Improvement of short-span seeking performance in a dual-stage hard disk drive actuator

This paper proposes an alternative method to improve short-span seeking performance of a compensator based control system for a dual-stage servo actuator. The short-span seeking performance is improved by presetting initial conditions of the compensator during the short-span seek commands. This results in faster response of the secondary control loop and hence in faster seek times within the range of the secondary actuator. The performance of the proposed initial conditions based method is compared with the performance of recently proposed methods using constant and dynamic saturations in the secondary loop. The results show that the performance of the proposed method is comparable with the performance of the method using the dynamic saturation and thus can be used as an alternative, simpler method, to achieve faster short-span seek times.