Multivariable controller design for hard drive dual-stage actuator servo systems

A multivariable multi-objective approach has been presented for the design of servo controller for a dual-stage actuator system. The designed control algorithm instructs the two actuators to cooperate towards a faster track seeking and better disturbance rejection than any actuator acting alone. Cooperation is explicitly formulated as control objectives and the optimal control algorithm is designed using the H2 control theory and regulator theory. Each actuator´s involvement in the cooperation can be further adjusted by changing the design weighting coefficients, while the design procedure guarantees the stability of the control system.