Nonlinear adaptive impedance control of virtual tool-tissue interaction for use in endoscopic sinus surgery simulation system

In this article, a nonlinear adaptive impedance control strategy is proposed to adjust the impedance of a one-degree of freedom Falcon robot to a pre-defined nonlinear impedance which is an approximate mathematical representation of the sino-nasal tissue. Further developments can be used for a training simulator system for the otolaryngology surgery training purposes. The stability of the proposed control strategy and convergence of tracking error are proved by using Lyapunov Stability Theorem. Two different scenarios are considered for simulation studies including a declining contact force and also an oscillatory contact force between the user hand and the haptic interface device. Eventually, The proposed controller is compared to the impedance controller developed in [1]. Although both controllers show good tracking and convergence performance, our proposed controller requires less computational efforts and consequently lower time to accomplish the relevant simulations.