In a minimally invasive surgical (MIS) robot, the remote center of motion (RCM) mechanism is usually used to realize the constrained motion of the surgical instrument. In this paper, a novel design method for planar 2DOF RCM mechanisms is proposed based on closed-loop cable transmissions. The concept is to utilize several coupled cable transmissions to constrain a serial kinematic chain. Through the analysis and determination of the transmission ratios for these cable transmissions, a class of planar 2DOF RCM mechanisms without any active or passive translational joints is obtained, which prov...
