Stiffness measurement method of repulsive passive magnetic bearing in SGMSCMG

To measure the stiffness such as displacement stiffness and angular stiffness of repulsive passive magnetic bearing accurately, a new stiffness measurement method is proposed for the single gimbal magnetically suspended control moment gyroscope (SGMSCMG) with repulsive passive axial magnetic bearing with segmented Halbach magnetized array and active radial magnetic bearings. First, the suspension force and stiffness characteristics of the repulsive passive magnetic bearing are studied using finite element method (FEM). Second, the detailed stiffness measurement method of repulsive passive axial magnetic bearing is proposed. It includes four procedures such as measurement of the current stiffness of the active radial magnetic bearing, measurement of the displacement stiffness of the repulsive axial magnetic bearing, measurement of the displacement stiffness of the active radial magnetic bearing and measurement of the synthesis displacement stiffness and angular stiffness of SGMSCMG. A prototyped SGMSCMG with angular moments of 200 Nms is manufactured, which is of repulsive passive axial magnetic bearing with Halbach magnetized array and active radial magnetic bearings. The proposed stiffness measurement method of repulsive passive axial magnetic bearing with Halbach magnetized array is verified by prototyped experiments.