Optimization of initial value compensation for settle control in hard disk drives

A method is proposed for optimal settle control using 1-degree-of-freedom (1-DOF) control and initial value compensation (IVC) in hard disk drives. A feedforward control signal is injected into the control system during settle control to compensate the initial conditions when switching from seek to settle control. A transfer matrix from initial conditions to feedforward control input is calculated by least square optimization to minimize a cost function defined by position error, control effort and jerk. Simulation and experimental results are presented