A microdrive track following controller design using robust and perfect tracking control with nonlinear compensation

Pivot bearing friction and flex cable nonlinearity are the two major torque nonlinearities which lead to performance degradation in hard disk drive (HDD) tracking tasks. Based on a comprehensive model of typical voice-coil-motor (VCM) actuator, which explicitly captures the characteristics of pivot bearing friction and flex cable nonlinearity, this paper presents the design of a parameterized controller for a microdrive using the robust and perfect tracking (RPT) technique combined with nonlinear torque compensation and integral enhancement. Simulation and experimental results show that the controller is capable of achieving fast settling and eliminating static bias.