An intraoperative lumbar neurological force monitoring system with high-density flexible pressure sensor array

In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order to improve the nerve root retractor,this paper proposes an intraoperative lumbar neurological force monitoring system.The core module of this system is the improved nerve root retractor equipped with the high density flexible pressure sensor array.The high density microneedle array and multiple pressure detection units are used in the pressure sensor to realise sensitive pressure monitoring in a narrow surgical operation area.The sensing area is 4 mm×17 mm,including 6 detection units.The sensitivity of sensor is 67.30%/N in the range of 0-5 N.This system is used for in vitro animal experiments,which can continuously detect pressure.

Extraction of cable forces due to dead load in cable-stayed bridges under random vehicle loads

To extract the cable forces due to dead load in cable-stayed bridges from the monitoring data,the effects of various factors are eliminated step by step by different statistical methods.The information of cable tension sensors recorded by the health monitoring system of Nanjing No.3 Yangtze River Bridge is taken as an example. Temperature effects are eliminated by linear fitting analysis;a 5-level wavelet de-noising method is applied to eliminate the noise signal by the wavelet basis function of DB8.The rest cable force data is tested by the method of extreme-value type-Ⅲ distribution, and the fitted location parameter is selected as the cable force due to dead load.The results show that the cable force has a linear relationship with temperature. Sometimes, the temperature effect is significant.Noise effect accounts for a small percentage,and the vehicle loads effect has twice the temperature effect on the traffic volume in 2007. The calculation results of other stay cables verify the reliability and validity of the proposed method.

AN INTELLIGENT TOOL CONDITION MONITORING SYSTEM USING FUZZY NEURAL NETWORKS

Reliable on line cutting tool conditioning monitoring is an essential feature of automatic machine tool and flexible manufacturing system (FMS) and computer integrated manufacturing system (CIMS). Recently artificial neural networks (ANNs) are used for this purpose in conjunction with suitable sensory systems. The present work in Norwegian University of Science and Technology (NTNU) uses back propagation neural networks (BP) and fuzzy neural networks (FNN) to process the cutting tool state data measured with force and acoustic emission (AE) sensors, and implements a valuable on line tool condition monitoring system using the ANNs. Different ANN structures are designed and investigated to estimate the tool wear state based on the fusion of acoustic emission and force signals. Finally, four case studies are introduced for the sensing and ANN processing of the tool wear states and the failures of the tool with practical experiment examples. The results indicate that a tool wear identification system can be achieved using the sensors integration with ANNs, and that ANNs provide a very effective method of implementing sensor integration for on line monitoring of tool wear states and abnormalities.

Application of remote monitoring technology in landslides in the Luoshan mining area

With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the underground mine and the open-pit mine. Based on the theory that sliding force is greater than the shear resistance (resisting force) at the potential slip surface is the necessary and sufficient condition to occur the landslide as the sliding criterion, the principle and method for sliding force remote monitoring is presented, and the functional relationship between the human mechanical quantity and the natural sliding force is derived, hereby, the natural sliding force can be calculated according to the human mechanical quantity. Based on above principle and method, a new system of landslide remote monitoring is designed and 53 systems are installed on the landslide body in the Luoshan mining area, which make up the landslide remote monitoring network. According to the results of field test around 8 months, monitoring curves between sliding force and time are obtained, which can describe and forecast the develop trend of landslide. According to above analysis, the results show that this system has some following advantages: (1) real-time monitoring; (2) remote intelligent transmission; (3) landslides early warning.

Reliability Analysis of Numerical Simulation of Sea-Crossing Bridge Deformation Under Wave Forces

To study on the numerical simulation calculation reliability of sea-crossing bridge under complex wave forces,the paper applied GPS deformation monitoring and numerical simulation calculation by researching Qingdao Jiaozhou Bay Sea-Crossing Bridge.The db3 wavelet three-layer decomposition was used on the horizontal movement of the sea-crossing bridge and the wind speed of the waves to analyze their correlation.The complex wave forces value of Qingdao Jiaozhou Bay Sea-Crossing Bridge was loaded on FLAC3D software successfully to make numerical simulation calculation of bridge deformation.Since the accuracy of the GPS deformation monitoring reaches millimeter level,it was used to monitor the exact value of the bridge deformation to judge the reliability of numerical simulation.The relative errors of displacement in X,Y and Z directions were between 33%and 41%through comparison.It could be seen that the numerical simulation error was relatively large,which was mainly due to various environmental factors and the deviation of applied wave forces.However,numerical simulation generally reflects the deformation law of the sea-crossing bridge under complex wave forces,providing an effectively technical support for the safe operation assessment of the sea-crossing bridge.

A new device for stress monitoring in continuously welded rails using bi-directional strain method

The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.

基于GPRS和Flexi Force传感器的足底压力监测系统设计

针对传统足底压力监测系统空间和区域的局限性,利用GPRS和Flexi Force实现移动无线通信条件下的足底压力远程数据采集。利用GPRS的Internet接入功能,建立数据采集模块与远程主机之间的无线通信,将通过Flexi Force薄膜压力传感器采集的足跟压力数据无线传输到指定设备上,真正实现足底压力远程监测。

Study and application of vibrating wire strain gauge in monitoring cable tension of FAST cable-net

A cable net structure is selected to support its reflecting triangular aluminum panels of FAST(five-hundred-meter aperture spherical radio telescope).To ensure the security and stability of the supporting structure,cable force of typical cables must be monitored on line.Considering the stringent requirements in installation,accuracy,long-term stability and EMI(Electromagnetic interference),most of the commonly used cable force measurement methods or sensors are not suitable for the cable force monitoring of the supporting cable-net of FAST.A method is presents to accomplish the cable force monitoring,which uses a vibrating wire strain gauge to monitor the strain of linear strain area at the anchor head.Experiments have been carried out to verify the feasibility.The method has a series of advantages,such as high reliability,high accuracy,good dynamic performance and durability,easiness of maintenance,technical maturity in industry and EMI shielding.Theoretical analysis shows that there is a linear relationship between the cable body force and anchor head surface strain,and experimental results proves a good linear relationship with excellent repeatability between the cable body force and anchor head surface strain measured by the vibrating wire strain gauge,with a linear fit better than 0.98.Mean square error in practical measuring is 2.5t.The relative error is better than 4%within the scope of the cable force in FAST operation which meets practical demand in FAST engineering.

基于PLC与Force Control保护渣熔点熔速测定仪的设计

介绍了Force Control组态软件设计人机界面的一个保护渣熔点熔速测定仪,利用德国西门子公司的S7-200系列PLC编程软件来实现控制;利用北京三维力控科技有限公司的组态软件Force Control设计界面监控熔点仪的运行状况。实现了对保护渣熔点熔速测定仪的实时监控和操作。

卫星遥感赋能旱情监测:进展与展望

我国干旱灾害发生频繁,造成的损失严重。传统的干旱监测主要基于气象和水文数据,在监测面上的旱情时存在局限。基于新质生产力开展旱情监测迫在眉睫,也是新时期干旱灾害防御工作的重要着力点。近年来,随着卫星遥感技术快速发展,大范围、高精度、高频次、全天候对地观测能力基本形成,旱情遥感监测由早期的模型研究向业务化应用方向发展,多源遥感星地协同旱情监测、精细化旱情综合评估以及遥感、水文气象耦合的旱情预警是未来发展趋势。

基于力控组态软件的光伏微电网远程监控系统的设计

为提高光伏微电网的自动化程度和能源利用效率,保证光伏微电网安全稳定运行,以智慧新能源实训系统V2.0为研究基础,基于力控组态软件设计开发了光伏微电网远程监控系统。该系统由上位监控机和前端数据采集单元组成。数据采集模块以西门子S7-1200plc控制器为核心,通过RS485通信总线,将环境模拟平台的太阳光照度、温度、湿度、太阳倾角等数据采集传输给PLC控制器。PLC控制器通过PROFENET通信,将采集数据传输给力控组态软件,以达到实时数据采集、监测显示、管理控制等远程控制的目的。

基于多层石墨烯薄膜的柔性传感器研究

为了在结构监测领域探索新型的传感材料和技术,对一种以多层石墨烯薄膜作为敏感材料的柔性传感器展开了研究,进行结构应变和冲击力信号监测。基于相似三角形的性质,设计了柔性传感器大应变范围内的标定实验,并通过悬臂钢梁实验对柔性传感器和电阻应变片的应变监测结果进行了比较。此外,还搭建了沙粒冲击实验平台,实现了沙粒在不同下落高度的冲击响应。实验结果表明:柔性传感器具有大变形的监测能力,可代替电阻应变片测量结构的应变,并可用于沙粒冲击力的测量,在结构监测领域具有广泛的应用前景。

智能化颈椎牵引系统设计

针对现有电动颈椎牵引装置的牵引力不稳定、牵引角度控制误差较大影响到颈椎病治疗效果和患者安全等问题,设计了一种基于物联网(IoT)的智能化颈椎牵引系统。该系统可对牵引力量、牵引角度进行自动精确控制,并通过构建IoT实现设备工作状态和患者状况等信息的实时监控。结果表明:该系统牵引力曲线平滑,实现了渐进式加力、等张牵引和渐退式减力;前屈后伸角度的平均偏差为0.182 5°,左右侧屈角度的平均偏差为0.264°,实现了牵引角度的精准控制,安全性和稳定性高,实现了颈椎牵引治疗的智能化。

光纤光栅索力传感器的酸碱耐久性

拉索作为斜拉桥的主要受力构件常处于复杂、恶劣的工作环境,传统的索力监测手段存在一定的局限性。将光纤光栅传感器内嵌封装进金属承压块上的凹槽,研制一种光纤光栅索力传感器,并对两种环氧树脂胶黏剂封装的光纤光栅索力传感器在酸碱腐蚀环境下的耐久性能进行研究,然后依托逆幂律模型与老化动力学理论,推导出传感器寿命预测方程。试验结果表明:该传感器的线性度和稳定性良好,传感器在腐蚀溶液中失效的主要原因是封装部位界相区胶黏剂受腐蚀剥落。A类传感器的耐酸碱性强于B类传感器,A类传感器在弱酸弱碱环境中的使用寿命均超过35年,大于斜拉桥拉索平均20年的换索年限,可以实现拉索全生命周期的监测。

对“水利测雨雷达”的新质生产力研究

高精准降雨监测预报对于支撑水旱灾害防御等水利业务预报、预警、预演、预案“四预”工作至关重要。水利测雨雷达系统主要观测近地面2 km高度范围内大气中的液态水,能够实现无缝隙、精细化监测并生成高精度实况定量降雨产品,具有较为精准的外推1~3 h降雨临近预报能力,是水利新质生产力的典型代表。系统梳理了我国降雨监测发展历程,包括无器具测量、雨量器萌芽、标准化人工雨量器、自动记录式雨量器和现代自动测雨五个阶段。在此基础上,从雨量站业务应用、天气雷达业务应用、气象卫星业务应用角度,分析当前“四预”业务中降雨监测现状与问题,进而梳理了水利测雨雷达发展进程并分析其技术优势,包括:能够实时生成超精细化的网格降雨实况数据,能够实现精细化网格化降雨预报,以及系统运行稳定高效。结合水利测雨雷达在河北省大清河流域以及湖南省捞刀河、浏阳河流域的良好应用成效,指出其作为水利新质生产力在赋能“四预”方面具有应用前景。

复杂曲面机器人磨抛技术研究现状与趋势展望综述

在航空、能源、交通、军工等国家战略领域中,针对复杂曲面零件的自动化、高质量和高效率磨抛需求,对近年来国内外工业机器人磨抛加工关键技术及集成系统的研究和应用进展进行了综述。首先,从复杂曲面机器人磨抛机理及工艺优化、磨抛运动轨迹规划、磨削力控制等方面总结了复杂曲面机器人磨抛技术的研究成果;然后,介绍了国内外机器人磨抛集成系统应用现状;最后,分析了复杂曲面机器人磨抛技术的主要问题以及发展趋势,为该技术的发展提供了重要的指导和方向。研究结果表明:当前该技术存在的主要问题包括磨抛机理不够清晰,数学模型不够准确,复杂曲面机器人磨抛轨迹规划效率不高,磨抛力的控制仍不够精准等;另外,磨抛工艺参数优化、机器人力位混合控制、机器人高精度标定与误差补偿、基于数字孪生的机器人磨抛在线监控、机器人磨抛细分应用场景等方面的研究和实践将极大地推动机器人磨抛技术的发展和应用。

h型双排桩在山地建筑边坡工程中应用

针对山地建筑边坡受用地限制而常用挡墙不太适用的问题,提出了h型双排桩结构形式,其由冠梁、腰梁、盖板、前排桩及后排桩组成。首先,假定h型双排桩的上部山体为滑裂体,采用传递系数法计算剩余下滑力,与双排桩抗滑力进行比较,判断边坡整体稳定性;假定h型双排桩为悬臂二阶柱结构,计算结构变形,判断变形是否满足正常使用要求。其次,依托某边坡工程进行实例论证,该工程竣工已近两年,监测数据表明边坡处于安全稳定可控状态。最后,h型双排桩解决了山地建筑边坡用地受限的难题,双排桩强有力的结构形式提高了悬臂式挡土高度,且双排桩盖板可兼作山地建筑的室外用地使用。

基于传统滑雪板的可穿戴式雪上摩擦力在线测量装置研究

竞技滑雪运动中雪上摩擦阻力影响运动员比赛成绩,而雪上摩擦影响因素众多,雪上摩擦阻力评测一直是冰雪竞技运动中的一大挑战.本文中设计了1种基于传统滑雪板的可穿戴式雪上摩擦力在线测量装置,将多个三分量传感器合理布置在传统滑雪板上,通过有线连接的方式,结合数据采集卡,对3个分量的力信号进行监测、采集和保存,并通过终端电脑实时反馈力信号变化.实验室静态测试中,该装置具有稳定的力学信号输出,并给出准确的摩擦系数测试结果.在模拟雪场测试时,其能够准确地评估不同雪上减阻蜡的润滑性能及其耐磨性能,还能够监测自由式滑雪运动中的犁式制动和犁式转弯等常规技术动作.该装置输出的力信号具有高精度和高灵敏度特性,为滑雪运动中雪上减阻蜡的性能评价、运动员施力动作监测等给出了1种可行方案.

密贴下穿既有地铁车站的新建通道拆撑影响分析

依托成都地铁8号线倪家桥站零距离密贴下穿既有地铁1号线倪家桥车站工程,采用数值模拟方法对比分析“先施作二衬再拆撑”和“先拆撑再施作二衬”对既有和新建结构的力学差异,并基于“先拆撑再施作二衬”工况进一步分析拆撑方案,最后通过实测现场实施的“先施作二衬再拆撑”工序下的既有车站底板沉降数据验证相关结论。研究结果表明:“先施作二衬再拆撑”既有车站弯矩及沉降、新建通道初支弯矩及二衬沉降变化不明显;“先拆撑再施作二衬”对于既有车站及新建通道影响则较为显著,一次性全部拆撑后既有及新建结构弯矩沿断面分布形态变化明显,在结构沉降方面,拆撑后既有车站及新建通道初支最大沉降突变量分别达4.86,7.30 mm;“先拆撑再施作二衬”工况下,采用顺序拆撑与跳仓拆撑,最不利部位出现在下穿通道纵向中部,跳仓拆撑引起新建通道初支沉降量大于顺序拆撑,但其施工效率更高,具体拆撑方式应根据施工安全控制标准及经济性要求合理选择。

采用门控循环单元神经网络和多特征融合的铣削刀具磨损监测

为实现汽车发动机缸盖生产中刀具磨损状态的监测,提高刀具磨损监测方法的计算效率和识别精度,基于门控循环单元神经网络和多特征融合方法提出了面向铣刀后刀面磨损带宽度识别的刀具状态监测方法。通过铣削力信号数据对所提出方法的有效性进行了验证,分析了不同超参数设置对模型识别精度的影响机制,给出了最优超参数,实现了对铣削刀具磨损的精确识别。