基于STL模型垂直切片的支撑自动生成算法研究

Support generation algorithm based on the vertical slice of STL model

针对光固化等快速成形工艺中须对零件加支撑的需求,本文提出一种新的支撑自动生成算法。该算法基于STL模型提取零件的悬吊点、下棱线、待支撑下表面的轮廓线等待支撑区域的关键特征,根据它们在xy平面的投影特征来优化布置分层基准线并进行垂直切片,应用所提出的基于垂直截面轮廓内待支撑边生成支撑多边形的算法,生成相应的变厚度薄壁形支撑。实际应用表明,该算法能够对成形零件的待支撑区域自动添加准确有效的支撑。

A new support generation algorithm is proposed to meet the need of adding support for the part fabricated by stereolithography. The key characteristics such as suspension points, suspension lines, and contour lines of the lower surface that needs support are extracted based on the STL model, these key characteristics are projected onto xy plane. According to the projection features the vertical slicing datum lines are laid out and vertical slicing is done. The proposed algorithm for generating support polygons is based on the edges that need support in two-dimen- sional contour obtained from vertical slicing STL model. Applying this algorithm the variable-thickness thin-wall supports are generated. Application shows that this algorithm automatically adds exact and reliable supports for parts.