Finite‐time nonsingular terminal sliding mode control of converter‐driven DC motor system subject to unmatched disturbances
Arshad Rauf, Muhammad Zafran, Awais Gul Khan, Abdul Rehman Tariq
Abstract
In this article, the problem of angular velocity trajectory tracking for converter-fed DC motor system with mismatched disturbances/uncertainties is investigated using a continuous nonsingular terminal sliding mode control. The fourth order dynamic model of the system is quite higher than the second order of the traditional one, which makes the control design more challenging in terms of availability of various signals and tuning of the overall control parameters. Also, the actuator dynamics of the converter not only increase the system order but also generate mismatched disturbances/uncertainties, which is difficult to counteract through baseline sliding mode controller. The disturbance estimation information obtained from the finite time disturbance observer is incorporated into the design of nonsingular terminal sliding manifold. Then, a nonsingular terminal sliding mode controller is designed to achieve finite time tracking performance despite matched and mismatched disturbances/uncertainties. In addition, it retains the fine properties of nominal performance recovery as well as chattering alleviation. Finally, the superiority of the proposed method is shown both through numerical simulation and experimental results.