六维力/力矩传感器研究发展综述

空间多维力/力矩传感器安装在空间机械臂的关节部位，随航天器一起发射进入太空，面临强振动、高冲击和大温差等复杂的恶劣环境,普通地面使用的多维力/力矩传感器要突破这些恶劣环境的限制方可使用。介绍了空间多维力/力矩传感器的研究发展现状，对空间多维力/力矩传感器在弹性体结构设计、过载保护、容错和温度补偿等方面的关键技术研究现状进行了详细阐述，并以此为基础对未来空间多维力/力矩传感器的研究方向提出了几点建议。     

空间多维力/力矩传感器关键技术研究综述

空间多维力/力矩传感器安装在空间机械臂的关节部位，随航天器一起发射进入太空，面临强振动、高冲击和大温差等复杂的恶劣环境,普通地面使用的多维力/力矩传感器要突破这些恶劣环境的限制方可使用。介绍了空间多维力/力矩传感器的研究发展现状，对空间多维力/力矩传感器在弹性体结构设计、过载保护、容错和温度补偿等方面的关键技术研究现状进行了详细阐述，并以此为基础对未来空间多维力/力矩传感器的研究方向提出了几点建议。     

基于激光多普勒测速法的2×106m/s2高冲击校准技术

在高冲击传感器动态性能校准中,实现高量程、宽脉冲激励是目前高冲击校准急需解决的问题。采用速度改变法校准原理,以气炮为激励源,利用激光多普勒测速方法测量砧体运动速度,建立高冲击校准系统。分析碰撞系统的作用原理,提出调整和控制激励脉宽的方法;分析测速误差,提出双光束差动侧向测速方法。实验结果表明:高冲击校准系统校准量程为2×106m/s2,激励脉宽在2×106m/s2时大于100μs,校准冲击灵敏度的扩展不确定度小于5%(k=2)。     

加速度传感器及其安装工艺对加速台车模拟试验测量结果的影响

为研究加速度传感器及其安装工艺对车辆加速台车模拟试验测量结果的影响,采用碰撞试验常用的压阻式和电容式加速度传感器对加速台车碰撞模拟试验进行了测试。在DIAdem和Matlab中计算了加速度传感器输出结果的偏差、相干函数、能量谱、冲击响应谱等参数,在时域和频域内分析了加速度传感器及其安装工艺对加速台车模拟试验测量结果的影响。     

水介质下的温度计响应时间仿真与试验研究

反应堆一回路冷却剂温度是核电站的重要监测参数,通常采用热电阻温度计进行测量。响应时间是热电阻温度计的关键技术指标。为获取准确的响应时间数值,对热电阻温度计水介质下响应时间仿真与试验进行了研究。基于反应堆一回路冷却剂的温度变化场景,通过控制变量方法对典型不同测量工况(温度、流速、压力)条件下的热电阻温度计响应时间开展仿真分析。通过仿真分析,研究了不同测量工况对传感器响应时间的影响和变化规律。采用实验室方法验证了热电阻温度计动态响应仿真计算结果的可靠性。该研究可以确保反应堆在发生较大温度瞬态变化时,热电阻温度计能快速、有效响应并及时实现停堆。     

一种新型工业机器人六维力传感器设计研究

采用理论分析和数值模拟方法研究新型结构传感器的可行性和力学特性.提出一种新型应变片式六维力传感器结构,运用电学理论阐述其测量原理,并借用数学方法分析其结构解耦特性.经合理简化,并对弹性球铰做等效处理,在Hyperworks中生成传感器各组构MNF,导入Adams/View后建立传感器仿真模型.分别在不同力和力矩工况下进行力学仿真,获得了传感器各部分的响应特性.理论分析和仿真结果表明:该结构测量方法合理可行,且力学性能较好.     

表面四电极含金属芯压电纤维的冲击振动传感特性研究

模仿昆虫毛发感受器的结构和功能,设计制备了一种能测量外部振动的表面四电极含金属芯压电纤维(FMPF)冲击振动传感器.采用干压成型法制备了含铂金芯的压电陶瓷纤维胚体,经过高温烧结、涂镀表面电极、高温极化后,制成FMPF传感器.基于压电方程和振动理论,建立了悬臂梁结构的FMPF冲击振动传感器的理论模型,分析了传感信号与冲击振动角度和幅值的关系.把FMPF固定在基体上,搭建了实验系统,测试了FMPF对冲击振动的响应,验证了理论模型.结果表明,FMPF的传感信号和冲击振动的幅值成线性关系,和方向成"8"字形关系.得出了FMPF传感器能够测量冲击振动幅值和方向的结论.     

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。     

海洋双光纤光栅压力传感器的温度响应特性

为满足海洋温深剖面连续拖曳测量的要求,测量海水深度的光纤布拉格光栅(FBG)压力传感器是利用FBG温补传感器来解决交叉敏感问题。由于二者对温度响应时间不一致,导致在中尺度旋涡、锋面等温度骤变海域测试海水压力时有所偏差。针对这一现象,设计出了一种新型的双光纤光栅压力传感器,通过在压力传感器的中心和边缘各封装温补和压力光纤光栅(边缘光栅不接触弹性膜片,仅受温度影响),使其对温度响应特性接近一致。实验测试结果表明:传感器的温补和压力光纤光栅对温度响应时间分别是1. 45 s和1. 52 s,响应一致性好。通过海试验证,FBG压力传感器与参考压力传感器ALEC—TD的相关系数高达0. 990 6,基本消除温度响应不一致导致的测量误差,能够达到准确测量压力的目的。     

S3C44B0X的柔性电子凸轮控制系统研究

电子凸轮在自动化产品中的应用日益广泛。重点分析了电子凸轮曲线在ARM微处理器中的设计及实现方法,提出了一种能够稳定输出方波脉冲,并且速度无零点、无跳变的算法结构,实现了枕式包装机中电子凸轮控制横封切刀的柔性变速旋转。本方案解决了传统机械凸轮安装困难、响应滞后、量测性差、成本较高等问题,采用色标传感器和编码器对包装长度和速度进行反馈,提高了包装精度,减少了系统的响应时间。     

AlGaN/GaN C-HEMT structures for dynamic stress detection

In our work, we investigated the possibility of dynamic stress detection based on the piezoelectric polarization using AlGaN/GaN circular high electron mobility transistors (C-HEMTs). In our knowledge, stress sensors in that account are introduced for the first time. The sensor structures exhibit good linearity in the piezoelectric response under dynamic stress conditions. The measurements reveal excellent stress detection sensitivity that is independent on the measured frequency range. The sensitivity of the devices can be easily increased by increase of the area of the Schottky gate ring electrode. The further increase of the sensitivity can be tuned by an optimal selection of the DC drain and gate bias.     

Micro-piezoelectric immunoassay chip for simultaneous detection of Hepatitis B virus and α-fetoprotein

In this paper, a piezoelectric diaphragm-based immunoassay chip was developed to simultaneously detect anti-Hepatitis B virus (HBV) and anti-alpha-fetoprotein (AFP). The chip was fabricated by micro-machining technology and consists of eight individual circular sensors with a diameter of 800 μm. Hepatitis B surface antigen (HBsAg), Hepatitis C core antigen (HBcAg) and AFP as the probe molecules were immobilized on different sensing spots on the chip. A solution containing anti-HBsAg and anti-AFP was applied into the reaction chambers in all sensors of the chip, and significant frequency shifts were only observed in the sensors with HBsAg and AFP for immunoassay detection. The fluorescence image further confirmed the successful detection of anti-HBsAg and anti-AFP. The total assay time was less than 2 h. The frequency shift-based calibration curves show a detection limit of 0.1 ng/ml and a dynamic detection range of 0.1-10,000 ng/ml for both anti-HBsAg and anti-AFP, respectively, thus demonstrating that the developed piezoelectric immunoassay chip has potential applications for rapid, specific, sensitive, and multiple detections of HBV.     

矩形压电片对Lamb波传感的方向性研究

矩形压电片被广泛用作超声Lamb波的传感器与驱动器。理论推导了矩形压电片对Lamb波（A₀模式）的传感灵敏度系数的函数表达式,同时对推导结果进行了实验验证。研究结果表明矩形压电片对Lamb波的传感具有很强的方向性。当Lamb波传播方向沿着矩形压电片长度方向时,矩形压电片传感响应电压最大。随着Lamb波入射角度的增大,响应电压幅值越来越小,当入射方向与矩形压电片长度方向垂直时,响应幅值达到最小。     

可用于多种压电传感器动态特性补偿方法的研究

提出了一种扩展压电传感器频率响应范围的动态特性补偿方法,其基本原理是用CCD器件构造出一个FIR滤波器的硬件补偿网络.只要对CCD器件的时钟频率加以变化,就可以补偿多种压电传感器的动态特性,扩展压电传感器的工作频带.仿真的结果表明应用这种动态补偿的方法可以显著地提高传感器的动态特性,有效改善传感器的动态品质.     

压电传感器测量路面动水压力研究

雨天动水压力的存在,不仅造成沥青路面易于出现水损害,加快路面使用性能衰减,而且影响到汽车行驶安全,准确测量动水压力数值的大小是研究其危害的有效途径。介绍压电传感器的基本原理。基于压电传感系统能够保证对结构动态压电数据的连续采集,通过自制的压电传感器和设计的标定与实验方案来分析实时采集的动态压电数据。研究结果表明:动水压力数值随着车速的增大而增加,车速为96 km/h时,动水压力达到0.35 MPa,压电传感器在测量动水压力中的应用将有助于解决或减轻沥青路面的水损害。     

The origin of low-order and high-order impedance-coupled resonant modes in piezoelectric-excited millimeter-sized cantilever (PEMC) sensors: Experiments and finite element models

The characteristics of both low-order and high-order resonant modes exhibited by piezoelectric-excited millimeter-sized cantilever (PEMC) sensors were investigated to determine the coupling between electrical impedance and resonant modes observed experimentally. Experimentally measured frequency response spectra correlated well (<5% difference; n = 10 sensors) with three-dimensional (3D) finite element model (FEM) calculations. FEM frequency response and eigen frequency analyses revealed the sensor's resonant modes were complex, and characterized by combinations of transverse, torsional, longitudinal, buckling, and lateral motion. The magnitude of average integrated charge and current density change in the piezoelectric (lead zirconate titanate; PZT) layer at resonance directly correlated with coupling of resonant modes to electrical impedance measurement. Of the 32 resonant modes predicted by eigen frequency analysis in the frequency range 0-1 MHz, only a subset of 17 modes produced charge and current density changes in the PZT layer greater than off-resonance values. Thus, only the subset of resonant modes was coupled to electrical impedance changes and could be exploited for sensing. Transverse, longitudinal, and lateral motion of the piezoelectric layer coupled strongly with the PZT electrical impedance, while torsional and buckling motion did not. Electrically decoupled resonant modes were made measurable by introducing minor geometric asymmetry in composite layer alignment. High-order modes were shown experimentally to exhibit sub-femtogram sensitivity to mass-changes in air. Such modes consisted of combinations of transverse and longitudinal modes in both sensor layers.     

Impact of ZnO gate interfacial layer on piezoelectric response of AlGaN/GaN C-HEMT based ring gate capacitor

We report on a piezoelectric response investigation of AlGaN/GaN circular high electron mobility transistor (C-HEMT) based ring gate capacitor as a new stress sensor device to be potentially applied for dynamic high-pressure sensing. A ring gate capacitor of C-HEMT with an additional ZnO gate interfacial layer was used to measure the changes in the piezoelectric charge induced directly by the variation of piezoelectric polarization of both gate piezoelectric layers (AlGaN, ZnO) for harmonic loading at different excitation frequences. Our experimental results show that about 10 nm thick piezoelectric ZnO layer grown on ring gate/AlGaN interface of C-HEMT can yield almost a 60% increase in the piezoelectric detection sensitivity of the device due to its higher piezoelectric coefficient. A three-dimensional CoventorWare simulation is carried out to confirm the increase in the measured piezoelectric response of ZnO based ring gate capacitor of C-HEMT.     

基于遗传算法的传感器动态特性改善方法

在动态测试中一些传感器的动态特性不能满足测试需求。为了改善传感器的动态特性提出了一种改进自回归模型,采用梯度下降法和遗传算法对其参数进行优化,通过对传感器进行逆建模来实现对传感器动态特性的改善。对腕力传感器的动态特性进行了改善并分析了传感器改善前后的时域和频域特性。在matlab平台对6阶系统的动态特性进行了改善。实验结果表明对CY-YD-205压电传感器动态特性的改善效果要比最小二乘法好。     

柔性压电传感器的设计

对柔性压电传感器的原理及灵敏度计算进行理论分析,对柔性压电传感器的结构进行设计并且对柔性压电传感器的性能进行测试.对柔性压电传感器的粘贴工艺进行了研究,初步得到柔性压电传感器的性能指标,为其以后在飞行试验中的应用奠定基础.     

Smart ultrasonic sensors systems: potential of aluminum nitride thin films for the excitation of the ultrasound at high frequencies

We investigated the potential of the aluminum nitride films to excite ultrasonic waves at frequencies >50?MHz. The deposition process of the aluminum nitride thin film layers on silicon substrates was investigated and optimized regarding their piezoelectric behavior. Large single element transducers were deposited on silicon substrates with aluminum electrodes, under different parameters for the magnetron sputter process, like pressure and bias voltage. Special test setup and a measuring station were created to characterize the sensors. Acoustical measurements were carried out in pulse echo mode up to 500?MHz and the values of piezoelectric charge constant (d₃₃) were determined. As a result, two parameter sets were found for the sputtering process to obtain an excellent piezoelectric charge constant of about 7.2?pC/N maximum. Then the sputtering process with these parameters was used to deposit sensors on various substrate materials and with different electrode sizes.