Research On Kinematics And Dynamics Of 3-PUU Parallel Mechanism

With applications in industry being more and more widened, the 3-DOF parallel mechanisms have become a main focus in the robotics research area recently. In this paper, a 3-DOF translational 3-PUU parallel mechanism with triangle platform is studied.Firstly, an overview to the recent research of 3-DOF mechanisms was present, and the previous research achievements and methods were introduced. Secondly, the topology structural analysis was studied. The kinematic characteristic matrix of the parallel mechanism was derived through the kinematic characteristic matrix of the serial mechanism, and the kinematic characteristic matrix of 3-PUU parallel mechanism was derived. It was proved that the moving platform only can do 3-DOF translation at the initial position and any position. The coordinate system was set up on the mechanism. Applying the method of coordinate transformation, the inverse kinematics was derived. The jacobian matrix of the 3-PUU parallel mechanism was derived by differential coefficient method and the singularity position was found. Based on inverse kinematics, the workspace had been performed by MATLAB.Thirdly, the dynamics equation was established by Kane method and the inverse dynamics was derived. Fourthly, the assembly condition of universal paires in the 3-PUU parallel mechanism determines the mechanism mobility, and screw theory is used to study the kinematics modality of the parallel mechanism under the different assembly condition of universal pairs. The 3-D pro/e model was builded according to machine design, and the practicality 3-PUU parallel mechanism was assembled with machanical parts. The kinematics modality was studied by the practicality parallel mechanism. Finally, the kinematics and dynamics simulation of 3-PUU parallel mechanism was studied in MATLAB and ADAMS software. A conclusion can be obtained that the theoretical data calculated by MATLAB was coincident to the emulational data obtained by ADAMS .From the simulation result, it is obvious that the kinematic and dynamic analysis of 3-PUU parallel mechanism was proved to be correct.