【摘要】 研究了一种常用的欠秩３—ＲＰＳ并联平台机构。提出采用虚拟机构的方法建立了雅可比矩阵， 又采用二次曲线分解理论识别了三阶螺旋系的主螺旋，讨论了３—ＲＰＳ机构在两种位形下的输出运动螺旋螺距ｈ 的各种取值，这对于从全局上了解机构的运动特性、轨迹规划和控制具有重要意义更多还原

【Abstract】 A used deficient in rank three RPS in parallel actuated manipulator mechanism is studied Firstly Jacobian matrix is established by using the virtual mechanism method The principal screws in the third order screw systems are identified by using the conic section degenerating theory All situations of the pitches of the twist of the end effector are discussed under two configurations It is important to know the overall kinematic characteristics of the mechanisms Therefore,The work presented in this paper is significant for the studies on the robot in trajectory planning and control更多还原