Adaptive ZPETC method for dual-stage actuator controller design in miniaturized optical disc drive

A swing-arm/PZT dual-stage actuator is designed to provide high performance solution to realize precise tracking and focusing operation of miniaturized optical disc drive (mini-ODD). Because of its dual-stage mechanical characteristics can perform the focusing action smoother and more precise for better fault and error tolerance, the servo system to control such a dual-stage system tends to be more effective than a conventional single-stage ODD system. However, it is not enough to restrain the unwanted outside disturbance. Therefore, the zero phase error tracking controller (ZPETC), as proposed by Tomizuka (1987), which is very sensitive to improve the modeling error in motion control is used for this dual-stage miniaturized actuator. This paper presents an adaptive ZPETC method in dual-stage actuator design to achieve better focusing performance.