Discrete-time LQG/LTR dual-stage controller design and implementation for high track density HDDs

This paper presents a LQG/LTR tracking servo design on a dual-stage actuator in hard disc drives (HDDs). The dual-stage actuator is considered as a multivariable plant rather than two independent actuators. Simulation and implementation results show that a bandwidth of 1.5 kHz is achieved. The settling time for step response is reduced to 0.6 ms. The track misregistration is reduced to 0.044 /spl mu/m.