激光多普勒测速的信号处理应用研究
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摘要
激光多普勒测速系统以其非接触测量、线性特性、较高分辨率和快速动态响应等技术优势,被广泛应用于科研和工业领域。但多普勒信号具有噪声干扰大、频率变化范围大、信号不连续等特点,对它的分析处理直接关系到整个激光多普勒测速系统性能的好坏,因而有效去除噪声,提高测量精度成为激光多普勒测速方面不可忽视的问题。
本文针对多普勒信号的特性,引入相应的信号处理方法。首先为降低噪声干扰的影响,引入了自适应滤波算法,在最小均方LMS算法的基础上,提出一种新的变步长LMS算法,该算法使用的变步长因子,兼顾了测量噪声方差和误差信号的具体变化过程,而且求变步长因子时计算量较小,使该算法具有更好的收敛性能和滤波效果。其次针对激光多普勒信号是一种密集型频谱的特性,研究了一种能根据频带带宽自适应地选择细化倍数的重采样算法,改进了传统的复调制Zoom-FFT算法,该算法对感兴趣的任意频带自适应地选择细化倍数,然后通过频谱校正算法进一步逼近真实频率,较好地解决制约传统复调制细化分析的计算速度问题,达到提高频率分辨率,快速细化的目的。通过仿真试验,精确地测得多普勒频率,验证了上述算法的高效性及鲁棒性。
The Laser Doppler Velocimeter (LDV) is widely used in the science research and industry fields due to its many technological advantages, such as non-contact measurement, linearity, high resolution and rapid dynamic response, etc. But the Doppler signal possess the characteristics of heavy noise interference, broad frequency change and discontinuous signal, its analysis and processing affects directly whether the whole system is better or not. Thus, removing the noise effectively and improving the measurement accuracy become a significant question for the LDV system.
A corresponding signal processing method is proposed in this paper according to the characteristics of Doppler signal. At first, in order to decrease the noise interference, a self-adapted filtering algorithm is introduced. On the basis of LMS algorithm, a novel LMS with varying step distance is presented. This vary step distance factor not only measures the detailed changing process of the noise variance and the error signal, but also needs relatively less computation, allows this improved algorithm to have better convergence property and filter effect. In addition, since the signal has a kind of dense spectrum, a re-sampled algorithm that can chose zooming multiple self-adapted according to frequency band is researched, is an improvement of traditional Zoom-FFT. For the frequency band of interest, after choosing the zooming multiple, is approached real frequency. This algorithm solves the problem of the traditional compound modulating that constrains the computing velocity, increases the high-frequency resolution and satisfies the demand of quickly zooming. Through the simulation, the frequency can be obtained accurately, and the high efficiency and robustness of proposed algorithm can be validated.
本文针对多普勒信号的特性,引入相应的信号处理方法。首先为降低噪声干扰的影响,引入了自适应滤波算法,在最小均方LMS算法的基础上,提出一种新的变步长LMS算法,该算法使用的变步长因子,兼顾了测量噪声方差和误差信号的具体变化过程,而且求变步长因子时计算量较小,使该算法具有更好的收敛性能和滤波效果。其次针对激光多普勒信号是一种密集型频谱的特性,研究了一种能根据频带带宽自适应地选择细化倍数的重采样算法,改进了传统的复调制Zoom-FFT算法,该算法对感兴趣的任意频带自适应地选择细化倍数,然后通过频谱校正算法进一步逼近真实频率,较好地解决制约传统复调制细化分析的计算速度问题,达到提高频率分辨率,快速细化的目的。通过仿真试验,精确地测得多普勒频率,验证了上述算法的高效性及鲁棒性。
The Laser Doppler Velocimeter (LDV) is widely used in the science research and industry fields due to its many technological advantages, such as non-contact measurement, linearity, high resolution and rapid dynamic response, etc. But the Doppler signal possess the characteristics of heavy noise interference, broad frequency change and discontinuous signal, its analysis and processing affects directly whether the whole system is better or not. Thus, removing the noise effectively and improving the measurement accuracy become a significant question for the LDV system.
A corresponding signal processing method is proposed in this paper according to the characteristics of Doppler signal. At first, in order to decrease the noise interference, a self-adapted filtering algorithm is introduced. On the basis of LMS algorithm, a novel LMS with varying step distance is presented. This vary step distance factor not only measures the detailed changing process of the noise variance and the error signal, but also needs relatively less computation, allows this improved algorithm to have better convergence property and filter effect. In addition, since the signal has a kind of dense spectrum, a re-sampled algorithm that can chose zooming multiple self-adapted according to frequency band is researched, is an improvement of traditional Zoom-FFT. For the frequency band of interest, after choosing the zooming multiple, is approached real frequency. This algorithm solves the problem of the traditional compound modulating that constrains the computing velocity, increases the high-frequency resolution and satisfies the demand of quickly zooming. Through the simulation, the frequency can be obtained accurately, and the high efficiency and robustness of proposed algorithm can be validated.
引文
[1]孙渝生.激光多普勒测速技术及其应用.第二版.上海科学技术文献出版社.1995:5-20页
[2]杜斯特等著.激光多普勒测速技术的原理和实践.第一版.科学出版社.1992:7-30页
[3]孙渝生,赵建新,范丽娟.激光多普勒测速技术的最新发展.传感器世界.1998(8):20-26页
[4]葛宁.多普勒激光测速仪在轴流风扇流场测量中的应用.南京航空航天大学学报.1996,8(4):565-567页
[5]Morio Toyoshima,Tetsuya Ohashi,Shigenobu Shinohara etal.New Digital DisplacementMeasuring Circuit for Aperiodic Vibration Using Self-Mixing Type LDV.IEEE.1994(5):336-339P
[6]Sang-Hee Nam,Sung-Kwang Park,Duck-Hoon Kim etal.Time Series Analysis on dysfunction of the Autonomous Nerve System measured non-invasively with the temperature variation using Laser Doppler Velocimeter.IEEE.January 1997:1701-1702P
[7]洪水棕等.现代测试技术.第一版.上海交通大学出版社.2002:161-165页
[8]Yeh Y,Cummins H Z.Localized flow measurements with a He-Ne laser spectrometer.Appl.Phys.Letter,1980,176(4):176-178P
[9]清华大学工程力学系激光测速组.激光多普勒测速仪的研制.全国第一届气动实验非接触测量会议文集(第二分册).1978:131-135页
[10]舒玮,王仕康.双光束激光流速计多普勒信号的理论分析.激光多普勒测速技术讨论会论文集.1978:86-91页
[11]孙厚钧,董增南,宋传琳等.偏振差动式LDA的测速机理及其应用.力学学报.1982(2):356-360页
[12]Sahin Kaya Ozdemir,Sotetsu Takamiya,Shigenobu Shinohara etal.Aspeckle velocimeter using a semiconductor laser with external optical feedback from a moving surface:effects of system parameters on the reproducibility and accuracy of measurements.Meas.Sci.Technol.2000(11):1447-1455P
[13]Shibata T,Shinohara S,Ikeda H etal.Laser speckle velocimeter using self-mixing laser diode.IEEE Traps.Instrum.Meas.1996(45):499-503P
[14]Ozdemir S K,Takasu T,Shinohara S etal.Simultaneous measurement of velocity and length of moving surfaces by a speckle velocimeter using two self-mixing laser diodes Appl.Opt.1999(38):1968-1974P
[15]Ozdemir S K,Ito S,Shinohara S etal.Correlation-based speckle velocimeter with self-mixing interference in a semiconductor laser Appl.Opt.1999(38):6859-6865P
[16]Hirlemen E Dan.A history review of phase-Doppler sizing anemometry.20th Aniversorv of PDA.Germany.1995(25):156-160P
[17]向永江.全光纤激光多普勒测速技术的研究.光学学报.1998,12(11):1053-1056页
[18]沈熊.流体近代测量技术新的成长点.国际学术动态.1998(7):75-76页
[19]Ibranhim K M,Bachalo W D.Evaluations of an Advanced Real-Time Signal Processing System Using the Foamier Transform,Proc of International Conference on Fluid Dynamic Measurement and Its Application.Beijing.1994(35):1320-1326P
[20]肖逾男.基于DSP芯片的激光多普勒测速仪的研制.武汉大学硕士学位论文.2004:49-50页
[21]特瑞恩LE著.王什康,沈熊,周作儿译.激光多普勒技术.清华大学出版社.1985:44-55页
[22]沈熊.激光多普勒测速技术及应用.北京:清华大学出版社.2004:33-54页
[23]F.杜斯特,A.梅林,J.H.怀特洛著.沈熊,许宏庆,周作元译.激光多普勒测速技术的原理和实践.北京:科学出版社.1992:23-44页
[24]韩微微.基于DSP芯片的激光多普勒测速仪的设计.大连理工大学硕士学位论文.2007:35-38页
[25]金国藩,李景镇.激光测量学.北京:科学出版社.1998:283-289页
[26]Sanjit K.Mitra.Digital Signal Processing.A Computer-Based Approach.McGraw-Hill Companies.Butterworths.2001(37):423-429P
[27]Rabiner.L,Gold.B.Theory and Application of Digital Signal Processing.Prentice Hall.1995(23):212-218P
[28]J.P.Porakis,D.G.Manolakis.Digital Signal Processing:Principles,Algorithms and Application.New York,1992(46):351-357P
[29]P.P.Vaidyanathan.Multirate Systems and Filter Banks.Prentice Hall:Englewood Cliffs,1993(11):516-521P
[30]许祖茂.固体激光多普勒测速仪研究.大连理工大学硕士学位论文.2005:29-30页
[31]沈熊,张松,董鹏等.激光测速数字相关信号处理器的研制.实验力学.1998(1):294-301页
[32]Ibrahim K M,Werthimer G D,Bachalo W D.Signal processing consideration for laser Doppler and phase Doppler application.5th Inter.Symposium on Appl.of Laser Techniques to Fluid Mechanics.Lisbon,1990(7):421-427P
[33]Ibrahim K M,Werthimer G D,Bachalo W D.The significance of the Fourier analysis in signal detection and processing in laser voppier and phase.6th inter.Symposium on Appl.of Laser Techniques to Fluid Mechanics.Lisbon,1992(6):713-719P
[34]Abouina sr T,Mayyas K.A robust vadable step-size LMS algorithm analysis and simulations.IEEE Trans.On Signal.1997,45(3):631-639P
[35]Pazaitis D I,Constantinides A G.A novel kurtosis driven variable step-size adaptive algorithm.IEEE Trans.On Signal.1999,47(3):864-872P
[36]Mader A,Puder H,Schmidt G U.Step-size control for acoustic echo cancellation filter an overview.Signal Processing.2000,80(9):1697-1719P
[37]覃景繁,欧阳景正.一种新的变步长自适应滤波算法.数据采集与处理.1997,12(3):171-194页
[38]Gitlin R D,Weinstein S D.On the design of gradient algorithms for digitally implemented adaptivefilters.IEEE Trans on CT.1973(2): 125-136P
[39]Yasukaws H,Shimada S,Furukrawal etal.Acoustic Echo Canceller with High Speech Quality.ICAS SO' 87:2125-2128P
[40]Gitlin R D,Weinstein S B.The Effects of Large Interference on the Tracking Capability of Digitally Implemented Echo Cancellers.IEEE Trans on COM.1978(6):632-638P
[41]叶华,吴伯修.变步长自适应滤波算法的研究.电子学报.1990(18):63-69页
[42]吴光弼,祝琳瑜.一种变步长LMS自适应滤波算法.电子学报.1994(22):55-60页
[43]高鹰,谢胜利.一种变步长LMS自适应滤波算法及分析.电子学报.2001(29):1094-1097页
[44]丁康,陈键林,苏向荣.平稳和非平稳振动信号的若干处理方法及发展.振动工程学报.2003(1):25-29页
[45]Runtz K J,Hack D A Multistage.DFT-FFT-CZT approach for accurate efficient analysis of sparsely distributed spectra.Proceedings of 2002 IEEE Candian conference on electrical computing engineering.2002:127-132P
[46]应启珩,冯一云,窦维蓓.离散时间信号分析和处理.北京:清华大学出版社.2001:155-159页
[47]Oppenheim A V,Schafer RW.Discrete-Time Signal Processing.Prentice-Hall.1989:623-628P
[48]李勇,黄遵熹,俞卞章.基于移位离散傅立叶变换的线性频率估计方法.西北工业大学学报.1995,13(3):414-417页
[49]沈希忠.连续信号频谱细化的算法探讨.上海冶金高等专科学校学报.2004(2):231-235页
[50]刘进明,应怀樵.FFT谱连续细化分析的傅立叶变换法.振动工程学报.1995(8):162-166页
[51]郭贵虎,胡新生.基于改进Zoom-FFT的信号检测算法研究.无线电工程.2003(5):26-28页
[52]王力,张冰,徐伟.基于MATLAB复调制ZOOM-FFT算法的分析与实现. 舰船电子工程.2006,(4):119-121页
[53]郭瑜,汤宝平,纪跃波等.基于解析信号和带通滤波的频率细化分析.重庆大学学报.2001,(7):17-21页
[54]李玉柏.基于DFT滤波器组实现Zoom-FFT算法分析.信号处理.2000(16):122-127页
[55]丁康,谢明,张彼德等.基于复解析带通滤波器的复调制细化谱分析原理和方法.振动工程学报.2001(1):30-35页
[2]杜斯特等著.激光多普勒测速技术的原理和实践.第一版.科学出版社.1992:7-30页
[3]孙渝生,赵建新,范丽娟.激光多普勒测速技术的最新发展.传感器世界.1998(8):20-26页
[4]葛宁.多普勒激光测速仪在轴流风扇流场测量中的应用.南京航空航天大学学报.1996,8(4):565-567页
[5]Morio Toyoshima,Tetsuya Ohashi,Shigenobu Shinohara etal.New Digital DisplacementMeasuring Circuit for Aperiodic Vibration Using Self-Mixing Type LDV.IEEE.1994(5):336-339P
[6]Sang-Hee Nam,Sung-Kwang Park,Duck-Hoon Kim etal.Time Series Analysis on dysfunction of the Autonomous Nerve System measured non-invasively with the temperature variation using Laser Doppler Velocimeter.IEEE.January 1997:1701-1702P
[7]洪水棕等.现代测试技术.第一版.上海交通大学出版社.2002:161-165页
[8]Yeh Y,Cummins H Z.Localized flow measurements with a He-Ne laser spectrometer.Appl.Phys.Letter,1980,176(4):176-178P
[9]清华大学工程力学系激光测速组.激光多普勒测速仪的研制.全国第一届气动实验非接触测量会议文集(第二分册).1978:131-135页
[10]舒玮,王仕康.双光束激光流速计多普勒信号的理论分析.激光多普勒测速技术讨论会论文集.1978:86-91页
[11]孙厚钧,董增南,宋传琳等.偏振差动式LDA的测速机理及其应用.力学学报.1982(2):356-360页
[12]Sahin Kaya Ozdemir,Sotetsu Takamiya,Shigenobu Shinohara etal.Aspeckle velocimeter using a semiconductor laser with external optical feedback from a moving surface:effects of system parameters on the reproducibility and accuracy of measurements.Meas.Sci.Technol.2000(11):1447-1455P
[13]Shibata T,Shinohara S,Ikeda H etal.Laser speckle velocimeter using self-mixing laser diode.IEEE Traps.Instrum.Meas.1996(45):499-503P
[14]Ozdemir S K,Takasu T,Shinohara S etal.Simultaneous measurement of velocity and length of moving surfaces by a speckle velocimeter using two self-mixing laser diodes Appl.Opt.1999(38):1968-1974P
[15]Ozdemir S K,Ito S,Shinohara S etal.Correlation-based speckle velocimeter with self-mixing interference in a semiconductor laser Appl.Opt.1999(38):6859-6865P
[16]Hirlemen E Dan.A history review of phase-Doppler sizing anemometry.20th Aniversorv of PDA.Germany.1995(25):156-160P
[17]向永江.全光纤激光多普勒测速技术的研究.光学学报.1998,12(11):1053-1056页
[18]沈熊.流体近代测量技术新的成长点.国际学术动态.1998(7):75-76页
[19]Ibranhim K M,Bachalo W D.Evaluations of an Advanced Real-Time Signal Processing System Using the Foamier Transform,Proc of International Conference on Fluid Dynamic Measurement and Its Application.Beijing.1994(35):1320-1326P
[20]肖逾男.基于DSP芯片的激光多普勒测速仪的研制.武汉大学硕士学位论文.2004:49-50页
[21]特瑞恩LE著.王什康,沈熊,周作儿译.激光多普勒技术.清华大学出版社.1985:44-55页
[22]沈熊.激光多普勒测速技术及应用.北京:清华大学出版社.2004:33-54页
[23]F.杜斯特,A.梅林,J.H.怀特洛著.沈熊,许宏庆,周作元译.激光多普勒测速技术的原理和实践.北京:科学出版社.1992:23-44页
[24]韩微微.基于DSP芯片的激光多普勒测速仪的设计.大连理工大学硕士学位论文.2007:35-38页
[25]金国藩,李景镇.激光测量学.北京:科学出版社.1998:283-289页
[26]Sanjit K.Mitra.Digital Signal Processing.A Computer-Based Approach.McGraw-Hill Companies.Butterworths.2001(37):423-429P
[27]Rabiner.L,Gold.B.Theory and Application of Digital Signal Processing.Prentice Hall.1995(23):212-218P
[28]J.P.Porakis,D.G.Manolakis.Digital Signal Processing:Principles,Algorithms and Application.New York,1992(46):351-357P
[29]P.P.Vaidyanathan.Multirate Systems and Filter Banks.Prentice Hall:Englewood Cliffs,1993(11):516-521P
[30]许祖茂.固体激光多普勒测速仪研究.大连理工大学硕士学位论文.2005:29-30页
[31]沈熊,张松,董鹏等.激光测速数字相关信号处理器的研制.实验力学.1998(1):294-301页
[32]Ibrahim K M,Werthimer G D,Bachalo W D.Signal processing consideration for laser Doppler and phase Doppler application.5th Inter.Symposium on Appl.of Laser Techniques to Fluid Mechanics.Lisbon,1990(7):421-427P
[33]Ibrahim K M,Werthimer G D,Bachalo W D.The significance of the Fourier analysis in signal detection and processing in laser voppier and phase.6th inter.Symposium on Appl.of Laser Techniques to Fluid Mechanics.Lisbon,1992(6):713-719P
[34]Abouina sr T,Mayyas K.A robust vadable step-size LMS algorithm analysis and simulations.IEEE Trans.On Signal.1997,45(3):631-639P
[35]Pazaitis D I,Constantinides A G.A novel kurtosis driven variable step-size adaptive algorithm.IEEE Trans.On Signal.1999,47(3):864-872P
[36]Mader A,Puder H,Schmidt G U.Step-size control for acoustic echo cancellation filter an overview.Signal Processing.2000,80(9):1697-1719P
[37]覃景繁,欧阳景正.一种新的变步长自适应滤波算法.数据采集与处理.1997,12(3):171-194页
[38]Gitlin R D,Weinstein S D.On the design of gradient algorithms for digitally implemented adaptivefilters.IEEE Trans on CT.1973(2): 125-136P
[39]Yasukaws H,Shimada S,Furukrawal etal.Acoustic Echo Canceller with High Speech Quality.ICAS SO' 87:2125-2128P
[40]Gitlin R D,Weinstein S B.The Effects of Large Interference on the Tracking Capability of Digitally Implemented Echo Cancellers.IEEE Trans on COM.1978(6):632-638P
[41]叶华,吴伯修.变步长自适应滤波算法的研究.电子学报.1990(18):63-69页
[42]吴光弼,祝琳瑜.一种变步长LMS自适应滤波算法.电子学报.1994(22):55-60页
[43]高鹰,谢胜利.一种变步长LMS自适应滤波算法及分析.电子学报.2001(29):1094-1097页
[44]丁康,陈键林,苏向荣.平稳和非平稳振动信号的若干处理方法及发展.振动工程学报.2003(1):25-29页
[45]Runtz K J,Hack D A Multistage.DFT-FFT-CZT approach for accurate efficient analysis of sparsely distributed spectra.Proceedings of 2002 IEEE Candian conference on electrical computing engineering.2002:127-132P
[46]应启珩,冯一云,窦维蓓.离散时间信号分析和处理.北京:清华大学出版社.2001:155-159页
[47]Oppenheim A V,Schafer RW.Discrete-Time Signal Processing.Prentice-Hall.1989:623-628P
[48]李勇,黄遵熹,俞卞章.基于移位离散傅立叶变换的线性频率估计方法.西北工业大学学报.1995,13(3):414-417页
[49]沈希忠.连续信号频谱细化的算法探讨.上海冶金高等专科学校学报.2004(2):231-235页
[50]刘进明,应怀樵.FFT谱连续细化分析的傅立叶变换法.振动工程学报.1995(8):162-166页
[51]郭贵虎,胡新生.基于改进Zoom-FFT的信号检测算法研究.无线电工程.2003(5):26-28页
[52]王力,张冰,徐伟.基于MATLAB复调制ZOOM-FFT算法的分析与实现. 舰船电子工程.2006,(4):119-121页
[53]郭瑜,汤宝平,纪跃波等.基于解析信号和带通滤波的频率细化分析.重庆大学学报.2001,(7):17-21页
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