A wavelet network control method for disk drives

This paper proposes a wavelet network control method to online learn and cancel repetitive errors in disk drives. In contrast to Fourier transforms, wavelet transforms can provide detailed local information of signals. Based on the wavelet transform, wavelets can approximate any finite energy function. This paper proposes wavelet networks to approximate periodic functions. Accordingly, a wavelet network controller is developed to eliminate repetitive error caused by repetitive disturbance. Experiments for flying height control of a disk drive system are implemented to demonstrate the present method in comparison with another method using Fourier series based network control.