Simulation-Based Comparison of Holding Strategies for a Multibranch Light Rail Service

2017 ◽  
Vol 2648 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Joshua J. Fabian ◽  
Gabriel E. Sánchez-Martínez
Keyword(s):  
Control Point ◽  
Light Rail ◽  
Massachusetts Bay ◽  
Real Time Control ◽  
Time Control ◽  
Special Events ◽  
Simulation Based ◽  
Transit Services ◽  
Rail Line ◽  
Demand Variability

Light rail transit services face many operational challenges, such as capacity constraints, mixed-traffic interference, and branch junctions. The service plans developed for these lines typically specify a precise schedule for each vehicle. Running time and demand variability, special events, and incidents make it challenging to adhere to schedules. Operators can enact real-time control actions to mitigate delays. This research compared the effectiveness of schedule- and headway-based holding strategies applied en route and at terminals (i.e., dispatching) on a simulation model of the Massachusetts Bay Transportation Authority Green Line, a four-branch light rail line. The effects of control point placement at terminals, along branches, along a central trunk, and in combinations of these three were studied, as were the effects of limiting holding at midroute stations. Holding strategies were compared on the basis of service and passenger-oriented performance. Headway-based holding was found to be a more effective method for ensuring that passengers experienced reasonable wait times within scheduled headways. Holding at terminals appeared to be the most beneficial to passengers; additional holding along the branches and limited holding along the trunk were shown to enhance these benefits. Holding only within the trunk of a multibranch service worsened service because of blockages from held trains.

scholarly journals Real-Time Control of the Heating of an Airfoil

2012 ◽  
Author(s):  
Francoise Rétat-Masson ◽  
Francisco Chinesta ◽  
Adrien Leygue ◽  
Elias Cueto ◽  
Laurent Dala ◽  
...  
Keyword(s):  
Real Time ◽  
Additional Data ◽  
Proper Generalized Decomposition ◽  
Real Time Control ◽  
Simulation Tools ◽  
Time Control ◽  
Application Systems ◽  
Simulation Based ◽  
On Line ◽  
Measurement Devices

Dynamic Data-Driven Application Systems constitute nowadays one of the most challenging applications of simulation-based Engineering Science [1]. DDDAS imply a set of techniques that allow the linkage of simulation tools with measurement devices for real-time control of systems and processes [2]. DDDAS entails the ability to dynamically incorporate additional data into an executing application, and in reverse, the ability of an application to dynamically steer the measurement process. These systems need accurate and fast simulation tools, hence the off-line computations to limit as much as possible the on-line computations. In order to obtain the most efficient solver, all the sources of variability are introduced as extra-coordinates as to solve only once the model off-line to obtain its most general solution to be then considered in on-line purpose. However, such models result defined in highly multidimensional spaces. A technique recently proposed, called Proper Generalized Decomposition [3], allows circumventing this redoubtable curse of dimensionality.

Real-Time Semi-Physical Simulation of Industry Design System Based on Virtual Reality Technology

2014 ◽  
Vol 607 ◽  
pp. 413-416 ◽  
Author(s):  
Jun Liu ◽  
Lin Xuan Zhang ◽  
Bing Cui
Keyword(s):  
Virtual Reality ◽  
Real Time ◽  
Physical Simulation ◽  
Design System ◽  
Joint Control ◽  
Real Time Control ◽  
Time Data ◽  
Time Control ◽  
Simulation Based ◽  
Virtual Prototyping Technology

Research how to realize real-time hardware in the loop (HIL) of industry design system by utilizing a variety of virtual reality (VR) hardware and software. In this paper, it introduces VR and virtual prototyping technology, and then proposes joint control and simulation based on ADAMS / Aircraft, Simulink, Flightgear three software. Moreover, the virtual scene, data gloves and real-time semi-physical simulation are analyzed and researched; finally as an example, build a real-time semi-physical simulation platform of the landing gear system for multi-wheel and multi-strut aircraft. The system can do kinematic and dynamic analysis, real-time control by visual prototyping and digital models through real-time data acquisition and co-simulation.

scholarly journals Real-Time Integrated Limited-Stop and Short-Turning Bus Control with Stochastic Travel Time

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Hu Zhang ◽  
Shuzhi Zhao ◽  
Yang Cao ◽  
Huasheng Liu ◽  
Shidong Liang
Keyword(s):  
Travel Time ◽  
Real Time ◽  
Control Method ◽  
Holding Time ◽  
Real Time Control ◽  
Transit System ◽  
Passenger Demand ◽  
Time Control ◽  
Transit Services ◽  
Stochastic Travel Time

In a traditional transit system, passenger arrival time and bus running time are typically random and uncoordinated. This randomness gives the appearance of unbalanced passenger demand and unreliable transit services. Therefore, this paper proposes a real-time control method for bus routes. In our method, buses skip some stations and turn back at appropriate stations, in order to balance passenger demand along the bus route and improve the overall transit service. Our real-time control method considers the typical changes in passenger demand and the stochastic travel time of buses. In this paper, the number of controlled vehicles at any given time is determined, and the bus holding time at the turn-back station is adopted. When implemented correctly, the optimal scheme indicates which stations should be skipped, where it is suitable for buses to turn back, and how long the holding time should be at turn-back stations, which in turn will minimize the total cost of a transit system. This paper formulates such an integrated strategy, presents the solution method of the formulation, and proves the validity of the real-time control method.

scholarly journals Monitoring and Inspection of Built Infrastructure Using Vision-based Algorithms and UAVs

2020 ◽  
Author(s):  
Manh Duong Phung
Keyword(s):  
Real Time ◽  
Weather Conditions ◽  
Light Rail ◽  
Processing Unit ◽  
Target Structure ◽  
Real Time Control ◽  
Time Control ◽  
System P ◽  
Testing Field ◽  
Base Structure

This study presents an inspecting system using real-time control unmanned aerial vehicles (UAVs) to investigate structural surfaces. The system operates under favourable weather conditions to inspect a target structure, which is the Wentworth light rail base structure in this study. The system includes a drone, a GoPro HERO4 camera, a controller and a mobile phone. The drone takes off the ground manually in the testing field to collect the data requiring for later analysis. The images are taken through HERO 4 camera and then transferred in real time to the remote processing unit such as a ground control station by the wireless connection established by a Wi-Fi router. An image processing method has been proposed to detect defects or damages such as cracks. The method based on intensity histogram algorithms to exploit the pixel group related to the crack contained in the low intensity interval. Experiments, simulation and comparisons have been conducted to evaluate the performance and validity of the proposed system.

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