基于复合光栅的PMP在钢轨三维在线测量中的应用

Application of PMP based on composite grating in 3D online measurement of rails

随着铁路向高速、重载及高密度运行的方向发展,钢轨磨耗及表面缺陷日益加剧。基于复合光栅的相位测量轮廓术(phase measurement profilometry, PMP)在保有传统PMP高精度优点的基础上,缩短了测量时间,提高了测量效率。以钢轨磨耗及表面缺陷的三维测量为目的,将传统PMP及基于复合光栅的PMP进行了仿真实现、实验验证与对比分析。同时,在铁路运用背景下,对基于复合光栅的PMP算法进行改进,衍生出基于双频率通道和2+1算法的复合光栅PMP,减小了频谱混叠,提高了测量精度。理论仿真及实验结果表明,改进后的方法测量精度有了明显的提升,且能较好的重建钢轨的三维形貌和表面缺陷,相较于传统复合光栅,测量精度提升了54.9%。

With the development of high-speed,heavy-duty and high-density railways,rail wear and surface defects are increasing.phase measurement profilometry(PMP)based on composite grating decreases the measurement time and improves the efficiency while maintaining the high precision of traditional PMP.The traditional PMP and composite grating-based PMP are simulated,experimentally verified and compared for the purpose of three-dimensional measurement of rail wear and surface defects.At the same time,under the background of railway application,the PMP algorithm based on composite grating is improved,and the composite grating PMP based on dual frequency channel and 2+1 algorithm is derived,which improves the measurement accuracy and reduces the spectrum aliasing.Theoretical simulation and experimental results show that the proposed method has improved the measurement accuracy,and can better reconstruct the three-dimensional shape and surface defects of the rail,and the relative accuracy is up to 54.9%.