Title :
Robust periodic disturbance compensation via multirate control
Author :
Duan, Chengwei ; Guo, G. ; Chong, T.C.
Author_Institution :
Data Storage Inst., Singapore
Abstract :
A multirate discretization based adaptive feedforward compensation (AFC) scheme is proposed for repeatable runout (RRO) compensation in hard disk drive (HDD) digital servo systems. By discretizing the plant via multirate sampling, we can attain the inverse of the closed-loop transfer function no matter whether the closed-loop system is a minimum phase and causal system or not. The proposed scheme cancels selected RRO components rapidly without amplifying unselected higher harmonics. The scheme is applied to RRO compensation in a spin stand servo system. Simulation and experiment results show that the scheme can attenuate selected RRO harmonics effectively especially around 2 kHz which cannot be achieved by the conventional AFC scheme
Keywords :
adaptive control; closed loop systems; compensation; disc drives; feedforward; hard discs; harmonic analysis; robust control; sampled data systems; servomechanisms; transfer functions; HDD; adaptive feedforward compensation; causal system; closed-loop transfer function; digital servo system; disturbance rejection; hard disk drive; inverse function; multirate control; multirate plant discretization; multirate sampling; repeatable runout compensation; robust periodic disturbance compensation; Adaptive control; Automatic frequency control; Control systems; Hard disks; Inverse problems; Programmable control; Rail to rail outputs; Robust control; Sampling methods; Servomechanisms;
Conference_Titel :
Asia-Pacific Magnetic Recording Conference, 2004. APMRC 2004
Conference_Location :
Seoul
Print_ISBN :
0-7803-8717-1
DOI :
10.1109/APMRC.2004.1521943
