Switching Stiffness Control of Lateral Motion in Magnetic Suspension System Using Lateral Displacement Detection with Hall Elements

The suppression of lateral vibration is investigated based on switching stiffness control strategy for partially active magnetic suspension system. In such magnetic suspension system, the motion in the normal direction of the suspended object (floator) is controlled actively while the motion in the lateral direction is passively supported. Therefore, it is often subject to vibration in the lateral direction. The application of switching stiffness control has been proposed to suppress such vibration by electromagnets placed in the normal direction. However, the conventional system used a displacement sensor in the lateral direction for detecting the lateral motion of the floator. It restricts the design of suspension system and causes high cost. In this work, it is proposed to detect the lateral motion of the floator with Hall elements instead of installing a sensor in the lateral of the floator. The proposed method of detecting the lateral motion is studied experimentally. The switching stiffness control is achieved based on the output of the fabricated detection device.