Design and kinematical performance analysis of a novel reconfigurable parallel mechanism with three remote center-of-motion modes

Abstract

In view of the demands for variability and safety in surgical procedures, this paper presents a novel reconfigurable parallel mechanism (RPM) capable of performing three remote center-of-motion (RCM) modes: 1R1T, 2R1T, and 3R1T. One of the RCM modes can transform into two distinct configurations from the switch configuration, in which one configuration offers a rotational degree-of-freedom (DOF) and a translational DOF in the YOZ plane, and the other configuration provides identical DOFs in the XOZ plane. A novel device is introduced for switching between the active and passive modes of the revolute joint, which serves as the basis for the RPM reconfiguration process. Utilizing screw theory, the mobility and actuation scheme of the RPM in each configuration are analyzed. Inverse kinematic analysis and Jacobian matrices are then carried out. Subsequently, kinematical performances, such as singularity, workspace, and dexterity, are studied. All results indicate that the proposed RPM has the ability to switch motion modes without requiring reassembly and can effectively meet the diverse demands of surgical procedures based on specific minimally invasive surgery (MIS) requirements.