scholarly journals Compositional modeling of railway Virtual Coupling with Stochastic Activity Networks

2021 ◽  
Author(s):  
Francesco Flammini ◽  
Stefano Marrone ◽  
Roberto Nardone ◽  
Valeria Vittorini
Keyword(s):  
Traffic Management ◽  
Travel Demand ◽  
Network Capacity ◽  
System Capacity ◽  
Railway Traffic ◽  
Stochastic Activity Networks ◽  
Activity Networks ◽  
Virtual Coupling ◽  
Railway Capacity ◽  
Stochastic Activity

AbstractThe current travel demand in railways requires the adoption of novel approaches and technologies in order to increase network capacity. Virtual Coupling is considered one of the most innovative solutions to increase railway capacity by drastically reducing train headway. The aim of this paper is to provide an approach to investigate the potential of Virtual Coupling in railways by composing stochastic activity networks model templates. The paper starts describing the Virtual Coupling paradigm with a focus on standard European railway traffic controllers. Based on stochastic activity network model templates, we provide an approach to perform quantitative evaluation of capacity increase in reference Virtual Coupling scenarios. The approach can be used to estimate system capacity over a modelled track portion, accounting for the scheduled service as well as possible failures. Due to its modularity, the approach can be extended towards the inclusion of safety model components. The contribution of this paper is a preliminary result of the PERFORMINGRAIL (PERformance-based Formal modelling and Optimal tRaffic Management for movING-block RAILway signalling) project funded by the European Shift2Rail Joint Undertaking.

Constraint-force driven control design for rail vehicle virtual coupling

2021 ◽  
pp. 107754632110079
Author(s):  
Bin Wang ◽  
Dengke Yang ◽  
Xinrong Zhang ◽  
Xingheng Jia
Keyword(s):  
Dynamic Model ◽  
Traffic Management ◽  
Control Method ◽  
Constraint Force ◽  
Explicit Equation ◽  
Coupling Problem ◽  
Railway Traffic ◽  
Rail Vehicle ◽  
Virtual Coupling ◽  
Traffic Management System

This study investigates the constraint-force driven control problem of virtual coupling. To solve the constraint force, the explicit equation of vehicle motion with equality constraints is established using the Udwadia–Kalaba approach. First of all, this study introduces a brief overview of virtual coupling concepts in the European Railway Traffic Management System and some scenes of virtual coupling. The control method is proposed to enable the mechanical system to follow the designed constraint. Moreover, the dynamic model for virtual coupling problem is established. Second, combined with the dynamic model, the equation constraint is designed to make the rail vehicle movenment reach the control objective. By solving the equation based on the Udwadia–Kalaba approach, the control inputs that can render the vehicle to move along the desired trajectory. Third, numerical simulation results demonstrate the effectiveness of the proposed method in virtual coupling problem.

On the Use of Stochastic Activity Networks for an Energy-Aware Simulation of Automatic Weather Stations

2016 ◽  
pp. 184-207
Author(s):  
Luca Cassano ◽  
Daniel Cesarini ◽  
Marco Avvenuti
Keyword(s):  
Remote Access ◽  
Solar Panels ◽  
Energy Aware ◽  
Storage Devices ◽  
Stochastic Activity Networks ◽  
Activity Networks ◽  
Weather Stations ◽  
Definition Of ◽  
Access To Data ◽  
Stochastic Activity

Automatic Weather Stations (AWSs) are embedded systems equipped with a number of sensors used to monitor harsh environments: glaciers and deserts. AWSs may also be equipped with some communication interfaces in order to enable remote access to data. These systems are generally far from power sources, and thus they are equipped with energy harvesting devices, wind turbines and solar panels, and storage devices, batteries. The design of an AWS represents a challenge, since designers have to maximize the sampled and transmitted data while considering the energy needs. We designed and implemented an energy-aware simulator of AWSs to support designers in the definition of the configuration of the system. The simulator relies on the Stochastic Activity Networks (SANs) formalism and has been developed using the Möbius tool. In this chapter we first show how we used SANs to model the components of an AWS, we then report results from validation experiments carried out by comparing the results of the simulator against a real-world AWS and finally show examples of its usage.

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