Multi-rate short-seeking control of dual-actuator hard disk drives for computation saving

This paper is concerned with multi-rate shortseeking control for a dual-actuator hard disk drive (HDD). Multi-rate control has been proposed to reduce the real time computation in HDD servos, and it has been shown that in track following control of HDDs, computation can be saved greatly without performance degradation by using multi-rate controllers. In this paper, we propose a novel short-seeking control method for dual-actuator HDDs based on multi-rate track following control and initial value adjustment. This method, which utilizes the same multi-rate controllers and same servo structure as track following, adjusts the initial values of the track-following controller for short seeking. Real time computation is greatly saved in two ways: (1) computation is saved by multi-rate scheme; (2) initial value adjustment of the feedback controller makes the use of the feedforward controller and reference trajectory unnecessary, which implies no real time computation for feedforward control is needed. Simulation and experimental results verify the effectiveness of the proposed method.