Mechanism analysis of a novel four-degree-of-freedom parallel manipulator based on larger workspace

Aiming at improving the problems of traditional parallel robot: covers larger area, smaller workspace. A systematic method is developed to obtain bigger workplace, magnification ratio of Z axis and the compact framework. The virtual axes are employed for reduce the constraining of parallel robot´s workspace caused by the length of the links. Based on those a four-degree-of-freedom (4-DoF) parallel mechanism was designed, which is equally replaced based on the concept of generalized pair and the principle of the equivalent kinematic chain; screw theory was used to analyze the DOF; the workspace shape of the traditional and this mechanism were defined by drawing, bigger workspace than traditional manipulator can see from the figure. In addition, the movement of the equalized form of the parallel mechanism is simulated with the MATLAB-SimMechanics.