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The Most Important Maglev Applications  [PDF]
Hamid Yaghoubi
Journal of Engineering , 2013, DOI: 10.1155/2013/537986
Abstract: The name maglev is derived from magnetic levitation. Magnetic levitation is a highly advanced technology. It has various uses. The common point in all applications is the lack of contact and thus no wear and friction. This increases efficiency, reduces maintenance costs, and increases the useful life of the system. The magnetic levitation technology can be used as an efficient technology in the various industries. There are already many countries that are attracted to maglev systems. Many systems have been proposed in different parts of the worlds. This paper tries to study the most important uses of magnetic levitation technology. The results clearly reflect that the maglev can be conveniently considered as a solution for the future engineering needs of the world. 1. Introduction In Gulliver’s Travels (1726), Jonathan Swift described the maglev island of Laputa, which was capable of achieving levitation heights of several kilometers. In Dick Tracy and Spiderman comics, magnetic levitation also achieved considerable heights. In 1842, Samuel Earnshaw, an English clergyman and scientist, proved another important limitation of magnetic levitation. He showed that stable contact-free levitation by forces between static magnets alone was impossible; the levitated part would be unstable to displacements in at least one direction. In March 1912, engineer and inventor Emile Bachelet had just learned that he had been granted a US patent for his “Levitated Transmitting Apparatus,” and he gave a public demonstration in New York of a model maglev train, with the hopes of exciting investors with the promise of high-speed ground transportation. One of the first major applications of magnetic levitation was in supporting airplane models in wind tunnels. Researchers had found that mechanical support structures sometimes interfere with airflow enough to produce more drag than the drag force on the model. The solution developed by Gene Covert and his MIT colleagues in the 1950s was magnetic levitation (although they called it a “magnetic suspension and balance system”). Another means of using a moving magnet to circumvent Earnshaw’s rule and achieve full levitation is to move the magnet in the presence of an electrical conductor, thereby inducing eddy currents in the conductor and associated repulsive forces on the magnet. This is the basis of the electrodynamic approach to maglev trains proposed by James Powell and Gordon Danby in the 1960s and developed most extensively by Japan National Railway. Strong superconducting electromagnets on the cars induce eddy currents in
A Review Note on Different Components of Simple Electromagnetic Levitation Systems
Banerjee Subrata,Sarkar Mrinal,Biswas Pabitra,Bhaduri Rupam
IETE Technical Review , 2011,
Abstract: Electromagnetic levitation is an important area of research. There is lot of applications of maglev in industry. Extensive research is going on for the last two decades throughout the world to design the latest form of the maglev system. Due to interdisciplinary nature, many aspects are still open in maglev research. The major components in an electromagnetic suspension system are (i) actuator, (ii) sensor, (iii) controller, and (iv) power amplifier. For the successful implementation for any maglev-based project, the basic knowledge of these components is necessary. In this manuscript, an extensive review of different components of electromagnetic levitation systems has been presented.
Theoretical research on multi-axis maglev low-frequency vibration sensor

- , 2018, DOI: 10.13700/j.bh.1001-5965.2017.0524
Abstract: 摘要 设计了一种新型结构的磁悬浮式低频振动传感器,用于航空航天微振动的多轴测量。该传感器采用电磁、永磁混合结构以及微弹簧作为支承元件,通过轴向位移检测电路和光电位移传感器对磁悬浮质量块与壳体间的相对位移进行检测,实现低频振动信号的多轴测量。动态测量时,磁悬浮质量块在电磁力、重力和弹力的共同作用下可回到平衡位置并实现稳定悬浮,通过调整传感器的控制电流,可主动控制系统等效刚度和等效阻尼,从而有效地降低了系统的固有频率,扩展了传感器的频率响应范围。理论分析得到该传感器的下限截止频率为0.6 Hz,实验结果表明该传感器具有良好的低频响应,本文方法为多轴低频振动传感器设计提供了新思路。
Abstract:A new maglev low-frequency vibration sensor was proposed, which was used for multi-axis measurement of aerospace micro-vibration. It used micro-spring and the hybrid structure with electromagnets and permanent magnets as the supporting element. The axial displacement detection circuit and the photoelectric displacement sensors were used to measure the relative displacement between the maglev mass block and the shell and realize the multi-axis measurement of low-frequency vibration signals. When the sensor was used for dynamic measurement, the maglev mass block could return to the equilibrium position and keep stable levitation under the combined action of electromagnetic attractive force, gravity and spring force. The equivalent bearing stiffness coefficient and the equivalent damping coefficient of the system could be controlled by adjusting the control current of the electromagnetic coil, which can reduce the natural frequency effectively and extend application range of the sensor. Theoretical analyses show that the lower-cut-off frequency of the sensor is 0.6 Hz and it has better low-frequency characteristics. The proposed method provides new thought for designing multi-axis low-frequency vibration sensor.
The Wonders of Levitation  [PDF]
M M J French
Physics , 2010, DOI: 10.1088/0031-9120/45/1/003
Abstract: I discuss some interesting classroom demonstrations of diamagnetism and how this effect can produce levitation. The possibilities for hands-on demonstrations of diamagnetic and superconducting levitation are discussed. To conclude I discuss some practical uses for levitation in daily life.
A Study on the Sensor Applications for Position Detection and Guideway Monitoring in High Speed Maglev  [PDF]
Jinho Lee, Jeongmin Jo, Yongjae Han, Changyoung Lee, Yan Sun
Modern Mechanical Engineering (MME) , 2014, DOI: 10.4236/mme.2014.44016
Abstract: The high speed maglev is mainly characterized by propulsion using linear synchronous motor (LSM) and vehicle levitation from the guideway surface. In LSM propulsion control, the position detection sensor is used to detect running vehicle position for synchronized current generation. To maintain the stable levitating condition during vehicle running, the irregularity of guideway surface should be monitored by sensors measuring the displacement and acceleration between vehicle and guideway. In this study, the application methods of these sensors in the high speed maglev are investigated and through the experiments by using the small-scale test bed, the validity of examined methods is confirmed.
"Bernoulli" Levitation  [PDF]
Chris Waltham,Sarah Bendall,Andrzej Kotlicki
Physics , 2002, DOI: 10.1119/1.1524162
Abstract: "Bernoulli" levitation is the basis of many popular counter-intuitive physics demonstrations. However, few of these lend themselves to a quantitative description without recourse to computational fluid dynamics. Levitation of a flat plate is the exception, and we present here a straightforward analysis which illustrates several principles of fluid mechanics in a pedagogically useful way.
Optimization of the Superconducting Linear Magnetic Bearing of a Maglev Vehicle  [PDF]
Lo?c Quéval,Guilherme G. Sotelo,Yassin Kharmiz,Daniel H. N. Dias,Felipe Sass,Víctor M. R. Zerme?o,Raimund Gottkehaskamp
Physics , 2015,
Abstract: Considering the need for cost/performance prediction and optimization of superconducting maglev vehicles, we develop and validate here a 3D finite element model to simulate superconducting linear magnetic bearings. Then we reduce the 3D model to a 2D model in order to decrease the computing time. This allows us to perform in a reasonable time a stochastic optimization considering the superconductor properties and the vehicle operation. We look for the permanent magnet guideway geometry that minimizes the cost and maximizes the lateral force during a displacement sequence, with a constraint on the minimum levitation force. The displacement sequence reproduces a regular maglev vehicle operation with both vertical and lateral movements. For the sake of comparison, our reference is the SupraTrans prototype bearing. The results of the optimization suggest that the bearing cost could be substantially reduced, while keeping the same performances as the initial design. Alternatively, the performances could be significantly improved for the same original cost.
Stability analysis of magnetic levitation system with vehicle-guideway interaction

HONG Hua-jie,LI Jie,ZHANG Meng,

控制理论与应用 , 2006,
Abstract: Since the emergence of the maglev train, the vehicle-guideway interaction vibration hasn't been well explored and settled.How to design the vehicle and guideway feasibly to attenuate the coupling vibration is a hot topic in the maglev train engineering.Firstly,the simplified vehicle-guideway coupling system is modeled in the paper.Based on the stable condition of single magnet levitation system and Nyquist stable theory,a hypothesis is then brought out to describe the phase diagram,and a sufficient condition is also induced to ensure system stability.Subsequently,the hypothesis is proved and the sufficient condition is simplified.Finally,the result is validated by digital evaluations.
Integral Cost-Benefit Analysis of Maglev Rail Projects Under Market Imperfections
J. Paul Elhorst,Jan Oosterhaven
Journal of Transport and Land Use , 2008,
Abstract: This article evaluates a new mode of high speed ground transportation, the magnetic levitation rail system (Maglev). The outcomes of this evaluation provide policy information on the interregional redistribution of employment and population and the national welfare improvement of two Dutch urban-conglomeration and two Dutch core-periphery projects. This article also compares the results of an integral cost- benefit analysis with those of a conventional cost-benefit analysis and concludes that the additional economic benefits due to market imperfections vary from –1% to +38% of the direct transport benefits, depending on the type of regions connected and the general condition of the economy.
Dynamics and Control of a Maglev Vehicle
Won ko
Journal of Systemics, Cybernetics and Informatics , 2006,
Abstract: In this paper, dynamics of a Maglev vehicle was analyzed and controls utilizing an optimized damping and an LQR algorithms were designed to stabilize the vehicle. The dynamics of magnetically levitated and propelled Maglev vehicle are complex and inherently unstable. Moreover, 6-DOF system dynamics is highly nonlinear and coupled. The proposed control schemes provide the dynamic stability and controllability, which computer simulations confirmed the effectiveness.
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