Anti-disturbance motion control of servo motors: An adaptive sliding-mode approach with disturbance observer...

This research presents a novel adaptive sliding-mode disturbance observer (NASMDO) with an adaptive non-singular terminal sliding-mode control (ANTSMC) method to solve the problem of time-varying disturbances and achieve high-accuracy control for servomotor systems. Firstly, an adaptive disturbance observer is designed using motor velocity information. Secondly, a sliding-mode-assisted term is designed with position information to estimate the residual disturbance observation error. The convergence performance is rigorously analyzed and demonstrated for NASMDO. Following this, a composite control method is formulated combined with ANTSMC to achieve high-accuracy control of the servomotor system with time-varying disturbances, which ensures the reaching towards a vicinity of the sliding-mode manifold in finite time. Lastly, realistic validations are carried out on a servomotor turntable device with a braking mechanism. The established composite anti-disturbance tracking control method exhibits superior robustness and performance. The tracking error of proposed method decreases by over 35 % on average compared to traditional methods under various disturbance conditions.