反求建模中常见二次曲面拟合方法.pdf

1m ~简交通大学学报 第42 卷第5 期 VoL42 No.5 21俯7 年 10 月 JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITY 0时， 2∞7 文意编号，0258-2724(2明口)05 -0553-05 反求建棋中常见二次曲面拟食方法 回怀文， 郭仕置在 (简简交浦大学机械工程学院，四川成都 61ω31 ) 摘 要:针对机械零件反求建棋过程中常见二次陶丽的农丽iU童问题，报出丁幽丽拟合分按计算法.该算法根据 数字化离散点的三维坐标及各点的法矢篷，利用零件袋菌的儿何特征建立拟合计算目标函敏，把二次曲在哥拟合 问题转化为线性最小二乘计算问题;通过拟合计算提取幽丽的几何参数，为建立饥械零件实体lk特征模刻打下 基础， 关键词，机械零件;反求建模;农ìilliJ重;二次由商拟合 中图分类号，TP391 :;t献栋ìH码，A Research on Algorithm of Quadric Surface Fitting in Reverse Modeling for Mechanical Parts 、、 TμN Huaíwen , GUO Sh阳hαng (School of Mechanical Er耶， Southw耐Jiaotong University , Chengdu 610031 , Chin.) Abstract: To solve the problem of quadric sunace reconstruction in reverse modeli鸣 for mech四ical par阔， a two-step fitting algorithm was presented. With this fitting algorithm , the objective function is built based on the coordinat制 of measuring pointB , Ihe normal vector of each point and Ihe geometrical features of mechanical part Bunaces , and as a result , the nonline町咄咄ation of quaclric fitting can be changed into a linear leas! 叫uare problem. Furthermore , the geometrical parameters of mechanical part surfaces can be gained !hrough fitting calculation 恤 provide a b..is for buíldin吕 solid model and feature model in the reverse engin朋ring for mechanical parts‘ Key words: mechanical part; reverse modeling; surface reconstruction; quadric surface fitting 机械零件反求J!1费是指极据表团数字化所获得的数据点云转化为 CAD 模型的过程.一般地，机械零件