Design, Analysis and Prototype a Novel Two-Limb 3R1T Parallel Robot with Remote Centre of Motion

The paper proposes a novel 3R1T cable-driven parallel robot mechanism with a Remote Centre of Motion (RCM) for Minimal Invasive Surgery (MIS). In particular, a cable-driven system designed to drive the rolling and linear motion of the surgical tool is integrated with a 5-bar spherical linkage which is to control the yaw and pitch motions. This design enables to placement of all motors on the base so as to minimize the moment of inertia of the moving structure, therefore leading to high precision. The conceptual and detailed design is first introduced, followed by cable pretension calculation and slippage error analysis, stress analysis on joints, and gravity-induced tool tip deviation. Bespoken components are fabricated using 3D printing and a prototype excluding motors is constructed. Preliminary tests validate the 3R1T mobility. The new robot shows great potential for medical applications.