Search results for "AUTOMOTIVE"
showing 10 items of 619 documents
A method for smoothly disengaging the load-holding valves of energy-efficient electro-hydraulic systems
2020
A novel self-contained, electro-hydraulic cylinder drive capable of passive load-holding, four-quadrant operations, and energy recovery was presented recently and implemented successfully. This solution improved greatly the energy efficiency and motion control in comparison to state-of-the-art, valve-controlled systems typically used in mobile or offshore applications. The passive load-holding function was realized by two pilot-operated check valves placed on the cylinder ports, where their pilot pressure is selected by a dedicated on/off electro valve. These valves can maintain the actuator position without consuming energy, as demonstrated on a single-boom crane. However, a reduced drop o…
An innovative mechanical motion converter for sea wave applications
2018
The paper shows an innovative system designed and developed by University of Palermo. The device is based on a simple mechanical converter able to transform a variable bidirectional linear motion into a unidirectional rotary motion. This technology can be successful used in sea wave applications, producing a mechanical output usable for the electrical energy production.
A stacked interleaved DC-DC buck converter for proton exchange membrane electrolyzer applications: Design and experimental validation
2019
Abstract Since the two last decades, hydrogen production has been attracting the attention of the scientific community thanks to its inherent very low pollution when energy coming from renewable energy sources (RESs) are used. However, it implies the use of DC/DC converters to interface source and load. These conversion systems must meet several requirements from current ripple point of view, energy efficiency, and performance to preserve the sustainability of hydrogen production. This article proposes the design and realization of a stacked interleaved buck converter to supply a proton exchange membrane electrolyzer. The converter is designed to ensure a low output current ripple and a sui…
A Tire Model for Off-Highway Vehicle Simulation on Short Wave Irregular Terrain
2010
Manufacturers of construction machinery are challenged in several ways concerning dynamic loads. Considering off-highway dump trucks that travel through high amplitude short wave irregular terrain with considerable speed two aspects concerning dynamics are important.The first is the legal requirements that prescribe the maximum limit on the vibration exposure on the operator which is a measure for ride comfort.The second is the importance of knowing the dynamic loading of the structural parts. In order to use the wide variety of computer-aided design tools to size and optimize mechanical joints, spring-damper elements and the welded structures it is crucial to have information on the time h…
Estimation of Passenger Car Equivalents for Two-Lane and Turbo Roundabouts Using AIMSUN
2020
The paper addresses issues related to Passenger Car Equivalents (PCEs) at roundabouts. Compared to other road units, the curvilinear elements of roundabout geometric design may impose greater constraints on vehicular trajectories and have a significant effect on the swept envelope of heavy vehicles. Specifically, the aim of the paper is to present the methodological approach which used traffic microsimulation to estimate PCEs. Focus is made on a case study which considered the conversion of a two-lane roundabout into a basic turbo roundabout with comparable size. Empirical capacity functions for both roundabouts were derived as target values to which simulated capacities by lane were compar…
An embedded datalogger with a fast acquisition rate for in-vehicle testing and monitoring
2011
A very compact and high performance datalogger for automotive in-vehicle testing is here described. The small logger dimensions and the availability of a CAN interface allows to easily implement multiple and distributed acquisition schemes, very challenging with traditional instrumentation. High acquisition rate, up to 100 Ksps/ch, and low cost was obtained through a very accurate hardware and software design.
Statistics-driven Development of OBD Systems: An Overview
2006
Automotive on-board diagnostic (OBD) systems are designed to keep critical components under control during vehicle functioning, and to alert the driver in case of severe malfunctions. OBD systems aimed at reducing polluting emissions are mandatory on new motor vehicles. Some research projects conducted in cooperation between universities and the automotive industry have been quite successful in terms of knowledge advancement and industrial gain. An updated overview of the adopted methodologies and results obtained are given in this article. Such results can be valuable for both theorists and practitioners, since they witness the use of statistics as a powerful catalyst of technical progress…
Optimizing Renewable Power Management in Transmission Congestion. An Energy Hub Model Using Hydrogen Storage
2021
Energy production from distributed renewable power plants underwent a takeoff in last years as never before. Nevertheless, the installation of technologies based on variable energy resources and their connection on transmission power lines might cause congestions due to the transmission capacity limits. This paper describes the modelization of a HV transmission line with local renewable production and its optimal management through an Energy Hub model. Aim of the study is to identify the optimal size of the power storage, based on an electoryzer, a hydrogen storage and a fuel cell, in order to minimize the congestion risks and to maximize the exploitation of renewable energy production.
Autonomous Demand Side Management of Electric Vehicles in a Distribution Grid
2019
The electricity demand due to the increasing number of EVs presents new challenges for the operation of the electricity network, especially for the distribution grids. The existing grid infrastructure may not be sufficient to meet the new demands imposed by the integration of EVs. Thus, EV charging may possibly lead to reliability and stability issues, especially during the peak demand periods. Demand side management (DSM) is a potential and promising approach for mitigation of the resulting impacts. In this work, we developed an autonomous DSM strategy for optimal charging of EVs to minimize the charging cost and we conducted a simulation study to evaluate the impacts to the grid operation…
A statistical monitoring approach for automotive on-board diagnostic systems
2007
The current generation of vehicle models are increasingly being equipped with on-board diagnostic (OBD) systems aimed at assessing the ‘state of health’ of important anti-pollution subsystems and components. In order to promptly diagnose and fix quality and reliability problems that may potentially affect such complex diagnostic systems, even during advanced development prior to mass production, some vehicle prototypes undergo a testing phase under realistic conditions of use (a mileage accumulation campaign). The aim of this work is to set up a statistical tool for improving the reliability of the OBD system by monitoring its operation during the mileage accumulation campaign of a new vehi…