以4-SPS并联机构为研究对象,采用加约束从动支链的构型演变方法得到一类2T2R(两个移动和两个转动)4自由度并联机构。根据速度Jacobian矩阵分析了机构的奇异位形,建立了4-SP xyz S/P x P z U xz并联机构的工作空间求解的约束条件,得到了...以4-SPS并联机构为研究对象,采用加约束从动支链的构型演变方法得到一类2T2R(两个移动和两个转动)4自由度并联机构。根据速度Jacobian矩阵分析了机构的奇异位形,建立了4-SP xyz S/P x P z U xz并联机构的工作空间求解的约束条件,得到了机构的位置和姿态工作空间,并提出利用'点集'近似计算位置工作空间大小的方法。引入敏感度概念,利用数值法解得了位置工作空间大小和姿态工作空间范围与机构尺度参数之间的关系,为机构尺度参数的选取提供了依据。展开更多
Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with...Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with actuation redundancy in parallel mechanism. Branched chains with actuation redundancy are synthesized for eliminating interior singularity of 3-translational and 1-rotational（3T1R） parallel mechanisms. Guided by the discriminance method of hybrid screw group according to Grassmann line geometry, all the possibilities are listed for the occurrence of interior singularities in 3T1R parallel mechanism. Based on the linear relevance of screw system and the principles of eliminating parallel mechanism singularity with actuation redundancy, different types of branched chains with actuation redundancy are synthesized systematically to indicate the layout and the number of the branched chainsinterior with actuation redundancy. A general method is proposed for the configuration synthesis of the branched chains with actuation redundancy of the redundant parallel mechanism, and it builds a solid foundation for the subsequent performance optimization of the redundant actuation parallel mechanism.展开更多
文摘以4-SPS并联机构为研究对象,采用加约束从动支链的构型演变方法得到一类2T2R(两个移动和两个转动)4自由度并联机构。根据速度Jacobian矩阵分析了机构的奇异位形,建立了4-SP xyz S/P x P z U xz并联机构的工作空间求解的约束条件,得到了机构的位置和姿态工作空间,并提出利用'点集'近似计算位置工作空间大小的方法。引入敏感度概念,利用数值法解得了位置工作空间大小和姿态工作空间范围与机构尺度参数之间的关系,为机构尺度参数的选取提供了依据。
基金Supported by Research Fund for the Doctoral Program of Higher Education,China(Grant No.20131333110008)
文摘Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with actuation redundancy in parallel mechanism. Branched chains with actuation redundancy are synthesized for eliminating interior singularity of 3-translational and 1-rotational（3T1R） parallel mechanisms. Guided by the discriminance method of hybrid screw group according to Grassmann line geometry, all the possibilities are listed for the occurrence of interior singularities in 3T1R parallel mechanism. Based on the linear relevance of screw system and the principles of eliminating parallel mechanism singularity with actuation redundancy, different types of branched chains with actuation redundancy are synthesized systematically to indicate the layout and the number of the branched chainsinterior with actuation redundancy. A general method is proposed for the configuration synthesis of the branched chains with actuation redundancy of the redundant parallel mechanism, and it builds a solid foundation for the subsequent performance optimization of the redundant actuation parallel mechanism.
