Automatic Railway Gate Control System Mini project
ABSTRACT
The aim of this project is to Automate unmanned railway gate using mechatronics.Present project is designed using 8051 microcontroller to avoid railway accidents happening at unattended railway gates, if implemented in spirit. This project utilizes two powerful IR transmitters and two receivers; one pair of transmitter and receiver is fixed at up side (from where the train comes) at a level higher than a human being in exact alignment and similarly the other pair is fixed at down side of the train direction. Sensor activation time is so adjusted by calculating the time taken at a certain speed to cross at least one compartment of standard minimum size of the Indian railway. We have considered 5 seconds for this project. Sensors are fixed at 1km on both sides of the gate. We call the sensor along the train direction as ‘foreside sensor’ and the other as ‘aft side sensor’. When foreside receiver gets activated, the gate motor is turned on in one direction and the gate is closed and stays closed until the train crosses the gate and reaches aft side sensors. When aft side receiver gets activated motor turns in opposite direction and gate opens and motor stops. Buzzer will immediately sound at the fore side receiver activation and gate will close after 5 seconds, so giving time to drivers to clear gate area in order to avoid trapping between the gates and stop sound after the train has crossed.
WORKING METHODOLOGY:
Present project is designed using 8051 microcontroller to avoid railway accidents happening at unattended railway gates, if implemented in spirit. This project utilizes two powerful IR transmitters and two receivers; one pair of transmitter and receiver is fixed at up side (from where the train comes) at a level higher than a human being in exact alignment and similarly the other pair is fixed at down side of the train direction. Sensor activation time is so adjusted by calculating the time taken at a certain speed to cross at least one compartment of standard minimum size of the Indian railway. We have considered 5 seconds for this project. Sensors are fixed at 1km on both sides of the gate. We call the sensor along the train direction as ‘foreside sensor’ and the other as ‘after side sensor’. When foreside receiver gets activated, the gate motor is turned on in one direction and the gate is closed and stays closed until the train crosses the gate and reaches aft side sensors. When aft side receiver gets activated motor turns in opposite direction and gate opens and motor stops. Buzzer will immediately sound at the fore side receiver activation and gate will close after 5 seconds, so giving time to drivers to clear gate area in order to avoid trapping between the gates and stop sound after the train has crossed.
Step Motor Advantages
Step motors convert electrical energy into precise mechanical motion. These motors rotate a specific incremental distance per each step. The number of steps executed controls the degree of rotation of the motor’s shaft. This characteristic makes step motors excellent for positioning applications. For example, a 1.8° step motor executing 100 steps will rotate exactly 180° with some small amount of non-cumulative error. The speed of step execution controls the rate of motor rotation. A 1.8° step motor executing steps at a speed of 200 steps per second will rotate at exactly 1 revolution per second.
Step motors can be very accurately controlled in terms of how far and how fast they will rotate. The number of steps the motor executes is equal to the number of pulse commands it is given. A step motor will rotate a distance and at a rate that is proportional to the number and frequency of its pulse commands.
Step motors have several advantages over other types of motors. One of the most impressive is their ability to position very accurately. NMB’s standard step motors have an accuracy of +/-5%. The error does not accumulate from step to step. This means that a standard step motor can take a single step and travel 1.8° +/-0.09°. Then it can take one million steps and travel 1,800,000° +/-0.09°. This characteristic gives a step motor almost perfect repeatability. In motor terms, repeatability is the ability to return to a previously held position. A step motor can achieve the same target position, revolution after revolution.
The aim of this project is to Automate unmanned railway gate using mechatronics.Present project is designed using 8051 microcontroller to avoid railway accidents happening at unattended railway gates, if implemented in spirit. This project utilizes two powerful IR transmitters and two receivers; one pair of transmitter and receiver is fixed at up side (from where the train comes) at a level higher than a human being in exact alignment and similarly the other pair is fixed at down side of the train direction. Sensor activation time is so adjusted by calculating the time taken at a certain speed to cross at least one compartment of standard minimum size of the Indian railway. We have considered 5 seconds for this project. Sensors are fixed at 1km on both sides of the gate. We call the sensor along the train direction as ‘foreside sensor’ and the other as ‘aft side sensor’. When foreside receiver gets activated, the gate motor is turned on in one direction and the gate is closed and stays closed until the train crosses the gate and reaches aft side sensors. When aft side receiver gets activated motor turns in opposite direction and gate opens and motor stops. Buzzer will immediately sound at the fore side receiver activation and gate will close after 5 seconds, so giving time to drivers to clear gate area in order to avoid trapping between the gates and stop sound after the train has crossed.
The same principle is applied for
track switching. Considering a situation wherein an express train and a local
train are traveling in opposite directions on the same track; the express train
is allowed to travel on the same track and the local train has to switch on to
the other track. Two sensors are placed at the either sides of the junction
where the track switches. If there’s a train approaching from the other side,
then another sensor placed along that direction gets activated and will send an
interrupt to the controller. The interrupt service routine switches the
track. Indicator lights have been provided to avoid collisions. Here the
switching operation is performed using a stepper motor. Assuming that within a
certain delay, the train has passed the track is switched back to its original
position, allowing the first train to pass without any interruption. This
concept of track switching can be applied at 1km distance from the stations.
WORKING METHODOLOGY:
Present project is designed using 8051 microcontroller to avoid railway accidents happening at unattended railway gates, if implemented in spirit. This project utilizes two powerful IR transmitters and two receivers; one pair of transmitter and receiver is fixed at up side (from where the train comes) at a level higher than a human being in exact alignment and similarly the other pair is fixed at down side of the train direction. Sensor activation time is so adjusted by calculating the time taken at a certain speed to cross at least one compartment of standard minimum size of the Indian railway. We have considered 5 seconds for this project. Sensors are fixed at 1km on both sides of the gate. We call the sensor along the train direction as ‘foreside sensor’ and the other as ‘after side sensor’. When foreside receiver gets activated, the gate motor is turned on in one direction and the gate is closed and stays closed until the train crosses the gate and reaches aft side sensors. When aft side receiver gets activated motor turns in opposite direction and gate opens and motor stops. Buzzer will immediately sound at the fore side receiver activation and gate will close after 5 seconds, so giving time to drivers to clear gate area in order to avoid trapping between the gates and stop sound after the train has crossed.
IR Circuits
This circuit has two stages: a
transmitter unit and a receiver unit. The transmitter unit consists of an
infrared LED and its associated circuitry.
IR Transitter
The transmitter circuit consists of
the following components:
- IC 555
- Resistors
- Capacitors
- IR LED
The IR LED emitting infrared light
is put on in the transmitting unit. To generate IR signal, 555 IC based astable
multivibrator is used. Infrared LED is driven through transistor BC 548.
IC 555 is used to construct an
astable multivibrator which has two quasi-stable states. It generates a square
wave of frequency 38kHz and amplitude 5Volts. It is required to switch ‘ON’ the
IR LED.
IR Transmitter
IR Receiver
The receiver circuit consists of the
following components:
- TSOP1738 (sensor)
- IC 555
- Resistors
- Capacitors
The receiver unit consists of a
sensor and its associated circuitry. In receiver section, the first part
is a sensor, which detects IR pulses transmitted by IR-LED. Whenever a train
crosses the sensor, the output of IR sensor momentarily transits through a low
state. As a result the monostable is triggered and a short pulse is applied to
the port pin of the 8051 microcontroller. On receiving a pulse from the sensor
circuit, the controller activates the circuitry required for closing and
opening of the gates and for track switching. The IR receiver circuit is shown
in the figure below.
IR Receiver
Stepper motor Driver circuit
Here a stepper motor is used for
controlling the gates. A stepper motor is a widely used device that
translates electrical pulses into mechanical movement. They function as their
name suggests – they “step” a little bit at a time. Steppers don’t simply
respond to a clock signal. They have several windings which need to be
energized in the correct sequence before the motor’s shaft will rotate.
Reversing the order of the sequence will cause the motor to rotate the other
way.
Step Motor Advantages
Step motors convert electrical energy into precise mechanical motion. These motors rotate a specific incremental distance per each step. The number of steps executed controls the degree of rotation of the motor’s shaft. This characteristic makes step motors excellent for positioning applications. For example, a 1.8° step motor executing 100 steps will rotate exactly 180° with some small amount of non-cumulative error. The speed of step execution controls the rate of motor rotation. A 1.8° step motor executing steps at a speed of 200 steps per second will rotate at exactly 1 revolution per second.
Step motors can be very accurately controlled in terms of how far and how fast they will rotate. The number of steps the motor executes is equal to the number of pulse commands it is given. A step motor will rotate a distance and at a rate that is proportional to the number and frequency of its pulse commands.
Step motors have several advantages over other types of motors. One of the most impressive is their ability to position very accurately. NMB’s standard step motors have an accuracy of +/-5%. The error does not accumulate from step to step. This means that a standard step motor can take a single step and travel 1.8° +/-0.09°. Then it can take one million steps and travel 1,800,000° +/-0.09°. This characteristic gives a step motor almost perfect repeatability. In motor terms, repeatability is the ability to return to a previously held position. A step motor can achieve the same target position, revolution after revolution.
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