Status of MSBS Study at NAL

Two Magnetic Suspension and Balance Systems (MSBS) at the National aerospace Laboracory ( NAL ) in Japan are introduced. They are 1Ocm MSBS and 60cm MSBS. They have lOcm x lOcm and 60cm x 60cm test sections. The control of suspending a model at the lOcm MSBS is the 6 degrees of freedom including the rolling moment control. The model for the rolling moment control has two pairs of small extra permanent magnets at both its ends plus a main cylindrical magnet. The rolling moment is generated by the magnetic forces acting on the extra magnets by controlled current passing through the four side coils independently. Test results show the roll angle of the model is controlled in this way. The dynamic calibration test was carried out at the MSBS in 5 degree of freedom without the rolling moment control. The model is a simple cylindrical magnet magnetized along its axis. The obtained results show that the dynamic calibration with measured magnetic field intensity is much superior to that with the coil currents. The 60cm MSBS was designed with some data obtained at the lOcm one. It is fundamentally proportional to the lOcm one in size and coils position. The measured magnetic field intensity is not so strong as expected at design. It was operated first in 1993. The control is 3 degree of freedom in the longitudinal direction. The size of it is the largest one in the world presently.