基于曲面重构方法的大型叶片加工定位问题研究  

Research on the Localization of Large Blade NC Machining Based on the Surface Reconstruction

作　　者：严思杰[1] 周云飞[1] 赖喜德[1] 陈学东[1] 

机构地区：[1]华中科技大学国家数控系统工程研究中心,湖北武汉430074

出　　处：《机床与液压》2006年第3期9-12,共4页Machine Tool & Hydraulics

基　　金：国家自然科学基金项目(50245011);国家重点基础研究发展计划(973)资助项目(2003CB716206)

摘　　要：大型水轮机叶片曲面翘曲,双面加工,笨重不易翻动,给其找正定位带来极大不便。长期以来,加工现场通常采用人工找正定位,其缺点是找正困难、效率低、精度差。本文通过反求工程方法将测量得到的大量离散毛坯表面数据,依据CAD模型的拓扑特征,重构毛坯表面,然后利用重构曲面与CAD模型曲面对应节点距离平方和构造目标函数,采用最小二乘法(LSQ)求解欧氏变换矩阵,从而达到毛坯加工余量均匀,实现计算机辅助定位的目的。实算证明:该方法能快速辅助找正;且对于表面质量高、边界规范的毛坯,定位比较准确。最后给出了一辅助定位实例。It is difficult for the localization of the large blade NC machining, which used to be measured by the probe of machine and adjusted manually. It is arduous and time - consuming, and even allowance can＇t be ensured for every measured point. The method of surface reconstruction was adopted to calculate the distance of the measured point to the designed surface, and the least - squares method was used to search the optimal location of surface matching. Transforming by the location matrix, even allowance can be ensured, this method can realize computer aided localization （CAL）, which enhances the precision of localization, saves much time, and greatly accelerates machining cycles while reduce machining cost. The practice shows the method is practical and useful.

关 键 词：叶片 最小二乘法 曲面重构 定位 数控加工 

分 类 号：TG659[金属学及工艺—金属切削加工及机床]