Title :
Advanced methods for repeatable runout compensation [disc drives]
Author :
Sacks, A.H. ; Bodson, M. ; Messner, W.
Author_Institution :
Data Storage Syst. Center, Carnegie Mellon Univ., Pittsburgh, PA, USA
fDate :
3/1/1995 12:00:00 AM
Abstract :
This paper presents and compares experimental results from two types of periodic disturbance compensation methods. The repeatable runout (RRO) cancellation techniques studied in this paper are adaptive feedforward cancellation (AFC) and repetitive control. Two modifications (phase advance and a feedthrough term) to the basic AFC structure are also studied experimentally. Of the AFC methods, the feedthrough technique is superior, but the repetitive controller provides better RRO rejection. Overall it is found that the removal of repeatable runout improved the tracking precision by as much as 53%.<>
Keywords :
adaptive control; closed loop systems; error compensation; feedforward; magnetic disc storage; position control; self-adjusting systems; adaptive feedforward cancellation; magnetic disc drives; periodic disturbance compensation methods; repeatable runout compensation; repetitive control; tracking precision; Adaptive control; Automatic frequency control; Control systems; Data storage systems; Drives; Geometry; Memory; Programmable control; Rail to rail outputs; Transfer functions;
Journal_Title :
Magnetics, IEEE Transactions on
