硬盘磁头快速精确定位伺服控制系统的设计

Design of a Fast and Precise Head Positioning Servo Control System for HDDS

针对以音圈电机作为伺服机构的硬盘磁头定位伺服系统的性能要求,设计了一个参数化的控制器并进行仿真和实验研究。在控制设计中,采用一种复合非线性反馈(CNF)控制技术,以提高控制系统的瞬态性能,达到快速的响应和低超调;通过设计一个降阶观测器对伺服系统中的未知扰动进行估计及补偿,消除扰动可能带来的稳态跟踪误差。仿真和实验结果表明硬盘磁头可以实现对目标磁道快速准确的定位。参数化设计的伺服控制器具有通用性,可推广应用到其他伺服系统。

A new parameterized controller is designed for a hard disk drive （HDD） head positioning servo system which currently uses the voice coil motor as its servo mechanism, The controller aims to meet the tougher performance specification in HDD head positioning. Simulation and experiment studies have been carded out, In the design of the controller, a so-called composite nonlinear feedback （CNF） control technology is adopted, which can improve the transient performance, and achieve fast response and low overshoot at the same time. A reduced-order observer is also designed to estimate and then compensate the unknown disturbance in the servo system. This effectively removes the static tracking error that would be caused by disturbances without compensation. Simulation and experimental results verify that the HDD head is capable of fast and precise positioning on target tracks. The parameterized design of the servo controller can be easily generalized to other servo systems.