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涡街流量计信号处理方法研究与系统设计 总被引:1,自引:0,他引:1
为提高涡街流量计的测量性能,提出一套双通道涡街流量计信号处理方法,通过测量通道与监测通道的配合,提升低流速的测量性能,运用脉动信号功率最大频率点周期估计算法,进一步提升测量的精度和抗震动性能,并设计基于MSP430的涡街信号处理系统。实验结果表明:该信号处理方法能有效提升涡街流量计的测量性能。 相似文献
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介绍了一种利用磁阻效应原理的磁敏转速传感器,可以同时输出脉冲电压信号和与转速高低成正比的直流电压。对不同的齿轮转速进行测量,实验结果表明,在0~12kHz的信号频率范围内,转速传感器性能稳定,测量结果准确有效。该转速传感器灵敏度高、抗干扰能力强,且电路简单、成本低廉,适用于农业机械的齿轮转速测量。 相似文献
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在动态频率特性测量和校准应用中,传统的线性调频信号频谱均匀分布、可设计参数单一,难以同时兼顾测量精度与测量效率。本文提出了一种基于非线性扫频方式的动态频率特性校准方法,可广泛用于传感器与仪器仪表的频率响应校准与标定。非线性扫频信号可以实现激励信号能量在频域内的非均匀分布,从而在某些重要频段内实现较高精度测量的同时,在其他频段通过牺牲一定的测量精度来保证测量速度,从而进一步优化频率特性测量的整体性能。仿真结果表明,在相同的扫频时间内,非线性扫频方法相比于线性扫频方法,能够将特定频段内的测量精度进一步提高。 相似文献
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本文介绍一个天线方向图自动测试系统,在信号录取、角度录取、天线旋转、辐射源的调节方面全部实现了自动化,尤其在信号录取支路使用了新的方法,并对天线旋转进行了自适应控制。具有精度高、测量迅速、性能稳定、价格低廉的特点。是一种在野外工作现场对天线进行在线快速测量的理想系统。本文通过理论分析,证明了新方法的优越性。 相似文献
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一种用于水声测量的宽带声脉冲产生方法 总被引:1,自引:0,他引:1
提出了一种用于水声测量的宽带声脉冲信号的产生方法,克服了系统瞬态响应的影响,通过试验验证了该方法具有简单、方便和实用的特点,可用于水声材料的声性能、近场声反演等水声测量。 相似文献
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滚动轴承在工业生产中起着关键作用,对其进行故障诊断研究具有重要意义。目前轴承诊断主要以振动信号分析为基础,而获取振动信号受接触式测量限制,声学故障诊断(ABD)具有非接触式测量的优点,但传统基于单通道的ABD存在测点选择难与局部诊断的不足。联合近场声全息(NAH)和灰度—梯度共生矩阵(GLGCM)并应用于滚动轴承故障诊断,利用NAH重建各轴承运行状态下的声场,得到声源附近重建面处的声像图,再从声像图中提取GLGCM特征,建立声场特性与轴承运行状态的内在联系,结合支持向量机模式分类,实现轴承故障诊断,实验研究证实方法的可行性与有效性。 相似文献
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针对目前陀螺导航装备缺乏动态性能测试方法的状况,本文提出并实现了车载动态性能测试系统.并根据航向数据非连续变化的特点,提出了基于周期平移的小波阈值降噪算法.该算法通过对信号的分段周期平移、阈值降噪、逆平移的方法实现降噪,有效地克服了常规小波阈值降噪算法带来的Pseudo-Gibbs现象.仿真及实测数据表明采用该算法能够在有效剔除异常点、消除噪声的同时,消除降噪信号中的Pseudo-Gibbs现象.跑车实验表明车载动态性能测试系统为陀螺导航设备提供了有效的解决方案和统一的测试平台. 相似文献
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在介绍一种变面积电容原理的非接触式角度传感器的基础上,提出了两种电容式角度传感器的测量方案.鉴于数字方法实现的测量方案性价比更加优越,从而构建了基于CPLD的电容式角度传感器测量电路,借助于复杂可编程逻辑器件完成传感器信号的鉴相、计数等处理.通过电路的试验以及误差分析,得出该测量电路具有精度高、速度快、抗干扰强、稳定性好等特点. 相似文献
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Jie Huang Ohnishi N. Sugie N. 《IEEE transactions on instrumentation and measurement》1995,44(3):733-738
This paper presents a system for sound source localization and separation inspired by the auditory mechanisms of biological systems. The system consists of three omni-directional microphones, banks of band-pass filters, and a personal computer with a digital signal processor. Sound sources are localized using arrival temporal disparities. The zero-crossing method is used to quickly detect the arrival temporal disparities at signal onset to cope with echo. Arrival temporal disparity histograms remove ambiguity and improve accuracy. The Histogram Mapping Method is introduced to localize multiple sound sources. The system separates multiple sound sources by obtaining their direction information from the localization process. Localization and separation experiments were conducted in an anechoic chamber and an empty room. Two sound sources, human voices, were used. Directions of the sound sources were localized within a few degrees. Sound sources were separated by 25 dB attenuation 相似文献
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Lesaffre M Farahi S Boccara AC Ramaz F Gross M 《Journal of the Optical Society of America. A, Optics, image science, and vision》2011,28(7):1436-1444
Acousto-optical coherence tomography (AOCT) is a variant of acousto-optic imaging (also called ultrasonic modulation imaging) that makes it possible to get the z resolution with acoustic and optic continuous wave beams. We describe here theoretically the AOCT effect, and we show that the acousto-optic "tagged photons" remain coherent if they are generated within a specific z region of the sample. We quantify the z selectivity for both the "tagged photon" field and for the Lesaffre et al. [Opt. Express 17, 18211 (2009)] photorefractive signal. 相似文献
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AbstractIn practice, we often need to sequentially monitor the performance of individual subjects or processes, so that interventions can be made in a timely manner to avoid unpleasant consequences (e.g., strokes or airplane crashes) once the longitudinal patterns of their performance variables deviate significantly from the regular patterns of well-functioning subjects or processes. Some statistical methods are available to handle this dynamic screening (DS) problem. Because the performance of the DS methods is related to their signal times, the conventional false positive rate (FPR) and false negative rate (FNR) cannot be effective in measuring their performance. So far, there is no existing metrics in the literature for properly measuring the performance of DS methods. In this article, we aim to fill this gap by proposing a new performance evaluation approach, called process monitoring receiver operating characteristic curve, which properly combines the signal times with (FPR,FNR). Numerical examples and theoretical justifications show that this approach provides an effective tool for measuring the performance of DS methods. Supplementary materials for this article are available online. 相似文献