ABSTRACT

The hard disk drive (HDD) plays an important role in the modern era of digital technology. The HDD industry began its journey in 1956, and since then, it has traveled through a history of extra-ordinary achievements which is rivaled only by the semiconductor revolution. The HDD includes several subsystems some of which are mechatronic systems, and the integration of all these subsystems to realize a practical product is a challenging task. The challenging task of the HDD servo engineers can be visualized using the following analogy, which helps one to comprehend the difficulties faced in making an HDD and thus to appreciate the achievements of researchers and engineers from a variety of disciplines. HDD sit in the middle of the storage pyramid, between the semiconductor memories and removable drives, and occupy the non-removable on-line data storage niche. Components used in HDD can be broadly classified into 4 categories - magnetic components, mechanical components, electro-mechanical components, and electronics.