• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.109-116
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• 2010

The magnet wheel which generates on its interfacing conductive part a repulsive force and a traction torque by rotation of permanent magnets is used to manipulate the conductive plate without mechanical contact. Here, the air-gap magnetic field of the magnet wheel is shielded partially to convert the traction torque into a linear thrust force. Although a magnitude of the thrust force is constant under the fixed open region, we can change the direction of force by varying a position of the shield sheet. So, the spatial position of conductive plate is controlled by not the force magnitude from each magnet wheel but the open position of shield sheet. This paper discusses non-contact conveyance system of the conductive plate using electromagnetic forces from multiple magnet wheels.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.626-632
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• 2013

When a conductive rod is put within rotating axial magnet wheels arranged parallel, three-axial magnetic forces generate on the rod. In some region, the forces has a property of negative stiffness, thus they can be applied to noncontact conveyance of the rod without a control load. Apart from the passive driving, the magnet wheel should be controlled for the rod to be stayed at the still state or be moved in a specified velocity. But, because a control input is just the rotating speed of the magnet wheel, the number of input is less than that of variables to be controlled. It means that levitation force and thrust force increase at the same time for increasing wheel speed, resulting from a strong couple between two forces. Thus, in this paper, a novel method, in which the longitudinal motion of the rod is controlled indirectly by the normal motion of the rod with respect to the wheel center, is introduced to manipulate the rod without mechanical contact on space.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.131-136
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• 1998

Based on the linear model of electromagnetic suspension (EMS) system, it is able to be further simplified into a standard second-order model with a modified PD control. In this paper static and dynamic characteristics of EMS with modified PD control are investigated when suspended weight of steel plate change. A experimental system has been built to verify static and dynamic characteristics of EMS system. Simulation and experiment are both given.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.200-206
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• 2014

This paper describes magnetically levitated vehicle with hybrid magnets, which have been studied by the authors in place of streetcars or conveyance system. An experimental vehicle of 20kg was magnetically levitated by using a small number of dry-cell batteries, which consisted of 10 Ni-MH cells of 1900mAh in series. The magnets were activated sequentially, because the internal resistance of the batteries suppressed the maximum current. The vehicle was kept levitating for about 2 hours and was stable against disturbance due to instantaneous external force. In this paper, dynamic characteristics of the magnetically levitated vehicle using a small number of dry cell batteries are presented.