基于二次测量的曲面反求自适应采样方法研究  

A Self-adapting Sampling Method Built on Two Measurements of Curved Face to Obtain Varied Arc Length in Reverse

作　　者：郭俊锋[1] 岳秀超 魏兴春[1] 

机构地区：[1]兰州理工大学机电工程学院,兰州730050

出　　处：《机械制造》2015年第7期41-45,共5页Machinery

基　　金：国家重大科技专项(编号:2014ZX04012015)

摘　　要：针对叶片CAD模型未知的情况,提出一种基于二次测量的曲面反求变弧长自适应采样方法。通过三坐标测量机测量反映叶片曲面形状的关键几何要素,重构曲面初始模型;基于初始模型获得的叶片曲率信息,确定采样方向和进给方向;基于变弧长自适应采样方法,使用三坐标测量机对叶片采样;基于获得的采样点坐标信息,反求出CAD模型。通过模拟仿真试验,在采样点数目能够准确反映曲面曲率的情况下,相对于采用等弧长、等弦弧比、等弦弧差自适应采样方法,采用变弧长自适应采样方法的曲面拟合精度明显提高。In case of unknown blade CAD model, A self-adapting sampling method proposed that was built on two measurements of the curved face to obtain the varied arc length in reverse. It adopted CMM measurements to reflect the key geometric elements of the curved faces of the blade thus the initial model of the curved faces could be Reconstructed. The sampling orientation and feed direction should be determined based on the information of the blade curvature collected from the initial model. Blade sampling was performed by CMM based on self-adapting sampling of the varied arc length. The CAD model was built in reverse on the collected coordinate information at the sampling points. Through simulation experiment, it showed that if the number of sampling points could accurately reflect the curvature of the curved face, surface fitting accuracy obtained by self-adapting sampling of the varied arc length was much better than the surface fitting accuracy obtained by other three methods for self-adapting sampling of constant arc length.

关 键 词：曲面反求 二次测量 曲率信息 变弧长 

分 类 号：TH123[机械工程—机械设计及理论] TP391[自动化与计算机技术—计算机应用技术]