TY - JOUR AB - In hands-on robotic surgery, the surgical tool is mounted on the end-effector of a robot and is directly manipulated by the surgeon. This simultaneously exploits the strengths of both humans and robots, such that the surgeon directly feels tool-tissue interactions and remains in control of the procedure, while taking advantage of the robot's higher precision and accuracy. A crucial challenge in hands-on robotics for delicate manipulation tasks, such as surgery, is that the user must interact with the dynamics of the robot at the end-effector, which can reduce dexterity and increase fatigue. This paper presents a null-space-based optimization technique for simultaneously minimizing the mass and friction of the robot that is experienced by the surgeon. By defining a novel optimization technique for minimizing the projection of the joint friction onto the end-effector, and integrating this with our previous techniques for minimizing the belted mass/inertia as perceived by the hand, a significant reduction in dynamics felt by the user is achieved. Experimental analyses in both simulation and human user trials demonstrate that the presented method can reduce the user-experienced dynamic mass and friction by, on average, 44% and 41%, respectively. The results presented robustly demonstrate that optimizing a robots pose can result in a more natural tool motion, potentially allowing future surgical robots to operate with increased usability, improved surgical outcomes, and wider clinical uptake. AU - Petersen,J AU - Bowyer,S AU - Rodriguez,y Baena F DO - 10.1109/TRO.2015.2507163 EP - 213 PY - 2016/// SN - 1552-3098 SP - 201 TI - Mass and friction optimization for natural motion in hands-on robotic surgery T2 - IEEE Transactions on Robotics UR - http://dx.doi.org/10.1109/TRO.2015.2507163 UR - https://ieeexplore.ieee.org/document/7384515 UR - http://hdl.handle.net/10044/1/28141 VL - 32 ER -