Robust time optimal controller design for hard disk drives

Robust time optimal control algorithm based on internal loop compensator is proposed. Internal loop compensator effectively isolates the hard disk system from the uncertain disturbances including modeling error, external disturbance, shock, and control torque saturation. We use the H/spl infin/ mixed sensitivity method for the optimization of internal loop compensator and proximate time optimal controller as a feedback controller to provide a time optimal property. The performance of the proposed controller is verified via simulation.