磁记录浮动块动态参数仿真

建立了考虑浮动系统动态特性综合分析的近似模型;在磁记录浮动块动态性能方面,给出了浮动系统动力参数(刚度、阻尼、固有频率)及其变化特性的仿真测试方法与结果。     

基于Matlab的测控系统动态性能优化与仿真

提出微位移传感器测控系统动态性能优化设计方法,建立系统数学模型和校正模型,借助Matlab控制系统工具箱、优化设计工具箱完成校正模型的参数寻优,实现测控系统动态性能的优化设计。仿真结果显示,该方法优化效果明显,拓展了工作频带,改善了系统的动态性能。     

基于单片机的取号排队系统的设计

针对传统排队办理业务模式的缺陷,设计并实现了一个银行智能排队系统,具体介绍了系统的设计与实现方法,给出了系统组成结构框图、主要的硬件电路和软件设计。实践证明,该系统性能可靠、稳定、可连续稳定地工作。     

磁记录非牛顿液膜润滑仿真

随着记录密度的不断提高，头盘浮动间隙不断减小。目前近场光、磁混合记录已经在研究10nm以下的浮动系统。由于浮动间隙已远小于空气分子平均自由程(室温下约65nm)而有使气膜浮动技术有失效的危险。非牛顿液膜浮动技术就是在这种背景下在近几年备受关注的。该文提出了一个新的非牛顿润滑液膜，建立了考虑表面粗糙度影响的非牛顿液膜浮动系统模型，对不同表面粗糙度形状系数进行了仿真研究。研究表明，非牛顿液膜浮动系统的性能与气膜的情况有很大的差异。     

通过结构优化改善光学系统性能的方法

影响光学系统特性的因素有光学元器件的离轴、离焦和倾斜等,消除或降低这些指标在外界激励下的响应幅值,是改善系统光学性能的最有效的方法.利用有限元法作为优化设计的方法,在对几个指标进行灵敏度分析的基础上,找出影响系统光学性能的敏感指标.对这些敏感指标进行优化设计就会显著的改善系统的光学性能.对系统进行的优化设计,改善了光机系统的响应,改善了系统的光学传递函数,提高了系统的光学性能,因此,通过结构优化改善系统的光学性能是完全可行的.     

基于单片机的银行智能排队系统设计与实现

针对传统银行业务办理模式的缺陷,提出了一种基于单片机控制和RS485通信网络的银行智能排队机系统,具体介绍了系统的设计与实现方法,给出了系统组成结构框图、主要的硬件电路和软件设计。实践证明,该系统性能可靠、稳定,可连续稳定地工作。     

一种抗干扰通信系统评估模型的设计与实现

利用仿真技术进行抗干扰通信系统性能评佰一种实用、经济且有效的方法。本文以地域通信网为背景,建立了通信模型,给出了系统的设计框图以及主流程图。     

PC/104在光电经纬仪控制系统的应用

本文将介绍嵌入式计算机ＰＣ／１０４模块在光电经纬仪伺服控制系统中的应用，以及ＰＣ／１０４的特点和选用的原由，给出系统软、硬件框图。并着重描述了ＰＣ／１０４模块在系统中的结构关系、任务功能及其在小型优化设计等方面的广闲使用前景。     

基于加权函数选择的伺服系统性能优化设计方法

为了尽可能提高伺服系统的性能, 提出一种基于加权函数选择的性能优化设计方法. 首先, 给出性能优化设计问题的描述; 其次, 给出了线性矩阵不等式(Linear matrix inequality, LMI)形式的优化指标; 再次, 提出一种基于加权函数选择的系统性能优化设计迭代算法; 最后, 利用Bode积分关系分析了算法的收敛性. 所提出的系统性能优化设计算法易于迭代计算, 仿真实例验证了算法的有效性.     

基于SIMULINK的非线性优化PID控制

提出了利用MATLAB优化控制工具箱与优化函数相结合对非线性系统PID控制器进行优化设计的方法,同时建立了基于MATLAB/SIMULINK的非线性系统仿真图.通过仿真试验,验证了该参数优化设计方法不仅方便快捷,而且使系统具有较好的控制精度和稳定性,可使系统的性能有所提高.     

Direct Monte Carlo simulation of air bearing effects in heat-assisted magnetic recording

Heat-assisted magnetic recording (HAMR) is a promising high density recording technology in current hard disk industry. It is proposed to use a heat source from the slider system for heating up the recording media in order to increase its storage density. The heat generated from a heat spot on the disk and/or the higher slider body temperature in HAMR system could affect the slider air bearing and flying height. This paper studies the heat effects on slider air bearing characteristics by using the direct Monte Carlo simulation (DSMC) method. The simulation results show that the heat spot less than 50?nm in diameter could not affect much to the air bearing; however, its location should be away from the bearing pressure peak to minimize the heat spot effect. Furthermore, high temperature slider could increase the bearing pressure and force and the trend of force increment is independent of the flow channel length.     

混合记录浮动特性

对磁混合记录中由近场馈热导致气膜温升的问题进行了讨论,对温升给浮动系统性能的影响进行了仿真研究,得到了影响规律及相关的结论。结果表明,对于采用近场光馈热的浮动系统的设计必须考虑温度的影响。     

Nanoscale dynamics of MEMS TFC active slider

With enabling of a thermal actuator, an air bearing slider can fly at sub-nanometer level spacing on a magnetic disk while the recording elements are functioning. At such spacing, the slider stability and head-disk interface reliability remains to be understood. In this study, a novel understanding on dynamics of the MEMS thermal flying-height control (TFC) slider in touchdown process is developed. By using average and variational-iteration methods, closed-form spectrum estimations of slider vibration are derived. The derived formulation offers an insight of the relationship between spectrum and interface parameters. Physics-based simulation is also conducted to quantify the spectrum of slider vibrations as a function of varied interfacial parameters. To further extend the analytical and numerical analysis, the experimental study of a TFC slider while flying on a rotating disk at sub-nanometer spacing are performed. The analysis reveals the dominance of the air bearing force among other interfacial forces at sub-nanometer spacing.     

Effects of environmental temperature and humidity on thermal flying height adjustment

Thermal actuated sliders are being widely used in today’s hard disk drive industry for its advantages of easier control of flying height (FH) and less risk of contacts with the disk. This article uses a coupled-field analysis method, which includes an air bearing model, a heat transfer model and a thermal-structural finite element model to investigate the FH changes of thermal actuated sliders at various environmental conditions. The mechanism of water vapour’s contribution to air bearing pressure loss is explained and a new humidity model is proposed to calculate this pressure loss. The temperature effects are also considered in the simulation models. It is observed that the environmental temperature and humidity have significant effects on slider’s FH changes, but their effects on the thermal protrusion height are limited. A humidity sensitivity study is also made and the results are discussed. It is found that the slider with thermal protrusion on its trailing pad will be more sensitive to the humidity. Besides air bearing stiffness, some other factors such as peak pressure, protrusion shape and air bearing surface (ABS) design will also contribute to the slider’s humidity sensitivity.     

Six-DOF vibrations of partial contact sliders in hard disk drives

A six-degree-of-freedom slider dynamic simulator is developed to analyze the slider’s motion in the vertical, pitch, roll, yaw, length and width directions. The modified time-dependent Reynolds equation is used to model the air bearing and a new second order slip model is used for a bounded contact air bearing pressure. The simulator considers the air bearing shear acting on the air bearing surface and the slider–disk contact and adhesion. Simulation results are analyzed for the effects of the disk surface micro-waviness and roughness, skew angle, slider–disk friction and micro-trailing pad width on the vertical bouncing, down-track and off-track vibrations of a micro-trailing pad partial contact slider.     

Numerical simulation of shock response of disk-suspension-slider air bearing systems in hard disk drives

 As non-traditional applications of hard disk drives emerge, their mechanical robustness during the operating state is of greater concern. A procedure for simulating the shock responses of a disk-suspension-slider air bearing system is proposed in this paper. A finite element model of the system is developed and modified, and it is used to obtain the dynamic normal load and moments applied to the air bearing slider. The dynamic load and moments are then used as input data for the air bearing dynamic simulator to calculate the dynamic flying attitudes. We obtain not only the responses of the structural components, but also the responses of the air bearing slider. The procedure is convenient for practical application, because it separates the work into two essentially uncoupled steps. It is used to simulate the shock response of a drive. The system modeled is linear if the load dimple of the suspension maintains contact with the slider, but it is non-linear if the dimple separates due to a strong shock. The air bearing has different responses for upward and downward shocks. Slider-asperity contacts occur when a strong shock is applied. Received: 5 July 2001 / Accepted: 11 December 2001     

超低飞高硬盘磁头动力学模型研究进展

随着硬盘记录密度的不断提高.磁头和盘片之间的间隙降低到只有几纳米,因而磁头的动力学特性对于硬盘整体性能的影响尤为重要.在过去几十年中,以Reynolds方程为基础,学者对磁头运动的物理模型进行了广泛的研究.首先介绍了5种常用的磁头运动模型,并进行了比较分析,对国内外的最新研究状况作了介绍,如模型的求解、磁头受力分析和磁头设计.最后,介绍了目前在空气轴承磁头(air bearing slider)研究中面临的主要问题以及对这些问题的看法.     

Shock response analysis of hard disk drive using flexible multibody dynamics formulation

Recent development of the shock analysis on the HDD is briefly reviewed. A flexible multi-body dynamics formulation is developed to simulate the shock response of the HDD. If one component in the HDD is changed, only mode shapes and frequencies of that component should be re-calculated and then used to obtain the system’s response. Steady state Reynolds equation is solved to obtain the air pressure on the slider and disk for various slider positions. An air pressure table is formed and used to model the non-linear air bearing during the simulation. Responses of flying height for different direction and shock duration time are analyzed. Results show that the flying state of the slider is more sensitive to the shock with shorter duration time.