Abstract: To improve the operating performance and supporting stability of digital align-positioning device based on parallel mechanism,the supporting points on parts were selected optimally.The kinematic model of the align-positioning device was established,and the position equation and mechanism Jacobean matrix were solved according to the vector graphics of the kinematic chain branches.The performance indexes of align-positioning device such as dexterity,capacity and stiffness were constructed according to mechanism Jacobean matrix|the supporting stability index was established according to locating Jacobean matrix.Thus the optimal supporting positions for wing were determined by considering the indexes optimization.The results showed that the big part's align-positioning device based on parallel mechanism was unrelated to evaluation index,but related to supporting stability,and each index was depended on the initial selection of supporting point,which provided a conference for the selection of big part locating supporting point.

Key words: parallel mechanism, performance index, stability index, mechanism Jacobean matrix, locating Jacobean matrix

摘要： 为了提高基于并联机构形式的数字化调姿装置的操作性能和支撑稳定性等,对部件上的支撑点位置进行了优化选择。建立了该定位调姿装置的运动学模型,根据分支机构运动链的矢量图形,求解了定位调姿装置的位置方程及机构雅克比矩阵|根据机构雅克比矩阵建立了调姿装置的灵活度、承载力和刚度等性能评价指标|根据定位雅克比矩阵建立了调姿装置对部件定位时的支撑稳定性指标|对上述指标进行综合评价,根据指标的优化得到了部件的优化支撑点位置。分析结果表明:基于并联机构形式的大部件调姿装置的性能评价指标和位姿无关,支撑稳定性和姿态有关,且各指标依赖于初始支撑点的选择,以上结论为大部件定位支撑点的选择提供了参考。

关键词: 并联机构, 性能评价指标, 稳定性指标, 机构雅克比矩阵, 定位雅克比矩阵