Kinematics And Dymamics Modeling And Simulation Of 3-RSR Parallel Manipulators

With applications in industry being more and more widened, study on 3-DOF (degree of freedom) parallel manipulators has recently become a main focus among the robotics research community. Kinematics and dynamics of 3-RSR parallel manipulators are investigated in this dissertation.Firstly, an overview to the recent research about 3-DOF manipulators is presented. The research achievements and methods previously used are introduced, additionally. Then, the kinematic analysis of a 3-RSR parallel manipulator is conducted, in which closed-form solution for direct kinematic problem, numerical solution for inverse kinematics to regular configuration, and closed-form inverse kinematics solution to symmetric configuration of 3-RSR parallel manipulators are addressed. Based on the solutions to inverse kinematics, study on its workspace has been performed, as well. Further, both derivational approach and screw theory are applied for the Jacobian analysis of 3-RSR parallel manipulator, and analysis on its singularities is also carried out. Thirdly, dynamic model of 3-RSR parallel manipulators is developed based on the kinematic analysis. First, the external forces, the external moments, the inertial and gravitational loading on the moving platform of 3-RSR parallel manipulator are mapped back to the actuated joints by the use of the Jacobian matrix, and then the dynamics model has been derived through directly employing Newton-Euler equation, on the basis of assumptions without significantly compromising the accuracy of model. In addition, Lagrange formulation is also applied to find the dynamic model so as to make comparson with that obtained previously, through a numerical example. Finally, a virtual prototype of a 3-RSR parallel manipulator is built and kinematic and dynamic simulations are shown with the software of ADAMS. As a result, the validaty and accuracy of both kinematics and dynamics obtained in this work have been verified.