基于U曲线法的油气润滑ECT系统图像重建病态优化

Image Reconstruction Ill-conditioned Optimization for Oil-air Lubrication ECT System Based on U-curve Method

采用U曲线法确定油气润滑ECT系统图像重建中的正则化参数,分析正则化处理后灵敏度矩阵的病态性;通过LBP算法和Tikhonov正则化算法分别对油气润滑ECT系统管道截面进行第一次图像重建;对第一次重建图像的灰度分布矩阵进行门限滤波阈值的优化,并对管道截面进行二次图像重建。结果表明:相较于L曲线法,U曲线法选取的正则化参数在削弱灵敏度矩阵病态程度方面的作用显著;第一次图像重建中,图像重建质量有较大改善;门限滤波阈值优化后的二次图像重建中,图像重建质量进一步提高。研究表明U曲线法确定的正则化参数和门限滤波阈值优化有助于提高油气润滑ECT系统的图像重建质量。

The regularization parameters in image reconstruction of oil-air lubrication ECT system were determined by U-curve method,the ill-conditioning of sensitivity matrix after regularization was analyzed.The first image reconstruction of the pipeline section of oil-air lubrication ECT system was completed by LBP algorithm and Tikhonov regularization algorithm respectively.The secondary image reconstruction of the pipeline section was completed after the threshold filtering threshold was optimized for gray distribution matrix of the first reconstructed image.The results show that the regularization parameters selected by U-curve method have a significant effect on weakening the ill-conditioning of sensitivity matrix compared with L-curve method.In the first image reconstruction,the image reconstruction quality is greatly improved,and in the secondary image reconstruction after threshold filtering threshold optimization,the image reconstruction quality is further improved.The research results show that both of the regularization parameters determined by U-curve method and threshold filter threshold optimization can improve the image reconstruction quality of oil-air lubrication ECT system.