MEMS差动电容加速度传感器

介绍了一种MEMS差动电容加速度传感器的设计及所达到的技术指标。对MEMS Sensor选择差动电容传感器的理论依据进行了分析，叙述了MEMS差动电容加速度传感器各项参数的设计依据，包括灵敏度、非线性、温度漂移、隔离度、频带宽度等，同时介绍了该传感器各项指标的测试数据。该传感器具有灵敏度高、参数设计合理，不用温度和线性补偿就达到了高线性和低漂移，结构合理，达到理想的横向隔离效果和宽的频率响应特性等特点。     

压电加速度传感器测量中的温度补偿设计

为了解决压电加速度传感器易受温度影响的缺点,通过分析其测量原理和温度变化对压电传感器性能的影响,提出了在压电加速度测量系统中加入热敏元件进行温度测量,并利用单片机软件进行自动实时温度补偿的方法。结果表明,实施温度补偿后,提高了压电加速度传感器的工作性能与可靠性。     

一种新型二节式差动变压器位移传感器的优化设计

论文对传统的二节式大位移传感器存在的问题进行了分析,继而提出了一种新型的二节式位移传感器,并对其进行了数学模型分析,用正交试验法对影响其性能的诸多因素进行了多参数择优,根据优化结果进行了试生产。实验证明其性能指标较同样外形尺寸的传统的二节式位移传感器有很大程度的提高。     

一种新型的光纤光栅高频加速度传感器

提出了一种新型的高频响应光纤光栅加速度传感器,并进行了理论分析和实验研究.传感器由钢管、质量块组成弹性系统.将光纤光栅粘贴于钢管内部来感知应变,利用双光纤光栅匹配滤波解调技术,直接输出光强度信号,取得了谐振频率3 232 Hz、线性测量范围0.1-4 g、线性灵敏度669 mV/g的较好结果.     

一种谐振式加速度传感器及其设计

为解决当前模拟输出式加速度传感器测试精度相对较低的问题,利用谐振式传感器重复性好、分辨率高、稳定性优良的特点,设计了一种谐振式加速度传感器.通过理论计算,得出了线加速度与敏感元件谐振频率之间的关系,并通过有限元软件对其进行了仿真计算.计算结果显示,传感器在空载状况下谐振频率的理论计算结果与有限元分析结果分别为722.2Hz与720.87Hz.在1g加速度下两种计算方法得到的谐振频率计算结果分别为727.3Hz与726.28Hz,两种情况的相对误差仅为0.18%与0.14%.对加工完毕的加速度传感器进行了测试,测试结果表明:在谐振状态下,传感器的敏感元件的谐振频率大约为718.2Hz,与理论计算及仿真结果基本接近,证明了设计的正确性.     

一种谐振式加速度传感器及其设计

为解决当前模拟输出式加速度传感器测试精度相对较低的问题,利用谐振式传感器重复性好、分辨率高、稳定性优良的特点,设计了一种谐振式加速度传感器。通过理论计算,得出了线加速度与敏感元件谐振频率之间的关系,并通过有限元软件对其进行了仿真计算。计算结果显示,传感器在空载状况下谐振频率的理论计算结果与有限元分析结果分别为722.2Hz与720.87Hz。在1g加速度下两种计算方法得到的谐振频率计算结果分别为727.3Hz与726.28Hz,两种情况的相对误差仅为0.18%与0.14%。对加工完毕的加速度传感器进行了测试,测试结果表明：在谐振状态下,传感器的敏感元件的谐振频率大约为718.2Hz,与理论计算及仿真结果基本接近,证明了设计的正确性。     

三角剪切型压电加速度传感器固有频率计算及优化北大核心CSCD

针对应用于高温环境的剪切型压电加速度传感器,建立了固有频率的计算模型,研究了刚度和几何结构参数对加速度传感器固有频率的影响。研究结果表明:该模型计算结果和有限元仿真结果基本一致。三角支柱的法向刚度对传感器整体刚度的影响最大。中心支柱的几何尺寸对固有频率影响最大,质量块的长宽以及压电片高度对固有频率也有较大影响。优化后的传感器实物样品,固有频率较优化前实现了约20%的提升,符合理论变化趋势。该计算模型和计算结果有助于优化三角剪切型压电加速度传感器。     

内装集成芯片的压电加速度传感器

综述了具有低功耗、能简化测量通道和方便应用于集成化控制系统的内装集成芯片压电加速度传感器的形成原理和众多优点，着重分析了使用时的一些特点，并介绍了具有国际先进水平的１００系列电压输出压电加速度传感器和６１０００型恒流电压源的基本特点和技术性能指标。     

气流式加速度传感器性能的研究

本文根据研制气流式加速度传感器所遇到的实际问题,用理论和实验的方法对其进行了分析和研究。并研究了工艺结构、供电电源电压和环境温度等因素对气流式加速度传感器性能的影响。分析了使气流式加速度传感吕的性能指标得到了提高的因素。     

PVDF压电式谐振传感器在密度测量中的实验研究

密度测量在现代生产生活中占有很重要的地位,因此研究出能够快速精确测量密度的方法会极大地改善生活和生产质量。现利用聚偏氟乙烯(PVDF)压电薄膜的压电效应和逆压电效应制成薄膜压电式谐振传感器,用于气体或液体的密度测量,从而得出传感器谐振频率与被测气体和液体密度之间存在的关系。从实验和分析结果看,该谐振传感器可用于气体或液体的密度测量,且测量结果具有较高的分辨力。     

Performance evaluation of piezoelectric and differential pressure sensor for vortex flowmeters

Piezoelectric and transient differential pressure sensors are two among the most widely employed sensors for vortex flowmeter application. The present study evaluates the performance of these two techniques under fully developed and disturbed flow conditions. Firstly, the location of the transient differential pressure sensor is optimized to obtain high amplitude signals and good linearity in Strouhal number. Empirical mode decomposition method in combination with autocorrelation decay is successfully employed at high Reynolds numbers to identify the vortex shedding frequency in presence of hydrodynamic noise. The performance of the differential pressure sensor deteriorates significantly under disturbed flow conditions at low Reynolds number due to the presence of low frequency components. This deterioration in the signal quality limits the lower operating range of the flowmeter with differential pressure sensor. The output signals of the piezoelectric sensor and differential pressure sensor under no flow condition are compared to obtain the background noise due to piping vibrations and electrical interferences. These results will help a designer to suggest robust signal processing algorithms for vortex frequency detection.     

基于压电式传感器的强夯振动测试分析(英文)

以山西大学城某新校区工程场地为例,对该场地强夯振动影响以及隔振沟的隔振效果进行了测试,对比了有无隔振沟工况下强夯振动对周围建筑物的影响,研究了不同夯击能下强夯振动在黄土地区填方地基中的衰减规律及如何确定强夯施工安全距离,提出了该场地的加速度和振源距的定量关系。通过与现有标准、规范的规定进行比较,分析得出了强夯施工振动对相邻建筑物影响的评价方法。监测结果表明,隔振沟在强夯施工中减振效果好,隔振沟对强夯振动水平速度的衰减幅度高达75%,且在6 000kN·m夯击能下,强夯安全距离为30m。     

基于径向基函数神经网络的压电式六维力传感器解耦算法

针对四点支撑结构的压电式六维力传感器线性度差,维间耦合严重的问题,提出了基于径向基函数(RBF)神经网络的解耦算法。分析了耦合产生的主要原因,建立了RBF神经网络模型。通过对六维力传感器进行标定实验获取解耦所需的实验数据,并对实验数据进行处理。然后采用RBF神经网络优化传感器输出系统的多维非线性解耦算法,解耦出传感器的输入输出映射关系,得到解耦后的传感器输出数据。对传感器解耦后的数据分析表明:采用RBF神经网络的解耦算法得到的最大Ⅰ类误差和Ⅱ类误差分别为1.29%、1.56%。结果显示:采用RBF神经网络的解耦算法,能够更加有效地减小传感器的Ⅰ类误差和Ⅱ类误差,满足了传感器两类误差指标均低于2%的要求。该算法有效地提高了传感器的测量精度,基本解决了传感器解耦困难的难题,     

Influence of temperature and humidity on the detection of benzene vapor by a piezoelectric crystal sensor

Abstract

The influence of temperature and humidity on the determination of benzene concentration were characterized using a piezoelectric crystal gas sensor. Sensing layers coated with polymethylphenylsiloxane and polyvinylchloride was used for real-time monitoring of benzene, a major atmospheric pollutant. When the humidity was varied from 35% to 75%, the detection limitations of the sensor were reduced and the response and frequency recovery times increased. However, when the temperature was increased from 5?°C to 60?°C, the response and recovery time were decreased but the sensitivity performance was degraded. Models were developed for the correlation between the benzene concentration and temperature and humidity.     

Low crosstalk switch unit for dense piezoelectric sensor networks

Structural health monitoring (SHM), on the basis of piezoelectric (PZT) sensors and lamb wave method, is efficient in estimating the state of monitored structures. Furthermore, to monitor large-scale structures, dense piezoelectric sensor networks are required, which usually contain many piezoelectric sensor pairs called actuator-sensor channels. In that case, considering the few data acquisition channels especially in the data acquisition board with a high sampling rate and limited quantity of signal amplifiers used in an integrated computer system, a switch unit is adopted to switch to different channels. Because of the high frequency and power of the lamb wave excitation signal, there exists a crosstalk signal in the switch unit. A large crosstalk signal is mixed into the response signal so that the on/off-line signal processing task is difficult to achieve. This paper first analyzes the crosstalk signal phenomenon, describes its production mechanism, and proposes a method to reduce it. Then a 24-switch channel low crosstalk switch unit based on a digital I/O board PCI7248 produced by Adlink technology is developed. An experiment is implemented to validate it. Its low crosstalk characteristics make it promote the real application of the SHM based active lamb wave method. Finally, a general software program based on LabVIEW software platform is developed to control this switch unit.     

压电材料动态称重传感器的融合设计方法

针对压电薄膜传感器测量受温度影响较大、压电石英传感器价格昂贵的问题,提出将2条压电石英传感器嵌入4排压电薄膜传感器的融合设计方法,建立压电薄膜传感器的等效安装模型及温度补偿算法,利用压电石英传感器对各排压电薄膜传感器进行实时准确的温度补偿。通过MATLAB软件,在正弦波路面激励下,当车速为10～120 km/h,环境温度为0～40℃时,对1/4车辆模型进行动态称重仿真实验。结果表明,融合设计的称重误差均值控制在0. 97%以内,比4排压电薄膜传感器精度提高23倍多,比4排压电石英传感器价格降低3倍多,实现了车辆动态称重的高精度低成本检测目的,工程应用价值好。     

基于压电传感器的石油钻具内孔修磨在线测偏系统

针对石油钻具内孔修磨过程中的轴线偏斜技术难题,提出利用压电式测力传感器进行在线测偏。此方案在石油钻具生产领域具有一定的创新性。     

基于PVDF压电传感器的高压输电塔健康监测研究

针对高压输电塔的健康监测问题,该文设计了一种聚偏氟乙烯薄膜(PVDF)压电传感器,可检测高压输电塔的固有频率,将测得的固有频率与健康时的固有频率对比,分辨出高压输电塔是否受到了损伤。测试结果显示,该PVDF压电传感器表现优良,可以用于实际的信息采集。     

Open-loop linear differential current sensor based on dual-mode Hall effect

This study proposes a novel double Hall linear differential sensor and investigates its output and temperature characteristics in detail. Finite element method is used to confirm the effectiveness of the proposed method. A practical, open-loop current sensor circuit is designed and constructed based on dual-mode Hall effect theory. Results show that the quiescent output voltage is significantly reduced, and that the signal amplitude is increased by 99.5%. Moreover, sensitivity is more than 40 mV/mT, linearity is 1.2% full scale, and the zero drift coefficient is 0.033 mV/°C. The differential output model can suppress common mode interference and zero drift. The sensor also exhibits temperature self-compensation and non-linear correction functions.