ABSTRACT
This chapter analyses the blending control idea to deal with the problem of rejecting several narrowband disturbances. It shows that the control blending is respectively applied in the control design for a 1.8-inch hard disk drive voice coil motor actuator in three cases. They are: reject two disturbances of frequencies higher than bandwidth, reject three disturbances with frequencies higher than bandwidth, and reject one disturbance with frequency lower than bandwidth and another one higher than bandwidth. The chapter presents a systematic approach using disturbance models only, which leads to the achievement of a satisfactory rejection of multi-frequency narrow band disturbances. It describes the problem of multi-frequency disturbance rejection into the control blending framework. The multi-frequency disturbance rejection problem is stated as follows: For narrowband disturbances design a feedback controller such that the closed-loop system is stable, and the disturbances different frequency ranges can be suppressed simultaneously.
