A Novel Family of Partially-Decoupled 2R1T RCM Mechanisms for Minimally Invasive Surgical Robot: Conceptual Design, Kinematics, Singularity and Workspace Analysis

The mechanisms with remote-center-motion attract researchers' attention owing to their features which provides the rotation motion around a remote center via their inherent geometric mechanical condition. In this paper, we propose a novel concept and a family of partially-decoupled 2R1T RCM mechanisms with only prismatic joints located on the base and on one side. First, the combination principle for a family of the partially-decoupled 2R1T RCM mechanisms is presented. Second, a family of the partially-decoupled 2R1T RCM mechanisms is proposed based on Lie group and submanifold method. Then, the kinematics and unified Jacobian matrix of one typical 2R1T RCM mechanism are analyzed; Finally, The singularity and workspace for the design 2R1T RCM mechanism are analyzed. The result shows that the proposed 2R1T mechanisms satisfy the motion and workspace requirements of minimally invasive surgery.