Abstract:A novel 3-RPPS parallel manipulator with 6-DOF was proposed. Its decoupling characteristics and the reference coordinate system of the manipulator were introduced. By establishing the kinematics model of the manipulator, the analytic formulae for solving the kinematics posture and the velocity of the manipulator were derived. By using polar coordinate boundary searching method, the workspace of the manipulator was solved and its volume was calculated. According to the designed trajectories of the moving platform, the rules of changes in lengths and velocities of the driving legs, and the position workspace with a given orientation and the orientation workspace with a given position of the manipulator were obtained by numerical simulations. Moreover, the range of assumed structure parameters with maximum workspace volume is obtained with optimization.