同轴陷波器分析

针对弱信号检测中的工频干扰,分析了双T网络陷波器的不足,提出了用RC零网络代替双T网络组成陷波滤波器,以实现同轴可调选频滤波,并给出了实用电路。     

用IIR格型陷波器消除信号中低频干扰的研究

为了有效地消除信号中的低频干扰,本文研究了IIR格型陷波滤波器的系数敏感度问题.在分析了三种格型滤波器的结构和敏感度的基础上,认为基于全滤波器的IIR陷波器在低频段具有最低的系数敏感度.通过一个设计实例说明了这种纯格型结构由于量化效应引起的频率偏移量要远远小于级联式格型结构.最后通过在电力线通信中的实际应用验证了该滤波器的性能.     

时变信号频率跟踪的一种新自适应陷波器方法

针对频率、幅值和相位均发生变化的时变信号,现有自适应陷波器(ANF)频率估计方法存在信号频率跟踪精确性和稳定性不足的问题,为此提出了一种基于新误差函数的ANF时变信号频率跟踪方法,通过新误差函数改善自适应算法收敛至最优频率解的精度与速度,以提高时变信号频率跟踪的精确性和稳定性。给出了新误差函数分析结果,新ANF方法实现步骤和该频率估计方法的Cramer-Rao下限。通过计算与现有ANF的时变信号频率跟踪方法性能进行了比较分析,并针对科里奥利质量流量计时变信号进行了现场实验验证。结果表明,该方法具有收敛速度快、跟踪精度高、更接近Cramer-Rao下限和抗噪性好的优点。     

陷波器在低刚性伺服系统共振抑制的应用

为了解决低刚性伺服系统存在的机械共振现象,以一套滚珠丝杆伺服系统为研究对象,对其物理模型进行简化和分析,得到了系统共振频率的理论值。同时,对滚珠丝杠伺服控制系统产生共振时的速度信号进行采集,使用Matlab对速度信号进行处理,得到了系统共振频率的实际值,比较得出共振频率实际值和理论值相符的结论。然后,针对共振频率设计特定的数字陷波滤波器。实验结果表明,陷波器成功滤掉输入信号中含有的共振频率,抑制了滚珠丝杠伺服控制系统的机械共振问题,为低刚性伺服系统解决机械共振的问题提供了实践依据。     

位标器陀螺转子动平衡测量的数字方法

介绍一种采用两步法进行位标器陀螺转子动平衡测量的数字方法.首先采用自适应数字陷波滤波器来进行频率的测量,然后采用线性最小二乘法来求出幅值和相位差的大小.两步的算法均为线性算法,具有收敛速度快、计算准确的特点.     

正交检波在自动阻抗匹配器信号检测中的应用研究

分析了自动阻抗匹配器中常规信号检测及相应匹配控制算法存在的不足,给出了高速模拟开关正交检波方案。理论分析表明,正交检波在自动阻抗匹配器信号检测中能够同时获得射频信号的幅值和相位信息;模拟实验结果表明,模拟开关正交检波方案有抑制噪声能力强、线性度好、动态范围宽等优点。与仅检测到射频信号的入射功率和反射功率相比,实时监测射频信号的幅值和相位信息,可以进一步提高自动阻抗匹配器的匹配性能。     

IIR数字滤波器在砌块成型机振动信号滤波中的应用

振动信号采集系统采集到的砌块成型机振动信号中包含大量的噪声污染,不加处理的振动信号可读性低,很难对其进行深入的分析。经讨论分析选用由MATLAB程序直接设计的IIR数字滤波器系统对砌块成型机振动信号进行处理。实例表明,这种方法对砌块成型机振台振动信号具有很好的滤波效果。     

基于时变信号模型和格型陷波器的科氏流量计信号处理方法

采用能跟踪频率变化的自适应格型陷波器对频率、幅值和相位均按照随机游动模型变化的科氏流量计传感器输出信号进行滤波，求其频率；采用自适应谱线增强器从含有噪声的数据中提取出信号；然后采用具有重叠窗的滑动Goertzel算法实时计算两路信号之间的相位差和时间差，求得质量流量。仿真和测试结果表明所研究的方法是有效的。     

混沌振子在强噪声背景信号检测中的应用

混沌振子在强噪声背景信号检测中的应用＊王冠宇陶国良陈行林建亚（浙江大学流体传动及控制国家重点实验室杭州３１００２７）０引言噪声干扰是信息科学的一项主要问题。混沌系统对小信号的敏感性以及对噪声的免疫力，使它在信号检测中非常具有潜力。对于一个非线性动力系...     

基于声音信号的汽车安全带卷收器质量检测方法研究

为提高汽车安全带生产现场质量检测效率,根据《QC/T987—2014汽车安全带卷收器性能要求和试验方法》搭建实验平台,采集卷收器合格品与次品工作过程中的声音信号,将卷积注意力模块(CBAM)嵌入残差网络(ResNet-18)残差块之前,设计CBAM-ResNet-18“Before Blocks”模型,对采集到的卷收器声音信号进行分类。与不加注意力机制的ResNet-18模型、在残差块后加注意力机制的CBAM-ResNet-18“Within Blocks”模型、传统分类模型支持向量机和随机森林相比,模型在卷收器声音信号分类任务中的混淆矩阵、准确率、精确率、召回率和F₁值等方面均表现良好。实验结果表明：所设计的模型对于基于声音信号的汽车安全带卷收器质量检测十分有效。     

Strapdown gyrocompass algorithm for AUV attitude determination using a digital filter

The strapdown gyrocompass can provide attitude by measuring the Earth’s gravity vector. In practical applications, there usually exists unwanted disturbance accelerometers that will distort the accelerometer measurements, hence a filtering out procedure is essential. Current attitude determination method based on pendulum cutting off technology has the limitation for vehicle moving mode. This paper proposes a new strapdown gyrocompass algorithm via processing the accelerometer measurement with Butterworth low-pass filter (LPF) to remove the high frequency dynamic disturbance components. When the gravity variation in inertial frame is regulated, LPF can be applied to properly get the gravity even in the presence of acceleration disturbances, and subsequently can be applied to calculate the strapdown gyrocompass attitude. The proposed algorithm does not require declination information and inertial element biases estimation. The field test has been conducted and the results verified the effectiveness and reliability of the proposed AUV attitude determination method and have also shown that the gravity is proportional to the latitude and altitude of AUV.     

数字加速度传感器ADXL210在轨检仪中的应用

介绍了一种轨道检测仪及其重要传感器数字加速度传感器ADXL210的工作原理、功能、应用，并给出了ADXL210与MCS－51单片机的接口硬件电路和软件程序。     

Mooring alignment for marine SINS using the digital filter

Strapdown inertial navigation system (SINS) is presently used in several applications related to aerospace system and marine navigation. The accurate initial attitude is essential to ensure the precise determination of the position and attitude of the moving platform, which is usually calculated using initial alignment. When the vehicle is moored, the SINS inevitably experience disturbing motion. The method of ground coarse alignment, which is based on the assumption that SINS is on a stationary carrier with limited vibration, therefore cannot be used to perform the SINS mooring alignment. In this paper, a novel method processing the gyro and accelerometer measurements with infinite impulse response (IIR) digital low-pass filter to remove the high frequency noise is investigated for marine mooring alignment. Its algorithmic principle is described in details. The results obtained from both simulation and mooring experiment show that the attitude determined by this novel method can meet the accurate alignment.     

A novel algorithm for marine strapdown gyrocompass based on digital filter

With the rapid development of strapdown gyrocompass, few corresponding strapdown algorithms occur in publications, so that we have to use the conventional one designed for platform gyrocompass. Enlightened by IXSEA ideals, we proposed a novel algorithm which is suitable for marine strapdown gyrocompass. In our proposed algorithm, gyro outputs are used to track the body frame rotation, and the observation of the pure gravity slow drift in the inertial gives the navigation frame rotation. We also separate the pure gravity from interferential accelerations with a FIR low-pass digital filter. The analysis and numerical results show the better performance of the proposed algorithm than the conventional one.     

数字滤波在光学镀膜宽光谱监控中的应用

使用CCD(电荷耦合器件)进行光学镀膜宽光谱监控过程中,监测信号受外界杂散光干扰、真空室内背景辐射等因数影响,信噪比低,难于准确监控。在对系统前端光路改造的基础上,采用了数字滤波技术对后期数据进行处理,达到信号压噪目的。实验证明该宽光谱膜厚监控系统具有稳定性好、精度较高、响应速度快等优点。     

An improved simplex-based adaptive evolutionary digital filter and its application for fault detection of rolling element bearings

The de-noising performance and convergence behavior of the adaptive evolutionary digital filter (EDF) are restricted by the factors of constant evolutionary coefficients and taking the reciprocal of average energy of residual signal as the fitness function. In this paper, an improved adaptive evolutionary digital filter based on the simplex method (EDF-SM) is proposed to overcome the shortcomings of the original EDF. A new evolutionary rule was constructed by introducing the simplex-based mutating method and by then combining this with the original cloning and mating methods. The reciprocal of sample entropy was taken as the fitness function and variable evolutionary coefficients were employed. Numerical examples show that the proposed EDF-SM exhibits a higher convergence rate and a better de-noising behavior than the other EDFs. The effectiveness of the proposed method in discovering fault characteristics and detecting faults of rolling element bearings is supported using an experimental test.     

数字式传感器在智能温度变送器设计中的应用

本文介绍了ＤＳ１６２０新型数字式温度传感器的工作原理及特点,提出了数字式热电偶冷端温度补偿的方法并将其用于智能温度变送器的设计中,解决了传统热电偶冷端（参比端）温度补偿器的型号匹配问题,克服了补偿电桥不能完全补偿的缺点,提高了测量精度,降低了变送器的成本。     

基于相关自适应器的EM-MWD信号检测系统设计

经EM-MWD(electromagnetic method measurement while drilling)电磁通道传输至地表的信号很微弱并且极易受到白噪声、奇异噪声、工频噪声及其谐波等干扰,导致信号特征参数提取的准确度降低,为了解决这一难题,通过对电磁波传输信道的研究,根据接收初始信号强度以及自适应检测和相关检测的特点,研究并设计了相关自适应器,并基于此设计了电磁随钻地表信号检测系统。然后用Hilbert变换求信号包络,完成了数据拟合和残差分析,并计算了信噪比、均方根误差和误码率,最后做了实验。仿真和实验结果表明,利用该检测系统,能够提高信号特征参数的准确度,达到有效降噪目的,对后续分析和研究提供了保证。     

数字化导管室的设计与应用

医院数字化建设是现代化医院的发展方向。本文介绍数字化导管室的设计方案、综合布线及临床应用,总结数字化导管室设计和实施过程中的难点和特点,并分析数字化导管室的发展趋势。