3-PSU&S并联机构的运动学分析与优化设计

Kinematic analysis and optimal design of 3-PSU&S parallel mechanism

面向卫星天线定位/跟踪重要需求,研究3转动自由度并联机构3-PSU&S的运动学设计问题。应用闭环矢量法建立机构位置逆解模型,并推导关节空间与操作空间的速度映射模型。借助力螺旋与运动螺旋的互易积定义机构功率传递系数,并以其在工作空间内的均值作为机构运动学性能评价指标。以上述评价指标最大化为目标,涉及相关的几何、工程约束,采用遗传算法实现3-PSU&S机构的尺度综合。该研究成果可为3-PSU&S并联机构样机的设计和制造奠定理论和技术基础。

To meet the accurate positioning and the high-speed tracking requirements of satellite antennae, the kinematic design of a three rotational parallel mechanism featuring the 3-_PSU＆S topology was investigated. The inverse position model was established by the closed-loop vector method, and the velocity mapping model from the joint space to the operating space was derived. By means of reciprocal product associated with the wrench and twist screw, the generalized virtual power transmissibil- ity was defined, then its average in the prescribed workspace was used to evaluate kinematic performance of the mechanism. By considering the geometrical/engineering constraints, the genetic algorithm was applied to maximize the proposed evaluation in- dex and dimensional synthesis of the 3-PSU＆S mechanism was achieved. The research established a theoretical and technical foundation for the prototype design and manufacture of 3-PSU＆S mechanism.