Finite-time robust position tracking control for DC motors under uncertain dynamics

Introduction. This study proposes a finite-time robust control law for position tracking of a DC motor under conditions of model uncertainty and external disturbances. The motor operates through a pulse-width modulation (PWM) unit and an H-bridge power circuit, aiming to achieve finite-time position tracking while minimizing the effects of model uncertainties and external disturbances. Problem. The main challenge lies in achieving accurate and rapid position and speed regulation for the DC motor while maintaining high performance, despite model inaccuracies and external disturbances. The goal of this paper is to design a robust finite-time position tracking control law for a DC motor based on the differential geometric approach, ensuring high tracking accuracy and control efficiency in the presence of disturbances and parameter uncertainties. Scientific novelty. The integration of finite-time control based on a virtual system, diffeomorphism transformation, and disturbance compensation introduces an innovative solution for DC motor position tracking under incomplete modeling and external perturbations. Methodology. The study employs the differential geometric method to construct a virtual system with finite-time characteristics and uses Lyapunov theory to prove global stability in the presence of uncertainties and disturbances. A finite-time virtual system is proposed after analyzing the incomplete dynamic model of the DC motor. Results. To validate the proposed approach, MATLAB simulations were conducted and compared with a conventional sliding mode controller. The results demonstrate improved settling time and robustness of the proposed method in DC motor position tracking. The findings confirm that the proposed controller provides intuitive and precise control, accurate position tracking, and enhanced performance regulation. It also exhibits strong robustness against model uncertainties and external disturbances. The practical value of the proposed method is considerable, as it offers a reliable and efficient position control scheme for DC motors using PWM. The method ensures precise position control and robust performance under varying conditions and external interferences, making it well-suited for real-world DC motor control applications. References 23, tables 1, figures 12.