Multi-input and single-output identification of dual-stage actuation systems in HDDs

In this paper, we consider identification of a class of multi-input single-output (MISO) systems, where the MISO system is composed of several single-input single-output (SISO) linear time-invariant systems and only the sum of the output of each SISO system can be measured. By exciting one SISO system and employing periodic inputs to the remaining SISO systems, we decompose the MISO system into the excited SISO system where its input and output can be calculated from the measured data. As such, the original parameters for each SISO system can be estimated using the well-established identification techniques. Simulation on identification of a dual-stage hard disk drive is carried out to demonstrate the efficacy of the proposed approach.