estimate how transportation cost is affected by the quality of service offered. The quality of service is assumed to be directly dependent on the size of the time windows. Smaller time windows mean better service. Three performance indicators are introduced. These indicators are calculated directly from the data without the need of a solution method. The introduced indicators are based mainly on a "request compatibility", which describes whether two visits can be scheduled consecutively in a route. Other two indicators are introduced, which get their values from a greedy constructive heuristic. After introducing the indicators, the correlation between indicators and transportation cost is examined. It is concluded that the indicators give a good first estimation on the transportation cost incurred when providing a certain quality of service. These indicators can be calculated easily in one of the first planning steps without the need of a sophisticated solution tool. The contribution of the paper is the introduction of a simple set of performance indicators that can be used to estimate the transportation cost of a routing problem with time window

Evaluation of a reactive dynamic route guidance strategy

The aim of the paper is to evaluate the performance of a new strategy which is able to control dynamic route guidance (DRG) systems, mainly in urban road networks. The purpose of this strategy is to achieve dynamic user equilibrium in the network, even in abnormal network conditions, for example when there is an unexpected increase in traffic volume. It is based on feedback concept and it reacts to the traffic conditions observed in real time by adopting a decentralized structure. A series of experiments was performed, by means of a traffic micro-simulator, in a section of an urban road network. In the situations examined, the results seem to be quite positive. The analyses of the link level show that all of the various travel alternatives to reach the destination become more advantageous for users if DRG devices become more widespread among vehicles. In some cases we observe that the strategy succeeds in maintaining the possible alternatives in equilibrium conditions, by distributing users among the feasible turns. At no point in our investigations do we observe an unstable behaviour of the system, even when the number of vehicles fitted with a DRG device increases