14 research outputs found
New Perspectives on Modelling and Control for Next Generation Intelligent Transport Systems
This PhD thesis contains 3 major application areas all within an Intelligent Transportation
System context.
The first problem we discuss considers models that make beneficial use of the large
amounts of data generated in the context of traffic systems. We use a Markov chain
model to do this, where important data can be taken into account in an aggregate form.
The Markovian model is simple and allows for fast computation, even on low end computers,
while at the same time allowing meaningful insight into a variety of traffic system
related issues. This allows us to both model and enable the control of aggregate, macroscopic
features of traffic networks. We then discuss three application areas for this model:
the modelling of congestion, emissions, and the dissipation of energy in electric vehicles.
The second problem we discuss is the control of pollution emissions in
eets of hybrid
vehicles. We consider parallel hybrids that have two power units, an internal combustion
engine and an electric motor. We propose a scheme in which we can in
uence the mix
of the two engines in each car based on simple broadcast signals from a central infrastructure.
The infrastructure monitors pollution levels and can thus make the vehicles
react to its changes. This leads to a context aware system that can be used to avoid pollution
peaks, yet does not restrict drivers unnecessarily. In this context we also discuss
technical constraints that have to be taken into account in the design of traffic control
algorithms that are of a microscopic nature, i.e. they affect the operation of individual
vehicles. We also investigate ideas on decentralised trading of emissions. The goal here
is to allocate the rights to pollute fairly among the
eet's vehicles.
Lastly we discuss the usage of decentralised stochastic assignment strategies in traffic
applications. Systems are considered in which reservation schemes can not reliably be
provided or enforced and there is a signifficant delay between decisions and their effect. In
particular, our approach facilitates taking into account the feedback induced into traffic
systems by providing forecasts to large groups of users. This feedback can invalidate the
predictions if not modelled carefully. At the same time our proposed strategies are simple
rules that are easy to follow, easy to accept, and significantly improve the performance
of the systems under study. We apply this approach to three application areas, the assignment
of electric vehicles to charging stations, the assignment of vehicles to parking
facilities, and the assignment of customers to bike sharing stations.
All discussed approaches are analysed using mathematical tools and validated through
extensive simulations
Delay-Tolerant Stochastic Algorithms for Parking Space Assignment
This paper introduces and illustrates some novel
stochastic policies that assign parking spaces to cars looking for
an available parking space. We analyze in detail both the main
features of a single park, i.e., how a car could conveniently decide
whether to try its luck at that parking lot or try elsewhere,
and the case when more parking lots are available, and how to
choose the best one. We discuss the practical requirements of
the proposed strategies in terms of infrastructure technology and
vehicles’ equipment and the mathematical properties of the proposed
algorithms in terms of robustness against delays, stability,
and reliability. Preliminary results obtained from simulations are
also provided to illustrate the feasibility and the potential of our
stochastic assignment policies
A Markov-chain based model for a bike-sharing system
Bike-sharing systems are recently becoming ubiquitous in most cities, as an environmentally friendly alternative to other means of transportation. An optimal management of the bike-sharing service would in principle benefit from the availability of a mathematical model underlying the system. Accordingly, in this paper we propose a Markov-chain based approach to model the bike-sharing system, which we believe has a potential to develop alternative methods to implement classic control actions in a bike-sharing system (e.g., in terms of implementing alternative relocation strategies or planning advertising campaigns). The proposed methodology is validated on real data from the bike-sharing system in Boston, USA, and a first application of the proposed model is preliminarily illustrated in the paper
A big-data model for multi-modal public transportation with application to macroscopic control and optimisation
This paper describes a Markov-chain-based approach to modelling multi-modal transportation networks. An advantage of the model is the ability to accommodate complex dynamics and handle huge amounts of data. The transition matrix of the Markov chain is built and the model is validated using the data extracted from a traffic simulator. A realistic test-case using multi-modal data from the city of London is given to further support the ability of the proposed methodology to handle big quantities of data. Then, we use the Markov chain as a control tool to improve the overall efficiency of a transportation network, and some practical examples are described to illustrate the potentials of the approach
New Perspectives on Modelling and Control for Next Generation Intelligent Transport Systems
This PhD thesis contains 3 major application areas all within an Intelligent Transportation
System context.
The first problem we discuss considers models that make beneficial use of the large
amounts of data generated in the context of traffic systems. We use a Markov chain
model to do this, where important data can be taken into account in an aggregate form.
The Markovian model is simple and allows for fast computation, even on low end computers,
while at the same time allowing meaningful insight into a variety of traffic system
related issues. This allows us to both model and enable the control of aggregate, macroscopic
features of traffic networks. We then discuss three application areas for this model:
the modelling of congestion, emissions, and the dissipation of energy in electric vehicles.
The second problem we discuss is the control of pollution emissions in
eets of hybrid
vehicles. We consider parallel hybrids that have two power units, an internal combustion
engine and an electric motor. We propose a scheme in which we can in
uence the mix
of the two engines in each car based on simple broadcast signals from a central infrastructure.
The infrastructure monitors pollution levels and can thus make the vehicles
react to its changes. This leads to a context aware system that can be used to avoid pollution
peaks, yet does not restrict drivers unnecessarily. In this context we also discuss
technical constraints that have to be taken into account in the design of traffic control
algorithms that are of a microscopic nature, i.e. they affect the operation of individual
vehicles. We also investigate ideas on decentralised trading of emissions. The goal here
is to allocate the rights to pollute fairly among the
eet's vehicles.
Lastly we discuss the usage of decentralised stochastic assignment strategies in traffic
applications. Systems are considered in which reservation schemes can not reliably be
provided or enforced and there is a signifficant delay between decisions and their effect. In
particular, our approach facilitates taking into account the feedback induced into traffic
systems by providing forecasts to large groups of users. This feedback can invalidate the
predictions if not modelled carefully. At the same time our proposed strategies are simple
rules that are easy to follow, easy to accept, and significantly improve the performance
of the systems under study. We apply this approach to three application areas, the assignment
of electric vehicles to charging stations, the assignment of vehicles to parking
facilities, and the assignment of customers to bike sharing stations.
All discussed approaches are analysed using mathematical tools and validated through
extensive simulations
New Perspectives on Modelling and Control for Next Generation Intelligent Transport Systems
This PhD thesis contains 3 major application areas all within an Intelligent Transportation
System context.
The first problem we discuss considers models that make beneficial use of the large
amounts of data generated in the context of traffic systems. We use a Markov chain
model to do this, where important data can be taken into account in an aggregate form.
The Markovian model is simple and allows for fast computation, even on low end computers,
while at the same time allowing meaningful insight into a variety of traffic system
related issues. This allows us to both model and enable the control of aggregate, macroscopic
features of traffic networks. We then discuss three application areas for this model:
the modelling of congestion, emissions, and the dissipation of energy in electric vehicles.
The second problem we discuss is the control of pollution emissions in
eets of hybrid
vehicles. We consider parallel hybrids that have two power units, an internal combustion
engine and an electric motor. We propose a scheme in which we can in
uence the mix
of the two engines in each car based on simple broadcast signals from a central infrastructure.
The infrastructure monitors pollution levels and can thus make the vehicles
react to its changes. This leads to a context aware system that can be used to avoid pollution
peaks, yet does not restrict drivers unnecessarily. In this context we also discuss
technical constraints that have to be taken into account in the design of traffic control
algorithms that are of a microscopic nature, i.e. they affect the operation of individual
vehicles. We also investigate ideas on decentralised trading of emissions. The goal here
is to allocate the rights to pollute fairly among the
eet's vehicles.
Lastly we discuss the usage of decentralised stochastic assignment strategies in traffic
applications. Systems are considered in which reservation schemes can not reliably be
provided or enforced and there is a signifficant delay between decisions and their effect. In
particular, our approach facilitates taking into account the feedback induced into traffic
systems by providing forecasts to large groups of users. This feedback can invalidate the
predictions if not modelled carefully. At the same time our proposed strategies are simple
rules that are easy to follow, easy to accept, and significantly improve the performance
of the systems under study. We apply this approach to three application areas, the assignment
of electric vehicles to charging stations, the assignment of vehicles to parking
facilities, and the assignment of customers to bike sharing stations.
All discussed approaches are analysed using mathematical tools and validated through
extensive simulations