ANALYSIS OF A NOVEL 6-DOF, 3-PPSP PARALLEL MANIPULATOR

A novel kinematic structure for a parallel manipulator with 6 DOF is p roposed. It consists of a platform that is connected to a fixed base b y means of 3-PPSP (P-prismatic joint, S-spherical joint) subchains. Ea ch subchain is connected to a passive prismatic joint at the one end, and a passive spherical joint at the other. The spherical joint is the n attached to perpendicularly arranged prismatic actuators that are fi xed to the base. Due to the efficient architecture, the closed-form so lutions of the inverse and forward kinematics can be easily obtained A s a consequence, this new kinematic structure can be servo controlled using simple inverse kinematics, because forward kinematics allows for measuring the platform's position and orientation in Cartesian space. Manipulator workspace determination is carried out through the comput ation of displacements in the prismatic joints. A Jacobian matrix for the proposed structure is derived so the relationship between actuator forces and output forces/moments of the mechanism can be analyzed. A series of simulations were performed to verify the results of the kine matics analyses and to evaluate the load characteristics of the system .