摘要
针对自由形状曲面工件超声检测中存在探头难于对准曲面法线方向和检测效率低的问题,提出了一种非等参数超声检测路径生成算法.对于CAD模型未知的曲面工件,首先采用超声波测距原理对工件进行仿形测量,然后应用B样条方法重构工件的曲面模型,最后根据重构的CAD模型用非等参数算法生成检测路径.该算法采用近似等弧长方法对参数曲面重新进行参数化,使曲面上各扫描点之间的弧长间距近似相等.应用结果表明,与等参数超声检测轨迹生成法相比,使用非等参数方法生成的扫描点间距分布更合理,在满足检测要求的情况下扫描点数明显减少.该算法能保证超声波入射方向和各扫描点曲面的法线方向一致,提高曲面工件的检测精度和检测效率.
In the ultrasonic inspection of free-form surface component, the probe is difficult to aim at the surface＇s normal direction and inspection efficiency is low. To solve these problems, a non-isoparametric path generation algorithm was proposed to generate ultrasonic scan path. For the component whose CAD model is unknown, first, profiling measurement based on ultrasonic distance measurement theory was used to measure the component＇s surface; then B-spline method was applied to restructure of the component＇s surface model; finally, based on the restructured CAD model, a non-isoparametric algorithm is used to generate scan path. This algorithm generates nearly arc-length interval inspection points by using nearly arc-length based parametric redistribution method. Compared with constant parametric path generation methods, this method can generate more efficient inspection paths by reducing the number of scan points, while maintaining inspection precision requirement. It is showed that this method can guarantee ultrasonic incidence direction aiming at the surface＇s normal direction, and increase inspection accuracy and efficiency.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2006年第5期763-767,共5页
Journal of Zhejiang University：Engineering Science
关键词
自由曲面
超声检测
曲面重构
路径规划
free-form surface
ultrasonic inspection
surfaces reconstruction
path generation
