振弦式质量传感器

美国 K-Tron Arizona 公司根据有关振弦的基本原理制成了一种振弦式质量传感器。它有一参比振弦和一承载振弦,利用两者振动频率的比值与所加负载间比例关系的变化来称量物体质量。从振弦测量系统中得到的数字信号通过一数字计数器直接送入微     

带有变截面弦丝的振弦传感器

振弦传感器能将压力、变形等各种物理量转换成弦的振动频率,并具有高的抗干扰性。因此,改善振弦传感器的特性是当前仪器制造的一个重要课题。作者曾提出采用中间较端部细的弦丝(图1)以降低温度误差和增加夹持的机械强度。此外当输入信号在较宽范围变动时,还可提高传感器的绝对灵敏度和耐振性。为了计算这种变截面弦丝的特性,必须找到固有频率与弦的几何形状以及张力间的关系式。这种弦丝的横向自由振动具有下列微分方程形式     

采用振弦式力接收器测量重量

近几年来，在松散物料定量称量技术中，对重量采集的质量要求越来越高。特别是对测量范围的很高分辨率和力接收器的高工作可靠性提出了要求。集成式测力传感器注定能满足定量秤之心脏－测力的高要求，它包括：按振弦原理进行测力以及重量的全数字化处理、适于计算机的串行接口、机械过载保护和诊断功能。振弦测力因测量行程很小，而使其振动灵敏性微小，这是其突出之点。下面几个因素特别有助于工艺过程技术中所要求的集成式测力传感     

振弦应变传感器校准装置的设计

基于弹性体振动理论,建立了振弦应变传感器输出频率与应变的数学模型表达式,提出该类传感器的校准方法,设计了校准装置.该装置利用计算机自动采集数据,并与电子表格结合,实现对振弦应变传感器进行可靠校准.     

传感器技术讲座 第七讲 数字式传感器及其应用(二)

二、频率式传感器频率式传感器的输出形式是频率,即单位时间内的脉冲数,所以也是一种数字式传感器。主要有振弦式、振梁式、振膜式和振筒式等。多用于压力、力、流量和温度的测量。 1.振弦式传感器振弦式传感器是把机械位移转换为弦振动,当外力张紧或放松振弦时,弦线的频率     

基于单片机P89V51RD2功率测量仪的设计

介绍振弦传感器的工作原理,并阐述了基于振弦传感器测量功率的原理,在此基础上论述了基于单片机P89V51RD2功率测量仪的设计。文章重点介绍了信号调理电路、频率/功率数字测量方法及显示电路的设计。     

一种新型频率(压力)测读仪的设计与开发

为了解决近年来房屋、桥梁垮塌事故屡有发生的问题,设计了一种新型频率(压力)测读仪,包括单钢弦振弦传感器、激振电路、接入检测电路和电平控制电路。将电磁感应技术和单片机控制技术应用到建筑应力测试中,开展了建筑安全状态的测试与评估,建立了频率与振弦张力之间的数学关系模型。通过专业力学实验室进行了相关指标的测试,结果表明:本频率(压力)测读仪能够快速准确地测算出当前建筑的应力值,检测精度高,读数方便,可靠性高,能为建筑的安全做好风险评估,具有良好的推广前景。     

高精度、高稳定度差动式振弦传感器及其测频系统

文中分析了振弦传感器线性度低、温度敏感性的原因,提出采用差动式结构、温度自补偿技术和平方算法,提高传感器的测量精度和稳定度,并给出了差动式结构的数学模型,给出了应用AT89C52单片机进行测频的方案和具体硬件电路.实验证明,采用该种方法,振弦传感器测量系统的测量精度和稳定度可达到10-5数量级.     

用振弦传感器检测平弹簧参数

平弹簧作为测量弹性元件,在各种仪器仪表中得到了广泛的应用,仪器的精度大多决定于这些弹簧的制造精度及选取形式。本文讨论了采用振弦传感器检测平弹簧参数的可能性。石英振弦传感器是用光学纯融凝石英焊接制成(图1)。在传感器结构中,杆1左侧粗大部分通过凸起物6固定在石英外壳4上,石英外壳本身又固定在金属管座2中。杆1的自由端焊在外壳4的工作区5上。振弦3焊接在杆1上,表面敷镀金属,通过密封引线7与自激振荡器线路相连。为了提高振弦的品质因数,外壳4的内腔保持真空。该传感器可以作为力变换器使用,使传感器     

基于无线通讯的多通道振弦传感器监测系统

该系统是一种利用振弦传感器和埋入式铜电阻温度计来测量大型土木工程内部应力及温度的32通道自动采集测量仪表.论证了应用振弦传感器和无线数传电台在工程中进行实时或动态监测的可行性.介绍了其工作原理,系统结构,功能特点和软件编程.目前此系统的各项指标已达到工程监测规范要求,并已在吉林省吉林市江湾大桥等多个大型土木工程中得到应用.     

斜视状态下航空遥感器像移的计算与补偿

航空遥感器成像过程中飞行器的向前飞行和姿态变化,使地面物体发出的光线相对于遥感器的光轴产生运动,从而引起共轭像点的运动,在成像介质上产生像移。运用光线矢量与光轴旋转变换相结合的方法,针对飞行器向前飞行使物体与光轴间发生的平移,以及飞行器姿态变化使光轴方向的改变,建立了光线矢量与光轴单位矢量间的关系,得到了航空遥感器在斜视状态下的像移模型。以实测遥感器的工作参数为条件,分析和计算了遥感器的像移,并给出了像移补偿的方法。实际应用证明光线矢量与光轴旋转变换相结合计算像移的方法,不仅综合了前向像移与姿态像移,而且计算简便,可推广于航空遥感器的研究中。     

光纤振动传感器在安防周界中的应用

介绍安防周界产品的发展过程，光纤振动传感器的工作原理、试验数据和工程实际应用情况，最后简要叙述了光纤振动传感器的市场前景。     

新型加速度传感器在倾角测量中的应用研究

详细介绍了新型三轴加速度传感器MMA7260Q的结构、工作原理及其功能.测试了此加速度传感器敏感轴随倾斜角度变化的输出特性,并利用其感受重力加速度在传感器三自由度上的大小,测量物体倾斜角的大小.推导了该传感器的计算公式,并介绍了MMA7260Q与MSP430单片机的接口电路.     

基于最小二乘原理的多传感器加权融合算法

以存在随机扰动环境中的不同参数多传感器为研究对象，基于最小二乘原理，提出了一种加权融合算法，推导出各传感器的权系数与测量方差的关系。并且根据测量信息，提出了一种方差估计学习算法，实现对各传感器测量方差的估计，从而对各传感器的权值进行合理的分配。该算法简单，能快速、准确的估计出待测物理量的状态信息。     

Conversion functions of a cluster single-coil eddy-current sensor

A set of conversion functions of a cluster single-coil eddy-current sensor as the sensor inductance dependences on the blade tip coordinate displacement is described. A simplified model of electromagnetic interaction between the sensitive elements and the object simulator, that is, a rectangular plate, is developed. The model ensures calculating the set of conversion functions in an analytical form. Results of calculating the set of conversion functions, which were obtained for the given geometrical parameters of the measurement object, sensor, and current directions of its sensitive elements, are illustrated.     

A self-sensing technology of active magnetic bearings using a phase modulation algorithm based on a high frequency voltage injection method

Conventional AMB(active magnetic bearings) systems consist of electromagnetic coils, position sensors, power amplifiers and a feedback controller. This hardware configuration can lead to a structural complexity, problems of space limitations for the installation, and position control difficulties due to the non-collocation of actuators and sensors. In this paper, a self-sensing mechanism is proposed to resolve such limitations of the general AMB system. The proposed self-sensing scheme uses a phase difference of the injected current of two opposite electromagnetic actuators while an object is levitating between the actuators. The relationship between the phase difference of injected currents and the position of a levitated object was theoretically derived and linearized. In order to realize the proposed self-sensing scheme, a signal processing algorithm was developed. The frequency response of the estimator was measured to verify the performance of the proposed self-sensing scheme. In addition, a magnetic levitation and a disturbance rejection response were experimentally obtained to verify the feasibility of the proposed self-sensing mechanism. Experimental results showed that the developed self-sensing technique has similar performance as a practical gap sensor.     

Development of an air servo displacement sensor

This paper introduces a new type of displacement sensor called an “air servo displacement sensor.” The sensor’s piston automatically follows a measured object using a pneumatic servomechanism with a nozzle-flapper that acts as a detecting device. Because the piston is supported by an aerostatic bearing, it experiences almost no friction. An optical linear scale mounted on the piston is used to measure the displacement of the measured object because the gap between the nozzle and the measured object is maintained at a constant level. As a result, this new sensor can successfully perform non-contact displacement measurements over a much longer measuring range, when compared to the traditional air micrometer. The optimal parameters for the sensor structure were obtained using simulations and experiments. Performance accuracy tests with a micrometer showed a repeatability error below ±0.5 μm and a linearity error below ±2 μm, with a measuring range beyond 10 mm. It has been verified that that the sensor exhibits a sufficient level of accuracy for the operational requirements.     

基于三轴加速度计的多维力传感器静态自校正

提出了一种多维力传感器的静态自校正方法.将三轴加速度计静态应用,可以测得其敏感轴与重力加速度的相对夹角.将多维力传感器中集成三轴加速度计,在校正过程中,旋转施加着标准砝码的多维力传感器,测量力传感器的输出,同时通过三轴加速度计测量力传感器的旋转角度姿态,计算得到砝码重力施加在传感器E的力向量,最终自动地得到多维力传感器的校止矩阵.实验结果表明,该方法显著地提高了校正效率,但与通常的标定台校正方法相比,较正精度略低.     

Development of a laser sensor for in-process guidance of an industrial robot

A pilot-type laser sensor for non-contacting distance measurement has been developed, which was aimed at application to in-process guidance of an industrial robot. A laser beam is emitted through a convex lens to an object and the reflected light is collected and focused by the lens. Diameter of its unfocused image is measured using one dimensional CCD-array, from which the distance is determined. Because the way of the beam emission and that of reflected light to the lens are the same, scanning of the beam to follow a path for robot guidance is easy and some geometric constraints, which may arise for a sensor using triangular principle, are removed. Geometric analyses for scanning the beam with a mirror are presented to determine the distance and position of an object point. A simple tracking control theory for the beam to follow a path and give informations about its position to a robot controller has been suggested and analyzed.     

水下大功率振源体结构及工艺设计

对水下大功率振源体结构的特殊性进行了简要的说明，对常用的耐压壳体材料进行了对比，着重介绍了采用Ti80合金材料时的主要加工工序、焊接工艺以及防止其焊接变形的措施。