Design and Implementation of a High Performance Hard Disk Drive Servo Controller Using Ga Based 2dof Robust Controller

Currently, HDD (Hard Disk Drive) with VCM actuator covers more than 80% of the HDD market. To enhance the capacity and ability of the system, a new class of servo controller is required to achieve both the robustness and performance of the entire system. This paper proposes a new technique for designing a robust controller for HDD with Voice Coil motor (VCM) actuator; the control design problem, H∞ loop shaping with structured controller, is solved by Genetic Algorithm (GA). The proposed technique does not only solve the problem of high order controller in the conventional design, but also still retains the robust performance of conventional H∞ control technique. In addition, structured pre-filter in the 2DOF control scheme is also designed by GA to enhance the performance in terms of time-domain tracking. Simulation and experimental results verify the effectiveness of our proposed technique.