激光多普勒测振啁啾噪声分析及其抑制方法  

Chirp Noise Analysis in Laser Doppler Vibration Measurement and Its Suppression Methods

作　　者：王亚豪 沈杨翊 孔新新[1,2] 张文喜 Wang Yahao;Shen Yangyi;Kong Xinxin;Zhang Wenxi(Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China;School of Optoelectronics,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院空天创新信息研究院,北京100094 [2]中国科学院大学光电学院,北京100049

出　　处：《光学学报》2024年第5期86-92,共7页Acta Optica Sinica

基　　金：国家重点研发计划(2022YFF0706300);中国科学院青年创新促进会项目(2020131,2023132)。

摘　　要：根据外差激光多普勒测振过程的物理原理,分析了其在目标存在低频高速运动情况下测量高频低速振动的过程。在这一过程中,因杂散光而产生的测量噪声表现出啁啾特性,该研究还阐明了这种噪声的影响和表现形式、特点。针对此啁啾噪声,提出了一种微分预处理解调方法,理论分析表明这种解调方法有明显的啁啾噪声抑制效果,并进一步进行了仿真和实验验证。搭建了存在杂散光的外差激光多普勒测振系统,对目标振动进行了测量,分别通过常规解调方法和微分预处理解调方法进行解调,实验结果验证了啁啾噪声的存在和微分预处理解调方法抑制啁啾噪声的有效性,该方法可使啁啾噪声功率下降约81.8%,可有效降低杂散光对测量结果的影响。Objective Based on the physical principle of the heterodyne laser Doppler vibration measurement process,we analyze the measurement process of high-frequency and low-speed movement in the presence of low-frequency and high-speed background movement.In the process,the measurement noise generated by the presence of stray light exhibits chirp characteristics,with the effects and patterns of chirp noise explained.In response to the chirp noise,we propose a derivative preprocessing method for demodulation.The theoretical analysis shows the method exerts a significant effect on suppressing chirp noise,which is verified by simulations and experiments.Meanwhile,we set a heterodyne laser Doppler vibration measurement system with stray light and measure the target vibration.The normal method and derivative preprocessing method are adopted respectively for demodulation.The experimental results verify the existence of chirp noise and the effectiveness of the derivative preprocessing method in suppressing chirp noise,which decreases the chirp noise power by about 81.8%.The method can effectively reduce the influence of stray light on vibration measurement.Heterodyne laser Doppler vibration measurement technology is a widely adopted non-contact and non-destructive movement measurement method,with the advantages of fast response speed and high resolution.It has a strong detection ability for single frequency movement and can quickly identify the characteristic frequency of target movement.However,in the presence of low-frequency high-speed background movement,the measurement of high-frequency low-speed movement is severely affected by chirp noise,which is caused by stray light and closely related to low-frequency highspeed background movement.The chirp noise can seriously affect the measurement of high-frequency low-speed movement,with errors even reaching tens of times larger than those of real movement.There is a lack of research on the principle of chirp noise caused by stray light and suppression methods of chirp noise.We de

关 键 词：信号处理 激光多普勒测振 啁啾噪声 杂散光 微分预处理 

分 类 号：O436[机械工程—光学工程]