Chattering-Free Sliding-Mode Control for Electromechanical Actuator with Backlash Nonlinearity

Considering the backlash nonlinearity and parameter time-varying characteristics in electromechanical actuators,a chattering-free sliding-mode control strategy is proposed in this paper to regulate the rudder angle and suppress unknown external disturbances. different from most existing backlash compensation methods,a special continuous function is addressed to approximate the backlash nonlinear dead-zone model. regarding the approximation error,unmodeled dynamics,and unknown external disturbances as a disturbance-like term,a strict feedback nonlinear model is established. based on this nonlinear model,a chattering-free nonsingular terminal sliding-mode controller is proposed to achieve the rudder angle tracking with a chattering elimination and tracking dynamic performance improvement. a lyapunov-based proof ensures the asymptotic stability and finite-time convergence of the closed-loop system. experimental results have verified the effectiveness of the proposed method. © 2017 dongqi ma et al.