针对现有的虚拟装配系统大部分是基于实体模型,其计算量大、渲染慢、装配速度慢并且难以处理来自不同CAD系统模型的问题,提出了基于面片模型的人机交互快速装配方法.利用面片所包含的几何信息通过边界表示法重构零部件装配所需的几何信息和空间位姿信息,给出了基于面片模型的装配约束定义.通过人机交互技术将复杂的约束组分解为多个单约束进行求解,实现了约束的快速、准确的求解;按照旋转矩阵和平移矩阵对零部件的空间位姿进行变化,实现装配;最后基于HOOPS三维图形数据平台开发了虚拟装配系统.实践证明,该方法可以有效地减少计算量、提高装配速度、实现协同装配.
Considering the most current virtual assembly systems based on entity model which holds the characteristics of high complexity of calculation, low efficiency of rendering, slow velocity of assembly and difficulties to handle the models from different CAD systems, a rapid assembly method of facet- based model was presented. Using the geometric information contained in the facets, the spatial position- orientation information and geometric information of components assembly required can be acquired by boundary representation method, through which the assembly constraint definitions of the facet-based model were proposed. With human-computer interaction technology, the complex constraint set was decomposed into multiple single-constraint and can be solved faster and more accurately. In order to achieve assembly, the spatial position and orientation of components was changed in accordance with rotation matrix and translation matrix. A virtual assembly system was developed based on HOOPS development platform. It has been demonstrated that this method can reduce the calculation complexity effectively, improve the speed of assembly greatly and realize collaborative assembly.