Singularity research for 6/6-PSS parallel manipulator based on the screw theory

A new parallel robot of high structure stiffness and speed response is designed to realize six-degree-of-freedom (6-DOF) in space of an experiment equipment. In order to avoid singularity of the robot, this article deduces the condition of singularity for the parallel manipulator from the relationship between the input of each chain and the output of moving platform base on the screw theory. And then it shows the singularity locus of the three-dimensional description by computer simulation. And the result provides a theoretical basis for trajectory planning and control strategy of this kind of parallel manipulator. In the actual use of the parallel manipulator, these singular points must be avoided, which can guarantee its stable operation.