Magnetic Levitation and Its Origins
Magnetic levitation is the process by which a train can run without having wheels and is based on the principle that magnets attract and repel each other when arranged in close proximity. Maglev trains are being developed around the world and are expected to be a much more efficient means of travel than conventional transportation systems.
The Origins of Magnetic Levitation
The idea of magnetic levitation originated in the 1930s. Scientists like Robert Goddard and Emile Bachelet conceived of the idea and began researching ways to achieve this feat.
The Role of Magnesium in Magnetic Levitation
Magnesium has been used for a long time to make magnets, which are made of ferromagnetic materials. This is because the material's temperature can be adjusted, allowing it to act like a superconductor when it is cold enough.
The Meissner Effect and Magnetic Levitation
Once a material reaches this critical temperature, however, the magnetic field is expelled from the superconductor. In the same way that frogs are attracted to magnets when they are suspended in air, these magnetic fields are pushed away from the superconductor and into space. This phenomenon, called the Meissner effect, is the basis for magnetic levitation.
How Magnetic Levitation Systems Work
Normally, magnets will push or pull each other; when they are in close proximity, however, they will attract each other and "float." These systems work by using coils of solenoids to induce current on the electromagnets in the track. A solenoid is an electric conductor wound into a coil with multiple loops.
The Importance of Current in Magnetic Levitation
Because the magnetic field in the solenoid is induced by the current flowing through the solenoid, it is important that the solenoid be able to generate a sufficient amount of current in order for the electromagnets to levitate the train. This can be done by increasing the number of turns in the solenoid.
The Components of a Magnetic Levitation System
A magnetic levitation system is composed of three key components: a sensor, a suspension controller, and an electromagnet. The sensor tells the suspension controller where to place the electromagnet, which in turn causes the electromagnet to produce forces that are capable of supporting the weight of the train.
The Role of the Suspension Controller
The electromagnetic force produced by the electromagnet is regulated by the suspension controller through input and output sensors. This allows the system to operate smoothly and consistently with minimal error.
Understanding the Principles of Magnetic Levitation
This lab is designed to provide an understanding of the fundamentals of magnet levitation. The lab also provides an opportunity for students to practice their analytical skills as well as build and test a small magnetic levitation cart.
Designing and Testing the Magnetic Levitation Cart
Using the information provided, the cart must be able to fit into the track, compete with the other groups, and meet the MDR equation for the section.
Controlling the Magnetic Levitation System
In addition to the basic design, the lab also focuses on how to control the magnetic levitation system for different load conditions. This is accomplished through the use of mathematical modeling and finite element analysis.
The Lab Setup
The lab includes a platform test bed and PC with a DSP controller board. The test bed interfaces with input/output sensor signals to allow for testing of the various subsystems of the magnetic levitation system. The PC-based controller board then uses these input/output data to determine a set of appropriate control strategies for the entire magnetic levitation system.
