08-06-2012, 04:43 PM
SIMULATION OF AN ANTI-COLLISION SYSTEM ON SAME TRACK FOR
RAILWAYS
anti collision railways.pdf (Size: 788.64 KB / Downloads: 38)
Indian Railways & Safety: present Perspective Indian
Railways are the world's second-largest railway, with 6,853 stations, 63,028 kilometers of track, 37,840 passenger
coaches and 222,147 freight cars. Annually it carries some 4.83 billion passengers and 492 million tons of freight.
Of the 11 million passengers who climb aboard one of 8,520 trains each day, about 550,000 have reserved
accommodations.
Safe transportation of passengers is the key business objective of any transportation system. Railways are
recognized as the safest mode of mass transportation and Safety has been recognized as the key issue for the
railways and one of its special attributes. All business strategies emanate from this theme and strive to achieve
Accident Free System. Safety is, therefore, the key performance index which the top managements need to monitor
and take preventive steps based on trends of accidents which are the manifestations of some of the unsafe practices
on the system.
Current Technologies used/ proposed to prevent collision:
The Anti-Collision Device (ACD) is a self-acting
microprocessor-based data communication device designed and developed by Konkan Railway [5].
The system consists of Loco ACD with a console (message display) for the driver (in each Loco Engine), Guard
ACD with remote (fitted in Guard Van), Station ACD with console (fitted in Station Masters' Cabin), Manned and
Unmanned Gates ACD with hooters and flashers (in each location) and Repeater ACDs (fitted at locations having
obstructions in radio communication such as hilly areas) which work in concert to prevent the following kinds of
collisions and accidents like-Head on collisions ,Rear end collisions ,Collisions due to derailment, Collisions at the
level crossing gates .
Technical detail of an anti-collision system:
It is impossible to entirely avoid situations that nobody has ever
thought of, but which could develop onto catastrophes. So for the safety purpose, anti collision system for railways
has been planned and developed. An Anti-Collision system developed for safety purpose consists of and uses the
following technologies like:
Proteus Simulation Software:
Proteus Virtual System Modeling (VSM) combines mixed mode SPICE circuit simulation, animated components
and microprocessor models to facilitate co simulation of complete microcontroller based designs. For the first time
ever, it is possible to develop and test such designs before a physical prototype is constructed. This is possible
because one can interact with the design using on screen indicators such as LED and LCD displays and actuators
such as switches and buttons. The simulation takes place in real time (or near enough to it): a 300 MHz Pentium II
can simulate a basic 8051 system clocking at over 12MHz. Proteus VSM also provides extensive debugging
facilities including breakpoints, single stepping and variable display for both assembly code and high level language
source.
Circuit Diagram of an anti-collision for railways
In load cell signal processing unit we have used compression type load cell which gives analog voltages. Whenever
the output voltage crosses 0.8 volt (which is equivalent to the 6 tones load) then the buffer IC 74 LS 245 gives ‘logic
1’.we have used eight digital voltmeter for each load cell for analysis and calibration purpose which will not be used
in final products. We have used seven NAND gates (two ICs 74S00 each containing 4 NAND gates).