轮廓度公差约束的叶片模型配准方法

Profile tolerance constrained registration method for blade model

针对公差非均匀分布的发动机叶片叶型检测评估问题,提出一种基于轮廓度公差约束的叶片模型配准方法。根据叶片轮廓度公差定义,给出一种基于中弧线的叶片轮廓度公差模型生成方法。建立了轮廓度公差约束的叶型截面配准数学模型,并给出了基于Nelder-Mead单纯形法的叶型截面带约束配准求解过程。采用仿真数据及实际叶片的三坐标测量数据与理论模型,对所讨论的模型配准方法进行了验证。结果表明,Nelder-Mead单纯型法可用于薄壁叶片模型的带约束配准求解;与最佳贴合配准相比,公差带约束配准方法可减少测量数据点集的超差点数目,为叶片检测评估提供更多参考。

Aiming at the inspection and evaluation problem of aero-engine blade surface with unuiform distribution of tolerance,a new registration method of blade model based on constraint of profile tolerance was developed. Accord-ing to the definition of contour tolerance, a generation method for blade contour tolerance model based on middle camber line was provided. A mathematic model for registration of blade section profile based on contour tolerance was built, and a solution process to the tolerance constrained registration of blade section profile based on Nelder- Mead simplex method was given. The validity of proposed method was verified by using simmulation data, actual CMM data and theoretic model of blade. The experiment results showed that Nelder-Mead simplex method could be used to resolve the problem of profile tolerence constrained blade model alignment. Campared with the best-fit meth-od ,the disscussed method could reduce the number of points outside the profile tolerance zone, which could be a-dopted as additional reference for blade inspection and evaluation.