Search results for "vehicles"
showing 10 items of 202 documents
Validation of the group nuclear safety climate questionnaire.
2013
Abstract Introduction Group safety climate is a leading indicator of safety performance in high reliability organizations. Zohar and Luria (2005) developed a Group Safety Climate scale (ZGSC) and found it to have a single factor. Method The ZGSC scale was used as a basis in this study with the researchers rewording almost half of the items on this scale, changing the referents from the leader to the group, and trying to validate a two-factor scale. The sample was composed of 566 employees in 50 groups from a Spanish nuclear power plant. Item analysis, reliability, correlations, aggregation indexes and CFA were performed. Results Results revealed that the construct was shared by each unit, a…
An embedded diagnostic system for wheelchairs brushless drives monitoring
2006
The implementation of a microcontroller based monitoring system for the diagnosis of a brushless synchronous motor drives is presented. It finds its primarily interest on motorized wheelchair for disabled people. The embedded system mainly controls all the principal parameters of the electrical drives together with the power supply system. Pre-failure and failure conditions are routinely logged and, depending on the malfunction severity, alarm messages are created and sent to a remote base station by using the GSM wireless network.
Forces and flow structures evolution on a car body in a sudden crosswind
2014
A vehicle driver is commonly exposed to strong side air flows, for example when passing through a wind gust. The aerodynamic efforts generated in these situations may induce undesired lateral deviations, which can lead to dramatic effects, if the driver is surprised. In order to simulate a sudden yaw angle change on a moving vehicle, a double wind tunnel facility, adapted from the one of Ryan, Dominy, 2000. Wake Surveys Behind a Passenger Car Subjected to a Transient Cross-wind Gust. SAE Technical Paper No. 2000-01-0874 is developed. Two Windsor car body models, differing from their rear geometry, are analysed. The transient evolution of the side force and yaw moment aerodynamic coefficient…
Eletric vehicles impact using renewable energy
2015
In this moment, the principle topics for the modern world are the reduction of environmental pollution and the production of energy from renewable sources (for example photovoltaic system, wind farm, hydroelectric plants, etc.). This particular attention is determined by different reasons, in particular from the Kyoto Protocol, and from different problems as greenhouse effect, acid rain and climate change. The scope of this work is to study, for different years (1997-2013) in Italy, the production of electric energy from renewable and non-renewable. At a later stage, the attention will be on the consumption of the electric energy divided for different sectors. In particular, we study the po…
Experimental test on a fuel cell powered brushless synchronous motor for automotive applications
2014
In this paper, a fuel cell powered motor emulator is proposed. The MATLAB/Simulink model including the fuel cell stack, the motor and drive models is described. The Urban Driving Cycle test is performed in MATLAB environment. Effective operating conditions of the whole fuel cell powered motor are accurately emulated according to actual regulations in force. The emulated current profile is used for experimental tests on a 5kW Nuvera PowerFlow stack. Thanks to the proposed approach, the motor and inverter drives are accurately emulated and the provided test-bench is used to evaluate performances of the stack under test for automotive applications. Simulation and experimental results are compa…
The strategies for the diffusion of EVs: Focus on Norway and Italy
2017
The goal of this work is to predict e-mobility trends which are essential for understanding the market and the infrastructure development over the next years. Nowadays among the many and different standards and rules there are two charging categories for electric vehicles: High power DC and AC charging modes. It will be interesting to see which technology will prevail in the next few years and if the charging mode option on a given EV affects its sales performance. This study presents the current e-mobility scenario in Norway and Italy, in particular analyzing: EV technical and commercial features, electric vehicle market related national incentive policies, technical and diffusion connecto…
Developing Passenger Car Equivalents for Freeways by Microsimulation
2015
Abstract In this paper a method of estimation of the passenger car equivalents for heavy vehicles on freeway is described. The variation in traffic quality was evaluated basing on a traffic demand characterized by different percentages of heavy vehicles. Aimsun micro-simulator was used to isolate traffic conditions difficult to capture on field, to replicate them to have a number of data as much as possible numerous, and to quantify the fundamental variables of traffic flow, namely the speed, flow, density, for a test freeway segment. Model calibration was accomplished by using traffic data collected at observation sections on the A22 Brenner Freeway, Italy. In order to check to what extent…
Microsimulation-based passenger car equivalents for heavy vehicles driving turbo-roundabouts
2016
Due to its geometric design, turbo-roundabouts impose greatest constraints to the vehicular trajectories; by consequence, one can expect a more unfavourable impact of heavy vehicles on the traffic conditions than on other types of roundabouts. The present paper addresses the question of how to estimate Passenger Car Equivalents (PCEs) for heavy vehicles driving turbo-roundabouts. The microsimulation approach used revealed as a useful tool for evaluating the variation of quality of traffic in presence of mixed fleets (different percentages of heavy vehicles). Based on the output of multiple runs of several scenarios simulation, capacity functions for each entry lane of the turbo-roundabout w…
Incremental forming of friction stir welded taylored sheets
2006
In the last decade sheet metal forming market has undergone substantial mutations since the development of more efficient strategies in terms of flexibility and cost reduction is strictly due. Such requirements are not consistent with traditional metal stamping processes which are characterized by complex equipment, capital and tooling costs; thus the industrial application of such processes is economically convenient just for large scale productions. For this reason most of the research work developed in the last years has been focused on the development of new sheet forming processes able to achieve the above discussed goals. Contemporary, with particular reference to the automotive indus…
Robust Energy Scheduling in Vehicle-to-Grid Networks
2017
The uncertainties brought by intermittent renewable generation and uncoordinated charging behaviors of EVs pose great challenges to the reliable operation of power systems, which motivates us to explore the integration of robust optimization with energy scheduling in V2G networks. In this article, we first introduce V2G robust energy scheduling problems and review the stateof- the art contributions from the perspectives of renewable energy integration, ancillary service provision, and proactive demand-side participation in the electricity market. Second, for each category of V2G applications, the corresponding problem formulations, robust solution concepts, and design approaches are describ…