Experimental Study on Chaotic Vibration of a Magnetically Levitated System.

The computer-simulated results of many interesting phenomena occur in a magnetically levitated dynamical system with a single degree of freedom have been previously reported by the authors. For the experimental study, an apparatus is constructed, composed of an arm swinging in the vertical plane and installed on a vertical shaker. The arm is levitated at one end by means of a repulsing pair of permanent magnets and the other end is supported by a bearing. When the shaker is harmonically excited, the arm exhibits ordinary harmonic vibration, many kinds of subharmonic vibrations, aperiodic motions and bifurcations. Some aperiodic motions are identified as chaos by means of the Poincare map and FFT analysis. The results satisfactorily agree with the simulated results, thus proving that the computer-simulated results are realistic and that a new dynamic model in which chaotic motion occurs has been discovered.