圆柱类部件高性能自动化相控阵超声成像检测理论与技术的研究

This project aims at exploring the automatic online ultrasonic nondestructive testing theory and methods with high performance for cylindrical components by means of phased array ultrasonic imaging. On the basis of theoretical analysis and experimental research on the interaction mechanism between helical acoustic field and flaws , and the propagation characteristics of acoustic waves in cylindrical medium, a kind of adaptive control theory and method for phased testing fields in nonuniform medium is established, by utilizing the beam coverage, information carrying capacity and defect sensitivity as synthetic optimization indicator. Meanwhile, combined with the acoustic frequency response characteristics of arc interface, the target testing data in the region of interest of multilayer cylindrical structures under helical scan mode are faithfully reconstructed. Moreover, the multi-pattern composite phased array ultrasonic imaging strategy is adopted and the testing procedures are also studied, and then, the quantitative ultrasonic nondestructive testing technique with high real-time performance and wide angle is realized..The successful implementation of this project will establish the theoretical foundation of quality monitoring for cylindrical products including the ones with variable sizes or structures , and supply a kind of key and common technology. The research results could change the passive situation of long-term dependence on import for high-performance automatic online ultrasonic nondestructive testing equipment, and be directly applied in the area of automatic online quality monitoring for cylindrical products to improve their quality and competitiveness and then drive the development of traditional and high-tech industry. Moreover, the related theory and technologies could be further extended to other applications to create greater social and economic benefits.

本项目旨在探讨利用相控阵超声成像对圆柱类部件实施高性能自动化在线超声无损检测的理论与方法。通过对螺旋声场与缺陷作用机理及其声波在圆柱介质中传播特性的理论分析和实验研究，采用声束覆盖率、信息携带量和缺陷敏感度等为综合优化指标，形成一种非均匀介质内相控检测声场的自适应控制理论与方法。同时，结合圆弧界面声学频响特性，高保真重建螺旋扫查方式下叠层圆柱结构感兴趣区域内的目标数据，并以多模式复合相控阵超声成像为策略，辅以检测工艺的研究，实现高实时和广角的定量超声无损检测技术。.本项目成功实施将为包括变尺寸或变结构在内的圆柱类产品质量监控奠定重要的理论基础，并也为该领域提供一种关键和共性的技术手段。研究成果将改变我国高性能自动化在线超声无损检测设备长期依赖进口的被动局面，直接应用于圆柱类产品的质量监控中，提高产品品质及竞争力，带动传统和高新技术产业的发展，而且进一步推广应用，将创造更大的社会和经济效益。

本项目旨在探讨利用相控阵超声成像实施对圆柱类部件或材料进行高性能自动化在线超声无损检测的理论和方法，在理论、技术和应用等多层面上开展了系统研究，取得了创新性成果有：在理论方面，揭示了螺旋声场与多尺度缺陷作用机理，实现了螺旋声场作用下缺陷散射声场的快速计算。同时，建立了螺旋坐标系下波动方程，并采用联合求解的思路，求解了螺旋坐标系下波动方程，进而根据界面处相位连续性及采用逐层递推的方式，创建了螺旋坐标系下叠层圆柱结构内声波信号传播理论模型；在技术方面，在波束域内利用信号协方差矩阵逆的高阶次幂乘逼近目标信号子空间，并以最小方差法获得波束合成的权值向量，投影到该信号子空间上，确定出波束域最优权值向量，发展了一种波束域非均匀介质内相控检测声场的多标优化自适应控制方法。利用分层界面相位连续不变性的特点及逐层声场递推的方式，实现了螺旋扫查下叠层圆柱结构内超声成像基础数据的高保真重建，突破了水耦合环境中圆柱类部件螺旋扫查超声成像所面临的技术障碍，进而创新实现了面向复杂叠层圆柱结构的相控阵超声频域合成孔径聚焦成像及相控阵超声全矩阵频域成像等技术，推进自动化相控阵超声成像技术在变尺寸或变结构圆柱类部件中的应用。同时，发展了基于多模式复合相控阵超声成像策略的高实时广角定量无损检测技术及基于深度学习的多角度扫查超声成像检测技术，有效协调实时成像与精细化定量表征之间的矛盾，奠定了自动化在线定量超声无损检测的技术基础。在应用方面，研发了一套基于螺旋扫查模式的钢管自动化在线超声成像检测系统，成功应用于无缝钢管实际生产流水线上，实现了钢管质量在线定量监控，在超声成像检测能力及性价比等方面表现出明显的优势。.本项目的研究成果为包括变尺寸或变结构在内的圆柱类部件或材料质量的自动化在线监控奠定了重要的理论基础，同时也为该领域提供了一种具有自主知识产权的关键技术手段。