基于螺旋理论的单闭环多自由度过约束机构综合

Structure Synthesis of Single Closed-loop Multi-degree of Freedom of Over-constrained Mechanism Based on Screw Theory

以螺旋理论为基础,分析构成单闭环过约束机构的约束数目、运动副数目和自由度数目之间的关系,给出针对单闭环过约束机构的自由度计算公式。按照约束螺旋的性质将过约束螺旋分为具有不同阶数的力约束和力偶约束两类,总结所有可能形式的独立过约束性质和数目及其组合。在给出特定过约束组合的条件下,应用虚功原理,以反螺旋理论为计算手段,得到多自由度单闭环机构的综合条件。应用解析的方法,得到满足机构为非瞬时运动的条件,给出机构的运动副轴线布置、运动副数目、运动副排列和空间几何条件。全面系统地解决了单闭环多自由度过约束机构的构型综合问题,群举所有可能的单闭环过约束并联机构。给出机构综合步骤以及部分典型机构的设计范例。

Based on screw theory, the relationship among the numbers of constraints, joints and degrees of freedom that constitute single closed-loop over-constraint mechanism are analyzed. Also the calculation formula of the degree of freedom for single closed-loop over-constrained mechanism is presented. Moreover, over-constraints are classified into two types of forces and couples which have different orders, in terms of reciprocal screws. All possible forms of characters of independent over-constraints and numbers...