Modeling and Applications of a Family of Five-Degree-of-Freedom Parallel Mechanisms With Kinematic and Actuation Redundancy

This paper introduces a family of statically balanced five-degree-of-freedom (5DOF) parallel mechanisms (PMs) with kinematic and actuation redundancy. Moving platforms o f this family of PMs can provide 4DOF Schonflies motion. Three applications are considered in this work. The first and second applications use kinematic redundancy to avoid parallel singularities and perform an auxiliary grasping task in sequence. The third application incorporates actuation redundancy into a kinematically redundant manipulator to increase the load-carrying capacity. Screw theory was used to derive the Jacobian of the 5DOF PM with kinematic and actuation redundancy. Parallel singularities can be completely alleviated by controlling the orientation of the redundant link, thereby obtaining a large rotational workspace, and actuation redundancy increases the load-carrying capacity. Using a commercially available multibody dynamic simulator, an example of trajectory was performed to illustrate the large rotational workspace of the first and second applications and compare the Euclidean norm of the vector of actuation torque of nonredundant and redundant PMs. Three prototypes were also developed to demonstrate the output motion and static balancing property.This work was supported in part by WC300 R&D Program (S2482672) funded by the Small and Medium Business Administration (SMBA, Korea), in part by the Technology Innovation Program (10052980, Development of microrobotic system for surgical treatment of chronic total occlusion) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea), and in part by the National Research Foundation of Korea (NRF) through the BK21 Plus Program, performed by ICT-based Medical Robotic Systems Team of Hanyang University, Department of Electronic Systems Engineering