Mixed-traffic network-simulation tool

Welcome to the page about the mixed-traffic railway capacity simulator tool. This page is still under construction and please visit this page regularly for updates and more complete information.

This tool has the following new features:

• allows junctions in the network and allows a particular route-specification in the presence of multiple routes between a train's source/destination
• allows reconciling w.r.t. multiple zero-mileposts (which is inevitable in a network simulation requirement)
• allows the infrastructure to be a heterogeneous mixture of absolute and automatic block signalling
• allows the block-working-time (a duration of time for which the block-section has to be unoccupied before the next train enters this block-section) to be specified for each block-section individually and differently.
• allows trains to change routes by leaving a route and joining elsewhere on another route (after a pre-specified amount of time). This is used for simulating train-reversals at key junctions and continuing elsewhere. This can also be used for scheduling the same train with different priorities along its journey: for example, high priority near important cities (to serve as commuter-train) and lower priority for later part of the train's journey.
• allows simulation to be in either seconds, or minutes, or other integer multiples of seconds: this feature was introduced but was not required eventually.
• allows skipping the simulation of a train if that train is unable to find a path for a pre-specified amount of time: this helps in completing a simulation, even if it means skipping a few trains.
• allows post-processing of the simulated-till-now trains even while the simulation of the remaining trains is still ongoing: relevant for long time-consuming simulations.

The simulation of about 9000 trains along the GQD (across multiple days) currently takes about 10 to 15 minutes on a fairly-moderate capability stand-alone PC, all using open-source software.

1) Source code

The full source-code (in java) is available at the source-code-file. This source code can be edited and executed using, for example, eclipse. This is recommended for java programmers and not for simulator users.

Some template infrastructure files are available at infrastructure-files.

A calibration tool to obtain the equivalent constant acceleration for an engine whose traction effort usually decreases with increasing speed is available in the acceleration-calibration-xlsx-file and an explanation about the xlsx file is at acceleration-calibration-explanation. This is also elaborated in Appendix A of the User Manual.

2) User manual

The procedure to install java (with version details), and procedure to input rail-section infrastructure and train details is in the user manual. The simulation procedure and the comparison features too are described in the user manual. This document (in pdf-file) is available at: User-manual

3) Code documentation

The link below points to the code repository and this is useful if some structured inputs need to be developed. The code itself is voluminous, representing many person-years of work.

The code documentation can be found at code-documentation

Contributors:

P. Sudarshan, Satwik R.V., Sidhartha Kumar, Bhushan Deo, Akshay Bajpai, Soham Naha, Chandrashekhar Bobade, Samruddhi Pai, Mitul Tyagi, Omkar Karmarkar, Shaival Parikh, Samay Pritam Singh, Tushar Pant, Sunil Kahalekar, Alok Srivastava, Manish Shukla, Abhishek Panigrahi

Contact persons:

Prof. Narayan Rangaraj,
Industrial Engineering and Operations Research (IEOR)
IIT Bombay, Powai, Mumbai 400 076
Email: narayan.rangaraj[AT]iitb.ac.in

and/or

Prof. Shiva Gopalakrishnan
Department of Mechanical Engineering,
IIT Bombay, Powai, Mumbai 400 076
Email: sgopalak[AT]iitb.ac.in

and/or

Profs. Kumar Appaiah, Madhu N. Belur,
Department of Electrical Engineering,
IIT Bombay, Powai, Mumbai 400 076
Email: {akumar,belur}[AT]ee.iitb.ac.in

Last modified: 19th November 2020