Preparation Structure Synthesis of 5-DOF Symmetrical Parallel Manipulator

Based on screw theory, the relationship between motion screw system of limbs and constraint screw system of moving platform is analyzed, and the explicit expressions between constraint force screw of moving platform and motion screw of limbs are established. A method of structure synthesis for 5-DOF parallel manipulator is advanced. The conditions of kinematics pairs for limbs with one ZPW of constraint are derived. All possible of limbs of force constraints are obtained according to the formula. Finally, a 3R2T 5-DOF parallel manipulator is used as an example to describe the synthesis procedure for symmetrical and non-symmetrical 5-DOF parallel manipulators. The result of motion simulation analysis of the new manipulators proves the legitimacy of the method