Bilateral control for surgical robot using sliding perturbation observer

In a surgery using a commercialized robot for laparoscopic surgeries such as Da Vinci, a surgeon performs a surgery only depending on visuals by cameras. As contact reaction force between a robot instrument for surgeries and organs during this kind of surgery, problems such as organ impairment, etc. occurs. In order to resolve this kind of problem, this paper introduces possibility of haptic function realization of laparoscopic surgery robot using bilateral control system and evaluates the possibility. For the realization of haptic function, force feedback is necessary. Attachment of force/torque sensor in a surgical robot instrument used in laparoscopic surgeries is difficult because of its cable operated structure and very small size. Therefore, in previous study, the possibility of estimation of reaction force worked on robot instrument using sliding perturbation observer(SPO) was confirmed. Reaction force estimated by using SPO is applied to bilateral control system. For bilateral control, the master uses impedance control and the slave uses sliding mode control(SMC). By using the 1 DOF master and a robot instrument, the experiment result of the proposed bilateral control system is illustrated.