新型3-P_CR_NS球面3自由度并联机构  

NOVEL 3-PcRNS SPHERICAL 3-DOF PARALLEL MECHANISM

作　　者：李秦川[1] 武传宇[1] 沈卫平[1] 胡旭东[1] 朱祖超[1] 黄真[2] 

机构地区：[1]浙江理工大学浙江省现代纺织装备技术重点实验室,杭州310018 [2]燕山大学机器人研究中心,秦皇岛066004

出　　处：《机械工程学报》2006年第11期44-48,共5页Journal of Mechanical Engineering

基　　金：国家自然科学基金(50075074);浙江省自然科学基金(Y104629)资助项目

摘　　要：提出一种新型3-PcR_NS球面3自由度并联机构,其分支运动链由一个带环形导轨的移动副P_C,一个转动副R_N(下标N表示三个分支中转动副的轴线都交于一点)和一个球铰S构成。运用约束螺旋理论,对该机构的自由度、奇异位形和输入选取进行分析。在一般非奇异位形下,该机构中三个P_CR_NS分支运动链对动平台施加三个汇交于机构中心点的约束力,约束机构动平台的3移动自由度,机构具有3转动自由度；在奇异位形下,三个P_CR_NS分支对动平台施加六个线性相关的约束力,其最大线性无关数为五,机构具有一个绕z轴的瞬时转动自由度。可选用带环形导轨的移动副P_C作为主动副,此外该机构动平台绕z轴的转动自由度和其他转动自由度解耦。A novel 3-PCRNS spherical 3-DOF parallel mechanism is proposed. The limb kinematic chain consists of a circular prismatic pair Pc, a revolute pair RN ,where the subscript N denotes the revolute axes in 3 limbs intersect at a common point, and a spherical joint S. Mobility, singularity and input selection of this mechanism is analyzed via screw theory. In the general non-singular configuration, the 3 PcRNS limb kinematic chain exerts 3 constraining forces on the moving platform, which intersect at a common point, the mechanism center. The 3 constraining forces constrains the 3 translational DOFs of the moving platform, thus the mechanism has 3 rotational DOFs. In the singular configuration, the 3 PcRNS limb kinematic chain exerts 6 constraining forces on the moving platform, which are linearly dependent. The maximum linear independent number of the 6 constraining forces is 5, thus 5 DOFs of the moving platform are restricted. The mechanism only has one instantaneous rotation DOF about the z axis. The circular prismatic pair can be actuated, thus the rotational DOF of the moving platform about the z axis is decoupled from the other 2 rotational DOFs.

关 键 词：并联机构 螺旋理论 自由度 

分 类 号：TH112[机械工程—机械设计及理论]