A Novel Hierarchical Sliding Mode Control Strategy for a Two-Wheeled Self-Balancing Vehicle

This paper develops a hierarchical sliding-mode controller (HSMC) to simultaneously accomplish velocity control and balancing control for a two-wheeled self-balancing vehicle (TWSBV). Based on the derived TWSBV model, two first-level sliding surfaces, relevant to velocity and position of TWSBV and tilt angle and tilt angular velocity of TWSBV respectively, and a second-level sliding surface, are defined. The asymptotic stability of the designed control system is proved theoretically using Lyapunov stability theory. Simulation results demonstrate that the proposed HSMC has fast and superior velocity tracking and self-balancing performance and strong robustness against partial parameter variations and external disturbances.