Hybrid Natural Admittance Control for laparoscopic surgery

A limitation of robotic surgery is deprivation of sensation of contact forces. Gentle interactions with tissue are desired, but at the same time kinematic constraints of the access portal must be obeyed. A new combination of previous algorithms of hybrid force/position control and Natural Admittance Control is described that achieves these objectives. This new algorithm is compared to a variation of Natural Admittance Control to show the need for the merger of two known algorithms. The hybrid controller is shown to be 3.5 times stiffer than the pure NAC controller in conforming to the portal constraint, without reducing tool tip responsiveness.