Magnetic levitation tables are recently applied to industrial applications. In this thesis, rejection of periodic disturbance of the magnetic levitation table is concerned. An adaptive feedforward controller design method based on the steepest gradient descent method is applied to reject the periodic disturbance. The method can be applied to magnetic levitation table without altering the characteristics. According to the on-line adaptation of the magnitude and the phase of the periodic disturbance, the controller cancels the disturbance by adding a canceling signal having identical magnitude and opposite phase to the plant. From the simulation results, the effectiveness of the method is demonstrated. Experimental results verify the analysis.

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