小型三维力传感器的设计和解耦测试研究

研制了一种小型电阻应变式3维力传感器,采用一种新型弹性体结构,其自上而下开有多层槽孔,4个电阻应变片贴于弹性体侧面,用于检测空间3维力。采用弹性体的位移变化量转化成应变片的应变量,运用有限元仿真分析力作用与应变关系,判定了具有该弹性体结构的传感器力解耦性能。针对实际3维力传感器进行静态标定和解耦计算,得到3维力解耦矩阵。3维力实验测试表明,所研制的传感器具有较高的精度,较好地消除了3维间的耦合性,能够满足小量程微小型机器人力反馈控制需求。     

应变测试系统分流校准方法设计

为了减小大型应变测试系统中长导线电阻带来的系统误差,提高多种试验切换效率,使系统在测试过程中具有更精确、更高效的特性,提出了一种结合分流校准电路和长导线电阻补偿算法的策略,根据应变片配桥方式和粘贴形态的不同,计算出实际的长导线电阻阻值与应变片静态阻值,采用计算值进行应变补偿取代了传统各种试验前必须使用高精密校准仪器对整个系统进行校准.理论分析及实验结果表明,这种策略能够准确计算出长导线电阻阻值和应变片静态阻值,采用计算值应变补偿效果达到满量程的0.09％以上,满足高精度需求,同时大幅度减小了传统试验前期的校准工作量,增大了试验范围,有效改善了系统测量精度和试验效率.     

机械手三维力传感器的设计

介绍了一种安装在医疗机械手腕部的三维力传感器,该传感器采用电阻应变式电桥的测量方法,其弹性体为两个扁环式结构,在两个扁环的相应敏感部位分别粘贴三组应变计,解决了三维传感器体积大、刚度低等问题;其具有量程大、体积小、精度高、横向干扰小等特点,在实际应用中收到了良好的效果.     

一种用于微型六维力传感器的集成式应变计设计

为实现六维力传感器的微型化与集成化,提出了一种新型的集成式应变计．该应变计由6组敏感栅组成,可与薄壁圆筒型弹性体组成微型六维力传感器．文中介绍了信号调理电路和数字化电路的组成．采用微型数字信号处理器和刚柔结合的电路板实现了传感器的电路集成．对传感器进行了静动态标定并分析了实验结果．     

高灵敏度三维力矩传感器设计与标定

为测量三维力矩并解决维间耦合问题,设计了一种测量微小力矩的电阻应变式传感器。分析了传感器电阻应变计组桥方案抑制维间力矩耦合的原理。通过有限元方法仿真计算出节点应变,实现传感器高灵敏度的目标。通过传感器静态标定实验得到了标定解耦矩阵,解决了由于加工误差和应变计粘贴误差带来的力矩耦合问题。实验表明:此传感器具有好的静态性能,线性度都控制在1%之内,迟滞误差也控制在0.12%以下。     

NiCrAlY薄膜应变计的研制

采用射频磁控溅射法在Ni基高温合金拉伸件上制备NiCrAlY薄膜应变计。研究了热稳定处理对NiCrAlY薄膜结构、表面形貌的影响,并且测试了NiCrAlY薄膜应变计的电学与应变性能。结果表明：热稳定处理后 NiCrAlY 薄膜应变计由于在表面形成了一层 Al2 O3膜,具有抗高温氧化的特性,在室温～800℃范围内,应变计电阻同温度呈线性变化,电阻温度系数（ TCR）约为290×10－6/℃,室温下的应变计系数（ GF）为2.1。     

中国微米纳米-PdCr薄膜电阻应变计研制及其高温应变敏感性能研究

在航空航天以及核电领域中,准确测量高温部件的应变、疲劳等结构参数十分重要,对满足高温应用环境的高温应变计需求非常迫切.在镍基合金基底上研制了PdCr薄膜电阻应变计,依次在基片上沉积NiCrAlY作为过渡层来增强附着性,沉积YSZ/Al2O3作为复合绝缘层满足绝缘性需求,溅射PdCr合金作为应变敏感层,并采用金属掩模对PdCr敏感层进行图形化,最后沉积Al2O3薄膜层作为高温保护层,并对PdCr薄膜应变计的应变敏感系数(GF)以及高温环境下的表观应变、漂移应变等性能进行了表征.结果表明,不同温度下PdCr薄膜应变计的电阻值随应变呈良好的线性关系;在常温下,其应变敏感系数为1.40;在800 ℃时,应变计的表观应变系数127 με/℃.应变计的电阻值随时间线性减小,导致的漂移应变约为1 800 με/hr,应变敏感系数为1.41.同时,对制备的PdCr薄膜应变计进行了可靠性评估和寿命评估.结果表明,其重复性测量误差约为5.71%,工作寿命超过10 h.     

Fabrication of ultra-high-sensitivity flexible strain sensor based on single ZnO nanowire

An ultra-high-sensitivity strain sensor based on a single ZnO nanowire (NW) was developed by nanowelding the NW onto a flexible substrate using a custom-built nano-manipulation system inside a scanning electron microscope (SEM). Onto the two ends of the NW were sputtered Au electrodes, to which conducting wires that connect to a multi-meter were glued. A thin methyl methacrylate polymer layer was used to insulate the strain sensor. The strain gauge was evaluated by attaching the sensor to a cantilever beam ex situ of the SEM, providing flexibility for repeated measurements. An applied force to the cantilever synchronously deformed and altered the NW resistance. The resistance variation of the strain gauge against the known strain on the cantilever showed that a gauge factor that is 200 times higher than that of a commercial strain sensor is feasible for the proposed device. The developed strain sensor is applicable for ultra-small mechanical strain on the order of 10⁻⁶.

     

基于八角环二维力传感器抓取力控制研究

设计了一种小型八角环二维力传感器,利用ANSYS仿真软件对传感器进行了有限元和应变节点分析,通过传感器静态标定实验得到了标定解耦矩阵,解决了由于加工误差和应变计粘贴误差带来的力矩耦合问题.设计了二指平行手爪,搭建了基于力外环控制的夹持器系统.运用手爪测量了不同材料之间的最大静摩擦系数.实际的抓取实验验证了基于力比例控制的稳定抓取具有良好效果.     

软测量技术在泵车臂架结构健康监测中的应用

利用混凝土泵车臂架应变信号计算其疲劳累积损伤的健康监测方案,由于应变片的使用寿命较短且不可靠,通过应变片直接测量泵车臂架应变信号不能适用于泵车臂架结构长期健康监测。采用软测量技术,基于最小二乘支持向量机（LS-SVM）建立软测量模型来间接获得泵车臂架应变信号。分析泵车臂架应变信号的特点,进而选择辅助变量。为了提高模型精度,对应变信号进行解耦,分别建立静态应变和动态应变的软测量模型进而得出总应变,利用遗传算法对模型参数进行了优化,与总体建模结果进行了比较。仿真分析结果表明,软测量技术为泵车臂架结构健康监测的工程实现提供了一种可行的方法,并且分别建立静态应变和动态应变的软测量模型比总体建模精度更高。     

高压传感器在高静压下的动态校准方法

提出了一种校准高压传感器频响特性的方法,动态校准系统主要由甘油油腔、霍普金森杆、气枪、应变片、电荷放大器、活塞式压力计和数据采集系统等组成.校准时先利用活塞式压力计在封闭式油腔中产生高静压,高静压作用于被校准的压力传感器.气枪发射子弹,子弹撞击霍普金森杆产生近似于冲激函数的窄脉冲应力波,应力波通过甘油传播并激励传感器,...     

A novel six-component force sensor of good measurement isotropy and sensitivities

In this work, a novel six-component force sensor with its force-sensing member in the form of four identical T-shaped bars is presented. The force-sensing member is subjected to finite element analysis in conjunction with a design optimization for high measurement sensitivities. Although significant measurement couplings exist in this six-component force sensor, however, they distribute only in a few sparse places in the calibration matrix, making the calculations for the force components relatively easy and quick. The condition number under the full rated loading conditions for this sensor is 1.543, which represents a rather good measurement isotropy, as compared to approximately 2–4 for a Maltese crossbar sensor under similar conditions. In addition, only 20 strain gauges are required in the design, which is less than that used in a Maltese crossbar type sensor, in which at least 24 strain gauges are used.     

表面粘贴式光纤光栅传感器的应变传递机理分析与实验研究

金属基底封装的光纤光栅应变传感器具有线性度高、重复性好、易标定等特点,在应用中由于光纤与基体不直接接触,测量的精度取决于粘结胶的特性.在分析FBG应变感知机理的基础上,基于力学仿真设计了金属基底结构,并建立了包含光纤光栅-壳体-粘胶层-基体的四层应变传递仿真模型,制作并利用悬臂梁进行了应变测试,取得了良好的实验结果且与仿真计算误差在0.5%以内.     

Interdigital capacitive strain gauges fabricated by direct-write thermal spray and ultrafast laser micromachining

There is a growing demand for in situ monitoring of strain in high-temperature, harsh environment systems. Resistive strain gauges, while popular and easy to implement, have several disadvantages when used at high-temperatures. This work presents the design, fabrication, and initial testing of capacitive strain gauges for use in high-temperature, harsh environments. The gauges are fabricated using a direct-write thermal spray technology in which a computer-controlled deposition system is used to fabricate silver gauge patterns onto polymer, composite, and alumina substrates to form the strain gauges. Gauges were also fabricated using ultrafast laser micromachining of blanket NiCr coatings thermal sprayed onto an alumina substrate. The typical gauge capacitance was 4–25 pF. Mechanical measurements performed included gauge factor, linearity, and zero shift. Temperature-based measurements include the temperature coefficient of capacitance (TCC) and thermal cycling tests. The devices show promise for use in harsh environments and in wireless strain monitoring applications.     

Piezo-tunneling strain sensors integrated on plastic by combining vacuum thin film coatings and 3D printing technologies

There is a growing demand for the integration of sensor functions on flexible substrates for wearable electronics, robotics or medical monitoring. For this, it is necessary to develop strain gauges both sensitive and integrable at low cost with a low thermal budget. The gauge factor of metal/insulator/metal piezo-tunneling strain sensors is first measured as a function of applied current and polarity, for different electrode materials (Al, Pt or Pd) and insulator (Al₂O₃) thicknesses. A maximum gauge factor of 90 is obtained with an Al/Al₂O₃ (10 nm)/Al junction and top electrode injection. Results are discussed based on the Fowler–Nordheim model and it is shown that the electron effective mass in Al₂O₃ most likely plays a major role in the observed mechano-sensitivity. Next, the feasibility of a low-pressure sensor demonstrator based on a 3D-printing process on a polymer substrate is shown with a sensitivity of 0.19 bar⁻¹ in the 0–450 mbar range.

     

钢领-钢丝圈摩擦力测试

一种新型的测试钢领钢丝圈摩擦力装置,该装置利用传感器原理,将钢领钢丝圈之间的摩擦力转化为悬臂梁的应变,粘贴在悬臂梁上的4个应变片相应产生变形,这四个应变片组成的电桥的输出电压就会发生变化,再将电压的变化量经过放大显示在动态应变仪上,最后对动态应变仪进行标定.在实验过程中,根据动态应变仪的读数,就可以得出即时的钢领钢丝圈摩擦力.从测试结果可以看出,该测试装置的精度可达0.5 g.     

Automated Bayesian quality control of streaming rain gauge data

Radar-rainfall data are being used in an increasing number of real-time applications because of their wide spatial and temporal coverage. Because of uncertainties in radar measurements and the relationship between radar measurements and rainfall on the ground, radar-rainfall data are often combined with rain gauge data to improve their accuracy. However, while rain gauges can provide accurate estimates of rainfall, their data are sometimes corrupted with errors caused by the environment in which the gauges are deployed. This study develops a real-time method for identifying measurement errors in rain gauge data streams. This method employs a dynamic Bayesian network (DBN) model of the rain gauge data stream to sequentially forecast the next rain gauge measurement from both the rain gauge and weather radar data streams and a decision rule-based classifier to identify data errors. Because of the uncertainty in the relationship between the radar and rainfall measurements, this method uses a statistical learning method (expectation maximization) to determine the best parameters for this relationship, given an adaptively sized moving window of previous measurements. The performance of the error detector developed in this study is demonstrated using a precipitation sensor network composed of five telemetered tipping bucket rain gauges and a WSR-88D weather radar. Through an analysis using synthetic errors, the false alarm rate and false negative rate were calculated to be 0.90% and 1.5%, respectively.     

非接触式水位计校准装置的研制与应用

为解决我国水利行业大量使用的超声波、雷达式等非接触式水位计的测量准确度问题,研制开发出一种非接触式水位计实验室校准装置。通过分析非接触式水位计的测量误差源,介绍非接触式水位计校准装置数据采集与控制、数据测量、升降、人机界面等子系统的设计,并对装置的计量误差进行测试分析,对实现的功能进行阐述。经过应用测试,验证该装置校准精度在1 mm以内,适应波束角15°,能很好地满足非接触式水位计的实验室校准工作,为行业内大量应用的非接触式水位计的校准提供新的手段,为水位测量仪器的数据准确性提供技术保障。     

Detection and prevention of slip using sensors with different properties embedded in elastic artificial skin on the basis of previous experience

In dexterous robotic manipulation, it is essential to control the force exerted by the robot hands while grasping. This paper describes a method by which robot hands can be controlled on the basis of previous experience of slippage of objects held by the hand. We developed an anthropomorphic human scale robot hand equipped with an elastic skin in which two types of sensor are randomly embedded. One of these sensors is a piezoelectric polyvinylidenefluoride (PVDF) film which can be used for the detection of pressure changes. The other is a strain gauge which can measure static pressure. In our system, PVDF films are used to detect slipping, and strain gauges to measure stresses which are caused by normal and shear forces. The stress measured by the strain gauges is used as input data to a neural network which controls the actuators of the robot. Once slip is detected, the neural network is updated to prevent it. We show that this system can control the grasp force of the robot hand and adapt it to the weight of the object. By using this method, it was shown that robots can hold objects safely.     

一种新型石油管道压力传感器的设计

提出一种新型带有无线数据传输功能的石油管道压力传感器。传感器采用十字梁结构设计,应变计全桥输出信号随管道内压力改变而变化。传感器通过无线传输的方式将监测数据传输到监测中心,对管道压力进行实时监测。通过应变计性能测试和系统标定,表明该传感器具有较好的灵敏度和线性度。