13,464 research outputs found
A numerical investigation of the jamming transition in traffic flow on diluted planar networks
In order to develop a toy model for car's traffic in cities, in this paper we
analyze, by means of numerical simulations, the transition among fluid regimes
and a congested jammed phase of the flow of "kinetically constrained" hard
spheres in planar random networks similar to urban roads. In order to explore
as timescales as possible, at a microscopic level we implement an event driven
dynamics as the infinite time limit of a class of already existing model (e.g.
"Follow the Leader") on an Erdos-Renyi two dimensional graph, the crossroads
being accounted by standard Kirchoff density conservations. We define a
dynamical order parameter as the ratio among the moving spheres versus the
total number and by varying two control parameters (density of the spheres and
coordination number of the network) we study the phase transition. At a
mesoscopic level it respects an, again suitable adapted, version of the
Lighthill-Whitham model, which belongs to the fluid-dynamical approach to the
problem. At a macroscopic level the model seems to display a continuous
transition from a fluid phase to a jammed phase when varying the density of the
spheres (the amount of cars in a city-like scenario) and a discontinuous jump
when varying the connectivity of the underlying network.Comment: accepted in Int.J.Mod.Phys.
A Distributed and Privacy-Aware Speed Advisory System for Optimising Conventional and Electric Vehicles Networks
One of the key ideas to make Intelligent Transportation Systems (ITS) work
effectively is to deploy advanced communication and cooperative control
technologies among the vehicles and road infrastructures. In this spirit, we
propose a consensus-based distributed speed advisory system that optimally
determines a recommended common speed for a given area in order that the group
emissions, or group battery consumptions, are minimised. Our algorithms achieve
this in a privacy-aware manner; namely, individual vehicles do not reveal
in-vehicle information to other vehicles or to infrastructure. A mobility
simulator is used to illustrate the efficacy of the algorithm, and
hardware-in-the-loop tests involving a real vehicle are given to illustrate
user acceptability and ease of the deployment.Comment: This is a journal paper based on the conference paper "Highway speed
limits, optimised consensus, and intelligent speed advisory systems"
presented at the 3rd International Conference on Connected Vehicles and Expo
(ICCVE 2014) in November 2014. This is the revised version of the paper
recently submitted to the IEEE Transactions on Intelligent Transportation
Systems for publicatio
A characteristic particle method for traffic flow simulations on highway networks
A characteristic particle method for the simulation of first order
macroscopic traffic models on road networks is presented. The approach is based
on the method "particleclaw", which solves scalar one dimensional hyperbolic
conservations laws exactly, except for a small error right around shocks. The
method is generalized to nonlinear network flows, where particle approximations
on the edges are suitably coupled together at the network nodes. It is
demonstrated in numerical examples that the resulting particle method can
approximate traffic jams accurately, while only devoting a few degrees of
freedom to each edge of the network.Comment: 15 pages, 5 figures. Accepted to the proceedings of the Sixth
International Workshop Meshfree Methods for PDE 201
Recommended from our members
All photonic analogue to digital and digital to analogue conversion techniques for digital radio over fibre system applications
Copyright @ 2011 IEEEWideband electronic analogue to digital conversion (ADC) systems have critical problems encountered in high-frequency broadband communication systems that the recent electronic ADCs (EADC) have experienced those such as uncertainty of sampling time. In this paper, an all photonic sampling and quantization ADC and photonic digital to analogue conversion system with six effective number of bits (ENOB) is designed. By using this photonic ADC (PADC), a novel digital radio over fibre link for wireless radio frequency (RF) signal transportation over 20 Km single mode fibre has been designed whose performance is investigated in this paper. In the digital radio over fibre, the dynamic range is independent of the fibre length
- …