基于旋量理论的装配模型中零件瞬时运动分析

Instantaneous Mobility Analysis of Parts in an Assembly Using Screw Theory

提出一种直接根据装配模型中零件几何信息和空间配置关系分析其零件瞬时运动特性的方法。该方法首先对不同零件CAD模型中面几何方程进行比较得到零件之间的面-面接触关系和类型,并应用旋量理论将面-面相对瞬时运动表示为螺旋;然后,对多个面接触上的螺旋进行交运算,生成零件之间的相对瞬时运动螺旋;最后,根据零件邻接关系图和邻接零件相对运动螺旋,对装配模型中零件整体瞬时可动性和驱动关系进行了分析,给出不相邻零件之间的相对瞬时运动螺旋计算方法和它们之间可驱动性的判断方法。论文通过实例验证了该方法的正确性及有效性。

We present a method for analyzing instantaneous motions of parts in an assembly according to their geometry information and space configurations. In this method, face-face contact relations and types between two parts are extracted by comparing geometry equations as well as the boundaries of part faces. Then, motion twists between faces are generated from their contact types by means of screw theory. After this, a twist that represents the mobility between two adjacent parts is obtained using screw intersection operations upon the motion twists of all contact face pairs between the two parts. Finally, the remote relative mobility and driving relationships between any two parts in an assembly are identified by analyzing the adjacent part motion twists. A practical example is used to validate the correctness and effectiveness of our method.