核电装备焊接制造高温应变特征DIC在线检测及智能校正控制方法研究

To meet the demand for high efficiency, stability and security of nuclear island key parts’ welding, this project is aimed to develop a new scientific approach and technology realization, which contains the dynamic process knowledge modeling characterization and real-time compensation control, suitable for the whole high temperature field strain in the heat-affected zone (HAZ) based on the digital image correlation method, liquid weld pool dynamic response and infrared radiation (IR) profile. This project consists of the real-time in-situ measuring and intelligent processing algorithm for high-temperature field strain near HAZ based on the digital image correlation technology. We explore the evolution mechanism of high-temperature field in HAZ, liquid weld pool and IR dynamic response at a certain heat input. It’s intended to develop a scientific solution for the intelligent characterization, the fused support vector machine knowledge model and real-time intelligent correction control strategy (fuzzy self-adaptive and knowledge rules). It will help to provide valuable scientific solution and technology realization to the bottle neck about controlling weld-forming and the mechanical properties of welded joint.

面向核电重大装备焊接制造的生产高效性、稳定性及运行安全性的背景需求，本项目试图探索一种基于数字图像相关技术的焊接热影响区全场高温应变、热像轮廓特征及液态熔池视觉响应的焊接动态过程知识模型表征及实时补偿控制的技术实现途径和科学方法。主要内容包括基于数字图像相关技术的近熔池全场高温应变在线表征及实时处理算法；不同热输入激励下的焊接热影响区高温全场应变、液态熔池及热像轮廓视觉动态响应及演变机制；设计基于焊接HAZ应变-熔池-热像轮廓等多信息融合的支持向量机知识模型；结合异质传感器信息、焊接动态过程知识模型，进一步给出核电关键部件焊缝成形及接头质量的在线智能校正控制（模糊自适应、基于知识规则）策略和方法。为探索从控制焊缝成形到控制接头综合性能的瓶颈难题提供有价值的技术实现途径和科学方法。

围绕焊接过程多源信息采集、基础数据集构建，建立焊接制造的热（工艺参数、线能量），形（液态熔池），性（热影响区应变）等多源信息耦合的知识模型，通过构建的平台开展焊接信息评价、反馈（或前馈）焊缝成形及接头性能的主动控制。本项目构建了机器人GTAW多信息采集、处理及控制系统平台，分别研制了二维、三维数字图像相关法（Digital Image Correlation，DIC）应变测量及表征，液态熔池分析、处理视觉传感模块；开发了基于灰度插值、图像子区模板匹配及全场迭代的焊接热影响区高温应变计算与表征算法；提出了适用于焊接过程中的基于相似度进行组合的立体匹配策略，以及相似度阈值的全局路径算法，形成三维DIC应变分析处理软件系统；设计了基于生成对抗网络的焊接熔池弧光滤除算法，并进一步开发了基于级联回归树的熔池轮廓提取算法，获取动态熔池几何特征尺寸；借助多源传感信息系统参数，构建基于LightGBM算法的焊接成型预测模型；最终形成了焊接信息评价、反馈（或前馈）焊缝成形及接头性能等补偿控制软件系统。