复杂产品装配干涉矩阵自动生成方法

Method for Automatic Generation of Assembly Interference Matrix of Complex Products

现有装配干涉矩阵生成方法极其耗时,且无法精确检测面片模型,难以应用于大装配模型的复杂产品。为此,引入基于投影的干涉检测方法,将三维求交问题转换为二维问题。其中,基于包围盒十字相交可直接检测出零件平移产生的硬干涉,扩展了包围盒的功能;利用层次化的虚设面进行模型的三角面片区域规划和相交运算,大幅度减少干涉检测中的三角面片求交次数,显著降低算法时耗;进行基于表示精度的二维三角面片求交,消除检测对象在曲面贴合处的伪干涉,并基于三角面片包围盒等判断干涉的正负方向。在此基础上,提出全面的装配干涉矩阵生成算法。开发Aero Assem装配设计系统,实现了该方法,并以某汽车前轴模型为例进行了应用验证,证明该方法在保证精确性的同时极大地提高了算法效率,能够有效应用于复杂产品的装配设计中。

Current methods for automatic generation of assembly interference matrix are time-consuming and also inaccurate to detect faceted models, so they are ineffective to complex products with large assembly models. Thus, a projection based interference detection method is introduced to convert the 3D intersection problem to a 2D one. In this method, the hard interference caused by translating parts can be directly determined based on cross bounding box overlap check, which expands the capabilities of the bounding boxes. Moreover, the hierarchical pseudo faces are used to partition the faceted models into sections for intersection check, by this way, the facet intersection test times are greatly reduced and so the interference detection time is considerably shortened. Then, the representation tolerance based 2D facet intersection test is executed to eliminate the fake interference between object pairs with touched curve surfaces. And the facet bounding boxes etc are used to determine whether positive or negative axis direction in which the relevant interference occurs. Based on the proposed interference detection method, an overall assembly interference matrix generation algorithm is presented, And an assembly design system called ＂AeroAssem＂ is developed to implement this algorithm. The precision and efficiency of this method are demonstrated by an automobile front axle case, proving that it can be effectively applied to the assembly design of complex products.