Discrete-time Model Predictive Control for Head-Positioning Servomechanism in a Dual-stage Hard Disk Drive

A dual-stage Hard disk drive (HDD) consists of a coarse actuator for large motion and a micro-actuator facilitating small but precise motion to improve tracking performance. Control design of dual-stage HDD servomechanism suffers from hard constraints due to actuator saturation limits and position output trajectory requirements. This paper presents a discrete time model predictive control using Laguerre functions with the application to a dual-stage hard disk drive which expressly considers actuator constrains and does not need any controller tuning for different references. Different simulation results are shown to substantiate the robust tracking performance of the controller and efficient disturbance rejection capability.