Kinematics Design Of A Class Of Parallel Manipulator With 2T2R DOF

To meet the requirements of industrial development for hybrid-configuration equipments of five-axis, a novel 2T2R parallel manipulator 2-PSS&(2-PRR)R is researched in this thesis, which consists of topology analysis, inverse kinematics, forward position analysis, workspace, singularity analysis and dimensional synthesis. The achievements can be listed as follow:(1) Topology analysis. A virtual model of the 2-PSS&(2-PRR)R manipulator is established and the structure of this manipulator is described in detail. A schematic diagram is drawn. The mobility of the manipulator is analyzed via screw theory.(2) Kinematic analysis. The kinematic model of the 2-PSS&(2-PRR)R manipulator is established by using the closed-loop vectors method. The inverse mapping of position, velocity and acceleration between the actuator and end effector can be obtained. Forward position analysis indicates that all solutions can be worked out by the Mathematica software.(3) Workspace and singularity analysis. Two kinds of workspace are defined aiming at the specific structure of the 2-PSS&(2-PRR)R manipulator. Taking into account of the constraining conditions such as actuated journey and joint angle, the two kinds of workspace are searched out with resort to different algorithms. The impact of dimensional parameters on the two kinds of workspace is thoroughly researched. The Jacobian matrix is obtained through derivation of constraint equations, and then the singlarity analysis is performed.(4) Dimensional synthesis. The dimensionless Jacobian matrix is deduced, whose algebraic features can be used to construct perpformance index. The monotonic analysis reveals the effect of dimensional parameters on the kinematic performance. And finally the optimal dimensions of the manipulator are determined by taking the geometric and engineering constraints into consideration.