2004 Volume 47 Issue 1 Pages 242-250
The object of this study is to develop a radial magnetic bearing which has nanometer rotational accuracy about a fixed center when rotating at high-speed. To achieve this objective, the vibration of the spindle caused by the unbalance force must be reduced. In this paper, we propose a method of control to reduce the vibration of the spindle. First, the center of inertia is estimated from measured coil currents and the rotational speed of the spindle. Subsequently, the references of the control system are modified on the basis of the estimated eccentricity, so that the spindle is constrained to rotate about the estimated center of inertia. Experimental results show that the spindle has a rotational accuracy of 13.2nm (3σ) at 2000min-1 and that the electromagnetic force synchronized with the rotation is 0.17N, which is 8.9% of the electromagnetic force when rotation is about the center of the profile.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering
JSME International Journal Series B Fluids and Thermal Engineering