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如何快速定位GIS放电位置,是局部放电在线检测的关键。基于超声波和超高频多传感器信息融合局部放电联合定位方法,是将来自放电位置这一目标的多源信息加以智能合成。声电联合定位检测系统采用到达时间差TDOA法,利用BP神经网络对超声波和超高频法的传感器采集数据进行融合。最后通过仿真验证,得出其定位准确率较单一方法大大提高。 相似文献
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鉴于输电设施污秽、裂化等问题引起的放电故障一直威胁着输电网的安全,本文对放电紫外探测技术进行了研究,使用光电倍增管(PMT)作为探测器设计放电紫外探测方案,提出一种无人机巡检电力线放电的紫外探测及定位方法。通过舵机的摆动带动PMT进行多角度探测,记录当前的探测位置和探测角度,利用测向交叉定位法求解得到放电点的初步定位坐标;为了精确定位放电点,对n组数据进行求解得到n(n-1)/2个放电点的初步定位坐标,剔除放电点的初步定位坐标中的异常点后,导入到K-means聚类算法中进行二次解算得到放电点的精确坐标。通过实验测试了PMT探测角度与放电紫外信号的关系,选取θ=90°作为舵机的摆动角度,实验结果表明,18m,30m和50m的放电巡检中,放电点的定位误差均在9.0%以内。该方法能够在无人机巡检电力线时满足放电点快速定位的需求。 相似文献
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几种工作方式各不相同的非接触式光学测量系统,目前正在座标测量机上进行试验。以自动对焦系统为基础的光电传感器也曾用于测量表面粗糙度。本文将对此种传感器用作圆度检查的实验情况提出报告。在记录圆度偏差的记录曲线上证实了光学传感器与常用的传感器的测量信号不一致。 相似文献
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新型变压器局放监测特高频传感器的研究 总被引:1,自引:0,他引:1
近年来,特高频法监测变压器内部局部放电得到了广泛的关注,而特高频传感器性能的优劣直接决定着特高频信号的接收.介绍并设计了一种新型变压器局部放电特高频传感器--Goubau天线,研究了阻抗匹配线圈对Goubau天线驻波比的影响,并仿真研究了传感器安装时手孔升高座对传感器驻波比的影响.进一步,在真型变压器上进行了局放监测实验.仿真和实测结果表明,设计的Goubau天线频带为400 ~1000MHz,并在该频段内有2个谐振点,方向图较好,阻抗匹配线圈能明显改善天线驻波比,手孔升高座对Goubau天线性能基本无影响,天线频域响应能够分辨不同的局部放电类型,适用于变压器局部放电特高频信号监测. 相似文献
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本文介绍了一种对相关流量计的光学探头两探测窗口的等效中心距进行实验标定的方法。成功地解决了光学传感器的参数定标问题,并为光学传感器的校验提供了一套检定设备。 相似文献
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局部放电既是GIS绝缘劣化的征兆和表现形式,又是绝缘进一步劣化的原因。对GIS进行局部放电检测能够有效地发现其内部早期的绝缘缺陷,以便采取措施,避免其进一步发展,提高GIS的可靠性。文章分析了GIS产生放电的原因,介绍了GIS局部放电的在线监测方法。 相似文献
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《仪表技术与传感器》2020,(1)
为了满足对室内浅层埋线探测的需求,利用电容传感器的边缘效应,设计了非平行板电容传感器的微小电容检测电路。使用multisim软件对交流电桥和差分运放电路进行仿真;实验验证电路功能,并采用MATLAB软件拟合实验数据。实验表明,在频率为10 kHz的正弦波作用下,该电路的电容检测灵敏度可达0.1 V/pF,满足浅层埋线探测系统的灵敏度要求。 相似文献
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设计了基于高精度直线驱动器和曲柄滑块机构的高精度二维角度调节机构,以实现2m口径望远镜中哈特曼探测器与自适应光学系统间的高精度对准与自动化调节。依据光学设计分析得出调节机构分别需满足±1°的调节范围和6"的调节精度。根据哈特曼探测器的外形结构和调节机构的整体布局,选择了调节机构中的主要参数,对整体调节机构进行了初始设计并分析了它的精度和动态特性。利用自准直仪设计了调节机构的检测系统,对设计的调节机构的调节范围、精度和动态性能进行了实际测量。结果表明:哈特曼探测器调节机构在俯仰和扭摆方向上的角度调节量均约为±1.2°,调节精度分别为0.43″和2.1″,均满足设计要求,为哈特曼探测器的高精度探测奠定了基础。 相似文献
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针对单一激励交流电磁探头检测任意方向裂纹容易出现漏检问题,设计了用于检测奥氏体不锈钢表面斜裂纹的新型双激励传感器,建立了奥氏体不锈钢表面裂纹交流电磁场检测仿真模型,开发了基于新型双激励传感器和高分辨率隧道效应磁阻传感器的金属平板表面裂纹检测系统。基于理论模型和试验系统研究了试件上裂纹走向和裂纹宽度对传感器拾取到磁场分量幅值的影响规律,研究了裂纹检测与方向判定方法。仿真和实验结果表明,利用磁场分量B_x、B_y畸变特征能够以相同的灵敏度检测出试件表面尺寸为15 mm×0.2 mm、深度大于3 mm的微小裂纹,并实现裂纹方向判定。引入宽度补偿参数后减小了横向、纵向裂纹判定误差,判定误差最大为3.9°。 相似文献
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波导型倏逝波传感器依赖于待测物与倏逝场的相互作用,其检测能力受制于倏逝波的强弱。一般而言,波导的倏逝波强度在内部传输光中占比很低,因此传感器灵敏度受到很大限制。提出的一种基于水凝胶聚合物的波导探针可以克服上述缺点。水凝胶具有的三维网状结构,可以方便待测物渗入波导内部,因此可以利用局域在波导内部的传输光进行探测,大幅提高探测光的利用效率。此外,实验通过其他聚合物单体的添加成功抑制了水凝胶波导遇水溶胀变形带来的额外光损。由于纯水凝胶制备的波导在吸水溶胀后会导致变形,从而带来额外的光损耗,因此除水凝胶之外还需掺入其他聚合物以维持波导的基本形状。实验表明,该水凝胶聚合物波导传感器对罗丹明B水溶液的吸收检测极限为1.0×10?9 g/mL,荧光检测极限为1.0×10?19 g/mL。相比于其他波导型倏逝波传感器,荧光检测极限提高了约7个数量级。该水凝胶聚合物波导传感器制备方法简单,成本低廉,可适应性高,灵敏度高,在医疗及环境监测等多个领域都有着广泛的应用前景。 相似文献
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用于视角偏转的光学膜表面微结构设计 总被引:1,自引:0,他引:1
针对传统的液晶显示器应用于一些驾驶舱时存在的特殊观看视角问题,设计了一种新型的光学膜,以使液晶显示器的最大亮度可根据观看者的位置实现特定角度的偏转。首先,基于现有背光的配光曲线,提出光学膜表面微结构为直角三角形;考虑由于直角边的全反射,半光强视角范围较窄且存在截止角,对微结构进行了棱高和角度的优化设计,使半光强处视角范围得到提高。为消除截止角并进一步增大半亮度视角范围,对微结构再次进行优化设计,提出了双峰折线形非对称的光学膜表面微结构。仿真结果表明:水平视角不变时,偏转膜垂直方向最大亮度在20°处,透过率为87.3%,半亮度视角为(-12.5°,45°)。根据设计结果加工了实际样品并进行了实验测试,测试结果表明:与传统的背光视角相比,偏转膜垂直方向最大亮度由原来的0°偏转到18.9°,半亮度视角由(-24.1°,23.5°)变为(-9.2°,45.3°),透过率为82.0%,满足了特定视角的观看要求。 相似文献
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Under the technical requirements of expanding measurement range and suppressing cavitation of flow sensors, the performance of a novel cavitation-resistance turbine flow sensor is taken as the research objective in this article. Based on theoretical analysis, a three-dimensional flow field CFD model of the turbine flow sensor with Realizable k-ε turbulence model and Schnerr&Sauer cavitation model is established. The cavitation tunnel experiment is performed to obtain the sensor characteristics. Finally, simulation and experiment results is analyzed and the feasibility of the CFD simulation of the sensor flow field is proved. The results show that this novel turbine flow sensor has the ability to resist cavitation, and the critical cavitation number σcr of the turbine flow sensor is below 0.4. Under a wide range of cavitation number (0.33~ σ ~1.6), Reynolds number(5 × 104~ Re ~8 × 105)and inflow angle α(−5°~ α~ 5°), the measurement meets the requirements. 相似文献
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Optical fiber Fabry-Perot interferometers have been widely used as sensors. A novel anhydrous ethanol-filled optical fiber Fabry-Perot temperature sensor was reported in this article. Based on the characteristics of the temperature-controlling refractive index, the ethanol may serve as a sensitive medium for a sensor. According to the experimental results, the refractive index of the ethanol was changed by approximately 0.02617 when the temperature increased from 16°C to 74°C. A cavity length of 94 μm was used to demonstrate the feasibility of this sensor. The resonance wavelength of the sensor shifted about ?0.42 nm/°C. The novel optical fiber Fabry-Perot temperature sensor was simple, compact, sensitive, and immune to electromagnetic interferences. 相似文献
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Subhankar Addya Sabitabrata Dey Sanjoy Mandal 《Sensing and Imaging: An International Journal》2017,18(1):33
Temperature sensor based on optical ring resonator has been demonstrated with its constituent material as silicon (Si-fiber) and germanium (Ge-fiber) in this work. It has been done through optical delay line signal processing technique in Z-domain. The group indices of both the materials vary with the change in temperature due to the thermo-optic effect in materials. Thus temperature dependence of free spectral range forms the basis of modeling the sensors. Silicon (Si) fiber based optical sensor can sense the temperature in the range 30–500 °C and that for germanium (Ge) fiber the range is ?25 to 300 °C. Obtained temperature sensitivities for Ge and Si-fibers are 5.55 and 2.97 MHz/°C respectively. 相似文献
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Mitsuhiro Okayasu 《Journal of Mechanical Science and Technology》2010,24(6):1261-1264
In this work, two visual systems to help visually impaired people walk were developed: the first is a white cane with a non-contact
detection system, and the second is a three-dimensional (3D) visual system. In place of the sense of sight, the sense of touch,
either via vibration or of pins, can relay information on objects and obstacles around people. In a white cane non-contact
detection system, two sets of ultrasonic sensors and vibrators, respectively, are employed to indicate the positions of both
low- and high-level obstructions in front of the visually impaired person. When objects are detected by the sensor, the vibrator
is strongly activated. In this system, the range of obstruction detection can be adjusted between 0.5 m and 5.5 m. By comparison,
the 3D visual system uses two different components, an infrared camera sensor to detect obstructions and a tooling apparatus,
incorporating a number of 1 mm diameter pins, by which their 3D shapes are derived. The pins are arranged in a 10×10 matrix
and move longitudinally between the retracted and extended positions based on the depth data between the infrared sensor and
the obstruction. Pins are elongated individually, so that each pin tip represents a specific area of the outer surface of
the object. This tactile 3D image can provide effective object information. 相似文献