A new family of constrained redundant parallel manipulators

This paper addresses the description and kinematic analysis of a new family of redundant parallel manipulators. The primary feature of the new family is to have a compact topology consisting of multi-degree of freedom non-identical limbs. In order to simplify the forward position analysis, the motion of the end-effector (platform) is decoupled into translational and rotational components with respect to the base. This kind of topology is in agreement with the parallel manipulator definition of IFToMM-a parallel manipulator "aEuro broken vertical bar that controls the motion of its end-effector by means of at least two kinematic chains going from the end effector towards the frameaEuro broken vertical bar". In fact, adding a kinematic pair to a limb of a non-redundant parallel manipulator creates asymmetrical parallel manipulator. Analytical expressions for the forward position, velocity, and acceleration of the parallel manipulators have been obtained and solved for an exemplary 7-DOF redundant parallel manipulator. The numerical results from the analytical expressions are verified by comparing them to the results from a mechanical system simulation software as if a real parallel manipulator is being run to collect the position, velocity, and acceleration data. Finally, based on the velocity formulation, the singularity analysis of the manipulator is also provided.