Optimal design and testing of a digital dual-stage actuator servo system

This study addresses an optimal dual-stage actuator (DSA) servo design in a discrete-time domain. Maximising the cooperation of a voice coil motor and a microactuator (MA), the authors design a discrete-time fixed-order DSA control system. The controller is applied to a disk drive with DSAs, and experimental results demonstrate remarkable improvements in track seek in the MA range as well as in track follow. It is shown that the optimal control system, with the interaction between the two actuators being minimised, delivers exemplary responses in a disk drive test, despite its minimum controller order.