Composite adaptive nonsingular-terminal-sliding-mode-control for electromechanical actuator

Nonsingular-terminal-sliding-mode-control(NTSMC) provides finite time convergence of the errors; however a high gain is usually required to compensate for the system uncertainties. This imposes a conservative condition on the system design. To relax this conservativeness, we apply the composite adaptive law to estimate the uncertain parameters in the system. Based on the estimated values, a composite adaptive nonsingular terminal sliding mode control(CANTSMC) is designed to compensate for the effects caused by the uncertain parameters. This scheme has been applied to an electromechanical actuator to compensate for the effects on the modeled dynamics caused by uncertain parameters. The close-loop stability and the finite-time convergence of the trajectory tracking error are also proved. The effectiveness of the proposed method is validated by simulation.