Combination Methods of Disturbance Cancellation and State Feedback Controls for Vibration Isolation Table Levitated by Repulsive-Type Actuator

Abstract

This paper proposes a method for controlling vibrations of a magnetic levitation table. The system considered in this paper is composed of permanent magnet and a permanent magnet with an electromagnet. The vibration is controlled by changing magnetic flux density of the permanent magnet by controlling electrical current in a coil of the electromagnet. Two kinds of control techniques are combined. One is the disturbance cancellation control in which the variation of the levitation force is controlled, which corresponds to the external force due to disturbances, and the other is the state feedback control. Experimental tests have been carried out to discuss the validity of this technique. The experimental results show that the technique proposed in this paper is applicable to isolate vibrations, and the transmissibility can be controlled to be nearly zero.