Trajectory tracking and stabilization of two-wheeled balancing mobile robot with hierarchical and sliding mode control

This paper presents a novel approach to stabilizing two-wheeled balancing mobile robots (2WBMR) using hierarchical sliding mode control (HSMC) combined with sliding mode control (SMC). The 2WBMR system, an inherently unstable underactuated mechanical system, is modeled and analyzed for its dynamic properties. The controller of the 2WBMR is divided into two main components due to the independent control of state variables: the HSMC controller performs velocity control and stabilizes the vehicle body, while the SMC controller manages the vehicle’s tilt angle. Moreover, our simulations demonstrate that the HSMC-SMC approach significantly outperforms the SMC method, particularly in terms of response time and error reduction during stable control of position, pitch angle, and rotation angle. Additionally, a rapidly exploring random tree (RRT) algorithm is implemented for trajectory planning, enabling the robot to navigate complex environments. Simulation results demonstrate that the proposed control strategy effectively stabilizes and trajectory tracking for the 2WBMR.