基于FPGA的线阵干涉条纹相位解包裹算法实现

Phase Unwrapping Algorithm for Linear Interference Fringe Based on FPGA

针对线阵图像传感器干涉条纹相位提取后存在残差点及噪声的问题,设计了一种易于在嵌入式系统中实现的信号处理算法。给出的逐点差值比较和累加滤波算法采用可变包裹系数得到相位解包裹初值,利用采取了防累积误差溢出措施的二阶IIR椭圆滤波器消除噪声,并在截取时进行四舍五入处理。利用FPGA技术实现了简单、快速和可靠的相位解包裹算法。实际测试结果表明,能够有效消除线阵干涉条纹相位残差点,并使相位信号平滑。实现了相位解包裹的目的,具有很好的工程应用价值。

A signal processing algorithm was designed to solve residual error and noise problems usually caused by phase extraction of interference fringes in linear array image sensor.The algorithm includes different point comparison,accumulation and filtering,and is easy to implement in embedded system.The initial value of phase unwrapping was obtained with a variable wrapping coefficient.The second-order IIR elliptic filter with anti-spillover of cumulative error was used to eliminate noise,and rounding was carried out when intercepting.A simple,fast and robust phase unwrapping algorithm was implemented by taking advantage of FPGA.The actual test results show that the phase residual error of linear interference fringes can be eliminated effectively and the phase signal is smoothed.The purpose of phase unwrapping is realized,with good engineering application value.