Active Modeling and Compensation for the Hysteresis of a Robotic Flexible Ureteroscopy

Hysteresis may be one of the most critical issues degrading the performance of the automatic operation of robotic flexible ureteroscopy, i.e., a robotic device handles the flexible ureteroscopy tracking a target automatically. In this paper, we proposed an active-model based scheme to estimate the hysteresis in real time. Firstly, we used the Coleman-Hodgdon model to describe the backlash hysteresis property of the flexible scope, and constructed the reference model of the bending angle. Secondly, a modeling error was introduced into the reference model, and the UKF-based estimator was used to estimate both the bending angle and the modeling error actively. Finally, we designed the hysteresis compensation based on this active estimation enhanced model. Extensive experiments were conducted on the self-built robotic ureteroscopy. The experimental results with the active modeling enhancement were presented and compared with those without it, to demonstrate the improvements achieved by the proposed scheme.