数字干涉图实时相位提取PSM-IP核的FPGA实现  

FPGA implementation of real-time phase extraction PSM-IP core for digital interferograms

作　　者：马峻[1,2] 毛露露 陈宏 陈寿宏 郭玲[1,2] 徐翠锋 Ma Jun;Mao Lulu;Chen Hong;Chen Shouhong;Guo Ling;Xu Cuifeng(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Automatic Detecting Technology and Instruments,Guilin 541004,China)

机构地区：[1]桂林电子科技大学电子工程与自动化学院,桂林541004 [2]广西自动检测技术与仪器重点实验室,桂林541004

出　　处：《电子测量与仪器学报》2019年第12期71-79,共9页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(61671008)资助项目。

摘　　要：针对现有数字干涉图相位提取技术多依赖计算机操作系统,不能满足高速信号处理的现状,提出了在FPGA上基于相移法(PSM)设计并实现PSM-IP核提取相位。PSM-IP核包括数字干涉图输入缓存模块、干涉图相移运算模块、干涉图反正切函数运算模块和相位信息输出模块等。在数字干涉图反正切函数运算模块中对坐标旋转数字计算机(CORDIC)算法进行了优化,并实现了流水线结构的反正切运算,从而可完成数字干涉图的实时相位提取。通过对计算机仿真图、云纹干涉仪实测干涉图和光栅投影条纹图测试,结果表明,利用PSM-IP核提取256×256 pixels数字干涉图的相位,均方根误差在1‰量级,运行时间小于1.4 ms,在保证精度的同时有效地缩短了相位提取时间,验证了利用PSM-IP核进行实时相位提取的有效性。In order to solve the existing digital interferogram phase extraction technology, most of them rely on computer to complete, it cannot meet the status of high-speed signal processing. A PSM-IP core designed and implemented on the field programmable gate array(FPGA) based on phase shift method(PSM) is proposed for extracting phase. The PSM-IP core includes a digital interferogram input buffer module, an interferogram phase shifting operation module, an interferogram inverse tangent function operation module and a phase information output module. The coordinate rotation digital computer(CORDIC) algorithm is optimized in the digital interferogram inverse tangent function operation module, and the arctangent operation of the pipeline structure is realized. Thus, real-time phase extraction of the digital interferograms can be completed. The computer simulation and real experiments results show that the PSM-IP core is used to extract the phase of the 256×256 pixels digital interferograms, the root mean square error is 1‰, the running time less than 1.4 ms, the phase extraction time is effectively shortened while ensuring the accuracy, and the effectiveness of real-time phase extraction using PSM-IP core is verified.

关 键 词：数字干涉图 相移法 CORDIC算法 相位提取 IP核 

分 类 号：TH744.3[机械工程—光学工程]