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2020 2

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关键词

BPSK 1

前向相位校正 1

勒让德多项式 1

厄米多项式 1

双正交码 1

同相/正交分量不平衡；正交频分复用；标准独立 1

拉盖尔多项式 1

数字通信 1

求根 1

科里奥利质量流量计；数字信号处理方法；两相流工况；正交解调；滑动离散傅里叶变换；希尔伯特变换 1

自适应信号处理 1

解调 1

调制与解调技术 1

高效扩频调制 1

高斯积分 1

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Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

《信息与电子工程前沿（英文）》 2015年第16卷第4期页码 301-310 doi: 10.1631/FITEE.1400205

摘要： Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency (RF) signal. In quadrature demodulation, RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal, which has high computational complexity. In this paper, we propose an efficient quadrature demodulation method for B-mode and color flow imaging, in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal, to reduce the computational complexity. The proposed method was evaluated with simulation and in vivo experiments. From the simulation results, the proposed quadrature demodulation method produced similar normalized residual sum of squares (NRSS) and velocity profile compared with the conventional quadrature demodulation method. In the in vivo color flow imaging experiments, the time of the demodulation process was 5.66 ms and 3.36 ms, for the conventional method and the proposed method, respectively. These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

关键词： B-mode ultrasound imaging Color flow imaging Quadrature demodulation Finite impulse response filter

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Digital Readout System for Micromachined Gyroscope and Analysis for its Demodulation Algorithm

ZHOU Bin, GAO Zhong-yu, CHEN Huai, ZHANG Rong, CHEN Zhi-yong

《机械工程前沿（英文）》 2006年第1卷第1期页码 106-110 doi: 10.1007/s11465-005-0016-5

摘要：

A new digital readout system for micromachined gyroscope has been proposed to implement flexible parameter adjustment, improve the control performance of gyroscope, and make error compensation. By digitalizing the output of the gyroscope, this system uses a floating-type digital signal processor (DSP) to process the signal demodulation and achieve the feedback control of the gyroscope. Therefore, the small change of capacitance in the micromachined gyroscope can be detected. A new demodulation algorithm of least mean square demodulation (LMSD) has been developed inside DSP. Simulation and measurement results show that LMSD can improve 29% of the noise performance compared with the typical multiplication method. In air pressure, a kind of vibration-wheel micromachined gyroscope has achieved a noise level of 0.0073 deg s^-1z(z^-1/2 over the 100-Hz bandwidth by using this digital readout technology.

关键词： demodulation algorithm vibration-wheel micromachined feedback flexible parameter pressure

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自适应BPSK解调方法研究

李炎新,胡爱群,宋宇波

《中国工程科学》 2006年第8卷第5期页码 49-51

摘要：

提出了一种新型的基于自适应滤波算法的解调二进制相移键控（BPSK）信号的方法。以常用的最小均方误差自适应算法（LMS）为例，讨论了新型的BPSK自适应解调的过程及其性能。该解调算法不需要自适应滤波器完成收敛，从而降低了采样频率。给出的理论性能与仿真结果表明，BPSK自适应解调的误码率仿真结果与理论值吻合非常好；而且该方法具有抗干扰性能强、输出响应快、便于数字信号处理（DSP）技术实现等特点，在相同的采样频率下其误码率优于相关解调的误码率。

关键词：数字通信自适应信号处理解调 BPSK

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科里奥利质量流量计气液两相流信号处理的改进

李春辉1,孙立军1,刘佳荣1,张扬1,李海洋2,王化祥1

《信息与电子工程前沿（英文）》 2021年第22卷第2期页码 141-286 doi: 10.1631/FITEE.1900558

摘要：科里奥利质量流量计作为一种日益流行的流量测量仪表，在单相流条件下表现出较高测量精度，并在工业上得到广泛应用。但在复杂流动条件下，例如两相流工况，由于各种因素（包括不合适的信号处理方法），测量精度会大大降低。本文分析了3种数字信号处理方法——正交解调（QD）、希尔伯特和滑动离散傅立叶变换法，分别用于处理传感器信号并在两相流工况下测试算法性能。在此基础上，分别改进了两相流条件下的信号处理方法。在仿真中使用随机游走模型分别建立单相流和两相流工况下的传感器信号，评估这3种方法的相位差跟踪性能。基于数字信号处理器，在其评估板上完成转换器程序设计。将转换器在单相流和两相流工况下测试，根据测量精度和算法复杂度评估改进的信号处理方法性能，结果表明QD算法在单相流工况下性能最佳。在两相流条件下，QD算法在160、250和420 kg/h流量点的测量指示误差和重复性能优于改进的希尔伯特算法，而希尔伯特算法在600 kg/h流量点的性能优于QD算法。

关键词：科里奥利质量流量计；数字信号处理方法；两相流工况；正交解调；滑动离散傅里叶变换；希尔伯特变换

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Analytical and numerical investigation into the longitudinal vibration of uniform nanotubes

null

《机械工程前沿（英文）》 2014年第9卷第2期页码 142-149 doi: 10.1007/s11465-014-0292-z

摘要：

In recent years, prediction of the behaviors of micro and nanostructures is going to be a matter of increasing concern considering their developments and uses in various engineering fields. Since carbon nanotubes show the specific properties such as strength and special electrical behaviors, they have become the main subject in nanotechnology researches. On the grounds that the classical continuum theory cannot accurately predict the mechanical behavior of nanostructures, nonlocal elasticity theory is used to model the nanoscaled systems. In this paper, a nonlocal model for nanorods is developed, and it is used to model the carbon nanotubes with the aim of the investigating into their longitudinal vibration. Following the derivation of governing equation of nanorods and estimation of nondimensional frequencies, the effect of nonlocal parameter and the length of the nanotube on the obtained frequencies are studied. Furthermore, differential quadrature method, as a numerical solution technique, is used to study the effect of these parameters on estimated frequencies for both classical and nonlocal theories.

关键词： continuum theory differential quadrature method nanorod longitudinal vibration

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高阶高斯积分节点的高精度数值计算

张庆礼,王晓梅,殷绍唐,江海河

《中国工程科学》 2008年第10卷第2期页码 35-40

摘要：

在工程数值计算、X射线衍射线形分析、光谱学等领域常使用高斯数值积分，高斯积分的节点及权重因子是数值积分的必须数据。研究了高次勒让德、拉盖尔和厄米多项式的零点，即高斯-勒让德、高斯-拉盖尔、高斯-厄米积分的节点的计算方法，给出了一种有效的高精度数值算法——搜索迭代方法（scan-iteration method，SIM）。根据勒让德、拉盖尔、厄米多项式的特点，对拉盖尔多项式、厄米多项式的定义稍做变化后，获得了计算多项式值的稳定递推关系。求它们的根时，先在一定范围内以一定的步长搜索根所在的

关键词：高斯积分勒让德多项式拉盖尔多项式厄米多项式求根

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Digital monitoring and health diagnosis for mechanical equipment operation safety based on fiber Bragg grating sensor

Zude ZHOU, Desheng JIANG, Quan LIU

《机械工程前沿（英文）》 2009年第4卷第1期页码 5-14 doi: 10.1007/s11465-009-0011-3

摘要： This paper introduces fiber Bragg grating (FBG) based on a fiber optic grating sensor developed to be embedded on mechanical equipment for digital monitoring and health diagnosis. The theoretical and experimental researches on the new-style FBG sensor (FBGS) technology, high-speed demodulation, and data transmission are discussed. The transmission characteristics between the FBG and the detection interface, modeling and compensation method for online distributed multi-parameter digital monitoring and methods for data processing, synchronous sampling, and long-term dynamic digital monitoring using embedded technology are also presented. The acquired information by an FBGS can be used for the optimization of maintenance schedules and refinement of mechanical equipment design. It is a challenge to gather real-time data from components working at high speed and in a severe environment of high temperature, high pressure, and high rotation speed. Currently, there are no sensors or technologies available for digital monitoring and health diagnosis under this rigorous situation for use in mechanical engineering operation safety. As a result, this paper introduces an online distributed and integrated digital monitoring system and health diagnosis. The new principle and new method will contribute to modern measurements in science and technology, mechanical engineering, and large mechanical equipment operation safety.

关键词： fiber Bragg grating sensor (FBGS) mechanical equipment operation safety embedded technology high-speed demodulation digital monitoring health diagnosis

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Velocity gradient elasticity for nonlinear vibration of carbon nanotube resonators

Hamid M. SEDIGHI, Hassen M. OUAKAD

《结构与土木工程前沿（英文）》 2020年第14卷第6期页码 1520-1530 doi: 10.1007/s11709-020-0672-x

摘要： In this study, for the first time, we investigate the nonlocality superimposed to the size effects on the nonlinear dynamics of an electrically actuated single-walled carbon-nanotube-based resonator. We undertake two models to capture the nanostructure nonlocal size effects: the strain and the velocity gradient theories. We use a reduced-order model based on the differential quadrature method (DQM) to discretize the governing nonlinear equation of motion and acquire a discretized-parameter nonlinear model of the system. The structural nonlinear behavior of the system assuming both strain and velocity gradient theories is investigated using the discretized model. The results suggest that nonlocal and size effects should not be neglected because they improve the prediction of corresponding dynamic amplitudes and, most importantly, the critical resonant frequencies of such nanoresonators. Neglecting these effects may impose a considerable source of error, which can be amended using more accurate modeling techniques.

关键词： velocity gradient elasticity theory nanotube resonators differential-quadrature method nonlinear vibration

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Anisotropy of multi-layered structure with sliding and bonded interlayer conditions

Lingyun YOU, Kezhen YAN, Jianhong MAN, Nengyuan LIU

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 632-645 doi: 10.1007/s11709-020-0617-4

摘要： A better understanding of the mechanical behavior of the multi-layered structure under external loading is the most important item for the structural design and the risk assessment. The objective of this study are to propose and develop an analytical solution for the mechanical behaviors of multi-layered structure generated by axisymmetric loading, and to investigate the impact of anisotropic layers and interlayer conditions on the multi-layered structure. To reach these objectives, first, according to the governing equations, the analytical solution for a single layer was formulated by adopting the spatial Hankel transform. Then the global matrix technique is applied to achieve the analytical solution of multi-layered structure in Hankel domain. The sliding and bonded interlayer conditions were considered in this process. Finally, the numerical inversion of integral transform was used to solve the components of displacement and stress in real domain. Gauss-Legendre quadrature is a key scheme in the numerical inversion process. Moreover, following by the verification of the proposed analytical solution, one typical three-layered flexible pavement was applied as the computing carrier of numerical analysis for the multi-layered structure. The results have shown that the anisotropic layers and the interlayer conditions significantly affect the mechanical behaviors of the proposed structure.

关键词： multi-layered structure Hankel transformation anisotropic transversely isotropic interlayer condition Gauss-Legendre quadrature

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基于双正交复序列的高效扩频调制方法

史小红

《中国工程科学》 2012年第14卷第3期页码 108-112

摘要：

提出了一种采用双正交复序列的高效扩频调制与解调方法（DoCS）。输入数据比特流被分割为长度为M的组，每组的M比特作为输入码字，从2M-2个长度为L的DoCS序列中选择一条序列进行发送，被选中的序列以QPSK方式调制在载波上，实现扩频通信。文中还提出了一种前向相位校正(FPC)方法来解决该系统中收发两端的载波同步问题。

关键词：调制与解调技术高效扩频调制前向相位校正双正交码

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OFDM直接变频接收机中通用的I/Q不平衡估计与补偿方法 None

Fang-lin GU, Shan WANG, Wen-wu WANG

《信息与电子工程前沿（英文）》 2018年第19卷第3期页码 388-397 doi: 10.1631/FITEE.1700003

摘要：直接变频接收机由于具有低功耗的特点，受到广泛关注，但是它存在较严重的同相/正交（I/Q）分量不平衡问题：I/Q不平衡会恶化接收信号的信噪比，进而影响系统的传输容量和能够支持的调制方式。本文首先分析了I/Q不平衡对OFDM接收机接收信号的影响，在此基础上，定义了一个统计量用于刻画OFDM系统的I/Q不平衡特性，并提出一种实现I/Q不平衡参数估计与补偿的方法。特别地，进一步证明该统计量不受传输信道影响，因而该方法适用于高斯白噪声和多径衰落信道等不同场景。仿真结果表明，该方法可以实现对OFDM系统I/Q不平衡的准确估计与补偿，使补偿后系统的误比特率性能接近于不存在I/Q不平衡的情形。更重要的是，由于该方法不依赖于导频信号，因而可以应用于采用不同标准的OFDM系统。

关键词：同相/正交分量不平衡；正交频分复用；标准独立

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标题作者时间类型操作

Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

期刊论文

Digital Readout System for Micromachined Gyroscope and Analysis for its Demodulation Algorithm

ZHOU Bin, GAO Zhong-yu, CHEN Huai, ZHANG Rong, CHEN Zhi-yong

期刊论文

自适应BPSK解调方法研究

李炎新,胡爱群,宋宇波

期刊论文