Model Prediction Based Dual-Stage Actuator Control in Discrete-Time Domain

This paper presents a voice coil motor (VCM) prediction based dual-stage actuator (DSA) control for fast seek and settling times. In the conventional control systems, VCM follows a reference signal, whereas a micro-actuator (MA) seeks a VCM position error signal (VPES) defined by an error between the reference signal and an estimated VCM position. In other words, VCM firstly seeks the reference signal and MA reduces the residual error (equivalently, VPES). In the conventional method, the calculated VPES was utilized in the next sampling period. But, the VPES is not the same as the VPES to be actually compensated because the VPES was calculated under the assumption that VCM doesn´t move. And, the error made seek and settle times slow in transient responses. In order to reduce the error, this paper suggests a new control scheme on the basis of VCM model prediction. From the test results, it is verified that the seek and settling times are obviously improved. Moreover, it is shown that frequency responses are also advanced through a maximum peak criteria.