04-04-2012, 05:09 PM
Train Collision Prevention and Signaling using RF
train collision and signalling.DOC (Size: 2.64 MB / Downloads: 103)
INTRODUCTION:
In this time there a lot of use of Automation. It is very essential in Railways. Our motto is to sense the trains, which are on the same track, with the help of pressure sensors and hence, control the collision of trains by signaling, blowing buzzer, and providing automatic braking with the help of RF signals. In this way Railway control is automated and it is very beneficial for Railway and all the people also.
Sometimes, we look around at all the gadgets and in a rare moment of inspiration or madness, we look at them all a little different connected in a way they are currently not, but perhaps should be, or at least “could” be. There might not be anything “new” but there are countless combinations of disparate technologies, which we think that all these when combined could give us a universal control over many important things in life and a few other random things like a Robot.
MICROCONTROLLER SECTION:
Requires three connections to be successfully done for it’s operation to begin.
1. +5v supply: This +5v supply is required for the controller to get start which is provided from the power supply section. This supply is provided at pin no.31and 40 of the 89c51 controller.
2. Crystal Oscillator: A crystal oscillator of 12 MHz is connected at pin no.19,x1 and pin no.18,x2 to generate the frequency for the controller. The crystal oscillator works on piezoelectric effect.The clock generated is used to determine the processing speed of the controller. Two capacitors are also connected one end with the oscillator while the other end is connected with the ground. As it is recommended in the book to connect two ceramic capacitor of 20 pf—40pf to stabilize the clock generated.
3. Reset section: It consists of an rc network consisting of 10M/35V capacitor and one resistance of 1k. This section is used to reset the controller connected at pin no.9 of AT89c51.
BRIDGE RECTIFIER
A diode bridge or bridge rectifier is an arrangement of four diodes connected in a bridge circuit as shown below, that provides the same polarity of output voltage for any polarity of the input voltage. When used in its most common application, for conversion of alternating current (AC) input into direct current (DC) output, it is known as a bridge rectifier. The bridge recitifier provides full wave rectification from a two wire AC input (saving the cost of a center tapped transformer) but has two diode drops rather than one reducing efficiency over a center tap based design for the same output voltage.
Schematic of a diode bridge:
VOLTAGE REGULATION
Another factor of importance in a power supply is the amount the dc output vtg changes over a range of ckt operation. The vtg provided at the output under no load condition is reduced when load current is drawn from the supply. The amount the dc vtg changes between the noload and load condition is described by the vtg regulation
VOLTAGE REGULATORS:
A Voltage Regulator (also called a "regulator") has only three legs and appears to be a comparatively simple device but it is actually a very complex integrated circuit. A regulator converts varying input voltage and produces a constant "regulated" output voltage. Voltage regulators are available in a variety of outputs, typically 5 volts, 9 volts and 12 volts. The last two digits in the name indicate the output voltage.
Conclusion
RF based train collision prediction and prevention forms a vital link in the train traffic management. It can be widely implemented in the railway department to reduce the probability of head on collision of the trains.
A display unit is used to display the train number which is coming from a fixed direction and a second display unit to display the train if it is coming from the different direction. It is mainly preferred to use where there are single track between stations or the traffic is too high that a single track is used for train traveling in both directions or due to some human mistake.
LED’s are also provided for better monitoring and management of the train information. On the whole it can serve the purpose of managing a large number of trains to meet the increasing trains on the same routes.