Fixed order PQ control design method for dual stage instrumented suspension

To achieve frequency separation between actuators of a dual-stage servoactuator system in a hard disk drive, the PQ control design method can be used.In the PQ method, the servo controller is designed by focusing on structuralinterference of the actuators. This paper provides a specific parametrization forfixed order feedback controllers used in the PQ-method for which the structuralinterference between actuators can be minimized. The proposed control designmethod is applied to a dual-stage instrumented suspension, where the additionalsensor of the instrumented suspension is used to attenuate high frequency disturbancecaused by windage turbulence in a hard disk drive