Following control of hard disk drive using derivative state constrained optimal H2 controls

The author presents following control of the hard disk drive using derivative state constrained optimal H₂ controls (H₂ẋ). The study in this paper concern to the control amount of NRPE (non repeatable position error) and PES (position error signal) of track following control in the hard disk drive process by the effective method. The derivative state constrained optimal H₂ control (H₂ẋ) has been formulated to suppress the rate of changes of state variables. It is suitable for the oscillated system and able to be used in non linear system. Thus, the derivative state constrained optimal H₂ control (H₂ẋ) has been applied to track following control in the hard disk drive for increasing the accuracy of head positioning by decreasing the effect from oscillation, variation and non linearity characteristic in its system. Finally, the simulation results show that our proposed method can satisfy the design specifications of track following servo control system effectively.