This application is a Positive Train Control (PTC) Back Office Server (BOS) with web interface, track/locomotive simulators, and Edge Message Protocol (EMP) messaging subsystems. Development has begun with the intention of growing into an open-source PTC solution after observing first-hand the difficulties railroads are currently experiencing as they attempt to meet PTC implementation deadlines imposed by congress. It is a work in progress and distributable free under the MIT license. All images obtained under the Creative Common License.
PTC's mandate is to prevent:
- Train on train collisions
- Over-speed derailments
- Incursions into work zone limits
- Movement through misaligned track-switches
Interoperability between railroads is also required, as defined by the Federal Railroad Administration's Interoperable Train Control (ITC) standard.
PTC-Sim currently implements broker-assisted EMP communication between simulated on-track devices (locomotives and 220 MHz radio base-stations) and the BOS. Locomotive tracking and computer-aided-dispatch (CAD) is facilitated by a web interface, where current device status and location are displayed graphically. For the simulation, each web client gets its own "sanbox", consisting of an independent broker and track/locomotive simulator.
From a Linux terminal, start the application with ./sim_bos.py, then navigate to `http://localhost:5000'
Each component exists as a seperate entity. Communication between entities occurs via EMP messaging over TCP/IP.
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Back Office Server : Displaying real-time device and locomotive status via its web interface. Plans exist to also provides CAD capabilities, such as communicating track restrictions to locomotives.
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Message Broker: An intermediate message translation system allowing bi-directional communication between track devices, locomotives, and the BOS. Currently, each component transports EMP messages via TCP/IP only. Future versions will implememnt Class C (IP based multicast protocol) and Class D (IP based point-to-point protocol) messaging.
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Track Simulator: Simulates on-track devices:
- Locomotives: Each locomotive travels along the track, broadcasting status messages (and eventually receiving CAD directives) over its two simulated 220 MHz radio transducers.
- 220 MHz Radio Base Stations: Receives locomotive status messages and transmits them to the Message Broker via LAN.
- Waysides: Receives status messages from it's attached switches via LAN, then broadcasts them over 220 MHz radio to the BOS.
- Switches: Each switch sends its current position (OPEN, CLOSED, or ERROR) to its parent wayside at regular intervals.
PTC-Sim
| app_config.dat - Application configuration information.
| lib_app.py - Shared application-level library.
| lib_messaging.py - Messaging subsystem library.
| lib_track.py - Track simulation class library.
| lib_web.py - Web interface library.
| LICENSE - MIT License.
| Procfile - Process definition, for use in virtual environments.
| requirements.txt - Dependencies, for use in virtual environments.
| runtime.txt - Python version def, for use in virtual environments.
| README.md - This document.
| sim_bos.py - The Back Office Server / web interface.
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+---docs - Contains documentation.
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+---logs - Created on startup to hold log files for each component.
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+---static - Static web content, such as images, css, and js.
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+---templates - Flask web templates
| home.html - The main device and locomotive satus page.
| layout.html - Top-level container template, including navbar.
|
+---track
| track_bases.json - JSON representation of the track's radio base stations.
| track_locos.json - JSON representation of the railroad's locomotives.
| track_rail.json - JSON representation of the track's main branch.
Requires Python 2.7. Other dependencies managed by the application include: Flask, Jinja, JQuery, and the GoogleMaps API.
To preview PTC-Sim, navigate to https://ptc-sim.herokuapp.com/
At this point in development, some features typical in a PTC deployment, such as authentication, encryption, high availability, redundancy, and persistent data have not been implemented. Track simulation is also currently restricted to a single branch, however locomotives are not currently aware of each other on that branch. Additionally, the following TODO items are in progress:
- Broker queue msg expire time
- Web Output: logs and broker queue monitor, to demonstrate msging system
- Base coverage overlays in website map display
- Segregated logs
- Ensure PEP8 for file headers, imports, and docstrings (model after Tack and connection, but move public members to class level-doc)
- Privatize necessary members and do validation on public members
- Readme screenshots and high-level PTC images
- Track Circuits, to aid col avoidance.