基于互易螺旋理论的无奇异完全各向同性移动并联机构型综合  

Type Synthesis of Non-singular Fully-isotropic Translational Parallel Mechanisms Based on Theory of Reciprocal Screw

作　　者：张彦斌[1] 刘宏昭[1] 吴鑫[2] 

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048 [2]河南科技大学机电工程学院,洛阳471003

出　　处：《机械工程学报》2008年第10期83-88,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(50575180);西安理工大学优秀博士学位论文研究基金(207-210003)资助项目。

摘　　要：基于互易螺旋理论提出一种无奇异完全各向同性纯移动并联机构型综合的系统方法。首先给出机构末端操作器输出运动的矩阵表达式,然后根据该表达式正雅可比矩阵为非零对角阵的条件确定出机构支路驱动螺旋的表达形式,并依据驱动螺旋与主动螺旋互易积为非零常数的条件确定出主动螺旋的形式,再根据驱动螺旋与同一分支中除主动螺旋外的所有其他运动螺旋互易积都为零的特点,确定出可动非驱动螺旋的类型及其轴线方向,从而按照机构分支连接度的不同进行机构支路的型综合。最后取3条所综合出的机构支路将动平台与静平台联接起来即可得到所期望的机构。最后对一种新型3-CRP无奇异完全各向同性移动并联机构进行运动学分析。结果表明,所提出的型综合方法正确可行。A systematic approach for type synthesis of non-singular fully-isotropic translational parallel mechanisms is proposed based on the theory of reciprocal screw. The matrix expression of the output motions of the end-effector of mechanism is presented firstly. According to the condition that the positive Jacobian matrix of the expression is a non-zero diagonal matrix throughout the entire workspace, the expressions of the actuated screws of each limb are determined. Then, the forms of the actuating screws of each leg are derived on the basis of the condition that the reciprocal product of actuated and actuating screws is a non-zero constant. The types and the axial directions of the actively unactuated screws are determined in light of the characteristic that the reciprocal products of the actuated screw and all other kinematic screws except the actuating screws in the identical limb are equal to zero. Type synthesis of three legs containing idle joints or not, thereby, is accomplished in terms of different co nnection degrees. Finally, the expected mechanisms are obtained by selecting three legs synthesized above to connect the platform with the base. The kinematic analysis of a novel 3-CRP parallel mechanism is performed and the result shows that the method of type synthesis for non-singular fully-isotropic parallel manipulators proposed here is correct and feasible.

关 键 词：并联机构 互易螺旋理论 完全各向同性 型综合 

分 类 号：TH112[机械工程—机械设计及理论]