大型储罐底板腐蚀浸入式声学定位方法

Immersion acoustic positioning method of corrosion for large tank bottom plate

为解决大型储罐底板腐蚀检测存在检测盲区的问题,提出浸入式声学检测方法,其中储罐底板腐蚀声源的定位是关键。基于时延估计的声源被动定位算法,结合储罐底板浸入式声学检测的特点,运用移动式平面五元十字基阵声学定位方法,模拟储罐底板定位并验证试验。结果表明:五元十字基阵定位算法在测向精度和测距精度上的误差均满足储罐腐蚀检测定位要求;测向精度不受声源角度φ和距离r的影响;测距精度仅与r成正相关,而与φ无关;得到测距相对误差与r的拟合关系式,确定浸入式声学检测单元的最大有效半径。

In order to avoid detection dead zone in corrosion detection of large-scale storage tank floor,an immersion acoustic method is proposed,of which locating corrosion sound source is a key. Based on a passive source localization algorithm featuring time delay estimation and considering characteristics of immersed acoustic detection of tank floor,a mobile planar five-element cross array acoustic method was applied to simulate positioning of bottom plate and verify the test. The results show that this method meets the requirement of corrosion detection in accuracy of direction finding and distance measurement. Direction finding accuracy is not affected by sound source angle φ and distance r while distance accuracy is only positively related to r and independent of φ. With the fitting relationship between relative error of distance and r obtained from experiment,the maximum effective radius of immersed acoustic detecting unit can be determined.