Adaptive backstepping sliding mode tracking control for DC motor servo system

Conventional sliding mode control (SMC) is so-called robust to the system uncertainty and the external disturbance, however, it requires the knowledge about the upper bound of uncertainties and external disturbances. In the practical system, uncertainties and external disturbances are often unknown. A adaptive backstepping sliding mode controller (ABSMC) is proposed to deal with the uncertainty in the direct current (DC) motor servo system. The stability of the system is proved based on Lyapunov theory. The adaptive method is used to estimate uncertainties and external disturbances, which avoids the need for the boundary knowledge of uncertainty. Simulation and experimental results show that, compared with the conventional SMC, the proposed method has shorter settle time and stronger robustness to the system with large motor parameters perturbation and external disturbance.