Robust Control of Hard Disk Drive Servo (Part 1)

This is the first video of a series on Robust Control applied to hard disk drive (HDD) servo. This video is about the concepts involved in Robust Control for SISO (Single-Input-Single-Output) systems to prepare the terrain for MIMO (Multiple-Input-Multiple-Output) systems in video # 2.

Initially I introduce the theory of Robust Control, and I do my best to establish the key points without the heavy mathematics. It is very important to understand these key points in order to design the robust controller.

How the HDD servo works is material for the third video. I focus mainly on track following. This requires an analysis of the VCM (voice coil motor or galvanometer) and the dynamics of the rotary arm. The idea is to obtain a complete mathematical model and to determine its uncertainties. The model is as realistic as possible, and its parameters and tolerances are obtained from the extended literature on this subject.

I use the Matlab Robust Control Tool Box to design the final controller. Through a model in the loop (MIL) simulation, using Simulink, I verify the goodness of the robust controller and conclude about its efficiency.

You can watch the part # 1 now. My intention in this video is to introduce the concepts using an intuitive approach, but some basic classical control concepts are needed.