Micromachined Accelerometers With Optical Interferometric Read-Out and Integrated Electrostatic Actuation

A micromachined accelerometer device structure with diffraction-based optical detection and integrated electrostatic actuation is introduced. The sensor consists of a bulk silicon proof mass electrode that moves vertically with respect to a rigid diffraction grating backplate electrode to provide interferometric detection resolution of the proof-mass displacement when illuminated with coherent light. The sensor architecture includes a monolithically integrated electrostatic actuation port that enables the application of precisely controlled broadband forces to the proof mass while the displacement is simultaneously and independently measured optically. This enables several useful features such as dynamic self-characterization and a variety of force-feedback modalities, including alteration of device dynamics in situ. These features are experimentally demonstrated with sensors that have been optoelectronically integrated into sub-cubic-millimeter volumes using an entirely surface-normal, rigid, and robust embodiment incorporating vertical cavity surface emitting lasers and integrated photodetector arrays. In addition to small form factor and high acceleration resolution, the ability to self-characterize and alter device dynamics in situ may be advantageous. This allows periodic calibration and in situ matching of sensor dynamics among an array of accelerometers or seismometers configured in a network.     

平面内运动热执行器的节点模型

本文提出了一种平面运动热执行器的热-电-机械耦合节点模型,此模型不仅可以仿真热执行器中随温度变化的热导率、电阻率和热膨胀率效应,而且可以仿真热执行器机械域的几何非线性效应,从而使用于仿真热执行器的行为的节点法模型实用化.ANSYS有限元仿真的结果证明此模型的不但精度较高,而且计算效率很高.     

Command-Shaping Techniques for Electrostatic MEMS Actuation: Analysis and Simulation

Precision positioning of microelectromechanical systems (MEMS) structures using electrostatic actuation has been widely used for optical and radio-frequency MEMS. How to achieve fast switching without exciting excessive residual vibration or structural impact is an important issue for these applications. This paper presents the analysis and simulation of applying command-shaping techniques for controlling MEMS electrostatic actuation. According to the nature of application fields, electrostatic actuators are classified into three categories: 1) lateral linear actuation; 2) vertical nonlinear actuation; and 3) pull-in actuation. Their corresponding linear or nonlinear command-shaping schemes are developed and presented. Both lumped element and continuous models of typical MEMS electrostatic actuated structures are simulated using Simulink and the finite-element method, and results indicate that the shaped command would yield a much superior response than that by the unshaped commands. Essential sensitivity studies are also conducted to examine the robustness of these shaping schemes, and results shows that within a certain level of parameter variation, these shapers are robust enough to retain the performance.     

Optical Near-Field Probe Integrated With Self-Aligned Bow-Tie Antenna and Electrostatic Actuator for Local Field Enhancement

Microelectromechanical systems (MEMS)-based near-field scanning optical microscopy (NSOM) probes with a bow-tie antenna structure consisting of two metal triangular electrodes separated by a narrow gap have been designed and fabricated. An electrostatic actuator is integrated on this bow-tie probe to decrease the gap width for enhancing the optical near-field intensity. A self-alignment process based on deep reactive ion etching and wet anisotropic etching is established to fabricate the symmetric bow-tie structure. The static and dynamic actuations of electrostatic actuators are examined. With the mechanical resonance of the antenna structure to lateral direction, NSOM imaging is performed in the visible range, and the subwavelength resolution beyond the diffraction limit of light is demonstrated.1655     

Reducing Base Reactions With Gyroscopic Actuation of Space-Robotic Systems

In this paper, control-moment gyroscopes (CMGs) are proposed as actuators for a spacecraft-mounted robotic arm to reduce reaction forces and torques on the spacecraft base. With the established kinematics and dynamics for a CMG robotic system, numerical simulations are performed for a general CMG system with an added payload. The analysis of an added payload’s effects on otherwise reactionless CMG systems motivates the examination of possible operations concepts to reduce base reactions and power consumption. Simulation results for an example closed-loop maneuver show that base reactions can be significantly reduced, or even eliminated, with CMG actuation while using the same amount of power as a robotic system driven by conventional joint motors.      

Analytical Model for Analysis and Design of V-Shaped Thermal Microactuators

An analytical solution of the thermoelastic bending/buckling problem of thermal microactuators is presented. V-shaped beam actuators are modeled using the theory of beam-column buckling. Axial (longitudinal) deformations including first-order nonlinear strain-displacement relations and thermal strains are included. The resulting nonlinear transcendental equations for the reaction forces are solved numerically and the solutions are compared with a nonlinear finite element (FE) model. A test actuator has also been fabricated and characterized. The obtained accuracy of the prediction is within 1.1% of the nonlinear FE solution and agrees well with the experimental data. A corresponding one-dimensional (1-D) heat transfer model has also been developed and validated against experimental$i$-$V$measurements at various temperatures. The developed analytical models are then used to analyze maximum stress and the heat transfer paths. It has been confirmed that the heat flux toward the substrate is a dominant heat dissipation route in sacrificially released devices.hfillhbox[1311]     

衔铁平行运动的磁微执行器Pull-in机理分析

与静电微执行器类似,磁微执行器中也存在重要的Pull-in失稳问题.但相对于静电微执行器详尽的模型相比,研究磁微执行器的文献很少.对于宏观器件,由于磁芯磁阻可以忽略,所以可利用电磁类比,得到Pull-in失稳参数.而对于微观器件,磁芯磁阻不可以忽略.不可利用电磁类比.基于小信号模型对衔铁平行运动的磁微执行器Pull-in的失稳现象首先进行了分析和建模,考虑了微磁芯磁阻,在建立磁微执行器动态小信号模型的基础上,分析发现衔铁平行运动的磁微执行器中不存在Pull-in现象.然后又采用能量法研究了同样的Pull-in失稳问题,得出了和力法相同的结论.最后,给出了一个分析实例,以反映微磁芯磁阻对Pull-in的影响,同时证实了衔铁平行运动的磁微执行器中不存在Pull-in现象的结论.结论对于磁微执行器的设计具有重要意义.     

星载厚膜混合集成SSPC故障分析与研究

以厚膜及半导体技术为基础的厚膜混合集成固态功率控制器(SSPC)具有智能化、高度集成、高可靠等突出优点,已广泛应用到宇航电子产品中.对某SSPC产品测试故障进行了研究,采用无损测试及显微检查方法,分析了SSPC生产测试过程中出现的短路、断路、跳闸、误动作等故障现象,从电路原理及生产过程对故障原因进行了系统分析,总结了不同质量问题所导致的测试故障情况,形成了典型的故障案例.结果表明,原材料问题及生产过程误操作是导致SSPC产品测试故障的两大原因,总结形成了相应检验方法及操作规范,对提升后续产品质量具有一定意义.     

Model Identification and Control of Electromagnetic Actuation in Continuous Casting Process With Improved Quality

This paper presents an original theoretical framework to model steel material properties in continuous casting line process. Specific properties arising from non-Newtonian dynamics are herein used to indicate the natural convergence of distributed parameter systems to fractional order transfer function models. Data driven identification from a real continuous casting line is used to identify model of the electromagnetic actuator device to control flow velocity of liquid steel. To ensure product specifications, a fractional order control is designed and validated on the system. A projection of the closed loop performance onto the quality assessment at end production line is also given in this paper.      

混合集成电路的电磁兼容设计

本文主要介绍了在混合电路设计时需考虑的电磁兼容问题,并分析了产生问题的原因.从电子系统电磁兼容性角度出发,详细地叙述了混合集成电路的布局和布线规则,并进行了讨论.     

磁微执行器的原理及应用

首先介绍了磁微执行器的驱动原理及其在发展中遇到的问题；然后具体分析了几种代表性的磁微执行顺；最后介绍了它们的几个典型应用。     

MEMS电磁致动机构多物理场耦合仿真与分析

为了解决电磁致动机构多物理场之间相互影响不明的问题,建立了电磁-结构多物理场耦合模型,并对微机电系统（Microelectromechanical System,MEMS）电磁致动机构的驱动特性进行了仿真研究。首先,以电压作为激励源,将磁矢势作为因变量引入,得到驱动器整体的磁场分布,实现电磁场耦合。然后通过麦克斯韦应力张量法得到滑块所受的电磁力,并作为载荷施加在滑块上进行瞬态动力学分析,实现电磁-结构场耦合,从而实现电磁致动机构的多物理场耦合仿真。最后,进一步研究了不同输入条件下电磁致动机构的驱动特性,阐明了响应时间、位移速度、最大电磁力和位移等不同输出条件的变化规律,分析了电压对驱动特性的影响,从而为MEMS电磁致动机构设计与驱动特性研究提供指导。     

一种高集成综合馈电网络设计

随着应用环境和平台不断变化,相控阵雷达朝着高集成、多功能和超宽带的方向发展。高集成综合馈电网络是实现这一目标的重要途径之一。本文论述了高集成综合馈电网络设计方案,并详细阐述了数字电路、微波和电源电路一体化设计过程。该方案在体积、功耗和性能等方面明显优于传统分体式设计方法。多次试飞试验结果表明该设计方案可行、可靠,是相控阵雷达集成化设计的重要技术。     

混合集成力敏传感器的研制

本文对半导体应变式传感器的非线性、温度零漂、灵敏度温度系数、蠕变等参数进行了研究,建立了电子线路综合补偿方法,并采用半导体平面工艺研制成功了小型硅应变片,与混合集成电路技术结合,使敏感元件与补偿、放大电路组合成为一体。     

基于柔性铰链支承的热驱动硅微机械手的力学模型及性能分析

微机械手是一种典型的微型执行器,是微型机电系统(MEMS)的重要研究内容之一.以基于柔性铰链的电热驱动硅微机械手为研究对象,建立了微夹钳的二次超静定力学模型,导出了钳口处输出位移的解析式,并在此基础上对硅微机械手的性能进行了分析.分析表明,微夹钳的输出位移与柔性铰链切割半径成正比,切割半径越大,输出位移越大;对各加载电压下的微夹钳输出位移,其试验和理论结果的变化趋势一致,即微夹钳输出位移随输入电压的增加基本呈线性增加.     

Nonlinear Control of an Electrostatic Micromirror Beyond Pull-In With Experimental Validation

This paper is aimed at demonstrating the potential benefits of applying nonlinear control techniques to a type of microelectromechanical system, namely, electrostatic micromirrors, in order to extend their stable operation range, enhance the system's performance, and allow controller tuning and system operation to be performed in a systematic manner. A nonlinear tracking control based on feedback linearization and trajectory planning has been developed. Aspects essential to the implementation, such as the prevention of devices from destruction due to contact, modeling and sensing schemes, the influence of the dynamics of the driving circuit on performance, and the device characterization, have been thoroughly addressed, and practical solutions have been proposed. The experimentation is performed on a setup built with low-cost commercial off-the-shelf instruments and components in a laboratory environment. The experimental results show that the developed control system can achieve stable operation beyond the pull-in position for both set-point and scanning controls.$hfill$ [2008-0268]      

High-Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit/Microfluidic Chip

A hybrid integrated circuit (IC)/microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 $times$ 61 array of pixels that are $30 times 38 mu hbox{m}^{2}$ in size, each of which can be individually addressed with a 50-V peak-to-peak dc-to-10-MHz radio-frequency voltage. These high-voltage pixels produce electric fields above the chip's surface with a magnitude $vert vec{E}vert approx 1 hbox{V}/muhbox{m}$ , resulting in strong dielectrophoresis (DEP) forces $vert vec{F}_{ rm DEP}vert approx 1 hbox{nN}$. Underneath the array of DEP pixels, there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis. The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC/microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications. $hfill$[2009-0142]      

融合混合知识与MCTS的针灸排序方案设定方法

传统的序列决策方法旨在对决策过程与决策步骤进行建模, 以求解得到最优的决策序列. 然而, 序列决策建模过程对目标函数的确定性要求高, 且序列搜索的算法多以深度优先或广度优先等遍历搜索为主, 鲜有考虑搜索过程的随机性. 蒙特卡洛树搜索算法(Monte Carlo tree search, MCTS)虽然适合求解随机序列搜索问题, 但目前仅应用于博弈型搜索过程, 鲜有探讨需要专家参与的知识约束序列决策的搜索策略, 另外, 传统MCTS算法往往存在搜索范围过大、收敛不及时等问题. 为此, 提出一种融合群决策经验型知识和部分确定型决策序列片段的混合知识约束的MCTS 序列决策方法, 并给出了详细的求解流程. 最后, 将所提方法应用于一类中风后吞咽功能障碍针灸穴位排序方案制订问题, 给出了融合混合知识与MCTS的针灸排序方案设定方法, 并与其他方法进行对比, 验证了所提方法的可行性和有效性, 为年轻医师的针灸方案制订技能的标准化培训工作奠定了方法基础.     

基于GAN技术的自能源混合建模与参数辨识方法

自能源（We-energy,WE）作为能源互联网的子单元旨在实现能量间的双向传输及灵活转换.由于自能源在不同工况下运行特性存在很大差异,现有方法还不能对其参数精确地辨识.为了解决上述问题,本文根据自能源网络结构提出了一种基于GAN技术的数据——机理混合驱动方法对自能源模型参数辨识.将GAN（Generative adversarial networks）模型中训练数据与专家经验结合进行模糊分类,解决了自能源在不同运行工况下的模型切换问题.通过应用含策略梯度反馈的改进GAN技术对模型进行训练,解决了自能源中输出序列离散的问题.仿真结果表明,提出的模型具有较高的辨识精度和更好的推广性,能有效地拟合系统不同工况下各节点的状态变化.