SU-8 Optical Accelerometers

This paper presents the optimization and characterization of SU-8 quad beam optical accelerometers based on intensity modulation. An applied acceleration causes a misalignment between three waveguides, resulting in variation of losses. Mechanical simulations have focused on the evaluation of sensitivity and the design of a robust junction between the mechanical beams and the inertial mass. Results demonstrate that perfectly rounded structures show at least 4.4 times less stress than L-shaped counterparts. Optical simulation predicts that the optimal configuration in terms of sensitivity is obtained when the waveguides are not completely misaligned, since then losses are insensitive to variations in acceleration. Numerical sensitivities ranging between 11.12 and 32.14 dB/g have been obtained. Fabrication has been simplified, now requiring only two photolithographic steps and electroplating Cu as a sacrificial layer. Experimental results show a reproducible experimental sensitivity of at least 13.1 dB/g     

加速度计的发展

介绍了加速度计的发展概况,综述了硅电容、硅压阻、压电、厚膜应变、力平衡、电子随道和热传导加速度计的结构、原理和发展趋势。     

基于KXR94加速度计的微型惯性测量装置设计

详细介绍基于MEMS（MicroElectroMechanicalSystem）和DSP的微型惯性测量装置的软硬件设计。该装置的MEMS传感器单元由微机械陀螺和微加速度计组成,可精确测量载体的3个轴向角速度信息和3个轴向加速度信息。经验证,该装置可精确测算出载体的航向角、俯仰角及位置等信息,并具有体积小、成本低、功耗低、抗冲击能力强等优点。     

Post-CMOS-Compatible Aluminum Nitride Resonant MEMS Accelerometers

This paper describes the development of aluminum nitride (AlN) resonant accelerometers that can be integrated directly over foundry CMOS circuitry. Acceleration is measured by a change in resonant frequency of AlN double-ended tuning-fork (DETF) resonators. The DETF resonators and an attached proof mass are composed of a 1- $muhbox{m}$ -thick piezoelectric AlN layer. Utilizing piezoelectric coupling for the resonator drive and sense, DETFs at 890 kHz have been realized with quality factors $(Q)$ of 5090 and a maximum power handling of 1 $muhbox{W}$. The linear drive of the piezoelectric coupling reduces upconversion of $1/f$ amplifier noise into $1/f^{3}$ phase noise close to the oscillator carrier. This results in lower oscillator phase noise, $-$96 dBc/Hz at 100-Hz offset from the carrier, and improved sensor resolution when the DETF resonators are oscillated by the readout electronics. Attached to a 110-ng proof mass, the accelerometer microsystem has a measured sensitivity of 3.4 Hz/G and a resolution of 0.9 $hbox{mG}/surdhbox{Hz}$ from 10 to 200 Hz, where the accelerometer bandwidth is limited by the measurement setup. Theoretical calculations predict an upper limit on the accelerometer bandwidth of 1.4 kHz.$hfill$ [2008-0190]      

独特的K剪切加速度计

介绍了一种独特的剪切设计石英加速度计,包括三向型和线,角加速度计。这一设计融合了压电石英的优异特性,为振动测量提供了操作简便,精度高和性能价格比优越的方案。     

基于Verilog-A的电容式MEMS加速度计模型

本文分析了传统MEMS电容式加速度计模型的不足,根据三明治结构电容式加速度计的特点,考虑了寄生电容和热机械噪声的影响,建立了用Verilog-A硬件描述语言实现的模型。该模型与主流集成电路设计环境相兼容,具有很强的可移植性。模拟验证结果表明,该模型如实反映了MEMS电容式加速度计的工作状态,能够为设计单片集成的微弱电容检测电路提供有效的帮助。     

硅微加速度传感器过载能力的研究

过载能力是加速度传感器的重要参数之一，缺少过载能力是早期硅微机械－岛结构的加速度传感器未能实用的重要原因，本文采用微机械限位结构解决了梁－岛结构压阻式加速度传感器的抗过载能力，并对设计进行了优化，采用这种方法使量程在５０ｇｎ以下的器件具备了１０００ｇｎ以上的过载能力，达到了实用的要求，本文还对测量器件过载能力的落锤法所产生冲击加速度的规律和标定方法进行了研究，并建立了测试系统，对器件进行了冲击过载     

Speaker Recognition on Single- and Multispeaker Data

Weber, Frederick, Peskin, Barbara, Newman, Michael, Corrada-Emmanuel, Andrés, and Gillick, Larry, Speaker Recognition on Single- and Multispeaker Data, Digital Signal Processing10(2000), 75–92.We discuss Dragon Systems' approach to the NIST Speaker Recognition tasks. For the one-speaker task, we employ a combination of methods: a basic GMM system and two LVCSR-based systems, one using standard mixture models and the other using nonparametric techniques. We discuss some explorations of the recently introduced two-speaker tasks based on the GMM system alone. “Cheating” tests using NIST-supplied keys lead us to some improvements in channel normalization, and illuminate the roles that speaker segmentation and segment selection play in these tasks.     

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.     

基于三维加速度的连续手势识别

由于基于图像处理的手势识别方法对环境背景要求较高且存在不稳定性问题,文章使用三维加速度传感器的连续数据进行手势识别.三维加速度传感器内置于大部分智能手机中,具有应用方便的特点.实验通过传感器获取加速度信号,经过低通滤波、去重力和特征提取的信号预处理过程后,结合隐马尔可夫模型和混合高斯模型的理论方法,实现手机手势的连续识别,并驱动应用层预先定义的交互命令.     

Placement of Accelerometers for High Sensing Resolution in Micromanipulation

High sensing resolution is required in sensing of surgical instrument motion in micromanipulation tasks. Accelerometers can be employed to sense physiological motion of the instrument during micromanipulation. Various configurations of accelerometer placement had been introduced in the past to sense motion of a rigid-body such as a surgical instrument. Placement (location and orientation) of accelerometers fixed in the instrument plays a significant role in achieving high sensing resolution. However, there is no literature or work on the effect of placement of accelerometers on sensing resolution. In this paper, an approach of placement of accelerometers within an available space to obtain highest possible sensing resolution in sensing of rigid-body motion in micromanipulation tasks is proposed. Superiority of the proposed placement approach is shown in sensing of a microsurgical instrument angular motion by comparing sensing resolutions achieved as a result of employing the configuration following the proposed approach and the existing configurations. Apart from achieving high sensing resolution, and design simplicity, the proposed placement approach also provides flexibility in placing accelerometers; hence it is especially useful in applications with limited available space to mount accelerometers.     

GPS失效时组合导航系统修正方法研究

针对采用低成本惯性元件的MEMS-IMU/GPS组合导航系统在GPS信号长时间失效后系统趋于发散的问题,在研究捷联航姿解算算法、加速计测量姿态角算法和磁传感器解算航向角算法的基础上,提出将航姿辅助修正算法引入组合导航系统中,一旦系统检测到无效信号出现,则能自动切换到辅助修正状态,使导航结果被抑制在0.5°左右;通过半实物仿真实验,证明了该方法能够有效解决GPS信号长时间失效后系统发散问题,满足了在低成本MEMS惯性元件基础上的高精度导航要求。     

Sub-Micro-Gravity In-Plane Accelerometers With Reduced Capacitive Gaps and Extra Seismic Mass

This paper presents a robust fabrication technique for manufacturing ultrasensitive micromechanical capacitive accelerometers in thick silicon-on-insulator substrates. The inertial mass of the sensor is significantly increased by keeping the full thickness of the handle layer attached to the top layer proof mass. High-aspect-ratio capacitive sense gaps are fabricated by depositing a layer of polysilicon on the sidewalls of low aspect- ratio trenches etched in silicon. Using this method, requirements on trench etching are relaxed, whereas the performance is preserved through the gap reduction technique. Therefore, this process flow can potentially enable accelerometers with capacitive gap aspect-ratio values of greater than 40:1, not easily realizable using conventional dry etching equipment. Also, no wet-etching step is involved in this process which in turn facilitates the fabrication of very sensitive motion sensors that utilize very compliant mechanical structures. Sub-micro-gravity in-plane accelerometers are fabricated and tested with measured sensitivity of 35 pF/g, bias instability of 8 mug, and footprint of <0.5 cm².     

基于加速度计的路形计算方法研究

传统的路形测量方法测量过程复杂且测量精度低,为了降低路形测量的难度以及提高路形计算的准确性,提出了一种基于加速度计的路形计算方法,主要由2个加速度计、一个激光位移传感器组成的测量系统为硬件条件,以加速度计所检测到的检测梁纵向加速度信号作为计算机主要输入信号,经过MATLAB软件滤波处理并对其进行二次积分所得到的检测梁纵向位移作为主要计算参数而求得道路的纵断面形状.在真实的道路上进行了验证,结果表明,所求得的路形与实际的路形接近,吻合度较好.计算方法具有结构简单,精度较高等优点,可满足对大多数路面形状的测量需求.     

静电吸合对力平衡式隧道加速度传感器的影响

隧尖与阳极之间的可控间距是关系到隧道加速度传感器能否正常工作的一个重要参数,静电吸合限制了该可控间距的范围,本文从理论上分析了静电吸合对隧道加速度传感器设计的影响。对于质量块作活塞式运动的平动型隧道加速度传感器,只有当隧尖与阳极之间的初始间距小于两个反馈电极之间的初始间距的三分之一加上发射间距的和时,力平衡才能实现。对于质量块由多根平行悬臂梁支承的隧道加速度传感器,首次提出并证明,增大隧尖与悬臂梁末端的水平距离可以扩大锥尖高度和锥尖与阳极之间的初始间距的取值范围,从而降低对传感器加工工艺的要求。     

Single- and Multiobjective Optimization on the Lattice of Cubes

This paper gives examples of optimization problems on a lattice of cubes in the single- and multiobjective cases. We describe a method for calculating the local curvature of a given surface of a large-area geological object at each point and for constructing its curvature surface based on these geophysical data. Such information is used in geology and geophysics for detecting the most probable storage areas of hydrocarbons [1–5]. Based on these results, we develop mathematical models and state single- and multiobjective optimization problems on a lattice of cubes for arranging a finite number of oil wells in an explored field. We describe a method for designing an equivalence set for solving multiobjective problems on the lattices of cubes of any dimensions. Finally, we show that a similar approach is applicable for stating and solving optimization problems on a lattice of cubes in different sectors of the economy.     

基于单片机的智能开关研制

电力开关作为连接元件在电力电子系统中使用十分广泛,传统开关一般采用机械元件实现电路的分合,在操作过程中易产生电弧和冲击电流.本文介绍的智能开关是集单片机、各类传感器、电力开关于一体新型开关,是未来的发展方向.     

基于微机械加速度计的振速水听器的设计与分析

对基于惯性传感器的同振球型振速水听器的工作原理进行了说明.采用多端口组件网络方法建立了用于振速水听器的梳齿式硅微机械加速度计的系统级模型.对内置加速度计,外部采用弹性连接的振速水听器在平面声波作用下的响应进行了仿真分析.分析结果表明,振速水听器不失真测量的工作带宽取决于其与水介质的密度比、波尺寸、与弹性连接构成振动系统以及加速度计自身振动系统的特性参数.多端口组件网络方法能够有效地实现振速水听器的建模与仿真.     

高g值加速度传感器的窄脉冲校准理论与方法

针对高g值加速度传感器动态特性校准中遇到的激励窄脉冲的宽度问题,提出了适用于高g值加速度传感器动态特性的窄脉冲校准准则.该准则给出了对不同谐振频率的高g值加速度传感器的动态特性进行校准时,校准所需的激励窄脉冲的最大脉冲宽度与传感器谐振频率的关系.依据该准则设计了窄脉冲校准系统,并对8309型高g值加速度传感器进行了校准实验.实验结果表明,该准则对于高g值加速度传感器频率响应特性的校准是有效的,按照该准则所定脉宽的脉冲能够激起被较准的高g值加速度传感器的各阶谐振频率.