Real Time System ProjectAnti Collision Railway System

Simulation

By

Ankit Singh (935502)Mohammad Tarique Abdullah

(935528)University Of Applied Sciences,

Frankfurt am Main

Introduction : What is an Anti collision Railways System?

• Anti Collision Railways system meant to AVOID collision of two or more than two trains.

• Anti Collision Railways System is a safety critical system which on failure will directly IMPACT Human Life.

• The recent HEAD ON COLLISION of two trains was in Brussel, Belgium on 5th Feb 2010 Where 20 people died.

Project Development:

• Linux Ubuntu 8.10• Erlang version 5.6.3 ( functional

Language)• Erlang: Supports distributed, fault-

tolerant, soft-real-time, non-stop applications.

• Emacs editor

Introduction: Simple Architecture

Major Components of the projectTrain Cache: - The Trains positions is updated to train caching system.-The Purpose of making an In-Memory Caching system is to make processing more faster. -As the data is more near to the CPU, the more effective & fast processing will be achieved.

Cache SET & GET operation:Tuple Description:

{Train_Position, Priority, Direction, Track_Number, {{TNStartCP, TNEndCP, Misc}, Status, ElapsedTime, AvgTime}}}

SET Method: traincache:set(“Train”,fraBer,{15,2, down, 1, { {40,60,8}, running, 0, 150 }}} )

GET Method:traincache:get(“Train”,fraBer)

Deadline monotonic Algorithm

Fixed-priority

• Uses relative deadlines: the shorter the relative deadline, the higher the priority

• RM and DM are identical if the relative deadline is proportional to its period

• Otherwise DM performs better in the sense that it can sometimes produce a feasible schedule when RM fails, while RM always fails when DM fails

Analyser/Scheduler

• anlyser:analyze() returns:[] – empty set ( All Clear)

{T1,clearToRun,T2, halt} or {T1,halt,T2, clearToRun} - One train

gain access to Critical Zone & one train need to wait outside critical zone.

{T1,halt,T2, halt} – DEADLOCK: Collision warning/Emergency Breaking mechanism Active. Both train need to stop on this message.

Various Scenarios I

Various Scenarios II

Actual Screen shot of the project (a)

Actual Screen shot of the project (a)

Graph Distance against timing of trains (case 1)

Graph Distance against timing of trains (case 2)

Anti Collision Railways system Simulation Modules

• traincache.erl, traincache_app.erl, traincache_sup.erl, traincache_app.app

• anlyser.erl, dms.erl• train.erl, • iSystem.erl, • definitions.hrl, • acts_yaws.erl

Many companies are using Erlang in their production systems:

• Amazon uses Erlang to implement SimpleDB, providing database services as a part of the Amazon Elastic Compute Cloud (EC2).

• Yahoo! uses it in its social bookmarking service, Delicious, which has more than 5 million users and 150 million bookmarked URLs.

• Facebook uses Erlang to power the backend of its chat service, handling more than 100 million active users.

• T-Mobile uses Erlang in its SMS and authentication systems.

• Motorola is using Erlang in call processing products in the public-safety industry.

• Ericsson uses Erlang in its support nodes, used in GPRS and 3G mobile networks worldwide.

The most popular open source Erlang applications include the following:

• The 3D subdivision modeler Wings 3D, used to model and texture polygon meshes.

• The Ejabberd system, which provides an Extensible Messaging and Presence Protocol (XMPP) based instant messaging (IM) application server.

• The CouchDB “schema-less” document-oriented database, providing scalability across multicore and multiserver clusters.

• The MochiWeb library that provides support for building lightweight HTTP servers. It is used to power services such as MochiBot and MochiAds, which serve dynamically generated content to millions of viewers daily.

• RabbitMQ, an AMQP messaging protocol implementation. AMQP is an emerging standard for high-performance enterprise messaging.

Conclusion-We successfully implemented in-memory centralised caching system which can be used by any other modules by simple 'set' & 'get' operation.

-Analyser/scheduler can make decision on run time on accessing the Train's data from cache.

-We succesfully implemented Real Time System Project for Simulation of 'anti collision railways System'.

References• Real Time System Design And Analysis: An Engineers Handbook THIRD

EDITION Phillip A. Laplante• Real-Time Scheduling Analysis: Office of Aviation Research• and Development Washington, D.C. 20591• Priority Inheritance Protocols: An Approach to Real Time Synchronization• Lui Sha, Ragunathan Rajkumar, John P. Lehoczky• Applying Fixed Priority Scheduling in Practice, Raimondas Lencevicius,

Alexander Ran, Nokia Research Center• Evaluation of GPS Measurements of Railway Track Geometric Position

Jana IŽVOLTOVÁ, Slovakia•

http://www.uffmm.org/science-technology/single/themes/computer-science/personal-sites/doeben-henisch/RTS/rts/node1.html