Precision Force Tracking Control of a Surgical Device Interacting With a Deformable Membrane

Well-designed robotic-assisted surgical systems have been widely applied in medical treatments to make surgical operations precise and efficient. For these, precise tracking of the interaction force between the surgical device and affected human tissues is an important aspect to improve the safety and surgery success rate. In this development, an adaptive integral terminal sliding mode force control scheme for a piezoelectric actuator-based ear surgical device is presented to achieve precision force tracking during the interaction with the tympanic membrane that is soft and deformable, an important aspect in the course of such a surgery. Particularly, a force error-based integral terminal sliding manifold is employed to guarantee the finite-time convergence performance. A related adaptive control law is developed and deployed to estimate the controller’s parameters and update the switching gain to accommodate system uncertainties, disturbances, and the complex contact environment. Then, the stability of the proposed control method is analyzed and discussed rigorously based upon the Lyapunov theory and method. Furthermore and rather importantly, comparative experiments with three other force controllers are conducted for both S-curve and sine waves with different frequencies. The force tracking results interacting with the deformable membrane demonstrate that the best performance is achieved by the proposed method with all the statistical errors within a suitably effective range of 2.5% and 9.0% of the maximum amplitude.