摘要
提出一种利用球面逼近空间变形曲面计算变形曲面上任意点法向矢量的算法。首先测得变形曲面上目标点周围离散点坐标,计算逼近球心初值;然后将离散点到逼近球面距离的均值作为目标函数,采用模式搜索算法,调整球心坐标值,经过循环迭代,最终获得与变形曲面的逼近精度在给定误差范围内的球面,进而计算出目标点的法向矢量。以机身某段壁板曲面为例,求解其变形后钻铆点的法向矢量,与其钻铆点理论法向矢量进行对比,结果表明,该算法求解稳定,计算效率及精度满足自动钻铆工艺要求,适合于空间变形曲面上任意点法向矢量的计算。
A method of calculating the normal vector of any point on the deformed surface based on approximating space deformed surface by sphere surface.Firstly,gathering coordinate of discrete points around the target points on the deformed surface,calculate the fitting spherical center as the original value for iteration.Secondly,calculate the distance between discrete points and the sphere,then the average distance is set as the searching target through the mode searching algorithm to adjust the coordinate of spherical center one by one.The error between the approximate sphere surface and the original deformed surface can be reduced by iterative computations until meet the specified one,and then the normal vector of the target point is calculated.Taking aircraft panel surface as example,calculating the normal vector of riveting drilling point on the deformed surface,compared with the real normal vector,the result shows that the algorithm is steady,which has high efficiency and precision,and is adaptive to calculating the normal vector of any point on the space deformed surface.
出处
《现代制造工程》
CSCD
北大核心
2010年第7期51-55,108,共6页
Modern Manufacturing Engineering
基金
国家863计划项目(2007AA041903)
关键词
球面逼近
法向矢量
变形曲面
sphere approximation
normal vector
deformational surface
