08-10-2016, 04:04 PM
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BASIC AIM:
Our project is to build a miniature working model of MAGLEV, or more specifically, we will make a car
that can be instructed to move forward or backward on a short magnetic linear track by means of
magnetic levitation.
BACKGROUND:
Magnetic levitation (maglev) is an innovative transportation technology. It is sometimes said to be the
first fundamental innovation in the field of railroad technology since the invention of the railway. A high
speed maglev train uses non-contact magnetic levitation, guidance and propulsion systems and has no
wheels, axles and transmission. The replacement of mechanical components by wear-free electronics
overcomes the technical restrictions of wheel-on-rail technology. Compared with traditional railways,
maglev systems have features that could constitute an attractive transportation alternative:
1. High Speed
2. High Safety
3. Less Pollution
4. Low Energy Consumption
PROJECT MOTIVATION:
Magnetism has fascinated humans for centuries. So we were looking for a project based on the
concept of magnetism. The idea for this project came after discussing with the coordinators and reading a Scientific American Article that described proposed maglev systems around the world
and their potential for future travel.
THEORY OF OPERATION:
Maglev is defined as a “family of technologies in which a vehicle is suspended, guided, and propelled by
means of magnetic forces”. It consists of two parts:
1. Propulsion System
2. Levitation System
The propulsion system used is known as a linear motor. Unlike a conventional motor, a linear motor
creates linear motion instead of circular motion. As mentioned above, the major principle behind its
operation is magnetic repulsion
The direction of these magnetic fields can be seen in figure. Since these magnetic fields are opposing
each other, there is a repulsive force, which pushes the electromagnet away. The electromagnet
experiences two repulsive forces, one from the electromagnet on one rail, and one from the other rail.
The direction of these repulsive forces is away from their respective permanent magnets, and since the
two permanent magnets are opposite of each other, in theory, the two repulsive forces would cancel
each other out, and the net force would zero. However, there is an extremely low probability that the
electromagnet is lined up exactly with the permanent magnets.
If the electromagnet is even the slightest bit off center - for example, if the electromagnet is further
down than center, the force from the left permanent magnet will have a right and a down component,
while the force from the right permanent magnet will have a left and down component. Though the left
and right components cancel each other out by symmetry, there is still a net down component, giving
the electromagnet, and therefore the train, a net acceleration downwards.
The electromagnet, initially when the train is started will in all probability not be perfectly lined up, so
there will be a net force downwards. Also, if the train has some velocity, the train will have enough
inertia to move to this point where it will feel the net force downwards, and will thus continue to move
even faster downwards. Furthermore, the train will be in the magnetic field - which is the field due to
the set of permanent magnets directly below the first set and the fields are pointing in the same
direction, so there is an attractive force downwards (and by the same symmetry arguments used above,
the train is also accelerated downwards by this set of forces as well).
When the train moves to the next set of magnets - the ones that it is attracted to – there will be an
attractive force that resists motion. However, a sensor in the circuit senses the change in magnetic field,
which sends a signal that causes the current to reverse. Thus the magnetic field of the electromagnet is
in the opposite direction, the attractive force becomes a repulsive force, and the propulsion cycle
continues.
To create levitation, a magnetic repulsion force is used to counteract the force of gravity. The right
magnetic material must be used to achieve levitation. Magnetic materials are classified into three
categories: paramagnetic, diamagnetic, and ferromagnetic. Among the three diamagnetic is the best
option to go with since it repels the permanent magnet placed near it .
ARDUINO AND CODING
Our coding logic is based on phenomenon of electromagnetic propulsion. After getting reading from hall
effect sensor placed at appropriate distances, we turn of current in that solenoid whose centre coincides
with that of guide way’s magnet. If centre of solenoid is between two magnets, we pass current in them
in such a way that the polarity of solenoid becomes opposite to that of approaching magnet such that
they attract each other. This is for one side of solenoid. Since magnets with opposite polarities are
placed on guide way, we don’t need to worry about other face of solenoid, it automatically gets
adjusted.
FURTHER IMPROVEMENTS
Though we could only levitate the train and not propel it forward because of many sort of problems we
faced, we intend to study the problems more and try to do the other part of the project as well.
BASIC AIM:
Our project is to build a miniature working model of MAGLEV, or more specifically, we will make a car
that can be instructed to move forward or backward on a short magnetic linear track by means of
magnetic levitation.
BACKGROUND:
Magnetic levitation (maglev) is an innovative transportation technology. It is sometimes said to be the
first fundamental innovation in the field of railroad technology since the invention of the railway. A high
speed maglev train uses non-contact magnetic levitation, guidance and propulsion systems and has no
wheels, axles and transmission. The replacement of mechanical components by wear-free electronics
overcomes the technical restrictions of wheel-on-rail technology. Compared with traditional railways,
maglev systems have features that could constitute an attractive transportation alternative:
1. High Speed
2. High Safety
3. Less Pollution
4. Low Energy Consumption
PROJECT MOTIVATION:
Magnetism has fascinated humans for centuries. So we were looking for a project based on the
concept of magnetism. The idea for this project came after discussing with the coordinators and reading a Scientific American Article that described proposed maglev systems around the world
and their potential for future travel.
THEORY OF OPERATION:
Maglev is defined as a “family of technologies in which a vehicle is suspended, guided, and propelled by
means of magnetic forces”. It consists of two parts:
1. Propulsion System
2. Levitation System
The propulsion system used is known as a linear motor. Unlike a conventional motor, a linear motor
creates linear motion instead of circular motion. As mentioned above, the major principle behind its
operation is magnetic repulsion
The direction of these magnetic fields can be seen in figure. Since these magnetic fields are opposing
each other, there is a repulsive force, which pushes the electromagnet away. The electromagnet
experiences two repulsive forces, one from the electromagnet on one rail, and one from the other rail.
The direction of these repulsive forces is away from their respective permanent magnets, and since the
two permanent magnets are opposite of each other, in theory, the two repulsive forces would cancel
each other out, and the net force would zero. However, there is an extremely low probability that the
electromagnet is lined up exactly with the permanent magnets.
If the electromagnet is even the slightest bit off center - for example, if the electromagnet is further
down than center, the force from the left permanent magnet will have a right and a down component,
while the force from the right permanent magnet will have a left and down component. Though the left
and right components cancel each other out by symmetry, there is still a net down component, giving
the electromagnet, and therefore the train, a net acceleration downwards.
The electromagnet, initially when the train is started will in all probability not be perfectly lined up, so
there will be a net force downwards. Also, if the train has some velocity, the train will have enough
inertia to move to this point where it will feel the net force downwards, and will thus continue to move
even faster downwards. Furthermore, the train will be in the magnetic field - which is the field due to
the set of permanent magnets directly below the first set and the fields are pointing in the same
direction, so there is an attractive force downwards (and by the same symmetry arguments used above,
the train is also accelerated downwards by this set of forces as well).
When the train moves to the next set of magnets - the ones that it is attracted to – there will be an
attractive force that resists motion. However, a sensor in the circuit senses the change in magnetic field,
which sends a signal that causes the current to reverse. Thus the magnetic field of the electromagnet is
in the opposite direction, the attractive force becomes a repulsive force, and the propulsion cycle
continues.
To create levitation, a magnetic repulsion force is used to counteract the force of gravity. The right
magnetic material must be used to achieve levitation. Magnetic materials are classified into three
categories: paramagnetic, diamagnetic, and ferromagnetic. Among the three diamagnetic is the best
option to go with since it repels the permanent magnet placed near it .
ARDUINO AND CODING
Our coding logic is based on phenomenon of electromagnetic propulsion. After getting reading from hall
effect sensor placed at appropriate distances, we turn of current in that solenoid whose centre coincides
with that of guide way’s magnet. If centre of solenoid is between two magnets, we pass current in them
in such a way that the polarity of solenoid becomes opposite to that of approaching magnet such that
they attract each other. This is for one side of solenoid. Since magnets with opposite polarities are
placed on guide way, we don’t need to worry about other face of solenoid, it automatically gets
adjusted.
FURTHER IMPROVEMENTS
Though we could only levitate the train and not propel it forward because of many sort of problems we
faced, we intend to study the problems more and try to do the other part of the project as well.