改进的二次1.5维谱估计在管道内检测中的应用

Application of Improved Secondary 1.5-D Spectrum Estimation in Pipeline Inner Inspection

针对手动壁厚获取算法存在劳动强度大、效率低等缺点,而现有自动壁厚获取算法精度又不高、容易误判且适应性不强,提出了改进的二次1.5维谱估计自动壁厚获取算法:对管道超声A波信号做1.5维谱估计,根据壁厚上下限对数据截取与补零,并在此基础上再做一次1.5维谱估计,获取壁厚信息.实验表明:该算法产生的壁厚数据精度高,相对误差在3%以内.

Aimed at the problem that the manual wall thickness acquisition algorithm has the disadvantages of large labor intensity, low efficiency, and so on, and the fact that the existing automatic wall thickness acquisition algorithm is not accurate and adaptable, the automatic wall thickness acquisition algorithm based on the improved secondary 1.5-D spectrum estimation was proposed. The pipeline ultrasonic A-wave signals were estimated by 1.5-D spectrum that were intercepted and filled zero by the upper and lower limit of the wall thickness. Then, the 1.5-D spectrum estimation was done again, and the wall thickness infor- mation was obtained. Experimental results show that the wall thickness data generated by this algorithm is more accurate and the relative error is within 3 %.