Abstract
The Iterative Learning Control (ILC) scheme is using the information in repetitive operation and progressive improving the tracking performance. The tracking error can be convergence to small range in a finite learning time. The performance of the iterative learning controller will be limited caused by non-repeatable disturbances. Thus wavelet transform was applied to handle the un-learnable dynamics. This thesis presents a wavelet-based controller on the brushless spindle velocity tracking. It can solve the nonlinear and uncertain problems that the traditional controller can not solve. Thus the spindle can track an arbitrary speed profile. About the hardware structure, the plant under study in the thesis is the spindle of an optical disk drive. Since the resolution of the speed signal from the spindle is too low, we choose a digital position converter (DPC) to improve the resolution. Thus that will enhance the performance of proposed controller.