飞机强度试验中结构健康监测采集控制系统

针对结构健康监测在全机疲劳试验中需要采用多种监测系统的特点,结合飞机强度疲劳试验对数据采集的要求,设计了一种将光栅光纤传感器、压电传感器和声发射传感器等集成为一体的飞机结构健康监测系统.设计了多类型传感器采集控制系统,其中采用了分布式、多任务的结构设计,解决了多台设备采集数据的同步性、有效性和一致性.针对多类传感器的数据源多、数据类型多的特点,设计了通用数据结构解决了多类传感器的数据合并处理问题.通过在某全机疲劳试验中的运用,验证了本系统是一种稳定、高效、易扩展的多传感器健康监测集成系统,能够获取更加可靠、全面的健康监测数据,为健康监测在全机疲劳试验中损伤的准确识别,提供了强有力的支撑.     

Design and development of microstrip patch antenna with circular and rectangular slot for structural health monitoring

Structural health monitoring (SHM) is the technique to identify the damage in the building or physical structures. Several structural health monitoring has been proposed in recent years. Increase in number of sensors and its wiring mechanism causes issue in signal processing demand, efficiency, and unreliability. In current state, already present sensors cannot be used for Structural Health Monitoring because of its high cost and low battery capacity, although none of these techniques are capable of monitoring the condition of complex physical structures. The measurement of strain can be done by using patch antenna as strain sensors. In currently available sensors only the wireless range. The main objective of this paper is to investigate the feasibility of using circular and rectangular slotted microstrip patch antenna as a strain sensor for structural health monitoring without these afore mentioned problems. These antenna sensors’ (slotted rectangular and circular microstrip patch antennas) simulation results are confirmed. From the simulation results, the sensor provides information about crack orientation.     

Monitoring civil structures with a wireless sensor network

Structural health monitoring (SHM) is an active area of research devoted to systems that can autonomously and proactively assess the structural integrity of bridges, buildings, and aerospace vehicles. Recent technological advances promise the eventual ability to cover a large civil structure with low-cost wireless sensors that can continuously monitor a building's structural health, but researchers face several obstacles to reaching this goal, including high data-rate, data-fidelity, and time-synchronization requirements. This article describes two systems the authors recently deployed in real-world structures.     

基于无线网络的医疗健康监测系统探究

针对人口老龄化的特点以及各个公共医疗服务系统间的用户医疗信息不流通的局限性,提出一种新型医疗健康监测系统,可对用户的身体状况进行全面监测。通过使用含多种传感器的嵌入式医疗诊断设备监测收集医学数据,并利用多用式无线网络将这些实测数据发送到相应的健康监测中心,与用户的永久性电子病历相融合,由该中心的医疗专家对两组数据进行分析诊断,采取必要的措施来协调配合家庭医疗服务中心和区域医疗服务部门,以最佳最安全的方式迅速应对各种医疗状况。     

基于压电晶体传感器的椭圆损伤定位算法

压电晶体传感器作为激励部件可以在结构中产生高频弹性应力波,其同裂纹等局部损伤发生相互作用将产生波动的能量耗散、波形反射以及波形干涉等现象.利用附在金属板上的压电激励器在结构产生的高频弹性应力波,并通过嵌入或附着在结构中的压电传感器进行接收,提出了一种基于TDOA模型的椭圆损伤定位算法.利用该算法可以获得损伤部位坐标的显式表达式,并能够对损伤区域的大小做出估计.仿真计算结果和实验证明该算法能够提供实时的"主动"损伤检测手段,同时可以准确快速地对结构中可能存在的损伤进行定位.     

地震模型宽带窄脉冲传感器

本文叙述了新型地震模型实验传感器的原理,介绍了两类新型压电材料(PVDF及3—3连结复合压电陶瓷),并由它们制备成两种新颖宽带、窄脉冲、无源及可逆式传感器。这些传感器首次成功地应用于150kHz至1MHz频段的地震模型实验。实验结果表明:它能区分水中6mm厚铝板,还能清晰分辨复杂多层地震模型体。 本文可供研制高分辨率的水声、医学及无损检测等传感器时参考。     

Tracking the harmonic response of magnetically-soft sensors for wireless temperature,stress, and corrosive monitoring

This paper describes the application of magnetically-soft ribbon-like sensors for measurement of temperature and stress, as well as corrosive monitoring, based upon changes in the amplitudes of the higher-order harmonics generated by the sensors in response to a magnetic interrogation signal. The sensors operate independently of mass loading, and so can be placed or rigidly embedded inside nonmetallic, opaque structures such as concrete or plastic. The passive harmonic-based sensor is remotely monitored through a single coplanar interrogation and detection coil. Effects due to the relative location of the sensor are eliminated by tracking harmonic amplitude ratios, thereby, enabling wide area monitoring. The wireless, passive, mass loading independent nature of the described sensor platform makes it ideally suited for long-term structural monitoring applications, such as measurement of temperature and stress inside concrete structures. A theoretical model is presented to explain the origin and behavior of the higher-order harmonics in response to temperature and stress.     

Architecture, cost-model and customization of real-time monitoring systems based on mobile biological sensor data-streams

Innovation in the fields of wireless data communications, mobile devices and biosensor technology enables the development of new types of monitoring systems that provide people with assistance anywhere and at any time. In this paper we present an architecture useful to build those kind of systems that monitor data streams generated by biological sensors attached to mobile users. We pay special attention to three aspects related to the system efficiency: selection of the optimal granularity, that is, the selection of the size of the input data stream package that has to be acquired in order to start a new processing cycle; the possible use of compression techniques to store and send the acquired input data stream and; finally, the performance of a local analysis versus a remote one. Moreover, we introduce two particular real systems to illustrate the suitability and applicability of our proposal: an anywhere and at any time monitoring system of heart arrhythmias and an apnea monitoring system.     

PVDF压电薄膜在结构监测中的应用初探

本研究对采秀ＰＶＤＦ压电薄膜监测结构的基本特性进行了较为系统的研究，分别做了ＰＶＤＦ压电薄膜监测结构的静态和动态响应实验，实验结果表明，ＰＶＤＦ压电薄膜监测结构应变的灵敏度提高，其静态响应的线性度好很好，而其动态响应同则有非线性和迟滞现象，对于用ＰＶＤＦ压电薄膜监测结构的冲击载荷也进行了初步的研究，实验结果表明采用ＰＶＤＦ压电薄膜可以实时监测结构所受的冲击载荷，并能及时反应出结构所受到的冲击损伤。     

压电晶体传感器激励模型及其在结构健康监测中的应用

在结构健康监测系统中,基于应力波的结构损伤诊断技术是一种主动的局部损伤检测方法.压电晶体传感器作为激励部件可以在结构中引入高频应力波;其同裂纹等局部损伤发生相互作用将产生波动的能量耗散、波形反射以及波形干涉等现象.通过对附着在无约束金属板上的压电晶体传感器(PZT)激励模型的理论分析及有限元数值计算,说明PZT能有效地产生检测应力波,并可将其应用在结构局部损伤检测中.     

压电传感技术的研究及应用

介绍了压电传感器的分类和测量原理,综述了国内外压电传感技术在航空航天、土木、机械、交通、医学等领域健康监测方面的主要应用实例。介绍了基于压电传感测试技术的桥梁振动监测研究,最后讨论了压电传感器在进一步实用化过程中面临的困难和需要解决的问题,并对其应用前景做了展望。     

一种基于新型传感器的便携式睡眠呼吸暂停监测仪

介绍了一种基于胸腹运动检测法,应用压电薄膜式传感器设计的新型便携式睡眠呼吸暂停监测仪,为睡眠呼吸暂停的普及检测提供了一种简易手段。     

Next generation structural health monitoring and its integration into aircraft design

Structural health monitoring (SHM) has become increasingly important with regard to ageing aircraft, required enhanced performance and the need to reduce aircraft operational cost. Affordable advanced miniaturized sensors and continuous improvement in data processing technology combined with powerful software algorithms has allowed non-destructive testing (NDT) to become an integral part of structural materials and has thus given structures a self-sensing functionality. This paper describes where to integrate SHM into the aircraft design process and how to validate the established loads monitoring process in comparison to an emerging damage monitoring solution, before more precisely describing a technology selection regarding damage monitoring. Acousto-ultrasonics is a technique being especially emphasized. Results from laboratory experiments will be shown and commented and a perspective of future trends will be given.     

基于改进栈式自编码器的风电机组发电机健康评估

风电机组发电机具有结构复杂、维修困难的特点,为对其进行健康评估,结合去噪自编码器与稀疏自编码器的特点,对传统栈式自编码器模型进行改进,利用模型的重构误差监测风电机组发电机的运行状态。将经离线测试得到的重构误差与在线监测得到的重构误差进行分布差异性比对,通过融合3种差异指标得到风电机组发电机的健康度。利用河北某风场实际数据对健康评估模型进行训练测试,通过实例分析证明该模型能够有效跟踪风电机组发电机的状态变化,具有故障早期识别的作用。     

Recent Advances on Vibration Control of Structures Under Dynamic Loading

In this paper, a review of recent journal articles on passive, active, semi-active, and hybrid vibration control of structures subjected to dynamic loading is presented. Passive systems reviewed include tuned mass damper (TMD), tuned liquid column damper (TLCD), tuned liquid column ball damper (TLCBD), circular TLCD (CTLCD), and pendulum TLCD (PTLCD). Active control systems include active tuned mass dampers (ATMD) and piezoelectric actuators. Semi-active systems include magnetorheological (MR) damper, negative stiffness devices (NSD), magneto-rheological damper TMD (MR-TMD), variable stiffness semi-active TMD (VS-STMD), variable damper STMD (VD-STMD), and recentering variable friction device (RVFD). Hybrid systems include active base isolation system and semi-active MR dampers with nonlinear base isolators. The current frontier of research is semi-active control of structures as well hybridization of various control systems. The problem is complex requiring integration of several different hardware and software technologies with structural design such as smart materials, adaptive dampers, actuators, sensors, and control and signal processing algorithms. This complexity also makes it an exciting area of research and development.     

基于以太网的风电场监控系统的研究与设计

针对风电场机组之间物理距离远、维护难度大等特点,设计了以ARM7和以太网控制芯片ENC28J60为平台,具有TCP/IP通信功能的风电场状态监控方案。给出了以太网接口的设计电路、网络协议栈的实现方法和程序总流程图,并进行测试实验,实现了远程PC对传感器数据的实时监测。实验结果表明,该系统能使用户方便的监控风电场的运行状态,从而有效地保护机组,避免设备过多的损坏。     

A fast BEM for the analysis of damaged structures with bonded piezoelectric sensors

A fast boundary element method for the analysis of three-dimensional solids with cracks and adhesively bonded piezoelectric patches, used as strain sensors, is presented. The piezoelectric sensors, as well as the adhesive layer, are modeled using a 3D state-space finite element approach. The piezoelectric patch model is formulated taking into account the full electro-mechanical coupling and embodying the suitable boundary conditions and it is eventually expressed in terms of the interface variables, to allow a straightforward coupling with the underlying host structure, which is modeled through a 3D dual boundary element method, for accurate analysis of cracks. The technique is computationally enhanced, in terms of memory storage and solution time, using the hierarchical format in conjunction with a GMRES solver. An original strategy retaining the advantages of the fast hierarchical solution without increasing the implementation complexity to take into account the piezoelectric patches is proposed for the solution of the final system. The presented work is a step towards modeling of structural health monitoring systems.     

Design, simulation and fabrication of piezoelectric micro generators for aero acoustic applications

Energy harvesters based on acoustic vibration sources can generate electrical power through piezoelectric transduction. Significant miniaturization of electro mechanical devices using MEMS fabrication technology has encouraged the creation of portable, miniature energy harvesters. A niche application is aero acoustics, where wasted, high dB and high frequency sound generated by aircrafts are transformed into useful energy. Having self-powered, miniature acoustic sensors allows noise detection monitoring systems to be self-sustaining. This paper illustrates an Aluminium doped Zinc Oxide (AZO) cantilever beam on stainless steel substrate with a top copper electrode. Design and finite element modelling of the design was conducted using Coventorware™. The AZO piezoelectric thin film was RF-sputtered on the stainless steel substrate. Characterizations were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) to evaluate the piezoelectric qualities and surface morphology, respectively. Experimental measurements indicate approximately 345.4 mV AC output voltage (open circuit voltage) is produced at vibration frequencies of 30 kHz. This is in accordance with the Coventorware™ simulation results. This measured power level is sufficient to power a miniature wireless acoustic sensor nodes to monitor noise generated by aircrafts.     

带谐振腔的微型压电风能采集器

为了提高基于风致振动机理的微型风能采集器在低速风作用下的输出功率,提出一种带谐振腔的微型压电风能采集器结构,该采集器由谐振腔和振动梁构成,振动梁由压电梁和柔性梁组成。谐振腔可以改变振动梁附近的流场分布,扩大作用于振动梁的动风载荷,从而提高了采集器在低速风作用下的输出功率。实验分析了风速、压电梁长度和柔性梁长度对采集器输出性能的影响。当谐振腔尺寸为64 mm×22 mm×14 mm,振动梁长度和宽度分别为38 mm和6.4 mm时,微型风能采集器在17 m/s风载荷作用下的最大输出功率达到1.28 mW。     

基于复杂参数的组态化显示监控系统

随着我国航天飞行器发射频率的不断提高,以及各类预先研究型号的增多,对飞行器的测试效率提出了更高的要求。传统测发控软件由于型号需求差异,人员安排等问题,软件的设计与实现手段不同,一套软件通常只能针对一个型号,需求一旦变更,需要花费大量的人力财力开发与维护软件,同时也对保障软件的可靠性带来难度。为克服现有技术的不足,对组态化设计进行研究,采用了通用化接口设计及显示终端界面加载与数据显示方法关键技术,提出了一种基于复杂参数组态化显控系统,达到一套软件应用于多个型号的通用化目标,极大降低了控件灵活扩展与集成的难度,实现飞行器复杂参数测试数据的实时监控与软件的复用,大大提高了开发效率。