Research on a novel four-degree-of-freedom parallel manipulator with scaling unit

Aiming at improving the limited workspace of traditional parallel robot, a systematic method is developed to obtain bigger working place and magnification ratio of Z axis. The virtual axes are employed for reduce the constraining of parallel robot´s working space caused by the length of the links. 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 was 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 Simmechanics of MATLAB.