Optimizing Floating Locations in Hard Disk Drive by Solving Max-min Optimization

TL;DR

This paper introduces a systematic heuristic method to optimize floating head positions in HDDs, reducing bump interference risk by transforming a complex max-min problem into a manageable arithmetic solution.

Contribution

It presents a novel approach to minimize bump hits during HDD floating operations by simplifying a complex max-min optimization into an efficient arithmetic problem.

Findings

Achieves a desirable trade-off between optimality and computational complexity.

Reduces a multivariable nonlinear problem from NP-hard to an arithmetic problem.

Derives worst-case scenarios for arbitrary bump locations.

Abstract

Floating operation is very critical in power management in hard disk drive (HDD), during which no control command is applied to the read/write head but a fixed current to counteract actuator flex bias. External disturbance induced drift of head may result in interference of head and bump on the disk during drifting, leading to consequent scratches and head degradation, which is a severe reliability concern in HDD. This paper proposes a unique systematic methodology to minimize the chances of hitting bump on the disk during drive floating. Essentially, it provides a heuristic solution to a class of max-min optimization problem which achieves desirable trade-off between optimality and computation complexity. Multivariable nonlinear optimization problem of this sort is reduced from NP-hard to an arithmetic problem. Also, worst-case is derived for arbitrary bump locations.