小波分析在激光自混合干涉位移传感器中的应用  

Application of wavelet analysis in laser self-mixing interferometry for displacement measurement

作　　者：杨颖[1,2] 李醒飞[1,2] 寇科[1] 王错[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]天津大学微光机电系统技术教育部重点实验室,天津300072

出　　处：《光电子．激光》2013年第6期1075-1081,共7页Journal of Optoelectronics·Laser

基　　金：高等学校博士学科点专项科研基金(20110032110052);精密测试技术及仪器国家重点实验室开放基金(PIL1006)资助项目

摘　　要：为减小激光自混合干涉位移传感器测量误差,提出了基于小波分析的自混合干涉信号处理方法。在进行全相位快速傅里叶变换(FFT)解调相位之前,利用离散小波分解、重构去除自混合干涉归一化信号的奇异点,有效降低调制电流斜率突变引入的高次谐波干扰,同时去除高频随机噪声干扰。简述了自混合干涉位移测量原理,介绍了基于小波分析的自混合干涉信号处理算法原理并进行了算法仿真,采用数值仿真分析了系统反馈水平及调制参数对测量误差的影响,利用压电陶瓷(PZT)对自混合干涉位移测量系统进行标定。结果表明,位移测量误差减小到2.45nm。应用小波分析处理干涉信号可减小激光自混合干涉位移传感器的测量误差。In order to reduce the measurement error of the displacement sensor based on self-mixing interference, a signal processing method based on wavelet analysis is proposed. Before the all-phase spectrum analysis, wavelet analysis is applied to remove the singular points of normalized signals. This method can reduce the impact of higher harmonic produced by the slope mutation of modulation current and diminish the disturbing of high-frequency noise very effectively. First, the principle of displacement measurement based on self-mixing interference is described briefly. Second,the signal processing algorithm is investigated with arithmetic simulation. Third, the influence of feedback level and modulation parameter on the error of displacement is analyzed by numerical simulation. At last, experiment system is established and the calibration result of piezoelectric ceramics is presented. Experimental results indicate that the displacement error can be decreased to 2.45 nm, so the wavelet analysis can reduce the displacement error of self-mixing interferometer.

关 键 词：自混合干涉 位移传感器 小波分析 

分 类 号：TH741[机械工程—光学工程] TH822[机械工程—仪器科学与技术]