基于混合卷积窗的激光多普勒信号处理研究  

Laser Doppler Signal Processing Based on Hybrid Convolution Window

作　　者：陈昊 张达[1] Chen Hao;Zhang Da(College of Automation and Electronic Engineering,Qingdao University of Science and Technology,Qingdao 266061,Shandong,China)

机构地区：[1]青岛科技大学自动化与电子工程学院,山东青岛266061

出　　处：《激光与光电子学进展》2023年第17期278-290,共13页Laser & Optoelectronics Progress

摘　　要：快速傅里叶变换是激光多普勒测速系统信号处理的一种常用方法,但在异步采样时存在频谱泄漏和栏栅效应,其处理精度偏低。为了提高检测精度,提出基于Nuttall窗函数和五项最大旁瓣衰减窗函数的混合卷积窗改进六谱线插值校正算法。混合卷积窗在保证良好的旁瓣特性的同时也能保证主瓣不过宽,改进六谱线插值可有效抑制栏栅效应在参数估计过程中的负面影响,提高分析精度。为了避免解高次方程,提出三次B样条插值来拟合插值系数,并推导出改进六谱线插值的频率校正公式。搭建了双光束后向散射差动式激光多普勒测速平台,利用仿真数据和实测信号验证了本文算法在低信噪比环境下有较好的频率和速度测量精度。Fast Fourier transform is a widely used method for signal processing in laser Doppler velocimetry systems.However,spectral leakage and fence effects occur in asynchronous sampling,and its processing accuracy is low.A hybrid convolution window based on the Nuttall window function and five-term maximum-sidelobe-decay window function is proposed to improve the detection accuracy of the six-spectral line interpolation correction algorithm.The hybrid convolution window can prevent the main lobe from becoming wide while ensuring good side lobe characteristics.The improved six-spectral line interpolation can effectively suppress the negative influence of the fence effect in the parameter estimation process and improve the analysis accuracy.The cubic B-spline interpolation is proposed to fit the interpolation coefficients to eliminate higher-order equations,and a frequency correction equation for the improved six-spectral line interpolation is derived.A dual-beam backscattering differential laser Doppler velocimetry platform is developed.The simulation data and measured signals demonstrate that the proposed algorithm exhibits good frequency and velocity measurement accuracy in the low signal-to-noise ratio environment.

关 键 词：激光光学 快速傅里叶变换 激光多普勒测速 频谱泄漏 混合卷积窗 六谱线插值 三次B样条 

分 类 号：O433[机械工程—光学工程]