机械运动方案知识库的对偶矢量表达及型综合

Representation of Knowledge Base for Mechanism Kinematic Schemes and Types Synthesis by Using Dual Vector

简要介绍了机械运动系统方案设计知识库的结构和螺旋理论及对偶矢量表达。提出了知识库基本元素的对偶矢量建模方法。通过输入运动旋量和输出运动旋量表达机构的运动行为要求和设计需求。在运动方案的型综合中,需要进行两项工作:一是将各备选机构坐标转换为机器的通用坐标;二是将各备选机构的轴线首末端空间方位按组合的先后顺序对齐。为此给出了基于对偶矢量表示的坐标变换和线性变换公式。最后列举了一个实例验证螺旋理论在概念设计中的可行性和意义。

The structure of knowledge base for mechanism kinematic schemes, screw theory and dual vector representation are introduced briefly. A modeling method using dual vector for elementary elements of mechanism knowledge base is proposed. Input motion screw and output motion screw are applied to represent design specification as well as kinematic behavior requirements. During types synthesis of kinematic scheme, there are two tasks need to be accomplished,one is transformation of each building block coordinate system in to machine (global) coordinate system, the other is linear transformation of each building block to align the axes. As a result,coordinate transformation of a line and linear transformation equations are deduced. Finally an application has been applied to show usefulness and feasibility of screw theory in conceptual design.