Small Magnetic Levitation System with a Millimeter-sized Cylindrical Rotor [in Japanese]
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In order to study contact-free levitation systems for micromachines, our group has developed a levitation system with a millimeter-sized cylindrical rotor. The system consists of a rotor (2.0mmφ×8mm, 95mg), a pair of electromagnets for levitation, two pair of photo diodes for sensing, and an analog PD controller. The photo diodes detect axial displacements and rotation speeds of the rotor. The rotor and the electromagnets are so small that the rotor in the radial direction is passively stabilized. This paper describes closed-loop frequency responses, follow-up control characteristics, impulse responses, and rotation decay characteristics. From the results, it is found that the levitating rotor makes a very quick response because of the small mass 95mg, and that photo diodes are useful for sensing rotation speeds, and that the levitation system is applicable to frictionless micromechanisms.
- The Journal of the Institute of Electrical Engineers of Japan
The Journal of the Institute of Electrical Engineers of Japan 119(6), 321-326, 1999-06
The Institute of Electrical Engineers of Japan