Hysteresis Compensation of Tendon-Sheath Mechanism Using Nonlinear Programming Based on Preisach Model

Tendon sheath mechanism (TSM) is an essential mechanical element for the implementation of flexible endoscopic systems owing to its small volume and simple structure. However, nonlinear characteristics, such as backlash, hysteresis and friction occur when employing such a component. In this study, we formulate a Preisach hysteresis model consisting of elementary hysteresis operators. Subsequently, we propose a compensation algorithm that repeatedly and sequentially solves a nonlinear optimization problem online, producing an inverse control signal for the desired output at every time step, compensating the nonlinear effects of TSM. The results indicate that the presented model and control scheme are promising for motion control in any application utilizing TSM.