A Seminar on ACD

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A Seminar Report on ANTI COLLISION DEVICES FOR TRAINPrepared by : Patel Jaymin V. Roll No Semester Class Year Guided by : 29 : 8th Semester : B.E. 4th (Electronics & Communication Engineering) : 2010-2011 : Prof Ketki Joshi

Department of Electronics and Communication Engineering 2010-11 Sarvajanik College of Engineering & Technology Dr. R.K. Desai Road, Athwalines, Surat-395001

Sarvajanik Education Society

Sarvajanik College of Engineering & Technology, SuratDepartment of Electronics and Communication Engineering,

CERTIFICATEThis is to certify that the Seminar report entitled ANTI COLLISION DEVICES FOR TRAIN is prepared & presented by Patel Jaymin V. (Roll no. 29) of B.E. IV Sem VII Electronics & communication Engineering department during year 2010-11. His work is satisfactory.

Signature of guide

Head of the Department Electronics & Communication Engineering

Signature of Jury Members

AcknowledgementI take this opportunity to express my sincere thanks and deep sense of gratitude to my guide Prof. Ketki Joshi for imparting me valuable guidance during my preparation of this seminar. She helped me by solving many of my doubts and suggesting many references. I would also like to offer my gratitude towards faculty member of Electronics & Communication Department, Who helped me by giving valuable suggestion and Encouragement which not helped me in preparing this presentation but also in having a better insight in the field. Lastly I express deep sense of gratitude toward my colleagues who directly or indirectly helped me while preparing this seminar.

ABSTRACTThe Anti Collision Device (ACD) Network is a Train Collision prevention system patented by Konkan Railway Corporation Limited. ACDs have knowledge embedded intelligence. They take inputs from GPS satellite system for position updates and network among themselves for exchanging information using their data radio modems to take decisions for timely auto-application of brakes to prevent dangerous 'collisions', thus forming a 'Raksha Kavach'. ACDs fitted act as a watchdog in the dark as they constantly remain in lookout for other train bound ACDs, within the braking distance required for their relative speeds. They communicate through their radios and identify each other. If they happen to find themselves on the same track and coming closer to each other, they automatically restrain and stop each other, thereby preventing dangerous head-on and rear-end collisions. Loco ACD of a train also applies brakes to reduce the train speed either to 15 km/h if on approach it receives a message from other train bound ACD that has stopped in a block section on adjacent track or to bring the train to a stop if train bound ACDs of other train are radiating 'train parted' message thereby preventing dangerous side collision that may occur due to infringement of adjacent track by a stopped or a 'parted' train, respectively.

1 INTRODUCTIONAnti-Collision Device (ACD) is a self-acting microprocessor-based data

communication device designed and developed by Kankan Railway. When installed on locomotives (along with an auto-braking unit - ABU), guard vans, stations and level-crossing gates (both manned and unmanned), the network of ACD systems prevents high-speed collisions in mid-sections, station areas and at level-crossing gates. The ACD uses both radio frequency and Global Positioning System (GPS) through satellites, whereby a train is automatically brought to a halt if the track ahead is not clear. The train starts braking 3 kms ahead of a blockade. The Anti-Collision Device, also called `Raksha Kavach,' envisages setting up a network of "self-acting" micro-processor based communication devices which automatically apply brakes on trains that are unknowingly getting into a "collision-like situation," including before stations and at mid-sections. At the mid-sections, where neither the protection of signals nor guidance is available to the driver, the ACD makes the loco intelligent and extends its capability to detect any collision-like situations in a range of 3 km, which the driver cannot detect on his own. Situations like collision between two approaching trains or between a derailed train on one track and an approaching train on the adjacent tract can thus be prevented. ACD senses an obstacle in path of the train or any another is coming on the same track from another side. Here, dealing with the condition of collision between two trains and try to find out the method to avoid the collision in normal and abnormal condition. So implementation of a device which can avoid the collision between two trains mean an ANTI COLLISION DEVICE (ACD) ACDs work on the principle of Distributed Control Systems. ACDs interact enroute with each other through radio communication within a radial range of 3 Kms. If 2 ACDs are at a risk of collision, the ACD system activates automatic braking. Intelligent braking system to ensure optimum braking and minimizes loss of operational time. Whenever a collision is sensed, the loco ACD applies the brakes automatically.


In early days the mode of transportation is very slow as the time passes world made progress and the different revolution takes place which demands the fast mode of transportation. The new generation of fast transportation are the railways, aero planes, cars etc. The railway transportation is very important for any nation. Railways is very fast service and hence there is a possibility of accidents like collisions, derailment and accident due to weather condition

3.Different types of the accidents 3.1 Rear-end Collision

A rear-end collision is a traffic accident wherein a vehicle (usually an automobile or a truck) crashes into the vehicle in front of it, so called because it hits its rear. It may also be a rail accident wherein a train runs into the rear of a preceding train. Typical scenarios for rearends are a sudden deceleration by the first car the following car that does not have the time to brake and collides with the first at a road junction the following car accelerates more rapidly than the leading.

3.2 Head on CollisionA head-on collision is one where the front ends of two ships, trains, planes or vehicles hit each other, as opposed to a side-collision or rear-end collision.With rail, a head-on collision often implies a collision on a single line railway. This usually means that at least one of the trains has passed a signal at danger, or that a signalman has made a major error. Head-on collisions may also occur at junctions, for similar reasons.

4. NEED OF A.C.D.The main modules of the ACD includes a GPS (Global Positioning System), which picks up signals from the constellation of GPS satellites that are being exclusively used for this purpose. The GPS submits the data to the Command and Control Unit (CCU) to extract the parameters related to the movement of locomotive like latitude, longitude, speed, angle, date and time. The antenna of the GPS receiver is fitted outside on the roof of the locomotive. The user-friendly device helps the driver to know the various positions in the form of audio-visual indications, like Station Approach, SOS (for head-on, rear-end and side collision situations) and Gate Open. Another module is the radio trans-receiver, which transmits the information and commands generated by the CCU and receives the information being sent by other ACDs when the two systems are within the radio-range of 3 km. The final module in the system is the braking mechanism, which envisages the CCU to take a decision for applying either the normal brake or the emergency brake on the locomotive as the situation required. "The electro-pneumatic braking is then applied through suitable solenoid interface installed for this purpose in the cab of the locomotive," the official explained. ACD is an intelligent friend to the engine driver, which can act on its own without any human intervention. It comprises a Command and Control Unit (CCU), a GPS Receiver, Radio Transmitter and Crew Interface. The CCU, which is the heart of the ACD, is a microprocessor-based module which processes the data and generates commands. The GPS Receiver picks up signals from GPS satellites and submits the same to the CCU to extract parameters related to the movement of the locomotive such as latitude, longitude, speed, angle, date and time. ACD prevents the head-on collision of two speeding trains, which accidentally happen to be on the same track. An ACD mounted on a train constantly looks out for signals from another ACD in a 3-km range. The moment both the trains are within the required

breaking distance, the ACDs, after analysing the data from the GPS, deduce that they are on the same track and are heading for a collision. Then the ACDs automatically apply the brakes, bringing both the trains to a halt without the intervention of the driver. The ACD can be used not only for avoiding head-on collisions but also to detect if a train has accidentally stopped on the same track as another, preventing a following train telescoping into its rear. Also, if two trains are moving on the same track but the separation distance is less than 2 km, the ACD will automatically regulate the following train's speed. It can also detect when the bogies of a train from an adjacent track derail on to a train's path. Konkan Railways has tested out 11 accident scenarios with the ACD. The ACD can be mounted not only on trains but also be installed at railway stations, level crossing gates (both manned and unmanned), and on guard vans. If a station is equipped with an ACD, the driver will receive the ``station approach'' warning as the train approaches the station. Also, the ACD can sense whether a level crossing gate is open or damaged and warn the driver, besides regulating the train's speed.