力值、转速复合传感器的设计与研究

对传感器的基本结构进行了详细分析,介绍了一种新研究设计的力值、转速复合传感器,该传感器在被测力的作用下,弹性体上的电阻应变计会产生电阻变化,再利用测量电桥将此电阻变化转换为电信号,同时传感器上安装齿盘测速装置并输出脉冲信号。     

惯性式低频振动传感器信号恢复研究

水力机组振动是表征水力机组运行稳定性的主要指标之一 ,然而水力机组转频太低 ,适合于低频振动信号测量的惯性式低频振动传感器 ,由于传感器本身频率特性造成其输出波形的低频段必然产生较大的畸变。为了获得实测低频振动信号的真实波形 ,本文对振动传感器输出的畸变波形恢复问题进行了初步探讨。     

气固两相流速度测量算法研究

论文的研究工作以炼铁厂高炉喷吹煤粉系统煤粉速度为测量对象,利用基于电容传感技术的电容式速度传感器测得煤粉流动噪声,提出了波形法和最小均方差法的测速方法,从理论上分析了波形法和最小均方差法的测速原理,且通过对现场采集的速度信号进行比较分析,从响应时间、适用的范围、与平均速度的接近程度及可靠性几方面比较了三种方法的优缺点,证明了波形法和最小均方差法是可以取代相关法测速的.     

流速剖面测量中的发射波形设计

在水体剖面的流速测量过程中,深度分辨率和速度分辨率是重要的性能指标。为了满足日益提高的测量分辨率要求,文章从模糊度函数出发,设计组合波形作为流速剖面测量的发射信号,并根据其测速原理提出相应的信号处理方法,最后通过数值仿真验证该方法的有效性。理论分析和仿真结果表明:与脉宽相同的单频发射信号相比,组合波形具有更好的深度分辨率;与其中的子波形相比,组合波形在具有相同深度分辨率的前提下,获得了更好的速度分辨率和输出信噪比。     

基于引信炮口磁探测的单线圈被动测速原理

现有的炮口实时测速都是通过改造发射系统和火控系统完成的,存在成本高,改造技术复杂和存在交联电路等诸多弊端.针对这些问题,提出了一种新的弹上被动测速方法.在分析弹丸运动、磁感应强度变化和单线圈传感器输出信号关系的基础上,提出通过捕获弹丸开始加速和出炮口时线圈输出的两个信号,来实现被动测速的原理,阐述了单线圈被动测速需要考虑的线圈设计、测试误差分析、盲区问题、信号处理以及装定对测速的影响等工程技术问题,列举了单线圈测速的若干优点,指出了需要进一步探讨和研究的问题.     

基于LABVIEW的传感器输出特性测试平台研制

基于LABVIEW8．5软件开发环境,利用NI数据采集卡,研制开发了传感器输出特性测试平台。该测试平台可以实现对传感器静动态输出信号进行数据采集与处理,波形显示、数字滤波、数据保存,并能生成测试报告。给出了该测试平台的软硬件构建方法,并通过实例验证了该系统具有良好的测试效果。     

激波压力传感器信号处理电路设计

针对声学靶装置中采用的一种激波传感器．设计了相应的传感器输出信号转换、处理电路,该信号处理电路由电荷放大电路和滤波电路组成。采用运算放大器OPA604设计了电荷放大电路,信号滤波电路采用集成有源滤波器UAF42进行设计。经实弹测试验证,利用该信号处理电路,得到了较好的弹丸激波压力波形。     

惯性式低频振动传感器信号恢复研究

水力机组振动是表征水力机组运行稳定性的主要指标之一,然而水力机组转频太低,适合于低频售测量的惯性式低频振动传感器,由于传感器本身频率特性造成其输出波形的低频段必然产生较大的畸变,为了获得实测低频振动信号的真实波形,本文对振动传感器输出的畸变波形恢复问题进行了初步探讨。     

流速和深度范围约束的脉冲相干多普勒声呐波形设计

针对低速水流场速度测量中要求更高测速精度难题,提出了满足测流环境约束使得测速精度最优的声呐波形参数动态设置方法。基于模糊函数和参量估计理论,研究了相干脉冲串信号测速精度与其波形参数的关系,详细分析了流速范围、探测距离和流场分布等环境因素对波形参数取值的约束,利用非线性规划方法得到测速精度最优的波形参数计算方法。实验结果证明了所提波形设计方法的正确性和实用性。     

固体火箭发动机旋转试验速度测试仪

本文根据固体火箭发动机旋转试验速度测量特声点,在分析国内外测速仪现状后,研制出新型的多功能测速仪。输入可以配接感应式和光电式测速传感器,输入电压信号有两种形式,方波信号和正弦波信号。输出三路电压信号,其中第一路接光线示波器记录,第二路接计算机数据采集记录,第三路输出由该机数字记录表显示测量结果。该仪器中设计有标准信号源,用于校验本机及检验速度记录系统性能,数字记录表示仪可以记录测速,还可以当作高精度频率计使用,测量100kHz以下的频率信号,该仪器运用于火箭发动机旋转试验速度测量及其它机械旋转速度的测量。是一种多功能式测速仪。 本文介绍了该测速仪的设计原理,工作原理,应用及分析,技术指标,为正确地选用测速仪提供了参考依据。     

B1 瓦特计测量声功率方法的分析和简化

本文给出郎之万Ｌａｎｇｅｖｉｎ型换能器及变幅杆振动节点、腹点处振幅比随负载的变化情况，分析了瓦特计法测量声功率本身存在的理论偏差，并给出了两性能相同的换能器对接系统的实验结果，表明这种方法在轻负载（不大于水负载）测量中的准确性，提出工程上简化的测量方法     

感应式测速传感器线圈结构简析

本文对感应式测速传感器的线圈结构进行了简要分析，探讨了影响测速精度的一些因素及提高测速精度的技术途径，试验结果表明。这此方法是可行的。     

Transducer for high speed and large thrust ultrasonic linear motor using two sandwich-type vibrators

A transducer for an ultrasonic motor using two sandwich-type vibrators has been proposed and designed. The vibrators cross at right angles with each other at the tip. The transducer has two vibration modes; one is a symmetrical mode and the other is anti-symmetric. The normal direction motion of the transducer tip is excited by the symmetrical mode. The lateral motion of the tip is excited by the anti-symmetrical mode. The transducer is designed so that these vibration modes are degenerated. To obtain high output force and high power, materials were carefully selected. Heat-treated high strength chromium manganese steel bolts were used for binding the PZT elements. A zirconia ceramics plate was bonded on the transducer tip as frictional material. The no-load maximum speed was 3.5 m/sec. The output force was 39 N at the driving voltage of 500 V(rms) and the preload of 150 N. At this condition the maximum efficiency was 28%, and the velocity was 0.55 m/sec. The maximum output force was 51 N, which was 17 times of the transducer weight. The maximum output power per unit weight was 76 W/kg.     

A new-style, slotted-cymbal transducer with large displacement and high energy transmission

The cymbal transducer had more improved performances than the moonie transducer, but as with the moonie end caps, flexural motion of the cymbal end caps would cause high-tangential stresses, which could lead to loss of mechanical output energy. So, a new-style design, called slotted-cymbal transducer, is presented in this paper. The slotted-cymbal transducer released the tangential stresses by adopting a new-style, radial-slotted cymbal end caps. Through theoretical calculation and finite element analysis in collaboration with measurements, the slotted-cymbal transducer was demonstrated to possess high performances of displacement and energy transmission. This design would decrease the fundamental resonance frequencies of systems by different numbers of slots, and it would have more potential applications of low frequency and large displacement.     

非线性压力传感器静态性能校准方法探讨

指出利用非线性传感器的输出测量值进行校准的方法不能真实地反映其固有特性。正确的方法是:利用其输出测量值进行解算,得到相应的被测量,然后再按被测量对传感器的静态性能进行校准。     

Calibration of an electronically scanned white-lightinterferometric transducer for measurements of high pressure

The paper deals with an electronically scanned white-light interferometric transducer for high-pressure measurements which consists of a sensor, a conditioning circuit, an analog-to-digital converter, and a digital signal processor of the output signal from the sensor. The calibration of such a transducer consists of identifying a function modeling the relationship between the raw result of measurement y, which is the output of the transducer, and the measured pressure p, taking into account an influence quantity-temperature T. An algorithm for calibration is proposed and studied     

A magnetoresistive readout transducer

A new type of reproduce transducer for reading magnetically recorded tapes is described. The device structure, which utilizes the magnetoresistive effect in a thin magnetic film deposited onto a nonmagnetic substrate, provides wavelength response characteristics comparable to existing technology. Indigenous noise effects are subordinate to tape noise. No intrinsic frequency limitations are experienced for recording bandwidths in existence today. Since the device detects the tape's fringing fields directly, the output is not a function of tape velocity. The device construction lends itself nicely to multichannel head assemblies. The transducer may also be used to detect digitally recorded information.     

High frame-rate blood vector velocity imaging using plane waves: simulations and preliminary experiments

Conventional ultrasound methods for acquiring color images of blood velocity are limited by a relatively low frame-rate and are restricted to give velocity estimates along the ultrasound beam direction only. To circumvent these limitations, the method presented in this paper uses 3 techniques: 1) The ultrasound is not focused during the transmissions of the ultrasound signals; 2) A 13-bit Barker code is transmitted simultaneously from each transducer element; and 3) The 2-D vector velocity of the blood is estimated using 2-D cross-correlation. A parameter study was performed using the Field II program, and performance of the method was investigated when a virtual blood vessel was scanned by a linear array transducer. An improved parameter set for the method was identified from the parameter study, and a flow rig measurement was performed using the same improved setup as in the simulations. Finally, the common carotid artery of a healthy male was scanned with a scan sequence that satisfies the limits set by the Food and Drug Administration. Vector velocity images were obtained with a frame-rate of 100 Hz where 40 speckle images are used for each vector velocity image. It was found that the blood flow approximately followed the vessel wall, and that maximum velocity was approximately 1 m/s, which is a normal value for a healthy person. To further evaluate the method, the test person was scanned with magnetic resonance (MR) angiography. The volume flow derived from the MR scanning was compared with that from the ultrasound scanning. A deviation of 9% between the 2 volume flow estimates was found.     

多方向压电振动能量收集装置及其优化设计

摘要：为实现对不同方向环境振动能量的收集,提出了一种新颖的多方向振动能量收集装置的设计结构,装置的换能部分采用了一种Rainbow型压电结构。为提高多方向振动能量收集装置收集能量的效果,以多方向振动能量收集装置输出的总电能为目标函数,综合考虑金属弹性基片的强度、装置振动的固有频率及装置的尺寸空间要求等多种因素,采用序列二次规划法对能量收集装置的结构参数进行了优化。该多方向振动能量收集装置经过优化后,在Y向激励时,其输出的总电能为37.146μJ,比优化前提高了30.82%,当沿装置体对角线方向激励时,结构装置输出的总电能为58.715μJ,比优化前提高了29.24%,装置的能量收集效果得到了明显提高。分析结果为多方向振动能量收集装置的设计、制造及应用提供了技术依据。     

Estimation of the surface normal velocity of high frequency ultrasound transducers

This paper is concerned with the characterization of the true locally resolved surface normal velocity of an assumed piston-type ultrasonic transducer. Instead of involving a very complicated direct pointwise measurement of the velocity distribution, an inverse problem is solved which yields a spatially discretized weighting vector for the surface normal velocity of the transducer. The study deals with a spherically focused high frequency transducer, which is driven in pulse-echo mode. As a means of posing the inverse problem, the active transducer surface is divided into annuli of equal surface so that for each annulus the spatial impulse response can be calculated. An acrylic glass plate acts as a simple structured target. The resulting ill-posed nonlinear inverse problem is solved with an iterative regularized Gauss-Newton algorithm. The solution of the inverse problem yields an estimated weight for the surface normal velocity for each annulus. Experimental results for a thin copper wire target are compared to simulation results for both uniform and estimated surface normal velocities.