Fuzzy and time-suboptimal control for dual track following and seeking of the magnetic hard disk drive

Track-seeking for a magnetic hard drive is a time optimal control problem where the objective is to move the R/W head from the current track to a specified destination track in minimum time using a bounded control effort. One difficulty is due to the nonlinear saturation and hysterisis behavior of the voice coil actuator. Therefore a dual fuzzy logic controller (FLC) for track seeking and track following is designed and implemented. The controller uses position and velocity to decide on the commanded electrical current. Once the reading head gets within a small distance of the target track, a linear pole placement design is implemented. We compare the performance of this controller with a time-suboptimal design obtained for the linearized version of the dynamics.