基于改进最大熵谱估计的长输管道内检测器

An in-line inspection device of long-distance pipelines based on improved maximum entropy spectrum estimation

对长输管道内检测器的机械结构、超声检测、检测定位、检测数据及信号处理等进行了分析,短时间序列、高分辨率、强抗噪能力的功率谱估计是管道超声内检测的关键技术,针对Burg最大熵谱估计存在的问题,从减小递推算法初始阶段误差出发,提出二阶预测误差滤波器系数倒推法,由二阶滤波器系数修正一阶反射系数,保证递推初始阶段最大熵原则,以适应短时间序列谱估计,研制了长输管道内检测器样机,经试验管道检测证明,腐蚀缺陷检测精度较高,内外定位较准确,应用前景很好。

Based on the analysis of the mechanism structure, ultrasonic inspection, orientation technology, inspection data and signal process, power entropy estimation what characterized short time serial, higher resolution and anti-noise was a key technology to inspect the wall of long-distance pipeline with ultrasonic. Aimed at the problem of Burg maximum entropy Spectral Estimation, the coefficient backward deduction of the second order prediction error filter was put forward through reduced original recurrence arithmetic error. The method based on recurrence original maximum entropy is that the second order filter coefficient can modify the first order reflection coefficient in order to fit the estimation of short time serial. The ultrasonic inner inspection pig was made. The test shows that it inspects and locates corrosion wall of sample quickly and precisely. It will be applied widely in the inspection long-distance pipeline in practice.