基于流线场模型驱动的复杂曲面激光再制造方法研究

The aim of this research project is to repair and strengthen the surface of large complex quick-wear parts. Based on the theory of streamline field, Data measuring and NC planning of laser remanufacturing system are researched. In order to improve the efficiency of complex surface measuring and to enhance the accuracy of damage repairing, the experimental platform of multi-degree-of-freedom (MDOF) laser remanufacturing is developed. Some important theories such as vision measurement, surface reconstruction, path optimization, track interpolation, etc, are studied in the project. To locate and measure damaged surfaces of large complex parts quickly, a new method of adaptive orthogonal scanning is proposed based on the line structured light 3D visual sensor. The streamline field model and whole linearization method are utilized to intelligently locate and measure damaged area of large complex parts. Some key algorithms such as boundary extracting, surface fitting, data splicing and model reconstruction are investigated to obtain accurate remanufacturing models. Considering the influence of laser beam on the cladding layer, the simplest streamline field of remanufacturing model is established to optimize whole trackes of laser beam. With some complicated constraints (e.g.interference-free constraint, workspace constraint and laser technique constraint), the multi-objective (e.g. fast speed of laser repairing, high quality of cladding layer and small residual stress) optimization algorithm is proposed to improve the process efficiency and forming quality of complex surfaces. The diretly real-time interpolation control module of laser beam is developed based on the streamline field model driven. The complex surface remanufacturing is simulated and analyzed. The achivements of the project can provide theoretical and technical supports for laser remanufacturing system of large complex quick-wear parts.

本项目以大型复杂曲面零件的损伤修复和表面强化为研究对象，开展基于流线场理论的复杂曲面激光再制造的数据测量与数控规划研究。针对大型复杂曲面零件的损伤定位较慢、测量效率较低的问题，采用流线场曲面构建的思想和整体线性化方法，建立以测量方向为流向的复杂曲面定向流线场构造模型，提出基于定向流线场的线结构光自适应正交网测量方法，研究复杂曲面零件的损伤定位、边界提取、数据拼接和模型重构算法，实现复杂曲面再制造模型的快速准确建模；分析再制造模型最简流线场的存在判定，提出基于最简流线场的复杂曲面激光再制造路径优化方法，研究复杂曲面的光束轨迹直接实时插补算法，开发基于流线场模型驱动的激光再制造数控加工系统，对典型复杂曲面零件的激光再制造进行仿真模拟和实验验证，探索实现"测量-加工"整体线性化的复杂曲面高精度激光再制造，为重大装备关键易损件的激光再制造系统研究提供重要的理论技术支持。

本项目以大型复杂曲面零件的损伤修复和表面强化为研究对象，开展了基于流线场理论的复杂曲面激光再制造的数据测量与数控规划研究。为了快速准确地获取复杂曲面再制造模型，建立了零件损伤的线结构光三维视觉测量系统，提出了适合于大型复杂曲面零件的自适应正交网测量方法。为了合理规划损伤零件的修复和再利用，提出了一种基于骨架树的增减材加工工艺规程算法，采用细分算法进行模型骨架的提取，建立带有模型拓扑、特征和全局形状信息的骨架树，用于模型特征比较。为了完成大型复杂曲面零件的远程无线数据测量，建立了以测量方向为流向的复杂曲面定向流线场，提出了基于机会网络和广义高斯混合算法的图像处理和无线传输方法，实现了三维模型数据的双目视觉无线测量；提出了基于NURBS曲线的3D非刚性点云的图像特征重构算法，对采集到的数据点云进行去噪、优化，进而提取边界和模型重构，最终获得了准确的再制造模型数据。为了提高复杂曲面激光再制造的加工效率和修复质量，提出了在修复曲面上建立流线场的路径生成方法，确立了以激光熔覆进给曲率最缓作为最优进给方向的流线场，实现了复杂曲面的激光再制造路径优化生成；建立了一种高效低成本的3+2轴激光熔覆加工平台，提出了基于3+2轴加工平台的激光熔覆路径生成算法，提高了复杂曲面激光再制造的加工效率和修复质量。搭建了多自由度的激光再制造实验平台，对典型复杂曲面零件的激光再制造进行仿真模拟和实验验证，建立了激光工艺参数与熔覆形貌的关系方程，分析了基于曲面流线场的复杂曲面激光再制造方法的加工效率和修复质量。为重大装备关键易损件的激光再制造系统研究提供了重要的理论技术支持。