Search results for "Vehicles"
showing 10 items of 202 documents
Suspension system performance optimization with discrete design variables
2013
Published version of an article in the journal: Structural and Multidisciplinary Optimization. Also available from the publisher at: http://dx.doi.org/10.1007/s00158-013-0888-7 Suspension systems on commercial vehicles have become an important feature meeting the requirements from costumers and legislation. The performance of the suspension system is often limited by available catalogue components. Additionally the suspension performance is restricted by the travel speed which highly influences the ride comfort. In this article a suspension system for an articulated dump truck is optimized in sense of reducing elapsed time for two specified duty cycles without violating a certain comfort th…
A ride comfort tyre model for off-highway vehicles
2014
Tyre modelling is a major challenge when using time domain multibody simulation models to evaluate ride comfort on off-highway commercial vehicles. Further, parameters for these big tyres are difficult to obtain and thus, commercial car tyre models are difficult to apply. In this research work, a simple vertical tyre model for off-highway ride comfort evaluation is suggested. A displaced volume approach has been developed and combined with the slip theory to yield a tyre model that can be characterised by only three parameters. Full scale measurements on a dump truck have been carried out. Force responses from measurements are compared to the simulation results. Acceleration responses and t…
The Multi-period Multi-trip Container Drayage Problem with Release and Due Dates
2021
Abstract The Container Drayage Problem (CDP) aims at routing a fleet of trucks, based at a common terminal, to serve customers while minimizing the total travel distance. Each trip starts from and ends at the terminal, and handles a subset of customers. Each customer requires either that a container is picked up or delivered. We introduce a more realistic variant, i.e., the Multi-trip Multi-period CDP with Release and Due Dates (MM-CDP-RDD), in which the planning horizon is composed of several periods (days). On each day, each truck may perform more than one trip respecting the Release and Due Dates (RDD) associated with customer services, corresponding to the first and the last day on whic…
Are long-haul truck drivers unusually alert? A comparison with long-haul airline pilots.
2020
Abstract Background Recent studies suggest heavy vehicle drivers self-estimate their sleepiness unexpectedly low during night duties. The present study compared sleepiness ratings of long-haul truck drivers with those of long-haul airline pilots during night and non-night duties. In addition, the correspondence between self-rated manifest and predicted latent sleepiness was examined in the two groups. Methods Twenty-two drivers and 33 pilots participated. Their working hours, sleep, on-duty sleepiness, and use of sleepiness countermeasures were measured in naturalistic conditions. Predictions of latent sleepiness were based on the measurements of working hours and sleep using the Sleep/Wake…
Accumulation of sleep loss among shift-working truck drivers.
2021
Sleep loss is known to contribute to road traffic accidents. Professional drivers are vulnerable to curtailment of sleep due to long driving bouts and shift work. To fill in the gap in the literature related to the buildup of sleep loss in irregular shift systems, we recorded the sleep and working hours of 47 shift-working long-haul truck drivers during a two-week period. Sleep (time in bed) was verified by actigraphy and sleep logs. Sleepiness was measured using the Karolinska Sleepiness Scale (KSS). Individual sleep need was based on self-assessments. We examined the accumulated sleep versus self-reported sleep need across the study period, using midnights as points of observation, and th…
Passenger Car Equivalent for Heavy Vehicles Crossing Turbo-roundabouts
2016
Abstract Turbo-roundabouts represent an innovative scheme of modern roundabouts which provides a spiraling traffic flow and requires drivers to choose their direction before entering the intersection, since raised lane separators mark the lanes on the ring. The configuration of the turbo-roundabout makes that patterns of conflict at entries with one and two conflicting traffic streams can coexist. This paper presents research efforts aimed at measuring quantitatively the effect of heavy vehicles on operational conditions of a turbo-roundabout. The study starts from the initial belief that the greatest constraints to the vehicular trajectories imposed by the turbo-roundabout necessarily impl…
Click and drive: Consumer attitude to product development: Towards future transformations of the driving experience
2016
Purpose – The purpose of this paper is to supply indications that may be useful in the process of development of new products that fully exploit the value potential of Internet of Things (IoT) technologies in the automotive industry. To this aim, the authors investigate how applications of the IoT to smart vehicles are perceived by consumers and describe different ways to increase their satisfaction. Design/methodology/approach – After a literature review focused on IoT and consumer behaviour in the automotive industry, the authors apply the Kano model to find the drivers for achieving customer satisfaction with new product developments in smartcars. Findings – Automotive companies need to…
Wireless Power Transfer for Electric Vehicles: System Design Approach and Energy Storage Characterization
2023
This thesis is the result of the research work carried out as part of the PhD course in Energy and Information Technology between November 2019 and January 2023 at the University of Palermo jointly with the University of Lisbon. The research project has been focused on wireless charging systems for electric vehicles. A wide-ranging analysis was conducted on the topic, with a particular focus on the design aspects of these systems. This thesis, a summary of the work carried out over the previous three years, is organized into two parts, identifying the macro research activities into which the project was been divided. The first part is focused on the design approach of the Wireless Power Tra…
Power Losses Minimization for Optimal Operating Maps in Power-Split HEVs: A Case Study on the Chevrolet Volt
2021
The power-split architecture is the most promising hybrid electric powertrain. However, a real advantage in energy saving while maintaining high performance can be achieved only by the implementation of a proper energy management strategy. This requires an optimized functional design before and a comprehensive analysis of the powertrain losses after, which could be rather challenging owing to the constructive complexity of the power-split transmission, especially for multi-mode architecture with multiple planetary gearing. This difficulty was overcome by a dimensionless model, already available in the literature, that enables the analysis of any power-split transmission, even in full electr…
Traffic congestion reduction based on vehicle platoons and intelligent crossroads interactions
2021
Intersections are at the core of urban congestion. For more than a decade, new approaches based on autonomous and connected driving have been proposed. They aim to improve the performance of traffic control at intersections, by harnessing connectivity and driving automation (longitudinal control). These approaches have in common the fact that vehicles can negotiate together their right of way to use the conflicting space. However, they are different in terms of the way they share the space and optimization techniques. The challenge is to define the sequence of access of vehicles to the common space (which one goes first, which is the second, and so on) and the speed profile of vehicles to a…