Disk drive control with the laser doppler vibrometer

磁性硬盘驱动器是当今广泛使用且不可或缺的存储介质。存储介质已被广泛应用于从笔记本电脑、移动音频播放器、汽车导航到安全和通信系统的各种应用。磁盘驱动器行业当前的目标是打破每平方英寸1万亿比特的存储密度障碍，这对传统的单级磁盘驱动器伺服施加了严格的性能规范。为了应对这一挑战，人们提出了几种双级驱动方案。然而，所有这些建议导致了多变量伺服系统，对于该系统，传统的标量设计技术变得不足以充分发挥该系统的潜力。因此，必须为两级多传感系统提出适当的设计方法，其中以明确和系统的方式追求最优、稳健的性能。本文的工作旨在将鲁棒控制理论应用于双级多传感系统的跟踪控制，并利用我们的控制器设计程序开发全面的用户友好的软件包。最终目标是发明一种通用的稳健伺服设计技术，适用于工程和科学的各个领域的控制问题。为了验证所设计控制器的有效性、鲁棒性、高效性和可实现性，将使用真实的硬盘驱动器实验装置对所得到的结果进行验证。对于实验室中的磁盘驱动器控制实验，激光多普勒振动仪是一种专门用于精确、非接触测量位移和振动的仪器，对于确定磁道跟踪控制性能的质量是必不可少的。在本项目中，该装置将用于各种目的，如动力学识别、悬架振动检测、伺服品质判断等。航空航天工程和生物等领域的其他应用也将受益于这项研究的结果，因为这些领域的许多问题在数学上与磁盘驱动器伺服中的问题相似。

Magnetic hard disk drives are widespread and indispensable storage media nowadays. The storage media has been widely used in various applications ranging from lap-top computers, mobile audio players, car navigation, to security and communication systems. A current goal of the magnetic disk drive industry is to break the 1 tera-bit per square inch storage density barrier, which imposes a stringent performance specification for the conventional single-stage disk drive servo. To meet the challenge, several dual-stage actuation schemes have been proposed. All these proposals, however, lead to a multivariable servo system for which conventional scalar design techniques become inadequate to fully exploit the potential of that system. Thus, it is imperative to come up with appropriate design methodologies for the dual-stage multi-sensing system, in which optimal, robust performance is pursued in an explicit and systematic way. This proposal is a response to this need.   The proposed work aims to apply robust control theory to track-following control for dual-stage multi-sensing systems and to develop comprehensive user-friendly software package utilizing our controller design procedures. The ultimate goal is to invent a universal robust servo design technique applicable to control problems in various fields of engineering and science. All the obtained results will be tested by using a real hard disk drive experimental setup, in order to demonstrate the validity, the robustness, the efficiency, and the realizability of the designed controller. For disk drive control experiments in a laboratory, the Laser Doppler Vibrometer, that is an instrument specialized for accurate, non-contacting measurements of displacements and vibrations, is indispensable to determine the quality of the track-following control performance. In this project, this device will be utilized for various purposes, such as dynamics identification, detection of suspension vibration, and servo quality judgment. Other applications in areas such as aerospace engineering and biology will also benefit from the outcome of this research, as many problems in these areas are mathematically similar to that in the disk drive servo.