梯形变截面悬臂梁式微质量传感器设计与分析

针对微小集中质量测量问题,提出并制备了一种梯形变截面悬臂梁式微质量传感器,建立了梯形变截面悬臂梁式微质量传感器的振动分析模型。采用有限元方法求解其振动控制方程,获得了微质量传感器的灵敏度。仿真分析结果表明,相对于等截面矩形悬臂梁式微质量传感器,单层压电和双层压电结构的变截面悬臂梁传感器的灵敏度分别提高了127.00%和263.00%。采用线切割工艺,加工制备了单压电层梯形变截面结构的微质量传感器并对传感器进行了实验测试,在误差允许范围内,仿真结果与实验结果基本一致,验证了采用梯形变截面悬臂梁式结构可以有效的提高传感器的灵敏度。     

一种高灵敏度FBG加速度传感器设计与仿真

采用悬臂梁与垫高块结构,设计了一种高灵敏度的光纤光栅加速度传感器,光栅栅区两端固定在悬臂梁与垫高块之间,提高了传感器的灵敏度,避免了出现啁啾或多峰现象,推导了设计计算的力学模型;对传感器进行了过载安全保护设计、光栅预拉伸设计等;采用有限元分析计算得出了悬臂梁应变分布情况及6阶固有频率,证明分析结果与设计计算吻合。     

双晶片悬臂梁式压电传感器的有限元仿真研究

压电传感器作为一种便捷、高效的传感器类型,越来越受到人们的青睐.为研究压电传感器机电耦合能力,将压电高聚物聚偏氟乙烯(PVDF)黏结而成的压电双晶片悬臂梁作为研究对象,利用有限元分析软件ANSYS Workbench,首先完成对模型的构建和模态分析,得出模型的固有频率和固有振型,再建立压电材料的压电本构方程,对压电双晶片悬臂梁模型发电量进行模拟仿真,最后将仿真结果与前人研究结果相对比.分析得出:在10 mm的形变量下,能够产生最大320 V左右的瞬时电压,这与前人的研究结果相近,验证了仿真结果的准确性,同时也证实了压电双晶片悬臂梁作为压电传感器的可行性.     

梁式称重传感器弹性体的固有频率的提高及结构参数优化

合理的结构参数组合能够提高悬臂梁式称重传感器弹性体的固有频率,并且能够改善传感器的响应特性。先通过Solidworks参数化建模软件建立悬臂梁式称重传感器的参数化三维模型。为实现参数传递不丢失,再建立Solidworks与ANSYS Workbench的无缝连接。在对悬臂梁式称重传感器进行模态分析的基础上,基于ANSYS Workbench的优化设计功能模块,对其进行优化计算分析,通过计算、分析相关参数对优化目标的敏感性和输入参数对优化目标的响应,来确定最佳的优化方案,并与原方案比较,结果表明:优化后的传感器固有频率提高了2. 47%,达到了优化目的。     

悬臂式涡街流量传感器频率特性优化方法

针对悬臂式涡街流量传感器固有频率较低,在大流量测量时信号失真较大的问题,研究了其固有频率的影响因素,并提出了固有频率的提高方法。仿真结果与实际测试表明:传感器悬臂梁总长度与上下部长度比例k是影响固有频率的主要因素。通过优化传感器的两项参数,125mm口径的传感器固有频率从原来的1620Hz提高到2880Hz,提升幅度达77.7%。     

微悬臂梁横向弹性系数标定技术

微悬臂梁是新型力学传感器的关键部件,其性能决定力学测试结果的准确度。为了定量研究微悬臂梁与样品表面间的相互作用力,须对微悬臂梁的力学性能进行表征。提出了一种新的微悬臂梁横向弹性系数标定方案:采用精密天平和光杠杆分别测得微悬臂梁的横向扭转力和扭转量,进而可得到微悬臂梁的横向弹性系数。对3种型号的微悬臂梁进行了横向弹性系数的实际标定,结果表明:均方差均小于5%,重复性良好,且与有限元仿真值一致。     

基于FBG的新型加速度计研究

设计了一种新型的差动式光纤布拉格光栅(Fiber Bragg grating,FBG)加速度计,论述了其传感结构的设计原理、理论分析和有限元仿真。文中设计的主梁与微梁相结合的差动结构形式,克服了传统悬臂梁结构FBG加速度计存在的固有频率与灵敏度相互制约的矛盾,提高了固有频率和灵敏度。同时,为了解决单悬臂梁结构加速度计存在的温度补偿问题,设计了差动式光学检测系统,使该加速度计的灵敏度较传统单悬臂梁结构提高了一倍。理论分析结果表明,该加速度计灵敏度可达到52.7pm/gn,固有频率250Hz。实验结果表明,该结构提高了加速度计的灵敏度,有效解决了FBG加速度计应变和温度交叉敏感问题,实验结果与仿真数据具有很好的一致性。     

Stewart型六维力传感器的标定方法研究

I、II类误差是影响Stewart型六维力传感器测量精度的主要因素,对Stewart型六维力传感器的测力原理和误差引入原因做了简要的介绍。为提高传感器的实际测量精度,减小测量误差,提出了一种基于标定杆的标定方案。通过理论分析验证了该方案的可行性并通过有限元仿真软件ANSYS完成了Stewart型六维力传感器的静态标定仿真实验,标定前后传感器测量精度的对比证明该方案可有效提高传感器的实际测量精度,降低I、II类误差。     

电阻应变计在机械振动测量中的应用

本文采用金属电阻应变片作为传感器,研究了悬臂梁在动荷载的作用下的若干动态参数的测量,包括固有频率、阻尼系数等。详细叙述了用电阻应变计测试技术测定悬臂梁在动荷载的作用下的若干动态参数的过程以及数据处理的方法;并对所测定悬臂梁的动态参数的准确性进行讨论,指出方案中的优点和不足。     

MEMS高g加速度传感器固有频率的优化及验证

由于设计的MEMS高g加速度传感器固有频率低,导致测试过程中出现谐振现象。本文分析了传感器的特殊结构参数对固有频率的影响,提出了一种优化固有频率的方法。该方法通过减小质量块质量和优化梁厚度与长度的比例来调整传感器的固有频率,并通过理论仿真验证了该结构的固有频率从330 kHz提高到550 kHz,然后利用动态测试系统对优化前后的高g加速度传感器分别在20 000gn和150 000gn作用下测试输出信号。实验表明该优化方法提高了该类传感器结构的固有频率,明显消除了测试中的谐振现象。     

六维力传感器的结构设计分析

为了改善现有六维力传感器的动态性能，提出了一种新型的六维力传感器弹性体结构。建立了结构模型，并采用有限元方法进行了静力学分析以及模态分析，分析了该传感器弹性体在各工况下的应变分布特征；随后对弹性体的关键尺寸参数进行了详细的设计，基于响应面分析法对数值计算结果进行拟合，建立了各工况下响应值与弹性体关键尺寸的回归方程。分析结果表明，该传感器具有良好的动态性能，其一阶固有频率高达3196.3 Hz，各个力分量的灵敏度均有提高，其中x方向力的灵敏度提高了26.09%。通过实验验证了该设计方案的可行性，该传感器的研制为高速作业机器人用多维力传感器的发展奠定了基础。     

A new edge-detected lift force flow sensor

A lift force gas flow sensor which uses the force normal to the fluid flow to measure the flow velocity has recently been introduced. Two thin plates mounted at an angle are deflected when they are subjected to fluid flow. For most mechanical flow sensors the flow sensitivity is closely connected to the time response. A weaker structure gives higher flow sensitivity but a lower natural frequency, i.e., a slower response time. The lift force sensor is designed for measurements of respiratory gas flow in ventilators, where, in addition to low flow restriction, both high sensitivity and fast response are required. A new type of suspension has now been realized for the lift force flow sensor. The detection is separated from the suspension of the airfoil plate with the strain gauges placed on separate detector beams. This leads to separate parameters for optimization of the lift force concept with "independent" control of flow sensitivity and natural frequency. This paper presents an analytical model, simulations and measurements on the new structure. The new edge-detected sensor has been experimentally evaluated for different lengths (100-600 /spl mu/m), widths (20-100 /spl mu/m) and thicknesses (8-20 /spl mu/m) of the detector beams. In accordance with the theory, the measurements show that the new structure has approximately three times the natural frequency of the old, center detected structure and similar or improved flow sensitivity. The evaluation has also resulted in a design scheme for optimal performance. A flow sensitivity of 0.65 /spl mu/V/V/(l/min)/sup 2/ has been obtained for the best edge-detected sensor with a natural frequency of 3.2 kHz.     

基于正弦力激励的预紧压电式力传感器的研究

为了校准预紧的压电式力传感器动态灵敏度并研究其频响特性和预紧结构的设计,首先介绍了正弦力激励的方法并建立校准数学模型。分别在传感器正立和倒立安装方式下进行测试,通过对比试验研究传感器端部等效质量引入的惯性力对传感器动态灵敏度的影响。然后根据传感器固有频率的落球测试方法,将传感器和附加质量块安装于振动系统。通过白噪声激励得到系统安装谐振频率,进而研究传感器有效频率范围和测量精度与安装谐振频率的关系。最后通过理论分析,说明传感器非对称设计的原因。试验结果表明,当附加质量块质量约为传感器质量的121倍时,可忽略端部等效质量对灵敏度标定的影响;压电式力传感器固有频率高达46kHz,但其有效使用频率范围受安装谐振频率限制,当试验频率与安装谐振频率比 时,压电式传感器精度等级为1%;传感器两端等效质量不同,预紧结构是非对称的,用于动态测试时要将端部等效质量轻的一端连接到被测物体。本研究结果可为开展传感器的现场标定和预紧结构的设计提供理论依据。     

加速度传感器壳体结构参数优化

合理的结构参数组合可提高加速度传感器壳体结构的固有频率,保证传感器在振动环境下输出信号稳定.通过建立竖直薄板力学模型,确定影响加速度传感器壳体固有频率的结构因素.基于响应面法思想,利用试验设计的方法,以加速度传感器壳体固有频率为指标,各结构参数为因素,设计二次回归正交旋转组合试验.通过ABAQUS 6.10软件建立各组试验结构参数组合下的分析模型并提取固有频率,最终确定使固有频率维持在较高水平的结构参数组合区间.通过对优化后参数进行验证性试验,表明优化后区间随机结构参数组合下加速度传感器壳体固有频率能够达到10 kHz以上.     

基于LMS Test.Lab的导电橡胶动态特性研究

搭建了基于LMS Test.Lab的分析试验系统,进行力锤系统与激振系统的配置,对导电橡胶进行了试验,并对测试数据进行分析.其结果对于进一步改进导电橡胶压力传感器提供了理论依据.研究表明:导电橡胶作为柔性压力传感器基材具有较好的阶跃响应特性与频率响应特性,其固有频率随着导电橡胶厚度的增大而增大.     

Optimizing the performance of a Coriolis-based angular rate sensor applying an analytical approach

This paper focuses on the optimization of a novel angular rate sensor element based on the Coriolis force working principle. The device is resonantly excited and consists of two mechanically coupled oscillators representing the drive and the sense unit. In order to minimize energy losses during operation, the device employs a single point suspension to the substrate. This is especially advantageous when choosing an antiphase torsional motion for the sense mode. Furthermore, thermally-induced stress resulting in undesired drift effects of the device is minimized. The excitation frequency of the electrostatic drive unit was chosen to be in the range from 10 to 15 kHz, according to automotive requirements. The optimization process started with a complete parameterization of the sensor geometry, providing the basis for an analytical model. This was set up via the so-called deformation algorithm, applying the Ritz method. Next, the eigenfrequencies and mode shapes of the sensor were calculated analytically and compared with FEM results. The inclusion of the Coriolis force induced response of the sense unit yielded signal values from the differential capacitive pickup. An advanced hill climbing algorithm was used, varying two geometrical parameters simultaneously in such a way that the difference in drive and sense frequencies was kept at a constant value of 200 Hz. Based on this procedure an optimized design was found with an increase in signal level of about 450% as compared to earlier versions (e.g. from 3 to 17 aF/°/s). In a last step, fabrication related perforation holes which are typical for surface micromachined devices were included in the model. For this configuration, a frequency matching step was performed by FEM calculations. Resulting stiffness values were fed into the analytical model yielding a final output signal of the sensor of 16 aF/°/s.     

Design and characterization of an integrated multifunction micro sensor

This paper describes the design and characterization of an integrated sensor fabricated on the silicon on insulator wafer by micro electro mechanical systems technology. The integrated sensor is comprised of a tri-axis accelerometer, an absolute pressure sensor and a spreading-resistance temperature (SRT) sensor. The optimal size of the sensor structure, natural frequency and cross interference of these three sensors were simulated and determined by finite element analysis. The accelerometer with the cross structure has high sensitivity, good linearity and high response frequency proved by the static and dynamic experiments. The zero-drift, thermal zero-drift and thermal sensitivity of the accelerometer and absolute pressure sensor were also tested. The arrangement of SRT sensor with the wave structure was designed in detail. The optimal location of the SRT sensor was at the edge of chip to avoid stress interference. The integrated sensor with low cost, low mutual interference, smaller volume and good performance can be applied in mobile device, small military plane without driver and some other situations for environmental monitoring.     

射孔器腔内压力测试系统的高频响应展宽研究

在射孔过程中射孔器腔内会产生二次压力脉冲,一次压力脉冲是一种对于腔内压力测试系统的抗冲击设计、频响设计以及传感器的选择的重要参数,二次脉冲是石油企业工程分析的重要参数。为了在高温、高压、高冲击环境中测得一次脉冲,为射孔器腔内压力测试系统的设计提供重要依据,延长射孔器枪内压力测试系统的使用寿命和降低高昂的成本实现信号的完整采集,保证动态测试精度,本文从实际应用需求出发,给出了系统频响展宽的总体设计方案和测试信号的技术指标。     

Kinematics and control of a fully parallel force-reflecting hand controller for manipulator teleoperation

Force feedback can enhance the efficiency of a teleoperation system by providing the operator with a sense of feel of the forces and torques arising from the interaction of the slave manipulator with the remote environment. This article addresses the kinematic analysis and control of a Parallel FOrce-Reflecting Hand Controller (PFORHC) whose design and implementation are based on a fully parallel mechanism. Kinematic analysis on the PFORHC is performed and results in a closed-form solution for the inverse kinematics. The forward kinematics is solved by Newton-Raphson's method. A fixed-gain PD control scheme is developed for force feedback control. Experiments are conducted to study the performance of the force-reflecting capability of the PFORHC. Experimental results show that the force control scheme utilizing a handgrip force sensor provides smaller steady-state errors as compared to the case utilizing no handgrip force sensor.     

加速度传感器安装方式的理论建模与响应分析

在传感器使用过程中,受其绝缘性能和安装方式的影响,通常会在传感器与被测对象之间安装绝缘过渡装置。而绝缘过渡装置性能的优异和结构的好坏直接影响着加速度传感器的最大响应频率。通过建立加速度传感器安装方式的理论模型,分析了影响传感器输出响应的主要因素。通过不同传感器、不同过渡装置及不同固定方式的组合,对传感器的输出响应进行了实验研究。结果表明：加速度传感器的最大响应频率受过渡装置的影响较大,过渡装置设计的好坏直接制约了传感器的频响范围。通过理论分析和实验研究,提出了提升带过渡装置传感器响应频率的方法。