Abstract
Series magnetic suspension is applied to force measurement. In a double series magnetic suspension system with PID control, the upper floator displaces when force acts on the lower floator. Therefore, the force can be estimated for the displacement of the upper floator. When the parameters are set appropriately, small force leads to large displacement so that the proposed measurement method can be suitable for noncontact measurement of microforce. An apparatus was fabricated to study the effectiveness of the proposed method experimentally.