基于NURBS曲面的汽轮机叶片激光熔覆再制造路径规划

Path Trajectory of Laser Cladding Remanufacturing for Turbine Blade Based on NURBS Surface

针对汽轮机叶片的复杂造型,提出一种基于NURBS曲面拟合的几何模型重构方法,得到了一种获取稳定的激光功率密度的路径规划方法。通过计算点在曲面上的曲率,将局部NURBS曲面拟合为曲率球,对激光束扫描面积进行简化计算。根据熔覆加工精度要求,调整激光头姿态沿曲面的法矢方向,约束激光束扫描面积,得到熔覆加工插补点,保证了基材表面获取稳定的激光功率密度。根据插补点的法向矢量计算得到机器人对应的位姿,利用CIMOCO软件验证熔覆轨迹的正确性;通过试验得到较好的熔覆层,证明了方法的可靠性和可行性,为复杂曲面的激光熔覆再制造提供了一种新方法。

Aiming at the complex modeling of turbine blades, a geometric model reconstruction method based on NURBS surface fitting was proposed, and a path planning way for obtaining stable laser power density was obtained. By calculating the curvature of the point on the surface, the local NURBS surface was fitted as a curvature sphere to simplify the calculation of the laser beam scanning area. According to the requirements for the precision of the cladding process, the laser beam scanning area was controlled by adjusting the posture of the laser head along the normal direction of the surface. Meanwhile, the interpolation point was obtained to ensure stable laser power density on the substrate surface. According to the normal vector of interpolation point, the corresponding pose of robot was obtained, and the correctness of laser cladding trajectory was verified by CIMOCO software. The high-quality cladding layer was experimentally prepared, which proved the reliability and feasibility of the method. A new method is provided for laser cladding remanufacturing of the complex curved surface.