PIs: Eduardo A. Misawa, Oklahoma State University, School of Mechanical and Aerospace Engineering Otis Funches, Seagate Technology
Proposal Number: 9978748
GOALI: Nonlinear Control of Advanced Hard Disk Drives
Project Abstract
This GOALIE research project explores and develops nonlinear control system design strategies that will allow the development of cost effective advanced hard disk drives with densities exceeding 100,000 tracks per inch. The objective is to achieve positioning accuracy within 5% of track width and fast average seek times, less than 3 ms, in the presence of thermal effects, shock and vibration. The ability to achieve these goals will be important to the disk drive industry to meet the demands expected during the next decade.
This challenge requires a combination of hardware developments and innovative servo-control strategies. Novel control design techniques will be based on digital variable structure control combined with ellipsoid-based saturation control algorithms and implementation using embedded control. The design techniques, supported by sound mathematical control theory, will be evaluated by designing control algorithms and tested using prototypes of advanced disk drives provided by Seagate. The experiments will be conducted in two phases, both using DSP-based embedded control: 1) using a laser interferometer to measure the actual position of the read/write head by point measurement; 2) using the position information written on the disk itself. In both cases, shock, vibration and thermal effects will be applied as disturbances. The results will be evaluated against the design specifications projected for future products. This research will also have strong impact on the development of new knowledge in the field of servo-control design techniques for high-precision motion control. Proposed activities will also have direct impact in the undergraduate and graduate education, through the involvement of graduate students in the research and by bringing the results of advanced research into the classroom.
