This paper proposes the nonsingular design principle, which can completely eliminate constraint/actuation singularity in parallel mechanism (PM), and accordingly designs a nonsingular redundant 2RPS-UPU+2SPS (R: revolute joint, P: actuated prismatic joint, S: spherical joint, U: universal joint) leg mechanism with R^xR^yT^z DOF (R^x: rotational DOF around x, R^y: rotational DOF around y, T^z: translational DOF along z, DOF: degree of freedom). Aiming at the defect that the conventional Jacobian matrix cannot reveal the linear correlation/noncorrelation between the constraint screws of the PM, the determination criteria of constraint and actuation singularity are derived and the design principle of redundantly actuated PM eliminating constraint/actuation singularity is constructed according to the reciprocal screw principle. Based on this, the design process of parallel leg mechanism without singularity is put forward. Finally, by analyzing the rank of complete Jacobian matrix composed of constraint Jacobian matrix and secondary constraint Jacobian matrix, it is verified that the redundant parallel leg mechanism in this paper can completely eliminate constraint singularity and actuation singularity. The research results make a necessary positive contribution for motion planning, optimization solving of forward kinematics parameters, dimensional synthesis and motion control of nonsingular parallel leg mechanism.

本文提出了一种非奇异的设计原理，该原理可以完全消除并联机构（PM）中的约束/致动奇异性，因此设计了一个非奇异的冗余2R P S-U P U + 2S P S（R：旋转接头，P：致动棱柱接头， S：球形关节，U：万向节）带有R ^x R ^y T ^z DOF的腿机构（R ^x：绕x旋转的自由度，R ^y：绕y旋转的自由度，T ^z：沿z的平移自由度，自由度：自由度）。针对传统的雅可比矩阵不能揭示永磁体约束螺丝之间线性相关/不相关的缺陷，推导了约束和致动奇异性的确定标准，并构造了冗余致动永磁体消除约束/致动奇异性的设计原理。到相互的螺丝原理。在此基础上，提出了无奇异点的并联腿机构的设计过程。最后，通过分析由约束雅可比矩阵和次级约束雅可比矩阵组成的完整雅可比矩阵的秩，验证了本文的冗余并行支腿机制可以完全消除约束奇异性和致动奇异性。